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With some diligence, you can catch all five bright planets in the evening this month! You’ll have to look hard for two of them, Mercury and Venus, which follow the sun below the horizon before nightfall at northerly latitudes. The Southern Hemisphere has the big advantage because Venus and Mercury stay out longer after dark. Jupiter, the second-brightest planet after Venus, is easy to spot in the west in early August and sinks toward the sunset throughout the month, to stage a magnificent conjunction with Venus on August 27. Mars is still a bright beacon, although fainter than Jupiter, still in a noticeable triangle with Saturn and the bright star Antares. Mars and Saturn are out until very late evening at mid-northern latitudes (or after midnight as seen from the Southern Hemisphere). Follow the links below to learn more about August planets in 2016.
Brilliant Venus sets soon after sunset
Fainter Mercury near Venus after sunset
Jupiter low in west after sunset
Mars, dusk until late night, shines near Saturn
Saturn, dusk until late night, shines near Mars
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Astronomy events, star parties, festivals, workshops
Visit a new EarthSky feature – Best Places to Stargaze – and add your fav.
Brilliant Venus sets soon after sunset . People have been reporting fleeting sightings of the brightest planet, Venus, in the west after sunset. If you see it, it’ll be low in the sunset glare, but surprisingly bright for being so low in the sky. Everyone on Earth has a shot at seeing it, but it’s easier from Earth’s Southern Hemisphere.
Watch for Venus below the moon and Mercury on August 4. Binoculars will enhance the view!
Venus and Mercury come closest together for the month on August 19, and then Venus and Jupiter stage a stunningly close conjunction on August 27.
Venus will become easier to see in the western evening sky in September, and even more so in October.
By the way, when Venus passed behind the sun in June, it passed directly behind it, as seen from Earth. That happened on June 6, 2016, and at that time Venus officially transitioned from our morning to our evening sky. Exactly four years previous to Venus’ passing directly behind the sun on June 6, 2016, Venus swung directly in front of the sun on June 6, 2012. You might remember that event: the widely watched transit of Venus, during which Venus crossed the sun’s face as seen from Earth (see photos). It was the last transit of Venus until December 11, 2117.
Fainter Mercury near Venus after sunset. Mercury shines as an evening “star” all month long, but – if you live at mid-northern latitudes or farther north – you might need binoculars to glimpse this little world near Venus in August 2016.
On the other hand, you might be able to catch Mercury with the eye alone. The only way to know is to look.
From the Southern Hemisphere or northern tropics, Mercury is presenting its best evening apparition for the year, possibly visible to the eye alone all month long.
Mercury will move farther away from the setting sun until it reaches its greatest elongation on August 16. Watch for Mercury to make a quasi-conjunction with Jupiter on August 19.
Click here for recommended almanacs; they can give you Mercury’s setting time in your sky.
Jupiter low in west after sunset. From mid-northern latitudes, the king planet sets about two hours after the sun in early August and about roughly one hour after the sun by the month’s end. From the Southern Hemisphere, Jupiter stays out until mid-evening in early August and around nightfall in late August.
From around the world, Jupiter will fade into the sunset by late August or early September. As Jupiter descends sunward throughout the month, it’ll have a quasi-conjunction with Mercury on August 19, and an actual conjunction with Venus on August 27.
As evening falls, Mars and Saturn shine in the southern sky, while Jupiter appears in the west. So it should be pretty easy to distinguish Jupiter from ruddy Mars, especially since these two brilliant worlds shine in different parts of the sky.
The moon swings close to Jupiter on the sky’s dome for several days, centered on or near August 5.
Mars, dusk until late night, shines near Saturn. Mars is still bright this month, though fainter than it was earlier in 2016! Saturn came closest to Earth for the year on June 3, less than four days after Mars’ closest approach to Earth on May 30. Although Mars and Saturn are beginning to fade a bit, they’re still plenty bright and easy to see – especially Mars!
Mars was at its brightest at its opposition on May 22. Jupiter was at its brightest during its opposition on March 8. Mars and Jupiter will remain spectacularly bright in the August night sky, but, by the month’s end, you’ll notice the brightness of Mars has waned somewhat.
Looking for a sky almanac? EarthSky recommends…
Here’s some really good news, though. Mars is near another planet on the sky’s dome, Saturn. Look for Mars and Saturn near Antares, the brightest star in the constellation Scorpius the Scorpion. They make a noticeable triangle on the sky’s dome.
Let the moon help guide your eye to Mars (plus Saturn and the bright star Antares) for several evenings, centered on or near August 11. Then watch for the moon to move away from Mars and to sail by Saturn on August 12.
Then watch for the conjunction of Mars and Saturn on August 24.
Saturn, dusk until late night, shines near Mars. Both Mars and Saturn are near a fainter object – still one of the sky’s brightest stars – Antares in the constellation Scorpius.
The ringed planet starts out the month appearing in the south to southwest sky at nightfall. At the beginning of the month, Saturn will soar to its highest point for the night around 8 p.m. local time (9 p.m. local Daylight Saving Time). By the month’s end, Saturn will be at its high point around 6 p.m. local time (7 p.m. local Daylight Saving Time).
Although Saturn shines on par with the sky’s brightest stars, its brilliance can’t match that of Mars. Look for Saturn near Mars all month long. These two worlds form a bright celestial triangle with the star Antares in the August night sky. Mars is brighter than Saturn, which in turn is brighter than Antares.
Mars will eventually catch up with Saturn on August 24, 2016, to present a conjunction of these two worlds in the August evening sky.
Watch for the moon to swing by Saturn for several days, centered on or near ” target=_blank>August 12.
Saturn, the farthest world that you can easily view with the eye alone, appears golden in color. It shines with a steady light. Binoculars don’t reveal Saturn’s gorgeous rings, by the way, although binoculars will enhance Saturn’s golden color. To see the rings, you need a small telescope. A telescope will also reveal one or more of Saturn’s many moons, most notably Titan.
Saturn’s rings are inclined at a little more than 26o from edge-on in August 2016, exhibiting their northern face. Next year, in October 2017, the rings will open most widely, displaying a maximum inclination of 27o.
As with so much in space (and on Earth), the appearance of Saturn’s rings from Earth is cyclical. In the year 2025, the rings will appear edge-on as seen from Earth. After that, we’ll begin to see the south side of Saturn’s rings, to increase to a maximum inclination of 27o by May 2032.
What do we mean by bright planet? By bright planet, we mean any solar system planet that is easily visible without an optical aid and that has been watched by our ancestors since time immemorial. In their outward order from the sun, the five bright planets are Mercury, Venus, Mars, Jupiter and Saturn. These planets actually do appear bright in our sky. They are typically as bright as – or brighter than – the brightest stars. Plus, these relatively nearby worlds tend to shine with a steadier light than the distant, twinkling stars. You can spot them, and come to know them as faithful friends, if you try.
Bottom line: In August 2016, Jupiter starts out the month above Mercury and Venus in the western evening sky. Toward the end of the month, Venus climbs above Mercury and then Jupiter. Saturn and the bright star Antares make a triangle with Mars on the sky’s dome, shining from dusk until late night.
Easily locate stars and constellations with EarthSky’s planisphere.
Don’t miss anything. Subscribe to EarthSky News by email
With some diligence, you can catch all five bright planets in the evening this month! You’ll have to look hard for two of them, Mercury and Venus, which follow the sun below the horizon before nightfall at northerly latitudes. The Southern Hemisphere has the big advantage because Venus and Mercury stay out longer after dark. Jupiter, the second-brightest planet after Venus, is easy to spot in the west in early August and sinks toward the sunset throughout the month, to stage a magnificent conjunction with Venus on August 27. Mars is still a bright beacon, although fainter than Jupiter, still in a noticeable triangle with Saturn and the bright star Antares. Mars and Saturn are out until very late evening at mid-northern latitudes (or after midnight as seen from the Southern Hemisphere). Follow the links below to learn more about August planets in 2016.
Brilliant Venus sets soon after sunset
Fainter Mercury near Venus after sunset
Jupiter low in west after sunset
Mars, dusk until late night, shines near Saturn
Saturn, dusk until late night, shines near Mars
Like what EarthSky offers? Sign up for our free daily newsletter today!
Astronomy events, star parties, festivals, workshops
Visit a new EarthSky feature – Best Places to Stargaze – and add your fav.
Brilliant Venus sets soon after sunset . People have been reporting fleeting sightings of the brightest planet, Venus, in the west after sunset. If you see it, it’ll be low in the sunset glare, but surprisingly bright for being so low in the sky. Everyone on Earth has a shot at seeing it, but it’s easier from Earth’s Southern Hemisphere.
Watch for Venus below the moon and Mercury on August 4. Binoculars will enhance the view!
Venus and Mercury come closest together for the month on August 19, and then Venus and Jupiter stage a stunningly close conjunction on August 27.
Venus will become easier to see in the western evening sky in September, and even more so in October.
By the way, when Venus passed behind the sun in June, it passed directly behind it, as seen from Earth. That happened on June 6, 2016, and at that time Venus officially transitioned from our morning to our evening sky. Exactly four years previous to Venus’ passing directly behind the sun on June 6, 2016, Venus swung directly in front of the sun on June 6, 2012. You might remember that event: the widely watched transit of Venus, during which Venus crossed the sun’s face as seen from Earth (see photos). It was the last transit of Venus until December 11, 2117.
Fainter Mercury near Venus after sunset. Mercury shines as an evening “star” all month long, but – if you live at mid-northern latitudes or farther north – you might need binoculars to glimpse this little world near Venus in August 2016.
On the other hand, you might be able to catch Mercury with the eye alone. The only way to know is to look.
From the Southern Hemisphere or northern tropics, Mercury is presenting its best evening apparition for the year, possibly visible to the eye alone all month long.
Mercury will move farther away from the setting sun until it reaches its greatest elongation on August 16. Watch for Mercury to make a quasi-conjunction with Jupiter on August 19.
Click here for recommended almanacs; they can give you Mercury’s setting time in your sky.
Jupiter low in west after sunset. From mid-northern latitudes, the king planet sets about two hours after the sun in early August and about roughly one hour after the sun by the month’s end. From the Southern Hemisphere, Jupiter stays out until mid-evening in early August and around nightfall in late August.
From around the world, Jupiter will fade into the sunset by late August or early September. As Jupiter descends sunward throughout the month, it’ll have a quasi-conjunction with Mercury on August 19, and an actual conjunction with Venus on August 27.
As evening falls, Mars and Saturn shine in the southern sky, while Jupiter appears in the west. So it should be pretty easy to distinguish Jupiter from ruddy Mars, especially since these two brilliant worlds shine in different parts of the sky.
The moon swings close to Jupiter on the sky’s dome for several days, centered on or near August 5.
Mars, dusk until late night, shines near Saturn. Mars is still bright this month, though fainter than it was earlier in 2016! Saturn came closest to Earth for the year on June 3, less than four days after Mars’ closest approach to Earth on May 30. Although Mars and Saturn are beginning to fade a bit, they’re still plenty bright and easy to see – especially Mars!
Mars was at its brightest at its opposition on May 22. Jupiter was at its brightest during its opposition on March 8. Mars and Jupiter will remain spectacularly bright in the August night sky, but, by the month’s end, you’ll notice the brightness of Mars has waned somewhat.
Looking for a sky almanac? EarthSky recommends…
Here’s some really good news, though. Mars is near another planet on the sky’s dome, Saturn. Look for Mars and Saturn near Antares, the brightest star in the constellation Scorpius the Scorpion. They make a noticeable triangle on the sky’s dome.
Let the moon help guide your eye to Mars (plus Saturn and the bright star Antares) for several evenings, centered on or near August 11. Then watch for the moon to move away from Mars and to sail by Saturn on August 12.
Then watch for the conjunction of Mars and Saturn on August 24.
Saturn, dusk until late night, shines near Mars. Both Mars and Saturn are near a fainter object – still one of the sky’s brightest stars – Antares in the constellation Scorpius.
The ringed planet starts out the month appearing in the south to southwest sky at nightfall. At the beginning of the month, Saturn will soar to its highest point for the night around 8 p.m. local time (9 p.m. local Daylight Saving Time). By the month’s end, Saturn will be at its high point around 6 p.m. local time (7 p.m. local Daylight Saving Time).
Although Saturn shines on par with the sky’s brightest stars, its brilliance can’t match that of Mars. Look for Saturn near Mars all month long. These two worlds form a bright celestial triangle with the star Antares in the August night sky. Mars is brighter than Saturn, which in turn is brighter than Antares.
Mars will eventually catch up with Saturn on August 24, 2016, to present a conjunction of these two worlds in the August evening sky.
Watch for the moon to swing by Saturn for several days, centered on or near ” target=_blank>August 12.
Saturn, the farthest world that you can easily view with the eye alone, appears golden in color. It shines with a steady light. Binoculars don’t reveal Saturn’s gorgeous rings, by the way, although binoculars will enhance Saturn’s golden color. To see the rings, you need a small telescope. A telescope will also reveal one or more of Saturn’s many moons, most notably Titan.
Saturn’s rings are inclined at a little more than 26o from edge-on in August 2016, exhibiting their northern face. Next year, in October 2017, the rings will open most widely, displaying a maximum inclination of 27o.
As with so much in space (and on Earth), the appearance of Saturn’s rings from Earth is cyclical. In the year 2025, the rings will appear edge-on as seen from Earth. After that, we’ll begin to see the south side of Saturn’s rings, to increase to a maximum inclination of 27o by May 2032.
What do we mean by bright planet? By bright planet, we mean any solar system planet that is easily visible without an optical aid and that has been watched by our ancestors since time immemorial. In their outward order from the sun, the five bright planets are Mercury, Venus, Mars, Jupiter and Saturn. These planets actually do appear bright in our sky. They are typically as bright as – or brighter than – the brightest stars. Plus, these relatively nearby worlds tend to shine with a steadier light than the distant, twinkling stars. You can spot them, and come to know them as faithful friends, if you try.
Bottom line: In August 2016, Jupiter starts out the month above Mercury and Venus in the western evening sky. Toward the end of the month, Venus climbs above Mercury and then Jupiter. Saturn and the bright star Antares make a triangle with Mars on the sky’s dome, shining from dusk until late night.
Easily locate stars and constellations with EarthSky’s planisphere.
Don’t miss anything. Subscribe to EarthSky News by email
SkS Highlights... Toon of the Week... Quote of the Week... Graphic of the Week... He Said What?... Coming Soon on SkS... Poster of the Week... SkS Week in Review... 97 Hours of Consensus...
These are the best arguments from the 3% of climate scientist 'skeptics.' Really. by Dana Nuccitelli (Climate Consensus-the 97%, Guardian) attracted the highest number of comments among the articles posted on SkS during the past week.
Hat tip to I Heart Climate Scientists
The global battle against climate change has passed a historic turning point with China’s huge coal burning finally having peaked, according to senior economists.
They say the moment may well be a significant milestone in the course of the Anthropocene, the current era in which human activity dominates the world’s environment.
China is the world’s biggest polluter and more than tripled its coal burning from 2000 to 2013, emitting billions of tonnes of climate-warming carbon dioxide. But its coal consumption peaked in 2014, much earlier than expected, and then began falling.
The economists argue in a new paper on Monday that this can now be seen as permanent trend, not a blip, due to major shifts in the Chinese economy and a crackdown on pollution.
“I think it is a real turning point,” said Lord Nicholas Stern, an eminent climate economist at the London School of Economics, who wrote the analysis with colleagues from Tsinghua University in Beijing. “I think historians really will see [the coal peak of] 2014 as a very important event in the history of the climate and economy of the world.”
China's coal peak hailed as turning point in climate change battle by Damian Carrington, Guardian, July 25, 2016
Check out Scientists have found a perfect illustration of how the climate is spiraling ‘out of control’ by Chelsea Harvey, Energy & Environment, Washington Post, July 28, 2016
Sen. James Inhofe says school children are being “brainwashed” into believing in climate change and that parents need to “un-brainwash” them.
Inhofe, an outspoken climate change skeptic and chairman of the Senate Environment and Public Works Committee, said he came to the realization when his granddaughter challenged him on his denial of the science behind global warming.
“Our kids are being brainwashed,” the Oklahoma Republican told conservative radio host Eric Metaxas on a recent appearance reported by the liberal blog Right Wing Watch.>
“My own granddaughter came home one day and said … ‘Popi, why is it you don’t understand global warming?’ I did some checking, and Eric, the stuff that they teach our kids nowadays, they are brainwashed — you have to un-brainwash them when they get out,” Inhofe said.
GOP chairman: Kids are ‘brainwashed’ on climate change by Timothy Cama, The Hill, July 27, 2016
Katharine Hayhoe's bio page & Quote source
High resolution JPEG (1024 pixels wide)
SkS Highlights... Toon of the Week... Quote of the Week... Graphic of the Week... He Said What?... Coming Soon on SkS... Poster of the Week... SkS Week in Review... 97 Hours of Consensus...
These are the best arguments from the 3% of climate scientist 'skeptics.' Really. by Dana Nuccitelli (Climate Consensus-the 97%, Guardian) attracted the highest number of comments among the articles posted on SkS during the past week.
Hat tip to I Heart Climate Scientists
The global battle against climate change has passed a historic turning point with China’s huge coal burning finally having peaked, according to senior economists.
They say the moment may well be a significant milestone in the course of the Anthropocene, the current era in which human activity dominates the world’s environment.
China is the world’s biggest polluter and more than tripled its coal burning from 2000 to 2013, emitting billions of tonnes of climate-warming carbon dioxide. But its coal consumption peaked in 2014, much earlier than expected, and then began falling.
The economists argue in a new paper on Monday that this can now be seen as permanent trend, not a blip, due to major shifts in the Chinese economy and a crackdown on pollution.
“I think it is a real turning point,” said Lord Nicholas Stern, an eminent climate economist at the London School of Economics, who wrote the analysis with colleagues from Tsinghua University in Beijing. “I think historians really will see [the coal peak of] 2014 as a very important event in the history of the climate and economy of the world.”
China's coal peak hailed as turning point in climate change battle by Damian Carrington, Guardian, July 25, 2016
Check out Scientists have found a perfect illustration of how the climate is spiraling ‘out of control’ by Chelsea Harvey, Energy & Environment, Washington Post, July 28, 2016
Sen. James Inhofe says school children are being “brainwashed” into believing in climate change and that parents need to “un-brainwash” them.
Inhofe, an outspoken climate change skeptic and chairman of the Senate Environment and Public Works Committee, said he came to the realization when his granddaughter challenged him on his denial of the science behind global warming.
“Our kids are being brainwashed,” the Oklahoma Republican told conservative radio host Eric Metaxas on a recent appearance reported by the liberal blog Right Wing Watch.>
“My own granddaughter came home one day and said … ‘Popi, why is it you don’t understand global warming?’ I did some checking, and Eric, the stuff that they teach our kids nowadays, they are brainwashed — you have to un-brainwash them when they get out,” Inhofe said.
GOP chairman: Kids are ‘brainwashed’ on climate change by Timothy Cama, The Hill, July 27, 2016
Katharine Hayhoe's bio page & Quote source
High resolution JPEG (1024 pixels wide)
“Even though the future seems far away, it is actually beginning right now.” -Mattie Stepanek
It’s been a fantastic week here at Starts With A Bang, where we’ve covered even more ground than normal! First off, for those of you not following me on SoundCloud, we’ve got a new science podcast out, on the last star in the Universe.
And now lets take a look at your inquiries, ideas and more on this edition of our comments of the week!
From Sinisa Lazarek on the MACHO content of our galaxy: “Maybe I’m nitpicking, but IMO “ten times more” is not “slightly more”. This of course doesn’t influence the DM halo AROUND the galaxy (where most of DM is). But I expected that 10x more machos would influence the mass content of our galaxy more than slightly.”
It’s not nitpicking; you’re asking a questions about magnitudes. If you thought something was 2% and it turns out to be 20%, that’s suddenly very significant. But if you thought something was 0.001% and it turns out to be 0.01%, then it doesn’t matter. When we talk about the mass content of our galaxy, we are still much less than 1% when talking about MACHOs over the mass range we’re discussing. So no, ten times more MACHOs still only influences the mass content of our galaxy slightly.
From eric on the consciousness problem: “Every night, the pattern of electrical activity that is the conscious “me” disappears. It doesn’t go underground somewhere in my brain or go into some standby/dormant mode, this pattern ceases to exist. Not there. Gone. Noneexistent. New patterns, associated with sleep and dreaming, take its place. Then when I wake up, my brain recreates the pattern that is “me” from stored information…probably not exactly the same as it was before, I just don’t notice the differences.”
Now, this is a hard problem and I don’t have an answer. But I would submit that MRI results would show that there is some brain (electrical) activity that is identifiably you that is still present while you are asleep. I would also submit that it is that electrical pattern that occurs in your brain that is identifiable as you. Here are some unanswered questions:
In other words, I don’t know that, for example, Will and Tom Riker aren’t both exactly 100% the same Will Riker that was born in Alaska? And yet, perhaps neither one actually is; perhaps the original “Will Riker” died the first time his body was deconstructed and reconstructed, with that line-of-consciousness coming to a total end. And perhaps all the memories and continuity experienced by the copy doesn’t mean that it isn’t murder every time one goes through the transporter. Is this different or the same than going to sleep and waking up?
I don’t even know how to test this with a working transporter. Ideas?
From Alan L. on dark matter and LUX: “So have DM particles yet managed to achieve a level of such extreme puniness that it would make DM, as envisaged post LUX, an extremely unlikely candidate to be one capable of pushing around Andromeda sized galaxies so to ensure a uniform rotational speeds across their width, as if DM particles in galactic haloes formed gangs of some kind of super powerful schoolyard bullies?”
You must understand that it is not the size, magnitude or puniness of dark matter that makes it viable or not as capable of accounting for the gravitational effect of the Universe. It is its density and its clustering properties, the latter of which are determined by its kinetic energy as a function of its mass. A class of dark matter that doesn’t interact with normal matter or itself at all, that has only gravitational interactions with anything in this Universe, would be the ultimate nightmare scenario for experimental physicists, and yet it is a very real possibility for what the nature of dark matter could be.
It is up to us to push those limits in all mass ranges as far as we can go. We are constantly re-evaluating what the science tells us with a view to the full suite of evidence available, and as a result DM was replaced by CDM was replaced by Lambda-CDM, and now we are starting to find that the density profiles do not match simulations quite as well as we had hoped, which is leading to modified models of CDM as part of the Lambda-CDM model. Just because you may not like the path that science is being led doesn’t mean that scientists aren’t doing exactly the job that the data tells them to do.
From Jerry on dark matter collisions: “Since two of the key pieces of evidence for dark matter is that galaxies rotate to fast to hold together and that dark matter can be mapped separating from galaxy clusters in collisions, what would happen to a galaxy that became completely separated from its dark matter halo after hitting an especially dense area of intergalactic matter?”
Intergalactic matter would only be able to stop the other intergalactic matter in a galaxy: things like plasma, dust, and neutral gas. You want to stop a star? You need something as dense and massive as a star. You want to stop a galaxy? You need to something that’s going to stop not an “averaged galaxy,” but each of the 100 billion+ stars in it. That’s why, in the Bullet Group, above, the luminous stars move unimpeded through the group, while the gas (in pink) separates. If you truly wanted to allow the dark matter to continue moving while making your imaginary super-star-stopper stop the galaxy, you would forever alter the stars by nature of stopping the baryonic matter in the galaxies.
In other words, the answer isn’t a universal physics one, but rather is dependent on how you do this thing that requires a severe, non-natural intervention.
From PJ on the galaxies behind Andromeda: “Interesting to note the visibility of other galaxies through Andromeda in the closeup photo, lower right of photo, reddish appearance.”
This is the less common type of galactic reddening we see: not due to redshift, but rather due to dust in a foreground galaxy! In fact, you will notice what appears to be a large population of red stars in this galaxy as well, and that’s because the “dust” tends to exist in a thin plane in the galaxy’s center. The stuff in front of the dust isn’t reddened, but everything behind it — including stars and galaxies — experiences this extinction effect.
Dust grains are of a size where smaller wavelengths are blocked much more easily than longer ones, and so the more dust we pass through, the redder things appear. (Even though there’s less red light, there’s a higher percentage of red light as compared to everything else!) If you were to look at a region that wasn’t dusty in Andromeda, the galaxies behind it would only appear red as a function of their redshift.
From Denier on the concept of dimensional reduction: “Would this mean it is possible to collapse 4 dimensions down to 2, or that the 4 dimensions that we perceive all around us are in fact 2 dimensions when viewed on the QM scale?”
It actually doesn’t mean either of those. The former is definitely not what’s being said, so drop that from your mind. The latter, though, is kind of close. Imagine you go to take a step in our three dimensional world. What direction will you go in? Realistically, you’ll likely go some distance in the x direction, some in the y and some in the z direction. The odds that you’ll come back to within a certain distance of your starting point on the second step are fairly low; you’d need to simultaneously get the exact opposite of each of those three directions that you took in your first step. If you were only two dimensional, you’d have better odds and in one dimension, even better odds.
What dimensional reduction says is that the “quantum mechanical fuzziness” of reality means that if you were to take the odds of returning to your starting point in four quantum dimensions, it’s the same as in two classical dimensions, meaning that quantum mechanics increases significantly your odds of a random return. That’s the big finding.
From See Noevo on superhero physics: “Do you have any articles in the works on Superman, or on each of the Marvel superheroes?”
I sure do. Go read it; you may enjoy it!
From Denier on the physics of One Punch Man: ““No sir” came the quick reply. “The damage is from the force of One Punch Man’s foot pushing against the Earth with enough force to instantly propel him to 99.99999997% the speed of light”.”
The whole comment is accurate, and pretty spot on. As James Kakalios often says, you need to set out what the laws of physics are and how they are different or violated/not violated at the outset, and then you can construct comic book realities in a consistent fashion. One Punch Man’s leap from the Moon back to Earth is more destructive to the Moon than his meteor-stopping punch is to Earth, even though the latter requires more energy. There must be something in that fist of his…
From Wow on a plausible dark energy explanation idea: “Imagine the [Casimir] plates half a universe apart. The energy density is lower inside, right? And as the plates get closer, the energy inside gets lower.
Now imagine that these plates are “unit metric” in the multidimensional universe of string theory.
Where all dimensions have the same metric, the energy is equally distributed in all dimensions. As the three dimensions expand, the higher dimensions “roll up”, and the “size” of the universal dimension shrinks and excludes more and more wavelengths, reducing the energy in those smaller dimensions.
However the energy goes SOMEWHERE, energy isn’t destroyed or created, it’s a constant total.
That energy goes into the remaining three dimensions.”
As far as we can tell, the vacuum expectation value (we can call that energy) in the space inside the plates is different (lower) from the energy outside of the plates. As the plates get closer, more EM modes are forbidden, and hence the energy gets lower still. Your analogy is saying, rather than close down one dimension, forbidding modes (as in the space between the plates, you can still move arbitrarily in the other two), close down all the “extra” dimensions of string theory, thereby increasing the vacuum energy of our space.
All we need is a full theory of string theory where we can calculate the string vacuum from first principles, and the size of the dimensions that are compactified, and we can test this theory. Unfortunately, “string vacua” are undetermined from first principles, and this is one of the biggest frustrations of the whole string theory enterprise. It’s a plausible idea, but not one that’s in currently calculable territory today.
From eric on cosmic rays: “I find cloud chambers fascinating to watch. Any time I see one in a museum or science exhibit, I usually end up standing there much longer than planned. Evidently they’re relatively easy to build (there are loads of DIY videos and guides on the web), but I haven’t yet taken my minor obsession to that stage. “
And for that, here is a video of a cloud chamber with cosmic rays flying through it (timelapse):
And finally, from Elle H.C. on cosmic rays and the LHC: “Objection: “The Large Hadron Collider (LHC) will collide in 2015 protons at √s ≃ 14 TeV. This impressive energy is still about a factor of 50 smaller than the centre-of-mass energy of the highest energy cosmic ray so far observed, assuming primary protons.”
While for the LHC the collision rate is even 1.000.000.000 higher then in nature. It’s like saying on elephant is more intense than all the +1 billion chinese people in the world.”
This is an invalid objection based on a misunderstanding of the different between energy, collision energy and center-of-mass energy. Let’s explain. A particle has a certain amount of kinetic energy relative to our reference frame: the energy of its motion. The highest energy we’ve ever created for a single particle (e.g., a proton, not counting particles made up of multiple protons) on Earth is ~6.5 TeV, which is an LHC proton. If you collide this proton with a fixed target, which is to say a proton at rest, you “only” get √(2mE) worth of energy for new particle creation, where m is the mass of the proton and E is the kinetic energy of the LHC proton. This is pretty lame for the LHC; we’d only get 114 GeV of energy, maximum, per collision for new particle creation. If you like, you can replace the LHC’s energy with an ultra-high-energy-cosmic-ray’s energy: 10^11 GeV, and find it reaches approximately 500 TeV of energy available for new creation. This is the center-of-mass energy referred to.
The way the LHC reaches 13 TeV for particle creation is by colliding 6.5 TeV protons with other 6.5 TeV protons moving with the opposite momentum. Assuming there are multiple UHECR sources in the Universe (there are), and that they shoot UHECRs at one another, it stands to reason that there are plenty of ultra-high-energy collisions, where “m” in that equation can be replaced by the energy of the other particle with an approximately equal-and-opposite energy. The Universe has had collisions that are ~10^7 times as powerful as what we make at the LHC. I’m not sure what your point is with the elephant analogy, but that’s what the physics says and means. The energy of these cosmic rays is real and unique, and it’s only that the center-of-mass collisions are both high energy and incredibly precisely localized that make the LHC interesting at all.
Thanks for a great week, and can’t wait for another fantastic one starting tomorrow!
“Even though the future seems far away, it is actually beginning right now.” -Mattie Stepanek
It’s been a fantastic week here at Starts With A Bang, where we’ve covered even more ground than normal! First off, for those of you not following me on SoundCloud, we’ve got a new science podcast out, on the last star in the Universe.
And now lets take a look at your inquiries, ideas and more on this edition of our comments of the week!
From Sinisa Lazarek on the MACHO content of our galaxy: “Maybe I’m nitpicking, but IMO “ten times more” is not “slightly more”. This of course doesn’t influence the DM halo AROUND the galaxy (where most of DM is). But I expected that 10x more machos would influence the mass content of our galaxy more than slightly.”
It’s not nitpicking; you’re asking a questions about magnitudes. If you thought something was 2% and it turns out to be 20%, that’s suddenly very significant. But if you thought something was 0.001% and it turns out to be 0.01%, then it doesn’t matter. When we talk about the mass content of our galaxy, we are still much less than 1% when talking about MACHOs over the mass range we’re discussing. So no, ten times more MACHOs still only influences the mass content of our galaxy slightly.
From eric on the consciousness problem: “Every night, the pattern of electrical activity that is the conscious “me” disappears. It doesn’t go underground somewhere in my brain or go into some standby/dormant mode, this pattern ceases to exist. Not there. Gone. Noneexistent. New patterns, associated with sleep and dreaming, take its place. Then when I wake up, my brain recreates the pattern that is “me” from stored information…probably not exactly the same as it was before, I just don’t notice the differences.”
Now, this is a hard problem and I don’t have an answer. But I would submit that MRI results would show that there is some brain (electrical) activity that is identifiably you that is still present while you are asleep. I would also submit that it is that electrical pattern that occurs in your brain that is identifiable as you. Here are some unanswered questions:
In other words, I don’t know that, for example, Will and Tom Riker aren’t both exactly 100% the same Will Riker that was born in Alaska? And yet, perhaps neither one actually is; perhaps the original “Will Riker” died the first time his body was deconstructed and reconstructed, with that line-of-consciousness coming to a total end. And perhaps all the memories and continuity experienced by the copy doesn’t mean that it isn’t murder every time one goes through the transporter. Is this different or the same than going to sleep and waking up?
I don’t even know how to test this with a working transporter. Ideas?
From Alan L. on dark matter and LUX: “So have DM particles yet managed to achieve a level of such extreme puniness that it would make DM, as envisaged post LUX, an extremely unlikely candidate to be one capable of pushing around Andromeda sized galaxies so to ensure a uniform rotational speeds across their width, as if DM particles in galactic haloes formed gangs of some kind of super powerful schoolyard bullies?”
You must understand that it is not the size, magnitude or puniness of dark matter that makes it viable or not as capable of accounting for the gravitational effect of the Universe. It is its density and its clustering properties, the latter of which are determined by its kinetic energy as a function of its mass. A class of dark matter that doesn’t interact with normal matter or itself at all, that has only gravitational interactions with anything in this Universe, would be the ultimate nightmare scenario for experimental physicists, and yet it is a very real possibility for what the nature of dark matter could be.
It is up to us to push those limits in all mass ranges as far as we can go. We are constantly re-evaluating what the science tells us with a view to the full suite of evidence available, and as a result DM was replaced by CDM was replaced by Lambda-CDM, and now we are starting to find that the density profiles do not match simulations quite as well as we had hoped, which is leading to modified models of CDM as part of the Lambda-CDM model. Just because you may not like the path that science is being led doesn’t mean that scientists aren’t doing exactly the job that the data tells them to do.
From Jerry on dark matter collisions: “Since two of the key pieces of evidence for dark matter is that galaxies rotate to fast to hold together and that dark matter can be mapped separating from galaxy clusters in collisions, what would happen to a galaxy that became completely separated from its dark matter halo after hitting an especially dense area of intergalactic matter?”
Intergalactic matter would only be able to stop the other intergalactic matter in a galaxy: things like plasma, dust, and neutral gas. You want to stop a star? You need something as dense and massive as a star. You want to stop a galaxy? You need to something that’s going to stop not an “averaged galaxy,” but each of the 100 billion+ stars in it. That’s why, in the Bullet Group, above, the luminous stars move unimpeded through the group, while the gas (in pink) separates. If you truly wanted to allow the dark matter to continue moving while making your imaginary super-star-stopper stop the galaxy, you would forever alter the stars by nature of stopping the baryonic matter in the galaxies.
In other words, the answer isn’t a universal physics one, but rather is dependent on how you do this thing that requires a severe, non-natural intervention.
From PJ on the galaxies behind Andromeda: “Interesting to note the visibility of other galaxies through Andromeda in the closeup photo, lower right of photo, reddish appearance.”
This is the less common type of galactic reddening we see: not due to redshift, but rather due to dust in a foreground galaxy! In fact, you will notice what appears to be a large population of red stars in this galaxy as well, and that’s because the “dust” tends to exist in a thin plane in the galaxy’s center. The stuff in front of the dust isn’t reddened, but everything behind it — including stars and galaxies — experiences this extinction effect.
Dust grains are of a size where smaller wavelengths are blocked much more easily than longer ones, and so the more dust we pass through, the redder things appear. (Even though there’s less red light, there’s a higher percentage of red light as compared to everything else!) If you were to look at a region that wasn’t dusty in Andromeda, the galaxies behind it would only appear red as a function of their redshift.
From Denier on the concept of dimensional reduction: “Would this mean it is possible to collapse 4 dimensions down to 2, or that the 4 dimensions that we perceive all around us are in fact 2 dimensions when viewed on the QM scale?”
It actually doesn’t mean either of those. The former is definitely not what’s being said, so drop that from your mind. The latter, though, is kind of close. Imagine you go to take a step in our three dimensional world. What direction will you go in? Realistically, you’ll likely go some distance in the x direction, some in the y and some in the z direction. The odds that you’ll come back to within a certain distance of your starting point on the second step are fairly low; you’d need to simultaneously get the exact opposite of each of those three directions that you took in your first step. If you were only two dimensional, you’d have better odds and in one dimension, even better odds.
What dimensional reduction says is that the “quantum mechanical fuzziness” of reality means that if you were to take the odds of returning to your starting point in four quantum dimensions, it’s the same as in two classical dimensions, meaning that quantum mechanics increases significantly your odds of a random return. That’s the big finding.
From See Noevo on superhero physics: “Do you have any articles in the works on Superman, or on each of the Marvel superheroes?”
I sure do. Go read it; you may enjoy it!
From Denier on the physics of One Punch Man: ““No sir” came the quick reply. “The damage is from the force of One Punch Man’s foot pushing against the Earth with enough force to instantly propel him to 99.99999997% the speed of light”.”
The whole comment is accurate, and pretty spot on. As James Kakalios often says, you need to set out what the laws of physics are and how they are different or violated/not violated at the outset, and then you can construct comic book realities in a consistent fashion. One Punch Man’s leap from the Moon back to Earth is more destructive to the Moon than his meteor-stopping punch is to Earth, even though the latter requires more energy. There must be something in that fist of his…
From Wow on a plausible dark energy explanation idea: “Imagine the [Casimir] plates half a universe apart. The energy density is lower inside, right? And as the plates get closer, the energy inside gets lower.
Now imagine that these plates are “unit metric” in the multidimensional universe of string theory.
Where all dimensions have the same metric, the energy is equally distributed in all dimensions. As the three dimensions expand, the higher dimensions “roll up”, and the “size” of the universal dimension shrinks and excludes more and more wavelengths, reducing the energy in those smaller dimensions.
However the energy goes SOMEWHERE, energy isn’t destroyed or created, it’s a constant total.
That energy goes into the remaining three dimensions.”
As far as we can tell, the vacuum expectation value (we can call that energy) in the space inside the plates is different (lower) from the energy outside of the plates. As the plates get closer, more EM modes are forbidden, and hence the energy gets lower still. Your analogy is saying, rather than close down one dimension, forbidding modes (as in the space between the plates, you can still move arbitrarily in the other two), close down all the “extra” dimensions of string theory, thereby increasing the vacuum energy of our space.
All we need is a full theory of string theory where we can calculate the string vacuum from first principles, and the size of the dimensions that are compactified, and we can test this theory. Unfortunately, “string vacua” are undetermined from first principles, and this is one of the biggest frustrations of the whole string theory enterprise. It’s a plausible idea, but not one that’s in currently calculable territory today.
From eric on cosmic rays: “I find cloud chambers fascinating to watch. Any time I see one in a museum or science exhibit, I usually end up standing there much longer than planned. Evidently they’re relatively easy to build (there are loads of DIY videos and guides on the web), but I haven’t yet taken my minor obsession to that stage. “
And for that, here is a video of a cloud chamber with cosmic rays flying through it (timelapse):
And finally, from Elle H.C. on cosmic rays and the LHC: “Objection: “The Large Hadron Collider (LHC) will collide in 2015 protons at √s ≃ 14 TeV. This impressive energy is still about a factor of 50 smaller than the centre-of-mass energy of the highest energy cosmic ray so far observed, assuming primary protons.”
While for the LHC the collision rate is even 1.000.000.000 higher then in nature. It’s like saying on elephant is more intense than all the +1 billion chinese people in the world.”
This is an invalid objection based on a misunderstanding of the different between energy, collision energy and center-of-mass energy. Let’s explain. A particle has a certain amount of kinetic energy relative to our reference frame: the energy of its motion. The highest energy we’ve ever created for a single particle (e.g., a proton, not counting particles made up of multiple protons) on Earth is ~6.5 TeV, which is an LHC proton. If you collide this proton with a fixed target, which is to say a proton at rest, you “only” get √(2mE) worth of energy for new particle creation, where m is the mass of the proton and E is the kinetic energy of the LHC proton. This is pretty lame for the LHC; we’d only get 114 GeV of energy, maximum, per collision for new particle creation. If you like, you can replace the LHC’s energy with an ultra-high-energy-cosmic-ray’s energy: 10^11 GeV, and find it reaches approximately 500 TeV of energy available for new creation. This is the center-of-mass energy referred to.
The way the LHC reaches 13 TeV for particle creation is by colliding 6.5 TeV protons with other 6.5 TeV protons moving with the opposite momentum. Assuming there are multiple UHECR sources in the Universe (there are), and that they shoot UHECRs at one another, it stands to reason that there are plenty of ultra-high-energy collisions, where “m” in that equation can be replaced by the energy of the other particle with an approximately equal-and-opposite energy. The Universe has had collisions that are ~10^7 times as powerful as what we make at the LHC. I’m not sure what your point is with the elephant analogy, but that’s what the physics says and means. The energy of these cosmic rays is real and unique, and it’s only that the center-of-mass collisions are both high energy and incredibly precisely localized that make the LHC interesting at all.
Thanks for a great week, and can’t wait for another fantastic one starting tomorrow!
By Vivienne Machi
A new Army video game is taking soldiers into the heart of foreign disaster zones and delivering real-world training from their laptop or tablet.
A joint task force — including U.S. Army South, the Army Research Laboratory, the office of foreign disaster assistance and the Army games for training program — has put Disaster Sim into the hands of soldiers after two years of research and development.
Disaster Sim was created by the Army Research Laboratory and programmers from the Institute for Creative Technologies at the University of Southern California as a cost-effective training tool for company grade officers and mid to junior non-commissioned officers engaged in foreign disaster relief, said Maj. Timothy Migliore, chief of the Army’s games for training program.
“The more ways you can involve actually doing the task or the job at hand, the faster you learn,” he said.
Hour-long vignettes based on real-world events familiarize users with operational environments they could encounter on the ground, and teach them how to work with the office of foreign disaster assistance, non-governmental agencies and the host country. The initial scenario challenges a soldier to respond to needs in Guatemala after an earthquake.
Although it was developed for Army South, the game’s editor authoring tools allow it to be tweaked by developers to assist other organizations at a minimal development cost, said Col. Michael Panko, U.S. Army South chief of training and exercises.
“If you’re Army Pacific, you can make it look like their area,” he said.
Migliore noted the cost-saving benefits of the game.
“If I can develop my own scenario and not have to go outside [the services], we’re saving the user money and saving the taxpayer money,” he said. Service members across the globe can download Disaster Sim and the authoring tools through an online portal at no charge. It cost approximately $700,000 to create the training application and the authoring tools, according to the Army Combined Arms Center – Training.
There used to be “a cultural resistance” to using video games as a training tool among the services, Migliore said.
But within the last 10 years, the military has shifted away from that mindset and embraced the virtual training possibilities that offer a more realistic experience at a lower cost, he said. “We’ve got a ton of what we’ve liked to call niche games that get to training requirements, and there’s nothing remotely that relates to Disaster Sim.”
By Vivienne Machi
A new Army video game is taking soldiers into the heart of foreign disaster zones and delivering real-world training from their laptop or tablet.
A joint task force — including U.S. Army South, the Army Research Laboratory, the office of foreign disaster assistance and the Army games for training program — has put Disaster Sim into the hands of soldiers after two years of research and development.
Disaster Sim was created by the Army Research Laboratory and programmers from the Institute for Creative Technologies at the University of Southern California as a cost-effective training tool for company grade officers and mid to junior non-commissioned officers engaged in foreign disaster relief, said Maj. Timothy Migliore, chief of the Army’s games for training program.
“The more ways you can involve actually doing the task or the job at hand, the faster you learn,” he said.
Hour-long vignettes based on real-world events familiarize users with operational environments they could encounter on the ground, and teach them how to work with the office of foreign disaster assistance, non-governmental agencies and the host country. The initial scenario challenges a soldier to respond to needs in Guatemala after an earthquake.
Although it was developed for Army South, the game’s editor authoring tools allow it to be tweaked by developers to assist other organizations at a minimal development cost, said Col. Michael Panko, U.S. Army South chief of training and exercises.
“If you’re Army Pacific, you can make it look like their area,” he said.
Migliore noted the cost-saving benefits of the game.
“If I can develop my own scenario and not have to go outside [the services], we’re saving the user money and saving the taxpayer money,” he said. Service members across the globe can download Disaster Sim and the authoring tools through an online portal at no charge. It cost approximately $700,000 to create the training application and the authoring tools, according to the Army Combined Arms Center – Training.
There used to be “a cultural resistance” to using video games as a training tool among the services, Migliore said.
But within the last 10 years, the military has shifted away from that mindset and embraced the virtual training possibilities that offer a more realistic experience at a lower cost, he said. “We’ve got a ton of what we’ve liked to call niche games that get to training requirements, and there’s nothing remotely that relates to Disaster Sim.”
Tonight … if you have a dark sky, make your acquaintance with the constellation Draco the Dragon, starting at nightfall. At mid-northern latitudes, Draco is a circumpolar constellation, meaning it is out all night long every night of the year. Northern Hemisphere summer evenings are the best time to look, because this is when the Dragon’s flashing eyes look down upon you from up high in the northern sky.
The chart at the top of this post – showing Draco – covers a lot more sky than our charts usually do. That’s because Draco is big! This serpentine star figure wanders in between the Big and Little Dippers, with its tail found between the bowl of the Big Dipper and the star Polaris.
I always notice the two stars in the Dragon’s head when looking at the bright star Vega in the constellation Lyra. If you’re familiar with the Summer Triangle, draw an imaginary line from the star Altair through the star Vega to find the Dragon’s eyes glaring at you from high overhead on July and August evenings. These two stars are Rastaban and Eltanin – lovely, romantic names for the Dragon’s stars.
Watch Draco tonight as it circles around the North Star, Polaris.
Another noteworthy star in Draco is Thuban, which is high in the sky in the evening at this time of year. Thuban is an interesting star because – around 3000 B.C. – Thuban used to be the Pole Star.
The constellation Draco, by the way, has been associated with a dragon in many cultures. A Babylonian myth links Draco to the dragon god Tiamat, who was subdued by the god of the sun.
Bottom line: Here is Draco the Dragon on a July evening. Meet Rastaban and Eltanin – lovely, romantic names for Dragon stars! They represent the Eyes of the Dragon.
EarthSky’s meteor shower guide for 2016
Help support posts like these at the EarthSky store. Fun astronomy gifts and tools for all ages!
Tonight … if you have a dark sky, make your acquaintance with the constellation Draco the Dragon, starting at nightfall. At mid-northern latitudes, Draco is a circumpolar constellation, meaning it is out all night long every night of the year. Northern Hemisphere summer evenings are the best time to look, because this is when the Dragon’s flashing eyes look down upon you from up high in the northern sky.
The chart at the top of this post – showing Draco – covers a lot more sky than our charts usually do. That’s because Draco is big! This serpentine star figure wanders in between the Big and Little Dippers, with its tail found between the bowl of the Big Dipper and the star Polaris.
I always notice the two stars in the Dragon’s head when looking at the bright star Vega in the constellation Lyra. If you’re familiar with the Summer Triangle, draw an imaginary line from the star Altair through the star Vega to find the Dragon’s eyes glaring at you from high overhead on July and August evenings. These two stars are Rastaban and Eltanin – lovely, romantic names for the Dragon’s stars.
Watch Draco tonight as it circles around the North Star, Polaris.
Another noteworthy star in Draco is Thuban, which is high in the sky in the evening at this time of year. Thuban is an interesting star because – around 3000 B.C. – Thuban used to be the Pole Star.
The constellation Draco, by the way, has been associated with a dragon in many cultures. A Babylonian myth links Draco to the dragon god Tiamat, who was subdued by the god of the sun.
Bottom line: Here is Draco the Dragon on a July evening. Meet Rastaban and Eltanin – lovely, romantic names for Dragon stars! They represent the Eyes of the Dragon.
EarthSky’s meteor shower guide for 2016
Help support posts like these at the EarthSky store. Fun astronomy gifts and tools for all ages!
A waning crescent moon is sometimes called an old moon. It’s seen in the east before dawn.
At this moon phase, the moon has moved nearly entirely around in its orbit of Earth, as measured from one new moon to the next. The next new moon will be August 2 at 2045 UTC. Translate to your time zone.
Because the moon is nearly on a line with the Earth and sun again, the day hemisphere of the moon is facing mostly away from us once more. We see only a slender fraction of the moon’s day side: a crescent moon.
Each morning before dawn, because the moon is moving eastward in orbit around Earth, the moon appears closer to the sunrise glare. We see less and less of the moon’s day side, and thus the crescent in the east before dawn appears thinner each day.
The moon, as always, is rising in the east day after day. But most people won’t see this moon phase unless they get up early. When the sun comes up, and the sky grows brighter, the waning crescent moon fades. Now the moon is so near the Earth/sun line that the sun’s glare is drowning this slim moon from view.
Still, the waning crescent is up there, nearly all day long, moving ahead of the sun across the sky’s dome. It sets in the west several hours or less before sunset.
As the moon orbits Earth, it changes phase in an orderly way. Follow these links to understand the various phases of the moon.
Four keys to understanding moon phases
Where’s the moon? Waxing crescent
Where’s the moon? First quarter
Where’s the moon? Waxing gibbous
What’s special about a full moon?
Where’s the moon? Waning gibbous
Where’s the moon? Last quarter
Where’s the moon? Waning crescent
Where’s the moon? New phase
Moon in 2016: Phases, cycles, eclipses, supermoons and more
A waning crescent moon is sometimes called an old moon. It’s seen in the east before dawn.
At this moon phase, the moon has moved nearly entirely around in its orbit of Earth, as measured from one new moon to the next. The next new moon will be August 2 at 2045 UTC. Translate to your time zone.
Because the moon is nearly on a line with the Earth and sun again, the day hemisphere of the moon is facing mostly away from us once more. We see only a slender fraction of the moon’s day side: a crescent moon.
Each morning before dawn, because the moon is moving eastward in orbit around Earth, the moon appears closer to the sunrise glare. We see less and less of the moon’s day side, and thus the crescent in the east before dawn appears thinner each day.
The moon, as always, is rising in the east day after day. But most people won’t see this moon phase unless they get up early. When the sun comes up, and the sky grows brighter, the waning crescent moon fades. Now the moon is so near the Earth/sun line that the sun’s glare is drowning this slim moon from view.
Still, the waning crescent is up there, nearly all day long, moving ahead of the sun across the sky’s dome. It sets in the west several hours or less before sunset.
As the moon orbits Earth, it changes phase in an orderly way. Follow these links to understand the various phases of the moon.
Four keys to understanding moon phases
Where’s the moon? Waxing crescent
Where’s the moon? First quarter
Where’s the moon? Waxing gibbous
What’s special about a full moon?
Where’s the moon? Waning gibbous
Where’s the moon? Last quarter
Where’s the moon? Waning crescent
Where’s the moon? New phase
Moon in 2016: Phases, cycles, eclipses, supermoons and more
This is a re-post from Inside Climate News by Bob Berwyn
Extreme heat waves like the current string of scorching days in the Midwest have become more frequent worldwide in the last 60 years, and climate scientists expect that human-caused global warming will exacerbate the dangerous trend in coming decades. It comes with potentially life-threatening consequences for millions of people.
Research has shown that overall mortality increases by 4 percent during heat waves compared to normal days in the U.S. A study in the journal Environmental Health Perspectives in 2011 suggested that rising summer temperatures could kill up to 2,200 more people per year in Chicago alone during the last two decades of the 21st century.
"The climate is changing faster than we've ever seen during the history of human civilization on this planet, and climate change is putting heat waves on steroids," Katharine Hayhoe, director of the Climate Science Center at Texas Tech University, said during a news conference on Thursday. "Heat waves are getting more frequent and stronger."
Temperatures this week soared into the 90s from Minnesota to Iowa, combining with high humidity to send heat indices well above the 100-degree Fahrenheit mark, considered a threshold for conditions dangerous to human health.
Current temperatures in large parts of the Midwest have been rising steadily for more than 100 years, with accelerated warming in the past few decades. According to the 2014 National Climate Assessment, the average temperature in the region increased by more than 1.5 degrees Fahrenheit between 1900 and 2010. Between 1950 and 2010, the rate of increase doubled, and since 1980, the pace of warming is three times faster than between 1900 and 2010.
But while the Midwest joins the overall warming trend, it has not been hit frequently by summer heat waves, according to Ken Kunkel of NOAA's National Centers for Environmental Information
"The Midwest has not experienced any substantial summer warming and this spills over into heat waves," he said. "The period of most heatwaves for the Midwest remains the 1930s Dust Bowl era." In North America, there has been an increase in heatwaves west of the Rocky Mountains, but to the east, generally not, he said
That leads to fears that the region is unprepared for the dangerous impacts of a stretch this hot. The lack of preparedness was a big reason a heat wave in Europe in 2003 was so deadly, killing more than 70,000 people.
"We see the biggest impacts when we have multi-day events," Hayhoe said. "And when nighttime temperatures don't cool off enough to give us a respite, that's when we start to see an impact on health. Especially the elderly and people with respiratory problems start flooding emergency rooms."
"The bottom line is we face a new normal and we're adapting to it on the city and regional level," said Christopher B. Coleman, mayor of St. Paul, Minn., and co-chair of the Mississippi River Cities & Towns Initiative. Also speaking during the press conference, he called the Mississippi River Valley an "acute climate impact zone," and said some of the less obvious impacts of extreme heat includes urban stormwater runoff that creates thermal pollution when it hits hot pavement.
The Midwest heatwave is peaking just as NOAA announced that last month was the warmest June on record for Earth. It was the 14th consecutive month that the average global temperature record was broken, making it the longest streak of record-warm months in 137 years, according to the agency's monthly state of the climate report. Averaged across land and sea surfaces, the global temperature was 1.62 degrees Fahrenheit above the 20th century average, topping the record set just last year. The last time the global temperature for June was below average was in 1976.
"The health consequences of climate change run an entire gamut, from worsening chronic disease, to an increase in vector and waterborne illnesses and disruption to food safety," said Rev. Miriam Burnett, president of Resource and Promotion of Health Alliance, Inc, a faith-based nonprofit focusing on public health in African-American communities. Extreme heat events even have social consequences, including putting strain on human interactions and generating anger and hostility, she said.
Scientists say there's little doubt that the buildup of heat trapping greenhouse gases is already causing more deadly heat waves worldwide. The increase has been widely documented and summarized in the latest Intergovernmental Panel on Climate Change assessment.
This is a re-post from Inside Climate News by Bob Berwyn
Extreme heat waves like the current string of scorching days in the Midwest have become more frequent worldwide in the last 60 years, and climate scientists expect that human-caused global warming will exacerbate the dangerous trend in coming decades. It comes with potentially life-threatening consequences for millions of people.
Research has shown that overall mortality increases by 4 percent during heat waves compared to normal days in the U.S. A study in the journal Environmental Health Perspectives in 2011 suggested that rising summer temperatures could kill up to 2,200 more people per year in Chicago alone during the last two decades of the 21st century.
"The climate is changing faster than we've ever seen during the history of human civilization on this planet, and climate change is putting heat waves on steroids," Katharine Hayhoe, director of the Climate Science Center at Texas Tech University, said during a news conference on Thursday. "Heat waves are getting more frequent and stronger."
Temperatures this week soared into the 90s from Minnesota to Iowa, combining with high humidity to send heat indices well above the 100-degree Fahrenheit mark, considered a threshold for conditions dangerous to human health.
Current temperatures in large parts of the Midwest have been rising steadily for more than 100 years, with accelerated warming in the past few decades. According to the 2014 National Climate Assessment, the average temperature in the region increased by more than 1.5 degrees Fahrenheit between 1900 and 2010. Between 1950 and 2010, the rate of increase doubled, and since 1980, the pace of warming is three times faster than between 1900 and 2010.
But while the Midwest joins the overall warming trend, it has not been hit frequently by summer heat waves, according to Ken Kunkel of NOAA's National Centers for Environmental Information
"The Midwest has not experienced any substantial summer warming and this spills over into heat waves," he said. "The period of most heatwaves for the Midwest remains the 1930s Dust Bowl era." In North America, there has been an increase in heatwaves west of the Rocky Mountains, but to the east, generally not, he said
That leads to fears that the region is unprepared for the dangerous impacts of a stretch this hot. The lack of preparedness was a big reason a heat wave in Europe in 2003 was so deadly, killing more than 70,000 people.
"We see the biggest impacts when we have multi-day events," Hayhoe said. "And when nighttime temperatures don't cool off enough to give us a respite, that's when we start to see an impact on health. Especially the elderly and people with respiratory problems start flooding emergency rooms."
"The bottom line is we face a new normal and we're adapting to it on the city and regional level," said Christopher B. Coleman, mayor of St. Paul, Minn., and co-chair of the Mississippi River Cities & Towns Initiative. Also speaking during the press conference, he called the Mississippi River Valley an "acute climate impact zone," and said some of the less obvious impacts of extreme heat includes urban stormwater runoff that creates thermal pollution when it hits hot pavement.
The Midwest heatwave is peaking just as NOAA announced that last month was the warmest June on record for Earth. It was the 14th consecutive month that the average global temperature record was broken, making it the longest streak of record-warm months in 137 years, according to the agency's monthly state of the climate report. Averaged across land and sea surfaces, the global temperature was 1.62 degrees Fahrenheit above the 20th century average, topping the record set just last year. The last time the global temperature for June was below average was in 1976.
"The health consequences of climate change run an entire gamut, from worsening chronic disease, to an increase in vector and waterborne illnesses and disruption to food safety," said Rev. Miriam Burnett, president of Resource and Promotion of Health Alliance, Inc, a faith-based nonprofit focusing on public health in African-American communities. Extreme heat events even have social consequences, including putting strain on human interactions and generating anger and hostility, she said.
Scientists say there's little doubt that the buildup of heat trapping greenhouse gases is already causing more deadly heat waves worldwide. The increase has been widely documented and summarized in the latest Intergovernmental Panel on Climate Change assessment.
For those of us who are concerned about global warming, two of the most critical questions we ask are, “how fast is the Earth warming?” and “how much will it warm in the future?”.
The first question can be answered in a number of ways. For instance, we can actually measure the rate of energy increase in the Earth’s system (primarily through measuring changing ocean temperatures). Alternatively, we can measure changes in the net inflow of heat at the top of the atmosphere using satellites. We can also measure the rate of sea-level rise to get an estimate of the warming rate.
Since much of sea-level rise is caused by thermal expansion of water, knowledge of the water-level rise allows us to deduce the warming rate. We can also use climate models (which are sophisticated computer calculations of the Earth’s climate) or our knowledge from Earth’s past (paleoclimatology).
Many studies use combinations of these study methods to attain estimates and typically the estimates are that the planet is warming at a rate of perhaps 0.5 to 1 Watt per square meter of Earth’s surface area. However, there is some discrepancy among the actual numbers.
So assuming we know how much heat is being accumulated by the Earth, how can we predict what the future climate will be? The main tool for this is climate models (although there are other independent ways we can study the future). With climate models, we can play “what-if scenarios” and input either current conditions or hypothetical conditions and watch the Earth’s climate evolve within the simulation.
Two incorrect but nevertheless consistent denial arguments are that the Earth isn’t warming and that climate models are inaccurate. A new study, published by Kevin Trenberth, Lijing Cheng, and others (I was also an author) answers these questions.
The study was just published in the journal Ocean Sciences; a draft of it is available here. In this study, we did a few new things. First, we presented a new estimate of ocean heating throughout its full depth (most studies only consider the top portion of the ocean). Second, we used a new technique to learn about ocean temperature changes in areas where there are very few measurements. Finally, we used a large group of computer models to predict warming rates, and we found excellent agreement between the predictions and the measurements.
According to the measurements, the Earth has gained 0.46 Watts per square meter between 1970 and 2005. Since, 1992 the rate is higher (0.75 Watts per square meter) and therefore shows an acceleration of the warming. To put this in perspective, this is the equivalent of 5,400,000,000,000 (or 5,400 billion) 60-watt light bulbs running continuously day and night. In my view, these numbers are the most accurate measurements of the rate at which the Earth is warming.
What about the next question – how did the models do? Amazingly well. From 1970 through 2005, the models on average showed a warming of 0.41 Watts per square meter and from 1992-2005 the models gave 0.77 Watts per meter squared. This means that since 1992, the models have been within 3 % of the measurements. In my mind, this agreement is the strongest vindication of the models ever found, and in fact, in our study we suggest that matches between climate models and ocean warming should be a major test of the models.
Despite these excellent results, scientists want to do better. During a conversation with Dr. Trenberth, he told me:
For those of us who are concerned about global warming, two of the most critical questions we ask are, “how fast is the Earth warming?” and “how much will it warm in the future?”.
The first question can be answered in a number of ways. For instance, we can actually measure the rate of energy increase in the Earth’s system (primarily through measuring changing ocean temperatures). Alternatively, we can measure changes in the net inflow of heat at the top of the atmosphere using satellites. We can also measure the rate of sea-level rise to get an estimate of the warming rate.
Since much of sea-level rise is caused by thermal expansion of water, knowledge of the water-level rise allows us to deduce the warming rate. We can also use climate models (which are sophisticated computer calculations of the Earth’s climate) or our knowledge from Earth’s past (paleoclimatology).
Many studies use combinations of these study methods to attain estimates and typically the estimates are that the planet is warming at a rate of perhaps 0.5 to 1 Watt per square meter of Earth’s surface area. However, there is some discrepancy among the actual numbers.
So assuming we know how much heat is being accumulated by the Earth, how can we predict what the future climate will be? The main tool for this is climate models (although there are other independent ways we can study the future). With climate models, we can play “what-if scenarios” and input either current conditions or hypothetical conditions and watch the Earth’s climate evolve within the simulation.
Two incorrect but nevertheless consistent denial arguments are that the Earth isn’t warming and that climate models are inaccurate. A new study, published by Kevin Trenberth, Lijing Cheng, and others (I was also an author) answers these questions.
The study was just published in the journal Ocean Sciences; a draft of it is available here. In this study, we did a few new things. First, we presented a new estimate of ocean heating throughout its full depth (most studies only consider the top portion of the ocean). Second, we used a new technique to learn about ocean temperature changes in areas where there are very few measurements. Finally, we used a large group of computer models to predict warming rates, and we found excellent agreement between the predictions and the measurements.
According to the measurements, the Earth has gained 0.46 Watts per square meter between 1970 and 2005. Since, 1992 the rate is higher (0.75 Watts per square meter) and therefore shows an acceleration of the warming. To put this in perspective, this is the equivalent of 5,400,000,000,000 (or 5,400 billion) 60-watt light bulbs running continuously day and night. In my view, these numbers are the most accurate measurements of the rate at which the Earth is warming.
What about the next question – how did the models do? Amazingly well. From 1970 through 2005, the models on average showed a warming of 0.41 Watts per square meter and from 1992-2005 the models gave 0.77 Watts per meter squared. This means that since 1992, the models have been within 3 % of the measurements. In my mind, this agreement is the strongest vindication of the models ever found, and in fact, in our study we suggest that matches between climate models and ocean warming should be a major test of the models.
Despite these excellent results, scientists want to do better. During a conversation with Dr. Trenberth, he told me:
Noah Charney, Postdoctoral Research Associate of Ecology and Evolutionary Biology, University of Arizona
This article was originally published on The Conversation. Read the original article.
We’ve heard the predictions of how greenhouse gas emissions will drive changes in the temperatures and precipitation people experience. But how these changes affect the world’s forests has broad implications for the future as well.
Could warmer winters, and thus longer growing seasons, cause trees to grow faster? If so, perhaps faster tree growth could slow the pace of climate change, since trees suck carbon out of the air as they grow.
Or perhaps hotter summers will mean more drought-like conditions, thereby hampering trees' ability to grow and thus cause deterioration of our woodlands.
In a recent paper, my colleagues and I set out to make a map of how climate change might influence tree growth across the entire continent of North America. To do this, we dug into historical records of tree growth over the period 1900-1950 collected by many dedicated field ecologists over the decades and deposited in the International Tree Ring Data Bank.
What we found was that the daily life of trees across much of North America will become more challenging, despite the potential benefit that rising carbon dioxide concentrations may have for trees. This is contrary to some scientists' hopes that climate change will strongly benefit northern latitude forests.
The first hurdle in predicting future tree growth is to understand how trees in different ecosystems respond to climate fluctuations.
You might guess that in cold northern forests, a little heat might help trees grow, whereas more heat in the desert Southwest is likely the last thing trees there want. This observation motivated previous scientists to formulate a “boreal greening” hypothesis – that global warming will cause northern boreal forests to grow faster and help mitigate climate change.
We used the historic tree ring data to map the relationship between regional climate and tree growth. Matching each growth ring to the weather patterns in the corresponding year, we can get a sense for how trees respond to climate fluctuations. For instance, we saw that above-average June temperatures caused faster tree growth in places with climates similar to Fairbanks, Alaska, but slower growth in Phoenix-like climates.
As the climate changes, we might expect the response of trees to change as well. For example, in Fairbanks, our models actually predict that, in the future, above-average June temperatures will be bad for tree growth there, which is opposite of the historic relationship. Why? Fairbanks warms up so much that it shifts to a new climatic zone in which additional warming is now a detriment. Other researchers have actually started to see such a shift occur on the ground in Alaska.
Once we characterize how trees respond to changes in climate across the continent, we can use the forecasts from the U.N.’s Intergovernmental Panel on Climate Change (IPCC) to predict the corresponding change in tree growth across the continent. For each pixel on our map of North America, we projected how forests will change based on both sets of information – the growth-climate relationship we established through the tree ring analysis and the projected changes in climate in the continent.
There is one more wrinkle to this puzzle that we examined. The changing climate is driven largely by a buildup of additional carbon dioxide, and plants use carbon dioxide to photosynthesize. Just as we breathe in oxygen to live, plants breathe in carbon dioxide to live. Thus, increased amounts of carbon dioxide might directly speed up tree growth. This is known as “carbon fertilization” because it’s like we are adding fertilizer to the plants through the air to help them grow.
Scientists are deeply divided about whether carbon fertilization of this type will actually cause increases in growth, and if so, how much. In our paper, we did not attempt to settle this debate. Instead, we just included multiple different possibilities for the strength of carbon fertilization.
To simulate carbon fertilization, we used a neat little trick suggested by Professor Graham Farquhar of Australian National University. The trick relies on the fact that as plants breathe in carbon dioxide, water escapes. Think of the pores on leaves as little mouths that open and close to breathe. The more plants need to open their mouths to breathe, the more water escapes. So plants try to keep their mouths as tightly closed as they can.
If the concentrations of carbon dioxide floating around in the air are very high, plants need open their mouths only a little bit for a small gulp of air without losing much water. Thus, as we fertilize the plants with carbon in the air, this directly decreases the amount of water the plants are able to retain – with more CO2, the leaves' pores will absorb the gas more efficiently and in the process lose less water.
Instead of trying to simulate more free carbon floating around in the air, we can just pretend that the plants receive more rainwater. The ultimate effect on growth should be essentially the same, because carbon uptake and water retention are directly linked.
In deserts where water is at a premium and plants are highly motivated to keep their mouths shut, a little carbon fertilization (or a little extra rain) should go a long way toward helping plants grow. By contrast, in rainforests where plants can keep their mouths wide open with little cost, carbon fertilization (or extra rain) might not do much to help the plants.
In our study, we simulated carbon fertilization by simply adding more future precipitation into our models. To satisfy those scientists who strongly believe that carbon fertilization will pan out, in some simulations we added extra water in proportion to the amount of extra carbon that is projected to be released into the atmosphere. To satisfy the nay-saying scientists who don’t believe the carbon fertilization effect will pan out, we also ran simulations without any increased water. And we ran simulations at all levels in between.
At the end of the day, our maps of how tree growth might respond to climate change are alarming.
Across much of the west and central parts of the continent, we see massive decreases in tree growth rates, with trees growing up to 75 percent slower by the second half of this century. However, in some areas near the continent’s coasts, such as the Pacific Northwest, western Canada and the southeastern United States, we saw some local increases in tree growth rates.
On average, without the carbon fertilization effect, our models project growth rates across the continent to fall by almost 20 percent under the worst-case climate change scenario put forth by the IPCC (this scenario has 6 degrees Celsius of warming forecast across the continent).
We found that it would take a very large carbon fertilization effect (unrealistically large, according to the opinion of several of our study’s co-authors) to offset this slowdown. And across much of the continent, our models projected slower growth rates no matter how large the carbon fertilization effect.
Also, we did not see a large increase in cold northern forest growth rates in our simulations. So, on average, we saw no “boreal greening.” If anything, we saw a slowdown of these forests. This is largely driven by the shift in how trees respond to climates in places like Fairbanks.
The implication of our analysis is that forests do not seem poised to save us from climate change.
Our models suggest that most of our forests will be growing more slowly in the future. This will, of course, have direct impacts on all the ways we and other species rely on trees. But it will also feed back into climate change itself. As global warming causes trees to absorb less carbon, there will be more carbon left in the air to cause faster warming, thus creating an accelerating cycle.
Furthermore, many sustained years of bad growth in trees will likely deplete the resources they need to survive, making them susceptible to severe droughts or insect outbreaks. This may mean that what we project as slower growth may translate into widespread tree death. In other words, the forest picture may be even gloomier than our models suggest.
In our models, we don’t take into account the way forests are changing due to changes in logging practices or forest management. In many areas, forests are regrowing faster simply because we stopped logging them recently. Such factors should be thought of as another layer to add on top of our projections.
This study, like any of its kind, is really our best guess at approximating the future. I think of such forecasts not as hard-and-fast predictions of what will happen, but as reasonable possibilities. There are so many unknowns involved, including the fact that future climates will likely be quite different from any we have seen in the past.
And of course the biggest unknown is how much willpower our human community will bring to the cause of clamping down on greenhouse gas emissions.
Noah Charney, Postdoctoral Research Associate of Ecology and Evolutionary Biology, University of Arizona
This article was originally published on The Conversation. Read the original article.
We’ve heard the predictions of how greenhouse gas emissions will drive changes in the temperatures and precipitation people experience. But how these changes affect the world’s forests has broad implications for the future as well.
Could warmer winters, and thus longer growing seasons, cause trees to grow faster? If so, perhaps faster tree growth could slow the pace of climate change, since trees suck carbon out of the air as they grow.
Or perhaps hotter summers will mean more drought-like conditions, thereby hampering trees' ability to grow and thus cause deterioration of our woodlands.
In a recent paper, my colleagues and I set out to make a map of how climate change might influence tree growth across the entire continent of North America. To do this, we dug into historical records of tree growth over the period 1900-1950 collected by many dedicated field ecologists over the decades and deposited in the International Tree Ring Data Bank.
What we found was that the daily life of trees across much of North America will become more challenging, despite the potential benefit that rising carbon dioxide concentrations may have for trees. This is contrary to some scientists' hopes that climate change will strongly benefit northern latitude forests.
The first hurdle in predicting future tree growth is to understand how trees in different ecosystems respond to climate fluctuations.
You might guess that in cold northern forests, a little heat might help trees grow, whereas more heat in the desert Southwest is likely the last thing trees there want. This observation motivated previous scientists to formulate a “boreal greening” hypothesis – that global warming will cause northern boreal forests to grow faster and help mitigate climate change.
We used the historic tree ring data to map the relationship between regional climate and tree growth. Matching each growth ring to the weather patterns in the corresponding year, we can get a sense for how trees respond to climate fluctuations. For instance, we saw that above-average June temperatures caused faster tree growth in places with climates similar to Fairbanks, Alaska, but slower growth in Phoenix-like climates.
As the climate changes, we might expect the response of trees to change as well. For example, in Fairbanks, our models actually predict that, in the future, above-average June temperatures will be bad for tree growth there, which is opposite of the historic relationship. Why? Fairbanks warms up so much that it shifts to a new climatic zone in which additional warming is now a detriment. Other researchers have actually started to see such a shift occur on the ground in Alaska.
Once we characterize how trees respond to changes in climate across the continent, we can use the forecasts from the U.N.’s Intergovernmental Panel on Climate Change (IPCC) to predict the corresponding change in tree growth across the continent. For each pixel on our map of North America, we projected how forests will change based on both sets of information – the growth-climate relationship we established through the tree ring analysis and the projected changes in climate in the continent.
There is one more wrinkle to this puzzle that we examined. The changing climate is driven largely by a buildup of additional carbon dioxide, and plants use carbon dioxide to photosynthesize. Just as we breathe in oxygen to live, plants breathe in carbon dioxide to live. Thus, increased amounts of carbon dioxide might directly speed up tree growth. This is known as “carbon fertilization” because it’s like we are adding fertilizer to the plants through the air to help them grow.
Scientists are deeply divided about whether carbon fertilization of this type will actually cause increases in growth, and if so, how much. In our paper, we did not attempt to settle this debate. Instead, we just included multiple different possibilities for the strength of carbon fertilization.
To simulate carbon fertilization, we used a neat little trick suggested by Professor Graham Farquhar of Australian National University. The trick relies on the fact that as plants breathe in carbon dioxide, water escapes. Think of the pores on leaves as little mouths that open and close to breathe. The more plants need to open their mouths to breathe, the more water escapes. So plants try to keep their mouths as tightly closed as they can.
If the concentrations of carbon dioxide floating around in the air are very high, plants need open their mouths only a little bit for a small gulp of air without losing much water. Thus, as we fertilize the plants with carbon in the air, this directly decreases the amount of water the plants are able to retain – with more CO2, the leaves' pores will absorb the gas more efficiently and in the process lose less water.
Instead of trying to simulate more free carbon floating around in the air, we can just pretend that the plants receive more rainwater. The ultimate effect on growth should be essentially the same, because carbon uptake and water retention are directly linked.
In deserts where water is at a premium and plants are highly motivated to keep their mouths shut, a little carbon fertilization (or a little extra rain) should go a long way toward helping plants grow. By contrast, in rainforests where plants can keep their mouths wide open with little cost, carbon fertilization (or extra rain) might not do much to help the plants.
In our study, we simulated carbon fertilization by simply adding more future precipitation into our models. To satisfy those scientists who strongly believe that carbon fertilization will pan out, in some simulations we added extra water in proportion to the amount of extra carbon that is projected to be released into the atmosphere. To satisfy the nay-saying scientists who don’t believe the carbon fertilization effect will pan out, we also ran simulations without any increased water. And we ran simulations at all levels in between.
At the end of the day, our maps of how tree growth might respond to climate change are alarming.
Across much of the west and central parts of the continent, we see massive decreases in tree growth rates, with trees growing up to 75 percent slower by the second half of this century. However, in some areas near the continent’s coasts, such as the Pacific Northwest, western Canada and the southeastern United States, we saw some local increases in tree growth rates.
On average, without the carbon fertilization effect, our models project growth rates across the continent to fall by almost 20 percent under the worst-case climate change scenario put forth by the IPCC (this scenario has 6 degrees Celsius of warming forecast across the continent).
We found that it would take a very large carbon fertilization effect (unrealistically large, according to the opinion of several of our study’s co-authors) to offset this slowdown. And across much of the continent, our models projected slower growth rates no matter how large the carbon fertilization effect.
Also, we did not see a large increase in cold northern forest growth rates in our simulations. So, on average, we saw no “boreal greening.” If anything, we saw a slowdown of these forests. This is largely driven by the shift in how trees respond to climates in places like Fairbanks.
The implication of our analysis is that forests do not seem poised to save us from climate change.
Our models suggest that most of our forests will be growing more slowly in the future. This will, of course, have direct impacts on all the ways we and other species rely on trees. But it will also feed back into climate change itself. As global warming causes trees to absorb less carbon, there will be more carbon left in the air to cause faster warming, thus creating an accelerating cycle.
Furthermore, many sustained years of bad growth in trees will likely deplete the resources they need to survive, making them susceptible to severe droughts or insect outbreaks. This may mean that what we project as slower growth may translate into widespread tree death. In other words, the forest picture may be even gloomier than our models suggest.
In our models, we don’t take into account the way forests are changing due to changes in logging practices or forest management. In many areas, forests are regrowing faster simply because we stopped logging them recently. Such factors should be thought of as another layer to add on top of our projections.
This study, like any of its kind, is really our best guess at approximating the future. I think of such forecasts not as hard-and-fast predictions of what will happen, but as reasonable possibilities. There are so many unknowns involved, including the fact that future climates will likely be quite different from any we have seen in the past.
And of course the biggest unknown is how much willpower our human community will bring to the cause of clamping down on greenhouse gas emissions.
A chronological listing of the news articles posted on the Skeptical Science Facebook page during the past week.
Sun July 24, 2016
Mon July 25, 2016
Tue July 26, 2016
Wed July 27, 2016
Thu July 28, 2016
Fri July 29, 2016
Sat July 30, 2016
A chronological listing of the news articles posted on the Skeptical Science Facebook page during the past week.
Sun July 24, 2016
Mon July 25, 2016
Tue July 26, 2016
Wed July 27, 2016
Thu July 28, 2016
Fri July 29, 2016
Sat July 30, 2016
“The world you see, nature’s greatest and most glorious creation, and the human mind which gazes and wonders at it, and is the most splendid part of it, these are our own everlasting possessions and will remain with us as long as we ourselves remain.” -Seneca
Asking where in space the Big Bang happened is like asking where the starting point of Earth’s surface is. There’s no one “point” where it began, unless you’re talking about a point in time. The reality is that, as far as space is concerned, the Big Bang occurred everywhere at once, and we have the evidence to prove it.
If the Big Bang were an explosion, we would discover ourselves in a Universe that had a preferred location with different densities surrounding it, but instead we see a Universe that has the same density everywhere. We’d see a Universe that looked different in different directions, yet we see one that’s uniform to better than one part in 10,000 in each direction we look. And we see a Universe that exhibits zero spatial curvature: one that’s indistinguishable from flat.
The Big Bang happened everywhere at once. This is how we know it, and this is what it means.
“The world you see, nature’s greatest and most glorious creation, and the human mind which gazes and wonders at it, and is the most splendid part of it, these are our own everlasting possessions and will remain with us as long as we ourselves remain.” -Seneca
Asking where in space the Big Bang happened is like asking where the starting point of Earth’s surface is. There’s no one “point” where it began, unless you’re talking about a point in time. The reality is that, as far as space is concerned, the Big Bang occurred everywhere at once, and we have the evidence to prove it.
If the Big Bang were an explosion, we would discover ourselves in a Universe that had a preferred location with different densities surrounding it, but instead we see a Universe that has the same density everywhere. We’d see a Universe that looked different in different directions, yet we see one that’s uniform to better than one part in 10,000 in each direction we look. And we see a Universe that exhibits zero spatial curvature: one that’s indistinguishable from flat.
The Big Bang happened everywhere at once. This is how we know it, and this is what it means.
Detectorist John Kvanli is the chairman of Rygene detektorklubb and one of Norway’s most prominent proponents of collaboration between amateurs and professionals in field archaeology. Of course he has a tattoo! It’s an Urnes brooch from c. AD 1100, in the final exquisite Christian style of Scandinavian animal art.
John tells me he has found several fragments of these fragile objects, but the one inked onto his upper right arm is a settlement excavation find from Lindholm Høje, across the fjord from Aalborg in northern Jutland. The needlework was done by the Martin Tattoo Studio in Pattaya, Thailand.
See Aard’s tattoo tag for more like these.
Detectorist John Kvanli is the chairman of Rygene detektorklubb and one of Norway’s most prominent proponents of collaboration between amateurs and professionals in field archaeology. Of course he has a tattoo! It’s an Urnes brooch from c. AD 1100, in the final exquisite Christian style of Scandinavian animal art.
John tells me he has found several fragments of these fragile objects, but the one inked onto his upper right arm is a settlement excavation find from Lindholm Høje, across the fjord from Aalborg in northern Jutland. The needlework was done by the Martin Tattoo Studio in Pattaya, Thailand.
See Aard’s tattoo tag for more like these.
This new time-lapse from the SKYGLOW Project visits Dry Tortugas National Park, one of the darkest and most remote places on U.S. east coast.
Our friend Harun Mehmedinovic of SKYGLOW wrote:
On a remote island hours away from Key West [Florida] lies the largest masonry structure in the Americas: Fort Jefferson. Built with 16 million bricks, but never finished, the fort served as a prison during Civil War. In 1935, President Franklin D. Roosevelt, upon visiting the island, named it a National Monument, and in 1992 it became part of Dry Tortugas National Park.
Besides serving as a safe haven for the most preserved coral reef in the United States, the set of islands that comprise the national park also protect countless marine animals and bird species. However, the true treasure of this amazing place was noted by one of its most famous prisoners, Dr. Samuel Mudd, who once noted that the the only escape from the hell of this prison was gazing at the night skies. Today, Dry Tortugas National Park is the darkest spot on the east coast.
Harun told us that the footage in this video is special because the National Park Service does not normally allow night photography at the park, but made an exception for this project.
This video was filmed as part of SKYGLOW, an ongoing crowdfunded quest to explore the effects and dangers of urban light pollution in contrast with some of the most incredible dark sky areas in North America. You can see more info on the video here.
Enjoying EarthSky? Sign up for our free daily newsletter today!
Bottom line: Time-lapse of night skies over Florida’s Dry Tortugas National Park.
This new time-lapse from the SKYGLOW Project visits Dry Tortugas National Park, one of the darkest and most remote places on U.S. east coast.
Our friend Harun Mehmedinovic of SKYGLOW wrote:
On a remote island hours away from Key West [Florida] lies the largest masonry structure in the Americas: Fort Jefferson. Built with 16 million bricks, but never finished, the fort served as a prison during Civil War. In 1935, President Franklin D. Roosevelt, upon visiting the island, named it a National Monument, and in 1992 it became part of Dry Tortugas National Park.
Besides serving as a safe haven for the most preserved coral reef in the United States, the set of islands that comprise the national park also protect countless marine animals and bird species. However, the true treasure of this amazing place was noted by one of its most famous prisoners, Dr. Samuel Mudd, who once noted that the the only escape from the hell of this prison was gazing at the night skies. Today, Dry Tortugas National Park is the darkest spot on the east coast.
Harun told us that the footage in this video is special because the National Park Service does not normally allow night photography at the park, but made an exception for this project.
This video was filmed as part of SKYGLOW, an ongoing crowdfunded quest to explore the effects and dangers of urban light pollution in contrast with some of the most incredible dark sky areas in North America. You can see more info on the video here.
Enjoying EarthSky? Sign up for our free daily newsletter today!
Bottom line: Time-lapse of night skies over Florida’s Dry Tortugas National Park.