August 2016 Open Thread [Deltoid]

from ScienceBlogs http://ift.tt/2aqJzJX

from ScienceBlogs http://ift.tt/2aqJzJX

August 2016 guide to the 5 bright planets

Skywatcher, by Predrag Agatonovic.

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.

In late July and early August 2016, look from the sunset direction eastward to catch all 5 bright planets after sunset. Green line depicts the ecliptic, or sun’s path across the sky. Look for the planets along the sun’s path. Read more.

Will you see the moon and Venus on August 3? Maybe. Then watch the moon appear higher in the west after sunset each evening, near Jupiter and Mercury.

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.

Here’s Venus, caught from a plane over southern Oregon, on July 28, 2016. Notice the bright twilight background. Photo by Gemini Brett.

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.

Look for the moon near Jupiter on August 5 and August 6. Binoculars could come in handy. The green line depicts the ecliptic – Earth’s orbital plane projected on the great dome of 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.

View larger | Mikhail Chubarets in the Ukraine made this chart. It shows the view of Mars through a telescope in 2016. We never see Mars as a disk like this with the eye alone. But you can see why Mars has been so bright to the eye in 2016.

Use the moon to find the planets Mars and Saturn plus the star Antares on August 10, August 11 and August 12. The green line depicts the ecliptic – the sun’s yearly path and the moon’s monthly path in front of the constellations of the zodiac.

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.

Mars moves in between the planet Saturn and the star Antares on August 24, 2016.Read more

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.

Tom Wildoner over-exposed Saturn itself to capture this view of Saturn’s moons on June 25, 2016. Visit Tom at LeisurelyScientist.com.

Contrasting the size of Saturn and its rings with our planet Earth via Hubble Heritage Team.

Saturn’s rings are inclined at a little more than 26^o 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 27^o.

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 27^o by May 2032.

Click here for recommended almanacs. They can help you know when the planets rise, transit and set in your sky

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.

From late January, and through mid-February, 5 bright planets were visible at once in the predawn sky. This image is from February 8, 2016. It’s by Eliot Herman in Tucson, Arizona. View on Flickr.

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

from EarthSky http://ift.tt/IJfHCr

Skywatcher, by Predrag Agatonovic.

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.

In late July and early August 2016, look from the sunset direction eastward to catch all 5 bright planets after sunset. Green line depicts the ecliptic, or sun’s path across the sky. Look for the planets along the sun’s path. Read more.

Will you see the moon and Venus on August 3? Maybe. Then watch the moon appear higher in the west after sunset each evening, near Jupiter and Mercury.

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.

Here’s Venus, caught from a plane over southern Oregon, on July 28, 2016. Notice the bright twilight background. Photo by Gemini Brett.

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.

Look for the moon near Jupiter on August 5 and August 6. Binoculars could come in handy. The green line depicts the ecliptic – Earth’s orbital plane projected on the great dome of 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.

View larger | Mikhail Chubarets in the Ukraine made this chart. It shows the view of Mars through a telescope in 2016. We never see Mars as a disk like this with the eye alone. But you can see why Mars has been so bright to the eye in 2016.

Use the moon to find the planets Mars and Saturn plus the star Antares on August 10, August 11 and August 12. The green line depicts the ecliptic – the sun’s yearly path and the moon’s monthly path in front of the constellations of the zodiac.

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.

Mars moves in between the planet Saturn and the star Antares on August 24, 2016.Read more

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.

Tom Wildoner over-exposed Saturn itself to capture this view of Saturn’s moons on June 25, 2016. Visit Tom at LeisurelyScientist.com.

Contrasting the size of Saturn and its rings with our planet Earth via Hubble Heritage Team.

Saturn’s rings are inclined at a little more than 26^o 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 27^o.

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 27^o by May 2032.

Click here for recommended almanacs. They can help you know when the planets rise, transit and set in your sky

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.

From late January, and through mid-February, 5 bright planets were visible at once in the predawn sky. This image is from February 8, 2016. It’s by Eliot Herman in Tucson, Arizona. View on Flickr.

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

from EarthSky http://ift.tt/IJfHCr

2016 SkS Weekly Digest #31

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...

SkS Highlights

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. 

Toon of the Week

 

Hat tip to I Heart Climate Scientists

Quote of the Week 

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

Graphic of the Week

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 

He Said What?

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

Coming Soon on SkS

• A climate scientist and economist made big bucks betting on global warming (Dana)
• As nuclear power plants close, states need to bet big on energy storage (Eric Daniel Fournier & Alex Ricklefs)
• New research shows penguins will suffer in a warming world (John Abraham)
• Six charts show UK progress towards low-carbon energy (Simon Evans)
• Climate-related disasters raise conflict risk, study says (Robert McSweeney)
• 2016 SkS Weekly News Roundup #32 (John Hartz)
• 2016 SkS Weekly Digest #32 (John Hartz)

Poster of the Week

 

SkS Week in Review

• 2016 SkS Weekly News Roundup #31 by John Hartz
• Sizzling Midwest Previews a Hotter Future Climate by Bob Erwyn (InsideClimate News) 
• Analysis: How UK leaving the EU would increase climate targets for others by Simon Evans (InsideClimate News)
• Climate models are accurately predicting ocean and global warming by John Abraham (Climate Consensus-the 97%, Guardian)
• More CO2 won’t help northern forests or stave off climate change by Noah Charney (The Conversation US)
• These are the best arguments from the 3% of climate scientist 'skeptics.' Really. by Dana Nuccitelli (Climate Consensus-the 97%, Guardian)
• 2016 SkS Weekly Digest #30 by John Hartz

97 Hours of Consensus: Katharine Hayhoe

 

Katharine Hayhoe's bio page & Quote source

High resolution JPEG (1024 pixels wide)

from Skeptical Science http://ift.tt/2aa0WzR

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...

SkS Highlights

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. 

Toon of the Week

 

Hat tip to I Heart Climate Scientists

Quote of the Week 

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

Graphic of the Week

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 

He Said What?

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

Coming Soon on SkS

• A climate scientist and economist made big bucks betting on global warming (Dana)
• As nuclear power plants close, states need to bet big on energy storage (Eric Daniel Fournier & Alex Ricklefs)
• New research shows penguins will suffer in a warming world (John Abraham)
• Six charts show UK progress towards low-carbon energy (Simon Evans)
• Climate-related disasters raise conflict risk, study says (Robert McSweeney)
• 2016 SkS Weekly News Roundup #32 (John Hartz)
• 2016 SkS Weekly Digest #32 (John Hartz)

Poster of the Week

 

SkS Week in Review

• 2016 SkS Weekly News Roundup #31 by John Hartz
• Sizzling Midwest Previews a Hotter Future Climate by Bob Erwyn (InsideClimate News) 
• Analysis: How UK leaving the EU would increase climate targets for others by Simon Evans (InsideClimate News)
• Climate models are accurately predicting ocean and global warming by John Abraham (Climate Consensus-the 97%, Guardian)
• More CO2 won’t help northern forests or stave off climate change by Noah Charney (The Conversation US)
• These are the best arguments from the 3% of climate scientist 'skeptics.' Really. by Dana Nuccitelli (Climate Consensus-the 97%, Guardian)
• 2016 SkS Weekly Digest #30 by John Hartz

97 Hours of Consensus: Katharine Hayhoe

 

Katharine Hayhoe's bio page & Quote source

High resolution JPEG (1024 pixels wide)

from Skeptical Science http://ift.tt/2aa0WzR

Comments of the Week #120: from the Great Attractor to the highest-energy particles [Starts With A Bang]

“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.

Have a listen and enjoy; that’s all possible thanks to the generous donations of our Patreon supporters, as are the re-runs of each article, ad-free, on a 7-day delay over on Medium. Here were the new pieces of this past week:

• Will the ‘Great Attractor’ defeat dark energy? (for Ask Ethan),
• The stars of Andromeda, inside and out, as revealed by Hubble (for Mostly Mute Monday),
• Dimensional reduction: the key to physics’ greatest mystery? (contributed by Sabine Hossenfelder),
• The physics of stopping a meteor with one punch,
• Could dark energy be caused by a reaction to what’s in the Universe?, and
• What are the most energetic particles in the Universe?

And now lets take a look at your inquiries, ideas and more on this edition of our comments of the week!

Image credit: ESO/L. Calçada, of the illustration of the dark matter halo surrounding the luminous disk of our galaxy.

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.

A modern high field clinical MRI scanner. MRI machines are the largest medical or scientific use of helium today. Image credit: Wikimedia Commons user KasugaHuang, under a c.c.a.-s.a.-3.0 license.

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:

• Would that same electrical pattern existing elsewhere also be identifiable as you?
• Would you feel that same “youness” about it, waking up tomorrow as just electrical activity in another location, as you feel every day where you wake up?
• Is this continuity of our existence evidence of a real phenomenon, or is it an illusion?
• And if we created multiple copies of that electrical activity, would that continuity still exist?

Tom and Will Riker, together on the Enterprise after the former’s rescue. Image credit: Memory Alpha Wiki, by user ThomasHL, from the TNG episode Second Chances.

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?

The LUX underground detector, installed and in the tank. Image credit: C.H. Faham and the LUX collaboration.

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.

Composite image of the Bullet Group showing galaxies, hot gas (shown in pink) and dark matter (indicated in blue). Image credit: ESA / XMM-Newton / F. Gastaldello (INAF/IASF, Milano, Italy) / CFHTLS

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.

Closeup of a large region of the Andromeda galaxy’s disk, containing hundreds of open star clusters (identifiable as bright blue sparkles). Image credit: NASA, ESA, J. Dalcanton, B.F. Williams, L.C. Johnson (University of Washington), the PHAT team, and R. Gendler.

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.

A crude model of a spiral galaxy, with equal numbers of stars throughout the entire volume of it. Image credit: E. Siegel.

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.

Isotropic random walk on the euclidean lattice Z^3. This picture shows three different walks after 10 000 unit steps, all three starting from the origin. Image credit: Zweistein, under c.c.a.-s.a.-3.0.

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.

Image credit: DC Comics.

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!

Saitama having just punched through the meteor, stopping its momentum and breaking it apart. From the Anime, “One Punch Man.” Image credit: from Daisuki.net.

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…

An illustration of the Casimir effect, and how the forces on the outside of the plates are different from the forces on the inside. Image credit: Wikimedia commons user Emok, under a c.c.a.-by-s.a.-3.0 license.

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.

The production of a cosmic ray shower, produced by an incredibly energetic particle from far outside our Solar System. Image credit: Pierre Auger Observatory, via http://ift.tt/11Wasx4.

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):

plus one of a cloud chamber with a radioactive (uranium) source inside: Enjoy!

The spectrum of cosmic rays. Image credit: Hillas 2006, preprint arXiv:astro-ph/0607109 v2, via University of Hamburg.

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.

Image credit: CERN, via http://ift.tt/1qBVVNm.

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!

from ScienceBlogs http://ift.tt/2amEZPf

“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.

Have a listen and enjoy; that’s all possible thanks to the generous donations of our Patreon supporters, as are the re-runs of each article, ad-free, on a 7-day delay over on Medium. Here were the new pieces of this past week:

• Will the ‘Great Attractor’ defeat dark energy? (for Ask Ethan),
• The stars of Andromeda, inside and out, as revealed by Hubble (for Mostly Mute Monday),
• Dimensional reduction: the key to physics’ greatest mystery? (contributed by Sabine Hossenfelder),
• The physics of stopping a meteor with one punch,
• Could dark energy be caused by a reaction to what’s in the Universe?, and
• What are the most energetic particles in the Universe?

And now lets take a look at your inquiries, ideas and more on this edition of our comments of the week!

Image credit: ESO/L. Calçada, of the illustration of the dark matter halo surrounding the luminous disk of our galaxy.

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.

A modern high field clinical MRI scanner. MRI machines are the largest medical or scientific use of helium today. Image credit: Wikimedia Commons user KasugaHuang, under a c.c.a.-s.a.-3.0 license.

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:

• Would that same electrical pattern existing elsewhere also be identifiable as you?
• Would you feel that same “youness” about it, waking up tomorrow as just electrical activity in another location, as you feel every day where you wake up?
• Is this continuity of our existence evidence of a real phenomenon, or is it an illusion?
• And if we created multiple copies of that electrical activity, would that continuity still exist?

Tom and Will Riker, together on the Enterprise after the former’s rescue. Image credit: Memory Alpha Wiki, by user ThomasHL, from the TNG episode Second Chances.

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?

The LUX underground detector, installed and in the tank. Image credit: C.H. Faham and the LUX collaboration.

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.

Composite image of the Bullet Group showing galaxies, hot gas (shown in pink) and dark matter (indicated in blue). Image credit: ESA / XMM-Newton / F. Gastaldello (INAF/IASF, Milano, Italy) / CFHTLS

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.

Closeup of a large region of the Andromeda galaxy’s disk, containing hundreds of open star clusters (identifiable as bright blue sparkles). Image credit: NASA, ESA, J. Dalcanton, B.F. Williams, L.C. Johnson (University of Washington), the PHAT team, and R. Gendler.

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.

A crude model of a spiral galaxy, with equal numbers of stars throughout the entire volume of it. Image credit: E. Siegel.

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.

Isotropic random walk on the euclidean lattice Z^3. This picture shows three different walks after 10 000 unit steps, all three starting from the origin. Image credit: Zweistein, under c.c.a.-s.a.-3.0.

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.

Image credit: DC Comics.

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!

Saitama having just punched through the meteor, stopping its momentum and breaking it apart. From the Anime, “One Punch Man.” Image credit: from Daisuki.net.

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…

An illustration of the Casimir effect, and how the forces on the outside of the plates are different from the forces on the inside. Image credit: Wikimedia commons user Emok, under a c.c.a.-by-s.a.-3.0 license.

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.

The production of a cosmic ray shower, produced by an incredibly energetic particle from far outside our Solar System. Image credit: Pierre Auger Observatory, via http://ift.tt/11Wasx4.

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):

plus one of a cloud chamber with a radioactive (uranium) source inside: Enjoy!

The spectrum of cosmic rays. Image credit: Hillas 2006, preprint arXiv:astro-ph/0607109 v2, via University of Hamburg.

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.

Image credit: CERN, via http://ift.tt/1qBVVNm.

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!

from ScienceBlogs http://ift.tt/2amEZPf

Army Releases Disaster Response Video Game

U.S. Army courtesy photo

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.”

from Armed with Science http://ift.tt/2am9tB5

U.S. Army courtesy photo

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.”

from Armed with Science http://ift.tt/2am9tB5

Draco, great Dragon of the north

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.

Draco, with Ursa Minor or the Little Dipper, as depicted in Urania’s Mirror, a set of constellation cards published in London c. 1825.

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!

from EarthSky http://ift.tt/1RjPjpe

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.

Draco, with Ursa Minor or the Little Dipper, as depicted in Urania’s Mirror, a set of constellation cards published in London c. 1825.

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!

from EarthSky http://ift.tt/1RjPjpe

Where’s the moon? Waning crescent

Moon on the morning of July 29, 2016, the morning of its occultation of the star Aldebaran (shown at left). Photo from our friend Lunar 101 – MoonBook.

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.

Moon on the morning of July 30, 2016 from our friend Dennis Chabot of Posne NightSky Astorophotography. Dennis reminds us that: “The Perseid meteor shower will put on a show peaking on evening of August 11 and morning of August 12.” A Perseid outburst is expected in 2016. That morning, the moon will be in a waxing gibbous phase, setting in the hours before dawn.

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

from EarthSky http://ift.tt/GLfilJ

Moon on the morning of July 29, 2016, the morning of its occultation of the star Aldebaran (shown at left). Photo from our friend Lunar 101 – MoonBook.

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.

Moon on the morning of July 30, 2016 from our friend Dennis Chabot of Posne NightSky Astorophotography. Dennis reminds us that: “The Perseid meteor shower will put on a show peaking on evening of August 11 and morning of August 12.” A Perseid outburst is expected in 2016. That morning, the moon will be in a waxing gibbous phase, setting in the hours before dawn.

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

from EarthSky http://ift.tt/GLfilJ