SkS Highlights... El Niño to La Niña... Toon of the Week... Quote of the Week... He Said What?... SkS in the News... SkS Spotlights... Coming Soon on SkS... Poster of the Week... SkS Week in Review... 97 Hours of Consensus...
SkS Highlights
Can the Republican Party solve its science denial problem? by Dana Nuccitelli garnered the highest number of comments among the articles posted on SkS during the past week. The article was originally posted on the Climate Consensus - the 97% Guardian blog maintained by Nuccitelli and John Abraham where it generated a lengthy and quite contentious comment thread. Click here to access the Guardian article and comment thread.
El Niño to La Niñposted on SkS during the past week. a
Withering drought and sizzling temperatures from El Nino have caused food and water shortages and ravaged farming across Asia, and experts warn of a double-whammy of possible flooding from its sibling, La Nina.
The current El Nino which began last year has been one of the strongest ever, leaving the Mekong River at its lowest level in decades, causing food-related unrest in the Philippines, and smothering vast regions in a months-long heat wave often topping 40 degrees Celsius (104 Fahrenheit).
Economic losses in Southeast Asia could top $10 billion, IHS Global Insight told AFP.
The regional fever is expected to break by mid-year but fears are growing that an equally forceful La Nina will follow.
That could bring heavy rain to an already flood-prone region, exacerbating agricultural damage and leaving crops vulnerable to disease and pests.
"Loss of oxygen in the oceans is one of the serious side effects of a warming atmosphere, and a major threat to marine life," said Matthew Long*, who is the lead author of the study. "Since oxygen concentrations in the ocean naturally vary depending on variations in winds and temperature at the surface, it's been challenging to attribute any de-oxygenation to climate change. This new study tells us when we can expect the effect from climate change to overwhelm the natural variability."
“The coal industry is being destroyed,” he* says. “And it’s scary to me because electricity is a staple of life — like potatoes were to the Irish. And Obama has largely destroyed reliable, low-cost, affordable electricity in America.”
*Robert E. Murray, chairman of the Murray Energy Corporation
The Carbon Pricing Leadership Coalition brings together leaders from across government, the private sector and civil society to share experience working with carbon pricing and to expand the evidence base for the most effective carbon pricing systems and policies.
The Coalition is a voluntary partnership of national and sub-national governments, businesses, and civil society organizations that agree to advance the carbon pricing agenda by working with each other towards the long-term objective of a carbon price applied throughout the global economy by:
strengthening carbon pricing policies to redirect investment commensurate with the scale of the climate challenge;
bringing forward and strengthening the implementation of existing carbon pricing policies to better manage investment risks and opportunities; and
enhancing cooperation to share information, expertise and lessons learned on developing and implementing carbon pricing through various "readiness" platforms
The Coalition will collect the evidence base, benefiting from experience around the world in designing and using carbon pricing, and use this input to help inform successful carbon pricing policy development and use of carbon pricing in businesses. It will also deepen understanding of the business and economic case for carbon pricing. In that role, it is developing pathways for use by companies, investors and governments that will illustrate plausible outlooks under a variety of carbon pricing policies and timelines. Finally, the coalition will work to bring together government and business in leadership dialogues that identify and address the most pressing issues, and in doing so, accelerate the use of carbon pricing around the world.
Coming Soon on SkS
Peabody coal's contrarian scientist witnesses lose their court case (John Abraham)
Handy resources when facing a firehose of falsehoods (Baerbel)
Scientists are figuring out the keys to convincing people about global warming (Dana)
Consensus on Consensus (AndyS)
Deep sea microbes may be key to oceans’ climate change feedback (Howard Lee)
SkS Highlights... El Niño to La Niña... Toon of the Week... Quote of the Week... He Said What?... SkS in the News... SkS Spotlights... Coming Soon on SkS... Poster of the Week... SkS Week in Review... 97 Hours of Consensus...
SkS Highlights
Can the Republican Party solve its science denial problem? by Dana Nuccitelli garnered the highest number of comments among the articles posted on SkS during the past week. The article was originally posted on the Climate Consensus - the 97% Guardian blog maintained by Nuccitelli and John Abraham where it generated a lengthy and quite contentious comment thread. Click here to access the Guardian article and comment thread.
El Niño to La Niñposted on SkS during the past week. a
Withering drought and sizzling temperatures from El Nino have caused food and water shortages and ravaged farming across Asia, and experts warn of a double-whammy of possible flooding from its sibling, La Nina.
The current El Nino which began last year has been one of the strongest ever, leaving the Mekong River at its lowest level in decades, causing food-related unrest in the Philippines, and smothering vast regions in a months-long heat wave often topping 40 degrees Celsius (104 Fahrenheit).
Economic losses in Southeast Asia could top $10 billion, IHS Global Insight told AFP.
The regional fever is expected to break by mid-year but fears are growing that an equally forceful La Nina will follow.
That could bring heavy rain to an already flood-prone region, exacerbating agricultural damage and leaving crops vulnerable to disease and pests.
"Loss of oxygen in the oceans is one of the serious side effects of a warming atmosphere, and a major threat to marine life," said Matthew Long*, who is the lead author of the study. "Since oxygen concentrations in the ocean naturally vary depending on variations in winds and temperature at the surface, it's been challenging to attribute any de-oxygenation to climate change. This new study tells us when we can expect the effect from climate change to overwhelm the natural variability."
“The coal industry is being destroyed,” he* says. “And it’s scary to me because electricity is a staple of life — like potatoes were to the Irish. And Obama has largely destroyed reliable, low-cost, affordable electricity in America.”
*Robert E. Murray, chairman of the Murray Energy Corporation
The Carbon Pricing Leadership Coalition brings together leaders from across government, the private sector and civil society to share experience working with carbon pricing and to expand the evidence base for the most effective carbon pricing systems and policies.
The Coalition is a voluntary partnership of national and sub-national governments, businesses, and civil society organizations that agree to advance the carbon pricing agenda by working with each other towards the long-term objective of a carbon price applied throughout the global economy by:
strengthening carbon pricing policies to redirect investment commensurate with the scale of the climate challenge;
bringing forward and strengthening the implementation of existing carbon pricing policies to better manage investment risks and opportunities; and
enhancing cooperation to share information, expertise and lessons learned on developing and implementing carbon pricing through various "readiness" platforms
The Coalition will collect the evidence base, benefiting from experience around the world in designing and using carbon pricing, and use this input to help inform successful carbon pricing policy development and use of carbon pricing in businesses. It will also deepen understanding of the business and economic case for carbon pricing. In that role, it is developing pathways for use by companies, investors and governments that will illustrate plausible outlooks under a variety of carbon pricing policies and timelines. Finally, the coalition will work to bring together government and business in leadership dialogues that identify and address the most pressing issues, and in doing so, accelerate the use of carbon pricing around the world.
Coming Soon on SkS
Peabody coal's contrarian scientist witnesses lose their court case (John Abraham)
Handy resources when facing a firehose of falsehoods (Baerbel)
Scientists are figuring out the keys to convincing people about global warming (Dana)
Consensus on Consensus (AndyS)
Deep sea microbes may be key to oceans’ climate change feedback (Howard Lee)
View larger. | Image via NASA/JPL-Caltech/Space Science Institute.
Are Saturn’s rings criss-crossed in this February, 2016, Cassini spacecraft image? No. It’s not a new discovery, just an illusion caused by the fact that Saturn’s rings aren’t solid objects. NASA said:
At first glance, Saturn’s rings appear to be intersecting themselves in an impossible way. In actuality, this view … shows the rings in front of the planet, upon which the shadow of the rings is cast.
Saturn’s rings are composed of millions of tiny moonlets. They aren’t solid; we can see through them. And that’s why we can see the shadow of the rings behind the rings themselves, creating this apparent criss-cross. Speaking of this image, NASA went on to say:
Saturn’s rings have complex and detailed structures, many of which can be seen here. In some cases, the reasons for the gaps and ringlets are known; for example, Pan (17 miles or 28 kilometers across) — seen here near image center — keeps open the Encke gap. But in other cases, the origins and natures of gaps and ringlets are still poorly understood.
This view looks toward the sunlit side of the rings from about 14 degrees above the ring plane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Feb. 11, 2016.
The view was acquired at a distance of approximately 1.2 million miles (1.9 million kilometers) from Pan and at a Sun-Pan-spacecraft, or phase, angle of 85 degrees. Image scale is 6 miles (10 kilometers) per pixel.
View larger. | Image via NASA/JPL-Caltech/Space Science Institute.
Are Saturn’s rings criss-crossed in this February, 2016, Cassini spacecraft image? No. It’s not a new discovery, just an illusion caused by the fact that Saturn’s rings aren’t solid objects. NASA said:
At first glance, Saturn’s rings appear to be intersecting themselves in an impossible way. In actuality, this view … shows the rings in front of the planet, upon which the shadow of the rings is cast.
Saturn’s rings are composed of millions of tiny moonlets. They aren’t solid; we can see through them. And that’s why we can see the shadow of the rings behind the rings themselves, creating this apparent criss-cross. Speaking of this image, NASA went on to say:
Saturn’s rings have complex and detailed structures, many of which can be seen here. In some cases, the reasons for the gaps and ringlets are known; for example, Pan (17 miles or 28 kilometers across) — seen here near image center — keeps open the Encke gap. But in other cases, the origins and natures of gaps and ringlets are still poorly understood.
This view looks toward the sunlit side of the rings from about 14 degrees above the ring plane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Feb. 11, 2016.
The view was acquired at a distance of approximately 1.2 million miles (1.9 million kilometers) from Pan and at a Sun-Pan-spacecraft, or phase, angle of 85 degrees. Image scale is 6 miles (10 kilometers) per pixel.
“Science is the only self-correcting human institution, but it also is a process that progresses only by showing itself to be wrong.” -Allan Sandage
As April leaves us and May commences here at Starts With A Bang, I’m so pleased to inform you that amazing things are happening! Thanks to the support of everyone on Patreon, we’re over 95% of the way towards our next goal: the creation of the most accurate, beautiful, scientific timeline of the Universe’s history poster ever made! We’ve also covered the following topics this past week for you to ring in on:
Our Podcasts are coming along, too, as our Patreon supporters have chosen May’s topic (on dark energy), and someone, unsolicited (Philipp Dettmer, thank you!) has made me my first piece of fanart of me!
Image credit: Japan Meteorological Association (JMA), of the monthly average temperatures in February, going back as far as temperature records do. Via the Sydney Morning Herald at http://ift.tt/1LqCRlA.
From Ragtag Media on climate tampering: “I back up my skepticism with not just my unabridged worldly opinion but with a variety of others.
Here, that this one: Massive Tampering With Temperatures In South America: http://ift.tt/1EmJj4J“
What you call “tampering” is what scientists call “adjustments”. Now you can say, “why don’t you just use the raw temperatures and be done with it,” but the reason is important: you are using these temperature measurements as proxies for the entire globe, and yet you are measuring them at limited, specific (often city-centric) locations located at ground-level. What do you do about the fact that paved roads increase (artificially) the temperatures you measure? What do you do about the fact that different stations give data with different quality levels? What do you do about fires when they occur nearby, or when factories are turned on vs. off?
If you say, “just give me the raw data,” you know you’re not accurately representing the global temperature. If you make the appropriate adjustments to the best of your scientific knowledge, how is that equivalent to “tampering” in any negative sense of the word? I’m going to say what I’ve said before to you: it sounds like you’re basing which argument you side with on the conclusions that are reached. If the temperature is warming, you refute that fact. If you accept warming temperatures, you refute that it’s human-caused. If you accept that it’s human-caused, you refute that it’s a bad thing. And if you accept that it’s a bad thing, you refute that there’s anything we can do. Remind me of where you are in that progression again?
Image credit: Breakthrough Starshot, of the laser sail concept for a “starchip” spaceship.
From PJ on slowing down a starshot: “Makes an interesting enigma – get to the target planet first, set up a power grid and laser site to slow the probes down on their arrival so that we can explore the local environment to decide where to set up our base.
The chicken and the egg again?”
Quite honestly, I think the conclusion we need to accept is not that we have to send a slowpoke-system to another star in order to properly explore it, but rather that sending a “starchip” starship to another system is just a cool technological feat on its own, and that the R&D that goes into developing the technology is fascinating and useful in its applications in a myriad of other ways. Think about the progress that will be made in:
light, strong, reflective materials,
laser technology,
laser collimation technology,
laser sail steering and stabilization,
miniaturization microchip technology,
and effectively 2D transmission and communication technology,
among others. We don’t need to get 100% of the way there to have something worth bragging about, or something that benefits society in a greater way than any individual efforts could do on their own.
A logarithmic chart of distances, showing the Voyager spacecraft, our Solar System and our nearest star, for comparison. Image credit: NASA / JPL-Caltech.
From Michael Kelsey on predicting the laser sail’s demise from collisions: “With an average interstellar density of a few atoms per cubic centimeter (1e-4 in hot, ionized regions to 1e+6 in molecular clouds), a solar sail with an area of 1 km2 at 0.2 c will see a flux of something like 6e+16 impacts per second, or a heat load of 192 kW.”
This is the main part of your estimation I’m unsure of. Your density numbers look good, your area looks good and your speed looks good. But impacts? I’m thinking of the famous Rutherford experiment, and the fact that if most of what we’re likely to encounter is ionized rather than neutral (and bound), most of these particles will simply pass through this thin sail with no collision at all. In other words, the number of impacts and the heat load may be many orders of magnitude lower than your estimate.
The concept art of a solar sail (Japan’s IKAROS project) at a distant planet or star system. Image credit: Andrzej Mirecki of Wikimedia Commons, under a c.c.a.-s.a.-3.0 license.
But I do wholeheartedly agree that each impact that does occur will not only be catastrophic as far as ionization (or even nuclear dissociation) goes, but a good fraction will conceivably result in e+/e- pair production as well. This is not necessarily going to be a happy, intact sail upon arrival is what I’m saying.
Jupiter and its rings, bands and other heat-sensitive features in the infrared. Image credit: user Trocche100 at the Italian Wikipedia.
From eric on the rings of the gas giants: “I am also amazed that the structures remaining after the ~5 billion years our solar system has been around, are structures that would be stable for >=5 billion years. What an amazing, miraculous coincidence. Oh celestial mechanics, you trickster you!”
There are a couple of important points to highlight: a fraction of the ringed systems present us with rings that appear to be truly stable, as they may exist for the remainder of the Solar System, while others require creation and shepherding by moons. The outer rings of Saturn — created by Enceladus and Phoebe — are of the latter type, as are the rings of Jupiter and Neptune. The main rings of Saturn, as well as the majority of Uranus’ rings, may be of the more stable type.
Image credit: NASA/JPL/Space Science Institute, of Saturn’s E-ring, with Enceladus as the brightest spot.
But, as Denier and Michael Kelsey rightly point out, that doesn’t mean it’s easy to determine whether Saturn’s rings are ~100 million years old, ~4.5 billion years old, any number in between, or whether these are even the first incarnation of rings around it. As we all need to remember, there are many things that erase the early history of our Solar System, and now that we’re finally here, all we can see are the survivors.
Image credit: Wikipedia / Wikimedia Commons user Qashqaiilove.
From Denier on the strong force: “Are the Color Force and the Strong Nuclear Force the same thing?”
Although there is a good discussion that follows Denier’s comment led by Michael Kelsey, I’d like to chime in a little bit as well here. The strong nuclear force is one of the fundamental forces, and it comes in two manifestations:
the binding force that holds mesons and baryons together through quark-gluon (or antiquark-gluon) interactions, and
the binding force that holds atomic nuclei together, through (virtual) meson interactions.
Color force is an analogy to help us visualize this. If we allow quarks to be colored red, green or blue, and antiquarks to be colored cyan, magenta and yellow, then we can arrive at a colorless combination by having either a quark-antiquark combo or a 3-quark/3-antiquark combo. (Or superpositions of those: 1-quark/4-antiquarks, 2-quarks/2-antiquarks, 6-quarks, etc.)
Image credit: E. Siegel, from his new book, Beyond The Galaxy.
You might imagine, from this, that there are six gluons, but in fact there are eight. (Because 3^2-1=8, which is a property of SU(3).) And while asymptotic freedom tells us that the strong force goes to zero at very short distances, it also goes to zero as soon as you begin moving away from a color-neutral entity. (I believe, IIRC, it scales as 1/r^6, which is why the strong nuclear force dies off so fast and we can’t have very large nuclei for long.) I wrote a longer piece on this a while ago called The Strong Force For Beginners that goes over some of this in more detail, that you may enjoy.
The four beams emerging from the new laser system on Unit Telescope 4 of the VLT. Image credit: ESO/F. Kamphues.
From Omega Centauri on guide stars, delays and adaptive optics: “Now how does the detector/computer combo, know which portions are delayed/advanced, from only looking at one image (unless its actually measuring the arrival time from a concentrated pule -which I really really doubt is possible)? Or is it just trying a bunch of perturbations and seeing what happens, or is their something really clever going on?”
The wonderful thing about light is that it always moves at the speed of light, so if you delay the light’s arrival time by a certain, known amount, you know exactly how much “behind” your moving mirror is the actual light. Take a close look at the snapshot below.
Image credit: Gemini Observatory – Adaptive Optics – Laser Guide Star, annotation by E. Siegel.
There’s a copy of the light being sent along the red path, while a fraction of the incoming light arrives at the purple path (at the bottom), telling us what the atmospheric distortion was at that moment. By time that red light arrives at the orange “distortion-removal” mirror, the purple signal has told the mirror what shape to be in to do the adaptation. As the next wavefront comes in, the mirror has adapted again. This adaptation is continuous and interpolated, and therefore imperfect, which is part of the inherent limitation of the technique. But the results are still amazing, and it kind of is like undistorting one snapshot at a time!
The effects of the Earth’s Atmosphere on the Telescopic Image of alpha Piscium from Edinburgh and from Alta Vista 10,700 ft., compared. From a 1863 engraving by Charles Piazzi Smyth, in the public domain.
From PJ on AO and giant telescopes for amateurs: “The best thing about the technology is that it will soon be possible for the backyard operator to run a similar setup in small scale. A 36 to 40 inch reflector in a dome is not out of the question in the near future. The cost of sodium lasers will eventually drop with demand. Quite a challenge, methinks.”
I hate to say it, but “amateurs” have had ~24″ telescopes at their disposal since the late 1800s, which is how Isaac Roberts took the very first picture of a galaxy beyond our own.
Image credit: Isaac Roberts, from A Selection of Photographs of Stars, Star-clusters and Nebulae, Volume II, The Universal Press, London, 1899.
The powerful sodium laser isn’t the most expensive part, either; the adaptive mirror is. If you can get your hands on that, the software is free, and the rest is up to you to put the whole configuration together. Jim Misti and Adam Block are two of the more famous astrophotographers I admire, and their “amateur” status is a testament to how much one can do with off-the-shelf technology!
Image credit: European Gravitational Observatory, Lionel BRET/EUROLIOS.
From See Noevo on the speed of gravity equalling the speed of light: “Must have been a slow news day in science.”
Some days, you report the news by talking about a new discovery (or new hype); other days, you make the news by talking about something that is known by the experts, but by bringing it to a level that non-experts can understand. Science is always happening, but science communication only happens as science communicators choose it. Hopefully you enjoyed learning about this!
Image credit: David Champion, Max Planck Institute for Radio Astronomy.
From Veri Tay on some blatantly untrue stuff: “Lol, gravity is instant, really all of modern so-called science is a bunch of lies. Primary light travels instantly – we see the universe in real-time.”
It must have been fun to just make all these authoritative sounding statements without any facts or evidence to back them up. If everything is instantaneous, why are there time delays in the arrival of everything from gravitational wave pulses to the arrival of New Horizons’ data from beyond Pluto to signals sent to-and-from the Moon.
Remember? Or at least, remember watching the footage of it? If you don’t, here’s what I want you to do. Take your cellphone and call your friend that you’re actually, physically with. Go have them sit in a car while you stand outside the car. Have a conversation with them on your cellphone and watch their lips move, and pay attention to when you hear their voice in your phone versus when you see their lips move. That’s your evidence, right there, that the Universe is not instantaneous.
And finally, from Naked Bunny with a whip on inhomogeneities: “I can safely say the water in my glass is of a uniform average density, even though most of the mass is concentrated into tiny nucleons surrounded by relatively vast stretches of space, and there are doubtless small temperature variations.”
One of my favorite analogies to use for the level of inhomogeneity in the Universe — and you can find this in my book — is the surface of the ocean. If you imagine the ocean, some 3 miles (5 km) deep, and surface level waves maybe 1-10 cm in magnitude, the differences between the peaks and troughs relative to the entire depth of the ocean is similar to the initial differences between overdense and underdense regions in the Universe.
Fluctuations in the ocean relative to fluctuations in the density of the Universe. Images credit: E. Siegel and the COBE satellite/NASA.
Over time, however, small scales have more time to gravitationally collapse, meaning we get greater density fluctuations on smaller scales today and smaller fluctuations, or smaller departures from the initial fluctuations, on the larger scales. That’s what we’ve got, and that’s consistent with what we expect!
Thanks for a great week, everyone, and I’ll see you back here tomorrow for more wonders of the Universe, more stories, more science and more Starts With A Bang!
from ScienceBlogs http://ift.tt/1NMf7ZX
“Science is the only self-correcting human institution, but it also is a process that progresses only by showing itself to be wrong.” -Allan Sandage
As April leaves us and May commences here at Starts With A Bang, I’m so pleased to inform you that amazing things are happening! Thanks to the support of everyone on Patreon, we’re over 95% of the way towards our next goal: the creation of the most accurate, beautiful, scientific timeline of the Universe’s history poster ever made! We’ve also covered the following topics this past week for you to ring in on:
Our Podcasts are coming along, too, as our Patreon supporters have chosen May’s topic (on dark energy), and someone, unsolicited (Philipp Dettmer, thank you!) has made me my first piece of fanart of me!
Image credit: Japan Meteorological Association (JMA), of the monthly average temperatures in February, going back as far as temperature records do. Via the Sydney Morning Herald at http://ift.tt/1LqCRlA.
From Ragtag Media on climate tampering: “I back up my skepticism with not just my unabridged worldly opinion but with a variety of others.
Here, that this one: Massive Tampering With Temperatures In South America: http://ift.tt/1EmJj4J“
What you call “tampering” is what scientists call “adjustments”. Now you can say, “why don’t you just use the raw temperatures and be done with it,” but the reason is important: you are using these temperature measurements as proxies for the entire globe, and yet you are measuring them at limited, specific (often city-centric) locations located at ground-level. What do you do about the fact that paved roads increase (artificially) the temperatures you measure? What do you do about the fact that different stations give data with different quality levels? What do you do about fires when they occur nearby, or when factories are turned on vs. off?
If you say, “just give me the raw data,” you know you’re not accurately representing the global temperature. If you make the appropriate adjustments to the best of your scientific knowledge, how is that equivalent to “tampering” in any negative sense of the word? I’m going to say what I’ve said before to you: it sounds like you’re basing which argument you side with on the conclusions that are reached. If the temperature is warming, you refute that fact. If you accept warming temperatures, you refute that it’s human-caused. If you accept that it’s human-caused, you refute that it’s a bad thing. And if you accept that it’s a bad thing, you refute that there’s anything we can do. Remind me of where you are in that progression again?
Image credit: Breakthrough Starshot, of the laser sail concept for a “starchip” spaceship.
From PJ on slowing down a starshot: “Makes an interesting enigma – get to the target planet first, set up a power grid and laser site to slow the probes down on their arrival so that we can explore the local environment to decide where to set up our base.
The chicken and the egg again?”
Quite honestly, I think the conclusion we need to accept is not that we have to send a slowpoke-system to another star in order to properly explore it, but rather that sending a “starchip” starship to another system is just a cool technological feat on its own, and that the R&D that goes into developing the technology is fascinating and useful in its applications in a myriad of other ways. Think about the progress that will be made in:
light, strong, reflective materials,
laser technology,
laser collimation technology,
laser sail steering and stabilization,
miniaturization microchip technology,
and effectively 2D transmission and communication technology,
among others. We don’t need to get 100% of the way there to have something worth bragging about, or something that benefits society in a greater way than any individual efforts could do on their own.
A logarithmic chart of distances, showing the Voyager spacecraft, our Solar System and our nearest star, for comparison. Image credit: NASA / JPL-Caltech.
From Michael Kelsey on predicting the laser sail’s demise from collisions: “With an average interstellar density of a few atoms per cubic centimeter (1e-4 in hot, ionized regions to 1e+6 in molecular clouds), a solar sail with an area of 1 km2 at 0.2 c will see a flux of something like 6e+16 impacts per second, or a heat load of 192 kW.”
This is the main part of your estimation I’m unsure of. Your density numbers look good, your area looks good and your speed looks good. But impacts? I’m thinking of the famous Rutherford experiment, and the fact that if most of what we’re likely to encounter is ionized rather than neutral (and bound), most of these particles will simply pass through this thin sail with no collision at all. In other words, the number of impacts and the heat load may be many orders of magnitude lower than your estimate.
The concept art of a solar sail (Japan’s IKAROS project) at a distant planet or star system. Image credit: Andrzej Mirecki of Wikimedia Commons, under a c.c.a.-s.a.-3.0 license.
But I do wholeheartedly agree that each impact that does occur will not only be catastrophic as far as ionization (or even nuclear dissociation) goes, but a good fraction will conceivably result in e+/e- pair production as well. This is not necessarily going to be a happy, intact sail upon arrival is what I’m saying.
Jupiter and its rings, bands and other heat-sensitive features in the infrared. Image credit: user Trocche100 at the Italian Wikipedia.
From eric on the rings of the gas giants: “I am also amazed that the structures remaining after the ~5 billion years our solar system has been around, are structures that would be stable for >=5 billion years. What an amazing, miraculous coincidence. Oh celestial mechanics, you trickster you!”
There are a couple of important points to highlight: a fraction of the ringed systems present us with rings that appear to be truly stable, as they may exist for the remainder of the Solar System, while others require creation and shepherding by moons. The outer rings of Saturn — created by Enceladus and Phoebe — are of the latter type, as are the rings of Jupiter and Neptune. The main rings of Saturn, as well as the majority of Uranus’ rings, may be of the more stable type.
Image credit: NASA/JPL/Space Science Institute, of Saturn’s E-ring, with Enceladus as the brightest spot.
But, as Denier and Michael Kelsey rightly point out, that doesn’t mean it’s easy to determine whether Saturn’s rings are ~100 million years old, ~4.5 billion years old, any number in between, or whether these are even the first incarnation of rings around it. As we all need to remember, there are many things that erase the early history of our Solar System, and now that we’re finally here, all we can see are the survivors.
Image credit: Wikipedia / Wikimedia Commons user Qashqaiilove.
From Denier on the strong force: “Are the Color Force and the Strong Nuclear Force the same thing?”
Although there is a good discussion that follows Denier’s comment led by Michael Kelsey, I’d like to chime in a little bit as well here. The strong nuclear force is one of the fundamental forces, and it comes in two manifestations:
the binding force that holds mesons and baryons together through quark-gluon (or antiquark-gluon) interactions, and
the binding force that holds atomic nuclei together, through (virtual) meson interactions.
Color force is an analogy to help us visualize this. If we allow quarks to be colored red, green or blue, and antiquarks to be colored cyan, magenta and yellow, then we can arrive at a colorless combination by having either a quark-antiquark combo or a 3-quark/3-antiquark combo. (Or superpositions of those: 1-quark/4-antiquarks, 2-quarks/2-antiquarks, 6-quarks, etc.)
Image credit: E. Siegel, from his new book, Beyond The Galaxy.
You might imagine, from this, that there are six gluons, but in fact there are eight. (Because 3^2-1=8, which is a property of SU(3).) And while asymptotic freedom tells us that the strong force goes to zero at very short distances, it also goes to zero as soon as you begin moving away from a color-neutral entity. (I believe, IIRC, it scales as 1/r^6, which is why the strong nuclear force dies off so fast and we can’t have very large nuclei for long.) I wrote a longer piece on this a while ago called The Strong Force For Beginners that goes over some of this in more detail, that you may enjoy.
The four beams emerging from the new laser system on Unit Telescope 4 of the VLT. Image credit: ESO/F. Kamphues.
From Omega Centauri on guide stars, delays and adaptive optics: “Now how does the detector/computer combo, know which portions are delayed/advanced, from only looking at one image (unless its actually measuring the arrival time from a concentrated pule -which I really really doubt is possible)? Or is it just trying a bunch of perturbations and seeing what happens, or is their something really clever going on?”
The wonderful thing about light is that it always moves at the speed of light, so if you delay the light’s arrival time by a certain, known amount, you know exactly how much “behind” your moving mirror is the actual light. Take a close look at the snapshot below.
Image credit: Gemini Observatory – Adaptive Optics – Laser Guide Star, annotation by E. Siegel.
There’s a copy of the light being sent along the red path, while a fraction of the incoming light arrives at the purple path (at the bottom), telling us what the atmospheric distortion was at that moment. By time that red light arrives at the orange “distortion-removal” mirror, the purple signal has told the mirror what shape to be in to do the adaptation. As the next wavefront comes in, the mirror has adapted again. This adaptation is continuous and interpolated, and therefore imperfect, which is part of the inherent limitation of the technique. But the results are still amazing, and it kind of is like undistorting one snapshot at a time!
The effects of the Earth’s Atmosphere on the Telescopic Image of alpha Piscium from Edinburgh and from Alta Vista 10,700 ft., compared. From a 1863 engraving by Charles Piazzi Smyth, in the public domain.
From PJ on AO and giant telescopes for amateurs: “The best thing about the technology is that it will soon be possible for the backyard operator to run a similar setup in small scale. A 36 to 40 inch reflector in a dome is not out of the question in the near future. The cost of sodium lasers will eventually drop with demand. Quite a challenge, methinks.”
I hate to say it, but “amateurs” have had ~24″ telescopes at their disposal since the late 1800s, which is how Isaac Roberts took the very first picture of a galaxy beyond our own.
Image credit: Isaac Roberts, from A Selection of Photographs of Stars, Star-clusters and Nebulae, Volume II, The Universal Press, London, 1899.
The powerful sodium laser isn’t the most expensive part, either; the adaptive mirror is. If you can get your hands on that, the software is free, and the rest is up to you to put the whole configuration together. Jim Misti and Adam Block are two of the more famous astrophotographers I admire, and their “amateur” status is a testament to how much one can do with off-the-shelf technology!
Image credit: European Gravitational Observatory, Lionel BRET/EUROLIOS.
From See Noevo on the speed of gravity equalling the speed of light: “Must have been a slow news day in science.”
Some days, you report the news by talking about a new discovery (or new hype); other days, you make the news by talking about something that is known by the experts, but by bringing it to a level that non-experts can understand. Science is always happening, but science communication only happens as science communicators choose it. Hopefully you enjoyed learning about this!
Image credit: David Champion, Max Planck Institute for Radio Astronomy.
From Veri Tay on some blatantly untrue stuff: “Lol, gravity is instant, really all of modern so-called science is a bunch of lies. Primary light travels instantly – we see the universe in real-time.”
It must have been fun to just make all these authoritative sounding statements without any facts or evidence to back them up. If everything is instantaneous, why are there time delays in the arrival of everything from gravitational wave pulses to the arrival of New Horizons’ data from beyond Pluto to signals sent to-and-from the Moon.
Remember? Or at least, remember watching the footage of it? If you don’t, here’s what I want you to do. Take your cellphone and call your friend that you’re actually, physically with. Go have them sit in a car while you stand outside the car. Have a conversation with them on your cellphone and watch their lips move, and pay attention to when you hear their voice in your phone versus when you see their lips move. That’s your evidence, right there, that the Universe is not instantaneous.
And finally, from Naked Bunny with a whip on inhomogeneities: “I can safely say the water in my glass is of a uniform average density, even though most of the mass is concentrated into tiny nucleons surrounded by relatively vast stretches of space, and there are doubtless small temperature variations.”
One of my favorite analogies to use for the level of inhomogeneity in the Universe — and you can find this in my book — is the surface of the ocean. If you imagine the ocean, some 3 miles (5 km) deep, and surface level waves maybe 1-10 cm in magnitude, the differences between the peaks and troughs relative to the entire depth of the ocean is similar to the initial differences between overdense and underdense regions in the Universe.
Fluctuations in the ocean relative to fluctuations in the density of the Universe. Images credit: E. Siegel and the COBE satellite/NASA.
Over time, however, small scales have more time to gravitationally collapse, meaning we get greater density fluctuations on smaller scales today and smaller fluctuations, or smaller departures from the initial fluctuations, on the larger scales. That’s what we’ve got, and that’s consistent with what we expect!
Thanks for a great week, everyone, and I’ll see you back here tomorrow for more wonders of the Universe, more stories, more science and more Starts With A Bang!
Most Blue Moons are not blue in color. This photo was created using special filters. Image via EarthSky Facebook friend Jv Noriega.
In recent years, people have been using the name Blue Moon for the second of two full moons in a single calendar month. An older definition says a Blue Moon is the third of four full moons in a single season. Someday, you might see an actual blue-colored moon. The term once in a blue moon used to mean something rare. Now that the rules for naming Blue Moons include several different possibilities, Blue Moons are pretty common! Follow the links below to learn more about Blue Moons:
Desert Blue Moon from our friend Priya Kumar in Oman. August, 2012. Thank you, Priya!
Can a moon be blue in color? There’s one kind of blue moon that is still rare. It’s very rare that you would see a blue-colored moon, although unusual sky conditions – certain-sized particles of dust or smoke – can create them.
Blue-colored moons aren’t predictable. So don’t be misled by the photo above. The sorts of moons people commonly call Blue Moons aren’t usually blue.
For more about truly blue-colored moons, click here.
The last monthly Blue Moon happened on July 31, 2015. In recent decades, many people have begun using the name Blue Moon to describe the second full moon of a calendar month. There was a full moon on July 2, 2015. There was another full moon on July 31. So the July 31 full moon was called a Blue Moon, according to this definition.
The time between one full moon and the next is close to the length of a calendar month. So the only time one month can have two full moons is when the first full moon happens in the first few days of the month. This happens every 2-3 years, so these sorts of Blue Moons come about that often.
When was the last Blue Moon, according to the monthly definition? It happened on July 31, 2015. The next one will be on January 31, 2018.
Another beautiful image by our friend Jv Noriega – the moon among fast-moving clouds. Will the next Blue Moon be blue in color like this? No. This image was made using blue filters, too. Thank you, Jv!
The idea of a Blue Moon as the second full moon in a month stemmed from the March 1946 issue of Sky and Telescope magazine, which contained an article called “Once in a Blue Moon” by James Hugh Pruett. Pruett was referring to the 1937 Maine Farmer’s Almanac, but he inadvertently simplified the definition. He wrote:
Seven times in 19 years there were — and still are — 13 full moons in a year. This gives 11 months with one full moon each and one with two. This second in a month, so I interpret it, was called Blue Moon.
Had James Hugh Pruett looked at the actual date of the 1937 Blue Moon, he would have found that it had occurred on August 21, 1937. Also, there were only 12 full moons in 1937. You need 13 full moons in one calendar year to have two full moons in one calendar month. However, that fortuitous oversight gave birth to a new and perfectly understandable definition for Blue Moon.
EarthSky’s Deborah Byrd happened upon a copy of this old 1946 issue of Sky and Telescope in the stacks of the Peridier Library at the University of Texas Astronomy Department in the late 1970s. Afterward, she began using the term Blue Moon to describe the second full moon in a calendar month on the radio. Later, this definition of Blue Moon was also popularized by a book for children by Margot McLoon-Basta and Alice Sigel, called “Kids’ World Almanac of Records and Facts,” published in New York by World Almanac Publications, in 1985. The second-full-moon-in-a-month definition was also used in the board game Trivial Pursuit.
Today, it has become part of folklore.
What most call a Blue Moon isn't blue in color. It's only Blue in name. This great moon photo from EarthSky Facebook friend Rebecca Lacey in Cambridge, Idaho.
Blue Moon as third full moon of four in a season. The Maine Farmer’s Almanac defined a Blue Moon as an extra full moon that occurred in a season. One season – winter, spring, fall, summer – typically has three full moons. If a season has four full moons, then the third full moon may be called a Blue Moon.
There was a Blue Moon by this definition happened on November 21, 2010. Another occurred on August 20-21, 2013. And the next one will occur on May 21, 2016.
Which Blue Moon definition is better? In recent years, a controversy has raged – mainly among purists – about which Blue Moon definition is better. The idea of a Blue Moon as the third of four in a season may be older than the idea of a Blue Moon as the second full moon in a month. Is it better? Is one definition right and the other wrong?
Opinions vary, but, remember, this is folklore. So we, the folk, get to decide. In the 21st century, both sorts of full moons have been called Blue.
Can there be two Blue Moons in a single calendar year? Yes. It last happened in 1999. There were two full moons in January and two full moons in March and no full moon in February. So both January and March had Blue Moons.
The next year of double monthly blue moons is coming up in January and March, 2018 – and then, after that, in January and March, 2037.
Very rarely, a monthly Blue Moon (second of two full moons in one calendar month) and a seasonal Blue Moon (third of four full moons in one season) can occur in the same calendar year. But for this to happen, you need 13 full moons in one calendar year AND 13 full moons in between successive December solstices. This will next happen in the year 2048, when a monthly Blue Moon falls on January 31, and a seasonal Blue Moon on August 23.
Bottom line: A blue-colored moon is rare. But folklore has defined two different kinds of Blue Moons, and moons that are Blue by name have become pretty common. A Blue Moon can be the second full moon in a month. We had that sort of Blue Moon on July 31, 2015. Or it can be the third of four full moons in a season. That’ll be the next Blue Moon, on May 21, 2016.
from EarthSky http://ift.tt/16hhATz
Most Blue Moons are not blue in color. This photo was created using special filters. Image via EarthSky Facebook friend Jv Noriega.
In recent years, people have been using the name Blue Moon for the second of two full moons in a single calendar month. An older definition says a Blue Moon is the third of four full moons in a single season. Someday, you might see an actual blue-colored moon. The term once in a blue moon used to mean something rare. Now that the rules for naming Blue Moons include several different possibilities, Blue Moons are pretty common! Follow the links below to learn more about Blue Moons:
Desert Blue Moon from our friend Priya Kumar in Oman. August, 2012. Thank you, Priya!
Can a moon be blue in color? There’s one kind of blue moon that is still rare. It’s very rare that you would see a blue-colored moon, although unusual sky conditions – certain-sized particles of dust or smoke – can create them.
Blue-colored moons aren’t predictable. So don’t be misled by the photo above. The sorts of moons people commonly call Blue Moons aren’t usually blue.
For more about truly blue-colored moons, click here.
The last monthly Blue Moon happened on July 31, 2015. In recent decades, many people have begun using the name Blue Moon to describe the second full moon of a calendar month. There was a full moon on July 2, 2015. There was another full moon on July 31. So the July 31 full moon was called a Blue Moon, according to this definition.
The time between one full moon and the next is close to the length of a calendar month. So the only time one month can have two full moons is when the first full moon happens in the first few days of the month. This happens every 2-3 years, so these sorts of Blue Moons come about that often.
When was the last Blue Moon, according to the monthly definition? It happened on July 31, 2015. The next one will be on January 31, 2018.
Another beautiful image by our friend Jv Noriega – the moon among fast-moving clouds. Will the next Blue Moon be blue in color like this? No. This image was made using blue filters, too. Thank you, Jv!
The idea of a Blue Moon as the second full moon in a month stemmed from the March 1946 issue of Sky and Telescope magazine, which contained an article called “Once in a Blue Moon” by James Hugh Pruett. Pruett was referring to the 1937 Maine Farmer’s Almanac, but he inadvertently simplified the definition. He wrote:
Seven times in 19 years there were — and still are — 13 full moons in a year. This gives 11 months with one full moon each and one with two. This second in a month, so I interpret it, was called Blue Moon.
Had James Hugh Pruett looked at the actual date of the 1937 Blue Moon, he would have found that it had occurred on August 21, 1937. Also, there were only 12 full moons in 1937. You need 13 full moons in one calendar year to have two full moons in one calendar month. However, that fortuitous oversight gave birth to a new and perfectly understandable definition for Blue Moon.
EarthSky’s Deborah Byrd happened upon a copy of this old 1946 issue of Sky and Telescope in the stacks of the Peridier Library at the University of Texas Astronomy Department in the late 1970s. Afterward, she began using the term Blue Moon to describe the second full moon in a calendar month on the radio. Later, this definition of Blue Moon was also popularized by a book for children by Margot McLoon-Basta and Alice Sigel, called “Kids’ World Almanac of Records and Facts,” published in New York by World Almanac Publications, in 1985. The second-full-moon-in-a-month definition was also used in the board game Trivial Pursuit.
Today, it has become part of folklore.
What most call a Blue Moon isn't blue in color. It's only Blue in name. This great moon photo from EarthSky Facebook friend Rebecca Lacey in Cambridge, Idaho.
Blue Moon as third full moon of four in a season. The Maine Farmer’s Almanac defined a Blue Moon as an extra full moon that occurred in a season. One season – winter, spring, fall, summer – typically has three full moons. If a season has four full moons, then the third full moon may be called a Blue Moon.
There was a Blue Moon by this definition happened on November 21, 2010. Another occurred on August 20-21, 2013. And the next one will occur on May 21, 2016.
Which Blue Moon definition is better? In recent years, a controversy has raged – mainly among purists – about which Blue Moon definition is better. The idea of a Blue Moon as the third of four in a season may be older than the idea of a Blue Moon as the second full moon in a month. Is it better? Is one definition right and the other wrong?
Opinions vary, but, remember, this is folklore. So we, the folk, get to decide. In the 21st century, both sorts of full moons have been called Blue.
Can there be two Blue Moons in a single calendar year? Yes. It last happened in 1999. There were two full moons in January and two full moons in March and no full moon in February. So both January and March had Blue Moons.
The next year of double monthly blue moons is coming up in January and March, 2018 – and then, after that, in January and March, 2037.
Very rarely, a monthly Blue Moon (second of two full moons in one calendar month) and a seasonal Blue Moon (third of four full moons in one season) can occur in the same calendar year. But for this to happen, you need 13 full moons in one calendar year AND 13 full moons in between successive December solstices. This will next happen in the year 2048, when a monthly Blue Moon falls on January 31, and a seasonal Blue Moon on August 23.
Bottom line: A blue-colored moon is rare. But folklore has defined two different kinds of Blue Moons, and moons that are Blue by name have become pretty common. A Blue Moon can be the second full moon in a month. We had that sort of Blue Moon on July 31, 2015. Or it can be the third of four full moons in a season. That’ll be the next Blue Moon, on May 21, 2016.
Tonight – and throughout the month of May – if you’re in a dark location, at northern temperate latitudes – you might be searching for one of the sky’s most spectacular sights, the starlit band of the Milky Way. You won’t find it in the early part of the night. That luminous band of stars arcing across the dome of sky is nowhere to be seen as evening falls in May. Where is the the Milky Way at nightfall this month?
For starters, remember that the disk of our Milky Way galaxy is flat, like a pancake. At northern temperate latitudes, as evening falls in the month of May, the plane of the pancake-shaped galactic disk pretty much coincides with the plane of your horizon.
Because the Milky Way rims the horizon in every direction at nightfall and early evening, we can’t see this roadway of stars until late at night.
An all-sky plot of the 25,000 brightest, whitest stars shows how these stars are concentrated along the Milky Way. This map shows our limited, inside view of the Milky Way galaxy. The large, dark patch near the middle of the picture is due to nearby dark nebulae, or clouds of gas and dust, which obscure the stars. Via altasoftheuniverse.com.
The galactic disk most closely aligns with the horizon at about 30 degrees North latitude – the latitude of St. Augustine, Florida. Appreciably north of this latitude, the galactic disk tilts a bit upward of the northern horizon. Appreciably south of 30 degrees north latitude, the galactic disk tilts a bit above the southern horizon.
Even so, the Milky Way is pretty much out of sight in our Northern Hemisphere sky during the evening hours in May.
Like the sun, the stars rise in the east and set in the west. If you stay up until late night – near midnight in early May, a couple of hours earlier by June – you’ll begin to see the the stars of the Summer Triangle – Deneb, Vega, and Altair – rising above your eastern horizon.
In a dark country sky, the Milky Way’s band of stars becomes visible as well, for the Milky Way passes right through the Summer Triangle. Watch for it, if you’re up late this month.
Bottom line: The Milky Way’s softly-glowing band of luminescence hides behind the horizon at nightfall and early evening in the month of May. But if you stay up until around midnight, you’ll begin to see the starlit band of the Milky Way rising in the eastern sky.
Tonight – and throughout the month of May – if you’re in a dark location, at northern temperate latitudes – you might be searching for one of the sky’s most spectacular sights, the starlit band of the Milky Way. You won’t find it in the early part of the night. That luminous band of stars arcing across the dome of sky is nowhere to be seen as evening falls in May. Where is the the Milky Way at nightfall this month?
For starters, remember that the disk of our Milky Way galaxy is flat, like a pancake. At northern temperate latitudes, as evening falls in the month of May, the plane of the pancake-shaped galactic disk pretty much coincides with the plane of your horizon.
Because the Milky Way rims the horizon in every direction at nightfall and early evening, we can’t see this roadway of stars until late at night.
An all-sky plot of the 25,000 brightest, whitest stars shows how these stars are concentrated along the Milky Way. This map shows our limited, inside view of the Milky Way galaxy. The large, dark patch near the middle of the picture is due to nearby dark nebulae, or clouds of gas and dust, which obscure the stars. Via altasoftheuniverse.com.
The galactic disk most closely aligns with the horizon at about 30 degrees North latitude – the latitude of St. Augustine, Florida. Appreciably north of this latitude, the galactic disk tilts a bit upward of the northern horizon. Appreciably south of 30 degrees north latitude, the galactic disk tilts a bit above the southern horizon.
Even so, the Milky Way is pretty much out of sight in our Northern Hemisphere sky during the evening hours in May.
Like the sun, the stars rise in the east and set in the west. If you stay up until late night – near midnight in early May, a couple of hours earlier by June – you’ll begin to see the the stars of the Summer Triangle – Deneb, Vega, and Altair – rising above your eastern horizon.
In a dark country sky, the Milky Way’s band of stars becomes visible as well, for the Milky Way passes right through the Summer Triangle. Watch for it, if you’re up late this month.
Bottom line: The Milky Way’s softly-glowing band of luminescence hides behind the horizon at nightfall and early evening in the month of May. But if you stay up until around midnight, you’ll begin to see the starlit band of the Milky Way rising in the eastern sky.
