Milky Way's Spiral Arms Could Not Have Caused Climate Change 86
KentuckyFC writes "One of the puzzles of Earth's climate history is an apparent 140-million-year cycle in the climate record. Various astronomers think this can be explained by the passage of the Sun through the spiral arms of the Milky Way, which also seems to have had a period of about 140 million years. The thinking is that in regions of denser star populations, supernovas would have been more common, bathing the Earth in cosmic rays more often. These cosmic rays would then have seeded the formation of clouds that cool the planet. But in recent years, astronomers have mapped out the structure of the galaxy in much more detail. And now a pair of US astronomers have reanalyzed this climate change idea in light of the new evidence. Their conclusion is that the climate change cycle cannot possibly have coincided with the movement of the Sun through the spiral arms. So whatever caused the 140-million-year climate change cycle on Earth, it wasn't the Sun's passage through the galaxy."
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Bummer how the latest economic crunch sent all the "green" masturbators back to their basements.
Yeah, look at them hiding in their basements [yahoo.com].
Note: (Score:1, Informative)
It was always expected to narrowly pass in the Democratic-dominated House.
Link again if it passes in the Democratic-dominated Senate (in which it is expected to have a much more difficult time).
Also, Congress became overwhelmingly Democratic in a knee-jerk reaction to the no-longer-popular Bush Administration - had a more moderate Republican been president, I posit that the Democrats would not have had such an overwhelming victory in 2008 and this bill would face much more opposition in both houses of Congr
Re:Climatologists struggle to stay relevant (Score:4, Insightful)
So what? Heart disease is more responsible for human deaths than murder, and yet we still take action against murderers.
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Yes, but your analogies suck.
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Neither are false analogies, they are useful examples. His illustrates the principle that just because something is not the top effect it is still worth correcting because if left unchecked it could be disastrous, yours demonstrates the principle that some problems are small and local enough that they don't matter. Both are useful, they just apply to different situations. Unlike hippos, you can't avoid the global climate. Unlike murder, you can't even avoid it by avoiding civilization. Human post-indus
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I'm pretty sure people have shot aggressive or troublesome hippos in the past. We've generally taken as much action as was needed against any big animal species to keep it in line. Unless you really mean to claim that anything short of total extinction doesn't count as taking action, yes, your analogy is false, but in a way that means you are asserting Mr. Slippery's analogy is true.
(We take some actions both against murderers and against heart disease. We generally catch a higher percentage of murderers th
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So what? Hippos are responsible for fewer human deaths than heart disease, but we don't take action against hippopotamuses.
Maybe you don't.
Your totally going to get your canoe bitten in half with that attitude.
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And normal cell proliferation causes most cancers, but smoking is still a bad idea.
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Another 2 degrees. 2. Not 20.
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We do not have 20 degrees more from man-made causes. Yes, inherent atmospheric effects raise the surface temperature. Those are not man-made. The 2 degrees centigrade is the purportedly man-made portion.
Surface Temperature relationship to Pressure (Score:1)
Something you may be interested in, though water vapor makes the calculation much more complex so this is for Venus.
Derivation:
The adiabatic lapse rate = dT/dz = -Mg/R*(y-1)/y = ~7.82K/km (I was lazy and used 100% CO2 for this, also y = gamma) which isn't too far off from the ALR calculated from measurements using least squares = ~7.74K/km.
T(z) = Tsurface - ALR*z, by definition (~= 735 - 7.82z).
The barometric equation is P = Psurface*e^(-Mgz/RT).
Solving for z = -RT/Mg*ln(P/Psurface),
and plugg
Since these comments are going to suck.... (Score:3, Insightful)
Because now the political "we don't cause GW" arguments will begin, and the bickering....
It shouldn't even be about global warming. It should be about national security. If you have no renewable resources, and rely on other (enemy) nations to provide that stuff to you and your way of life, you have a severe problem.
Let's get off oil if for nothing else, to bankrupt every middle eastern country out there. We won't bother maintaining a presence there if there's nothing to take advantage of.
Re:Since these comments are going to suck.... (Score:5, Insightful)
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Let's get off oil if for nothing else, to bankrupt every middle eastern country out there.
On the other hand, the only middle eastern countries that don't want to nuke the US to hell are those which are rich off oil.
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Uhm, the countries that have oil and we buy it from them don't want to nuke us.
The ones we take oil from do want to nuke us.
Either way, if we remove oil from the picture, it's a win-win.
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Where, exactly, does Iran fit into your perfectly classified view of oil and nuclear politics?
Re:Since these comments are going to suck.... (Score:5, Insightful)
Please list the countries from which we "take" oil.
Re:Since these comments are going to suck.... (Score:4, Informative)
Exactly. The people who rattle on about how the US invades countries for oil tend to fall silent when they find out that Canada is the largest exporter of oil to the US.
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Nice straw man. Time to learn about realpolitik.
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It's not about where in particular the US consumer's oil comes from, since it's all part of a single global market.
What's important, in geopolitical terms, is controlling the oil that other people are using. It gives tremendous political leverage internationally. This has almost nothing to do with domestic US politics.
Consider for instance how FDR would have gotten the USA into WWII, without having an effective monopoly control over global oil sales (in cooperation with the British and Dutch govt. in exile
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It's not about where in particular the US consumer's oil comes from, since it's all part of a single global market.
What's important, in geopolitical terms, is controlling the oil that other people are using. It gives tremendous political leverage internationally. This has almost nothing to do with domestic US politics.
Thanks. People go on about how oil is a fungible commodity, as if that means there's no profit or advantage in owning or controlling sources of it and that therefore the U.S. (and I guess no
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Exactly. The people who rattle on about how the US invades countries for oil tend to fall silent when they find out that Canada is the largest exporter of oil to the US.
Let's ignore that Canada still only supplies 9% of the oil the US consumes. It never was about oil for Americans, it was always about oil for American oil companies.
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Fair enough, though "American oil companies" is still misleading, as Shell's behaviour in Nigeria demonstrates. Given the chance, large corporations from anywhere often behave poorly.
I am no huge supporter of oil corporations, believe me. But I do get tired of the monomaniacal obsession with demonstrating how evil the US is in all things. It is frustrating to meet people who honestly believe that the US "steals" all of its oil.
By the way, Canada supplies about 23% of US petroleum, and 22% of crude oil, not
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Haha, point taken. I actually didn't realise it was that much.
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Iraq's government hasn't even settled the issue of which companies get to pay Iraq in exchange for the rights to work on that country's oil infrastructure and be involved in the selling of that country's oil. You know, selling. On the world market. It's a commodity. There is no "taking" going on. The US is putting more cash into supporting Iraq's nascent police and military and civil institutions than Iraq is making while selling oil (to the entire world market).
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We don't buy oil from Iraq. Mostly Canada, Mexico, Venezuela, and Nigeria.
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Iraq sold roughly $31 billion worth of oil in 2007, and double that in 2008. 2009 will be more still. That is damned peculiar, for "no one" buying it. It's a shame you haven't learned, yet, to use Google, and occasionally read about which companies and countries [entrepreneur.com] are regularly buying from Iraq. Because, you know, you'd look like less of an ass and whatnot.
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Where is the national security in forcing any remaining manufacturers offshore where they don't have to deal with carbon credits and higher electrical costs?
The US has 273 billion tons of proven coal reserves, far more than any other country, and that coal can be liquefactioned into gasoline.
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Again, FINITE RESOURCE.
Coal isn't renewable. That's kind of the point. We will just be down the same path and the same ultimate consequences at a more accelerated rate. You are thiinking on the span of what, maybe 50, 100 years? I am thinking a bit longer term.
Re:Since these comments are going to suck.... (Score:5, Insightful)
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Dude, there already *IS* a viable long term alternative to fossil fuels for baseload electrical power, heating, cooking and transportation.
It is called "nuclear".
See "The Economics of Nuclear Power" at http://www.world-nuclear.org/info/inf02.html [world-nuclear.org].
For the people who feel like ranting about nuclear waste, consider the sheer size of the installations that are being proposed for ground-level solar arrays or algae farms, and ask yourselves how many Astrodome-sized nuclear waste storage facilities could be built
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Where is the national security in forcing any remaining manufacturers offshore where they don't have to deal with carbon credits and higher electrical costs?
That's the elephant in the room that they don't want anyone to notice. Once the cap & tax hits, any business that can leave, will. Those that can't will raise their prices to consumers and if unable to maintain sufficient sales because nobody will be able to afford to buy anything, they will fail and disappear. These price increases will include ev
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Let's get off oil if for nothing else, to bankrupt every middle eastern country out there.
Suppose I don't care to bankrupt myself in order to bankrupt every Middle Eastern country out there? And how does destroying the US economy help national security? Frankly, the current situation isn't that bad to warrant such action.
Heh (Score:5, Funny)
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Unfortunately, Miss Daisy will still cite it as one of the many reasons she shouldn't have to keep her damn cat inside.
Hold on there, Wilbur (Score:2, Funny)
They're jumping to conclusions. It will be 140 million years before we have enough data to decide.
You know what this means? (Score:2, Funny)
I mean... it cant be us. Right?
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140 million years ago? sure, who else could it be?
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Decepticons (Score:1, Offtopic)
(Sorry, but my brain is still recovering from the 2.5-hour Mighty Transformin' Power Rangers movie I sat through as a favor for my friend who wanted to see it. The dramatic parts made me laugh, the action scenes nearly put me sleep, and the comedy bits made me wish my phone would ring.)
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Does your friend have a mental disability (includes being under the age of 12)? If so, well, you're a better friend than I. If not...you need to redefine "friend."
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I can't account for the other adults in the theater.
Farnsworth exists? (Score:2)
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It is difficult to say who is right (Score:5, Informative)
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ANY change? (Score:3, Informative)
You mean like that time that big ball of burning gas shot down and all dinosaurs died? Or did it just burn colder for a while back then?
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And the point of this article was that the possibility of the Milky Way impacting the Earth climate. Which is a ludicrous thing to even think about. I find it funny t
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Hrrm and that blocked out what? Oh THE SUN!
Oh, so it is "It ain't the fall but the sudden stop" logic?
Or in this case "It wasn't the asteroid impact blocking the sunlight, but Sun's rays being blocked by the asteroid impact".
Earth even changes the climate itself by slight variations in the orbit around the Sun. That was my point.
No.
No, that was not your point. Let me remind you what you said:
Ok once more for those people playing along in Rio Linda
Any change in the earths temperature, heat wave or ice age, is cause by that great big ball of gas 93 million miles away it's a little thing we like to call the SUN!
Sun, only Sun, and nothing but the Sun.
I find it funny the mods liked your post and missed mine completely.
Actually, they didn't. You were noticed. It is just that you got modded down cause your post sounded rather trollish.
Might have been that condescending euphemism for "dumb people" that you used to characterize anyone who might
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Just invalidates Cosmic Ray cloud seeding. (Score:2, Interesting)
A lot of the invalidations of these spaced theories tend to focus on the effects of cloud formation by cosmic rays, but are they so sure that these are the only effects that space could have? Space is pretty big, and the earth is pretty complex, and I would be willing to bet that there's going to be something out there in space, besides the obvious asteroid, that screws us.
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Agreed, there are too many unknowns and no theory is provable. However TFA does a credible job of dismissing a group of theories from further consideration, so it is significant in narrowing things down a little bit.
This wikipedia article on the galaxy [wikipedia.org] seems like a good overview of known data; a long article but well worth the reading, as recent observations have caused major changes to the model of the Galaxy a lot of us grew up with. The specific section I'm pointing to describes how Sol bobs from one
Not Arms (Score:3, Interesting)
In 1978 is was suggested that a galactic density wave, rather than passage through the arms, was responsible for the 140 My events. This wave, with a period 1/2 that of galactic rotation, eminates from the galactic core. http://www.springerlink.com/content/k1t6v868227t7403/ [springerlink.com]
The solar system doesn't just orbit the galaxy. It oscillates up and down through the galactic plane with a period of 88 +/- 5 My. This too has been suggested as being involved in extinctions, since the galactic plane is denser than the regions outside it.
I'm glad they got a better galactic map, and I'm sure it shows what they say. But the arms themselves aren't the only things hypothesized to be involved.
Re:Not Arms (Score:4, Interesting)
One of the problems with the suggestion of moving through the galactic plane being a major issue is that the Sun is currently very close to the main galactic plane at the moment. That is something that has to be explained if you want to use this concept to prove or disprove a hypothesis regarding the orbit our solar system takes through the galaxy.
What I would be curious about is the "CO2 data" that they are using, and the assumption that global temperatures have a direct correlation to this substance, not to mention the reliability of the measurement process over the scale of billions of years to calculate what levels of this gas were through more than just a couple of galactic years. Yes, I know there are attempts to measure global temperatures over time using the geologic record, but it seems to me that both the CO2 measurements as well as measurements of the orbit of the solar system have such huge margins of error that doing a statistical comparison of the two could give you virtually any kind of conclusion that you want.
I have to assume that this paper addresses these issues in some detail (I would love to read the original paper).
One other thing that struck me, in looking at the supposed solar system orbit that they plotted in this paper, is if they have accounted for the fact that the galaxy is a dynamic and not a static place? They calculated the path of the Sun over apparently three galactic years, but at the same time all of the objects that they used for measuring protuberance of the orbit are also moving in their own galactic orbits. If there is a model that they were able to develop that shows the galactic evolution of the Milky Way over the past 500 million years. Seriously, I had no idea that stellar parallax measurements (to accurately plot the positions of stars) were so accurate and have been for long enough to not only get a good fix on the position of a large number of stars in the Milky Way to be able to also plot the apparent trajectories of this many stars and galactic nebulae. That is some trick, and such a model would have a great many other uses besides trying to prove anthropogenic global warming (or disproving an alternative hypothesis).
My understanding was that stellar parallax measurements were only good to about 1 or 2 significant digits and getting the order of magnitude down. That may have improved with the Hubble and some other star surveys with really accurate telescopes, but I don't think it is too much better than that.
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A very coherent and insightful reply. Thank you.
The original paper re: galactic plane crossing is available at http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=1851772 [cambridge.org] but it costs US$20.
Being close to the galactic plane now may or may not be a significant threat if the density wave theory were also correct. It may be that they need to coincide for there to be enough matter density to initiate an event.
Something I don't believe any of the references considered was that the sun an
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This too has been suggested as being involved in extinctions, since the galactic plane is denser than the regions outside it.
One of the theories that makes sense to me is the increased chances for asteroid strike. This paper doesn't seem to touch on that.
the actual cause of global warming. (Score:2, Funny)
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So the sunspots have returned, where's your god, er, magnetic planet now?
Care to explain how EVERY observatory, especially those not under United States governmental control, would be even remotely willing to suppress this information?
However, that said, if you really believe this, can I buy your house/car/stereo for a dollar? I mean you won't have any use for it in a few months if you're right so put your money where your mouth is.
A big surprize. (Score:1)