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Milky Way's Spiral Arms Could Not Have Caused Climate Change
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."
It would have been a steaming hot mug, but he's cold already!
Bummer about how the Sun is more responsible for global warming than people. Bummer how the latest economic crunch sent all the "green" masturbators back to their basements. Whats next, are you going to get us worried about meteors and comets hitting the planet? Maybe DDT, or Swine Flu?
I want to delete my account but Slashdot doesn't allow it.
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.
The price is always right if someone else is paying.
This is the very technical (and long-winded) explanation for something along the lines of "We are telling you, Miss Daisy, that your cat was not put into that tree by giant ninja robots from outer space."
If you can read this, I forgot to post anonymously.
They're jumping to conclusions. It will be 140 million years before we have enough data to decide.
They've eliminated one pattern. They don't know if there might be something else, such as moving through the parts where the grues are. The grues move around, and the astronomers haven't spotted where they tend to be.
It must be the unicorns fault!
I mean... it cant be us. Right?
"Have you ever thought about just turning off the TV, sitting down with your kids, and hitting them?"
My theory is that the Decepticons are responsible.
(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.)
http://alternatives.rzero.com/
I have a hunch that the scientist that first theorized this prefaced it with "Good news, everyone!"
Anybody want my mod points?
Both Shaviv's and Melott's papers are based upon models of the Milky Way that are built from observations taken from a single point in the universe, and made during a negligible time frame. This model is then kept valid and unchanged for a timeframe of about 1.000.000.000 years, neglecting for example errors in measuring accelerations of the galaxy and of the solar system, the 3D structure of the galaxy, dark matter influence (and existence...) on the motion of the galaxy, etc. Still too much unknowns before reaching a definite answer, isn't it ?!?
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!
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.
This is my sig.
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 Congress.
I'd argue anyway that the majority of our Congressional representatives (regardless of party) are worthy of the moniker 'basement dweller.'
-Taylor
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?
Mit der Dummheit kämpfen Götter selbst vergebens
Maybe 140 million years is the limit of the cosmic time register. When the clock resets, the climate control system doesn't work properly for a bit until they patch it.
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/
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.
"I may be synthetic, but I'm not stupid." -- Bishop 341-B
the sun doesn't move through the spiral arms, the spiral arms move past the sun.
It's just a density wave.
We have 33C from the greenhouse gasses already and another 2C we're adding AGAIN on top of that.
And it would be true, too, if we added 20C we would be in serious trouble.
Looks like all the dust and emission particles are warming the sea surface temperatures. On our planet warmer water moves to the poles ( Quantum Information on a sphere in space moves to the poles). Its all fine and dandy until the arctic ocean fills with warm water and starts to evaporate into clouds. If the arctic is ice free in the winter the northern hemisphere will be measuring snow depth in kilometers instead of inches. Prior glacial maximums could have been caused by our planet moving through a dust cloud.
the single point WE'RE SITTING ON!!!
So the one with more data on is more likely to be correct, yes? Else more data is, you say, likely to make it incorrect. Which is daft.
Shit you really cannot handle it being man's fault, can you.
ANYTHING else, just not that.
Why?
"Slashdot requires you to wait between each successful posting of a comment to allow everyone a fair chance at posting a comment.
It's been 17 minutes since you last successfully posted a comment"
Ah, what crap through yonder orifice breaks...
Why demand from the government that they let you deed lots of your money to your kids on death? That's long term thinking. Your kid could have his throat cut before he gets it.
Why invest for your retirement? That's long-term thinking.
Why look after your heart? That's long-term thinking.
Why worry about copyright expiring in 50 years and demand it last 95? That's long-term thinking.
The actual cause of global warming, is a planet in the solar system that Nasa warned us about in 1983 (Washington Post) but was quickly repressed by the Government. Since then, the planet has progressed in it's sling orbit through our solar system. Currently, it resides just north of the Sun's south pole near the ecliptic. It's a magnetic brown dwarf with unusual moon swirls in 2 "tails", which is why ancient cultures depicted it as a winged planet. It's a magnetic powerhouse, which is why the Sun is uncharacteristically sunspot/activity quiet now -- the interloping planet has it's north pole pointing at the sun. The magma of the Earth is very responsive to a magnetic field; it roils due to the magnetic influence of this planet causing the Earth's crust to heat up -- hence, Global Warming. That simple. Don't look for the evidence of this in normal news channels, they are not allowed to report on this, neither are the astronauts or the astronomical observatories. Crow.
The actual cause of global warming, is a planet in the solar system that Nasa warned us about in 1983 (Washington Post) the news of which was quickly repressed by the U.S. Government. Since then, the planet has progressed in it's sling orbit through our solar system. Currently, it resides just north of the Sun's south pole near the ecliptic. It's a magnetic brown dwarf with unusual moon swirls in 2 "tails", which is why ancient cultures depicted it as a winged planet. It's a magnetic powerhouse, which is why the Sun is uncharacteristically sunspot/activity quiet now -- the interloping planet has it's south pole pointing at the sun. The magma of the Earth is very responsive to a magnetic field, ...it roils due to the magnetic influence of this planet causing the Earth's crust to heat up -- hence, Global Warming. That simple.
Don't look for the evidence of this in normal news channels, they are not allowed to report on this, neither are the astronauts or the astronomical observatories.
Crow.
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 plugging into T(z), we get T(P) = Tsurface - (y-1)/y*Mg/R*RT/Mg*ln(Psurface/P)
= T = Tsurface - (y-1)/y*T*ln(Psurface/P),
rearranging, T(P)*(1+(y-1)/y*(ln(Psurface)-ln(P))) = Tsurface
Thereforce T(P) = Tsurface/(1+(y-1)/y*(ln(Psurface)-ln(P)))
The road to hell is paved with good intentions.