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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."
Bummer how the latest economic crunch sent all the "green" masturbators back to their basements.
Yeah, look at them hiding in their basements.
So what? Heart disease is more responsible for human deaths than murder, and yet we still take action against murderers.
Tom Swiss | the infamous tms | my blog
You cannot wash away blood with blood
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.
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?"
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 ?!?
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.
The first 300 degrees Kelvin due to the sun might be all well and good, but when you add 20 degrees more by man-made causes you get big problems.
- These characters were randomly selected.
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
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.
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
Damn you kids, um Philo Farnsworth who invented the television and inertial confinement fusion amongst other things.
An Education is the Font of All Liberty
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.