Slashdot Mirror
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.
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.
Do you even lift?
These aren't the 'roids you're looking for.
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 ?!?
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
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.