Dinosaurs Done In By... Dark Matter?

bmahersciwriter writes "Theoretical physicists propose that the Sun periodically crosses into a dense layer of dark matter sandwiching the Milky Way. The gravitational push and pull that this creates disturbs debris in the Oort cloud sending deadly comets and asteroids ricocheting around the solar system. This passage happens, their admittedly speculative model suggests, every 35 million years, which jibes somewhat with evidence on impact craters. Take it with a dino-sized grain of salt."

Comments

Queue End of the world articles in 3,2,1

[fullmetal55]

GO!
seriously how long until someone claims that this happens every 35 million years and the clock is ticking down to Nov 10, 2016.

Look to the geological record

[wjcofkc]

If you look over the past 500 billion years, the geological record shows that there is a mass extinction event roughly every 62 million years. Even though there is some give and take, on that timescale it's almost like clockwork. Since this discovery, scientists of many disciplines have been trying to figure out what could be causing it. While I admit that it could be a cosmic coincidence, if not, then somewhere a culprit is lurking. There are also lesser extinction events every 26 - 35 million years.

For more on the 62 million year problem

More on mass extinction events in general

Re:magic

[FatdogHaiku]

I have found you can increase gravity locally by slamming down a 12 pack of beer. From this I can deduce that in order to stay together, the galaxies must be totally hammered...

Re:magic

[StevenMaurer]

Dark matter is not THEORETICAL. There is direct evidence for it. Quoting from the relevant wiki:

The most direct observational evidence to date for dark matter is in a system known as the Bullet Cluster. In most regions of the universe, dark matter and visible material are found together,[33] as expected because of their mutual gravitational attraction. In the Bullet Cluster, a collision between two galaxy clusters appears to have caused a separation of dark matter and baryonic matter. X-ray observations show that much of the baryonic matter (in the form of 107–108 Kelvin[34] gas, or plasma) in the system is concentrated in the center of the system. Electromagnetic interactions between passing gas particles caused them to slow down and settle near the point of impact. However, weak gravitational lensing observations of the same system show that much of the mass resides outside of the central region of baryonic gas.

In other words, gravitational lensing of light waves - which is 100% direct evidence of matter - shows a region where there is matter that is clearly non-baryonic (i.e. does not interact with the electromagnetic field, a.k.a. "dark"). This is not subject to dispute. The question of what, exactly, is dark matter - is indeed still a subject of scientific research. There are, however, a number of super-symmetric theories which posit super-partners for well known particles, the most stable of which turn out to have the exact characteristics we're noting observationally. It is important to note that these theories were not tailored to account for the dark matter, but seem to fit the observational evidence quite well so far. As with all science however, theories are subject to falsification at any times as soon as new evidence comes on the scene.