Cosmic ray mystery solved?

Eurekalert | University of Utah ^ | 11/8/07

[LexBaird]

Cosmic ray mystery solved?

Quick! Someone call Dr. Reed Richards!

[DBrow]

Yup! I did forget.

[LibWhacker]

And now calculate the velocity of a single iron nucleus at that energy!

And don't forget relativistic effects; namely, the faster an object goes, the more massive it gets relative to a slowpoke outside observer.

[Yossarian]

There are few places, if any, in the universe more violent than the inner accretion disk of a supermassive black hole!

[LibWhacker]

LOL

[KarlInOhio]

And now calculate the velocity of a single iron nucleus at that energy!

Pretty darn fast. I used the relativistic kinetic energy equation and I don't have a calculator with enough precision to give an answer other than the speed of light.

[Dr. Bogus Pachysandra]

But what about spaghettification?
“Look here brother,
Who you jivin’ with that Cosmik Debris?
(Now is that a real poncho or is that a Sears poncho?)”

[DBrow]

One odd thing about superenergetic particles is that at full energy, they don’t deposit much energy in the materials they traverse. Another way of saying this is that they have low Linear Energy transfer (LET). At lower energies, they deposit more energy per inch (do more damage).

So if you try to shield against them you can make the problem worse! Plus, as you stop it you generate secondaries like xrays and gammas (mesons and muons too for the really hot ones). The low LET at high energy also means that you cannot effectively shield anything, at least not until we can mine asteroids.

As the particle penetrates, it sheds energy faster and faster until it reaches a maximum, the Bragg peak. On the other side of Bragg, the particle loses punch as it passes through.

http://tvdg10.phy.bnl.gov/LETCalc.html

Here is a handy calculator for figuring out LET as a function of particle mass and energy.

[Chaguito]

Cosmic rays cause global cooling.

[Stonewall Jackson]

You called?

[Red Badger]

Unless you get hit in the head by one.......