cosmic rays
esiegel | December 6, 2013"The results of my observation are best explained by the assumption that a radiation of very great penetrating power enters our atmosphere from above." -Victor Hess
You might think of the largest and most powerful particle accelerators in the world -- places like SLAC, Fermilab and the Large Hadron Collider -- as the source of the highest energies we'll ever see. But everything we've ever done hear on Earth has absolutely nothing on the natural Universe itself! For this week's Ask Ethan, let's take a look at the simple question of our reader David Hurn, who asks:
Ever since I was a young…
esiegel | April 26, 2013"All our sweetest hours fly the fastest." -Virgil
If you've been around the block once or twice, you know that the speed of light in a vacuum -- 299,792,458 meters-per-second -- is the absolute maximum speed that any form of energy in the Universe can travel at. In shorthand, this speed is known as c to physicists.
Image credit: user Fx-1988 of deviantART.
But you or I, no matter how hard we try, will never attain that speed. There's a simple reason for this: we have mass. And for an object with mass, you can accelerate it all you want, but it would take an infinite amount of energy to…
esiegel | April 3, 2013"On what can we now place our hopes of solving the many riddles which still exist as to the origin and composition of cosmic rays?" -Victor Francis Hess
We've come a tremendously long way in our understanding of the Universe, but there are plenty of mysteries still to be revealed. Way back in the late 1800s, we noticed that there was an unaccounted-for excess in the amount of ionization in the upper atmosphere, something that our Sun and Earth, by themselves, couldn't explain.
Victor Francis Hess -- the originator of the quote atop -- decided to go see for himself, and conducted a series of…
esiegel | April 23, 2008Since the dawn of time man has yearned to destroy the sun. - C. M. Burns
There's no need to stop at the Sun, though. Since yesterday was Earth day, I thought it was only appropriate to spend today telling you how not only to destroy the Earth, but to effectively destroy the entire Universe. To tell you this story, we have to go all the way back to the beginning, to just before the big bang.
The big bang was when the Universe was hot, dense, full of energy, and expanding very quickly. The Universe was also spatially flat and the same temperature everywhere, and full of both matter and…