In our terrestrial view of things, the speed of light seems incredibly fast. But as soon as you view it against the vast distances of the universe, it’s unfortunately very slow. This animation illustrates, in realtime, the journey of a photon of light emitted from the surface of the sun and traveling across a portion of the solar system, from a human perspective.
I’ve taken liberties with certain things like the alignment of planets and asteroids, as well as ignoring the laws of relativity concerning what a photon actually “sees” or how time is experienced at the speed of light, but overall I’ve kept the size and distances of all the objects as accurate as possible. I also decided to end the animation just past Jupiter as I wanted to keep the running length below an hour.
Time travel makes great science fiction, but can it really be done? Travel into the future is already a reality, but visiting the past is a much tougher proposition, and may require fantastic resources such as a wormhole in space. Nevertheless, if going back in time is allowed, even in principle, then what about all those paradoxes that make time travel stories so intriguing?
Paul Davies is a physicist, cosmologist and astrobiologist at Arizona State University, where is Director of the Beyond Center for Fundamental Concepts in Science. He is the author of many books, including “How to Build a Time Machine” and, most recently, “The Eerie Silence: are we alone in the universe?”
Emmy Noether made perhaps the most significant discovery of the 20th century. A female Jewish intellectual in Nazi Germany (you can do that math), Emmy’s was a special approach to life. Noether’s Theorem ties the laws of nature — from Newton’s laws to thermodynamics to charge conservation — directly to the geometry of space and time, the very fabric of reality. It is the basis for the standard model of particle physics, quantum electrodynamics, and grand unified theories including supersymmetry and superstrings. As usual in physics, it gets really interesting when the theorem is violated: answers to the origin of mass and the matter-antimatter asymmetry problems emerge when Noether’s theorem is violated. Two things should bother you about Noether’s Theorem: (1) how come so few people have heard of Emmy Noether? and (2) why isn’t her theorem well known to lovers of science? With the help of a bunch of straw, Ransom Stephens solves these problems on June 16, 2010.
Ransom Stephens, Ph.D., is a professor of particle physics turned writer and speaker. He has worked on experiments at SLAC, Fermilab, CERN, and Cornell; discovered a new type of matter formed by the fusion of two photons, made the most precise measurements of rare bottom quark decays in the world, and was on the team that discovered the top quark. His new novel, The God Patent (TheGodPatent.com), is set in the battle between science and religion over the nature of the soul and the origin of the universe. It features a character based on the turn of the century mathematician, Emmy Noether.
Richard Prins' collection of pseudorandom perceptions