relativity
Category archives for relativity
What Newton’s 3 Laws Can Teach You
Posted by Ethan on February 24, 2011 “If I have ever made any valuable discoveries, it has been due more to patient attention, than to any other talent.” -Isaac Newton Born the year Galileo died, Isaac Newton is one of the most revered figures in all of physics. In addition to the work he did on optics, planetary motion and gravitation, Newton…
The Telescope’s Best Friend? Gravity!
Posted by Ethan on January 20, 2011 “What do we mean by setting a man free? You cannot free a man who dwells in a desert and is an unfeeling brute. There is no liberty except the liberty of some one making his way towards something. Such a man can be set free if you will teach him the meaning of thirst,…
Q & A: How is the Universe so big, given its age?
Posted by Ethan on January 5, 2011 “The size of the universe is no more depressing than the size of a cow.” -David Deutsch But it is bizarre, I’ll give you that. The most common scientific question I get asked is how, if the Universe is 13.7 billion years old, and the speed limit of the Universe is the speed of light,…
Big Bang Alternatives: Could my light just get tired?
Posted by Ethan on October 8, 2010 “You can’t have a light without a dark to stick it in.” -Arlo Guthrie You know the story. Every galaxy we look out at, with hardly any exceptions, appears to be moving away from us. Not only that, but the farther away a galaxy appears to be, the faster it appears to move away from…
Particle Physics + Relativity makes the impossible happen!
Posted by Ethan on September 3, 2010 “We have been forced to admit for the first time in history not only the possibility but the fact of the growth and decay of the elements of matter. With radium and with uranium we do not see anything but the decay. And yet, somewhere, somehow, it is almost certain that these elements must be…
There’s a hole in my spacetime! Or a string, or a wall…
Posted by Ethan on August 30, 2010 “The whole fabric of the space-time continuum is not merely curved, it is in fact totally bent.” -Douglas Adams As many of you know, if you take a whole bunch of mass, and you’ve got nothing going on except gravity, it’s going to gravitationally collapse. And if atoms, nuclei, pressure, and nuclear reactions don’t (or…
What is the Speed of Gravity?
Posted by Ethan on August 25, 2010 “The only problem with the speed of light, is it gets here too early in the morning.” -Danny Nevrath One of the most common questions I get asked is whether gravity is instantaneous, or whether there’s a speed limit to how fast the force of gravity can travel. It’s a good question! After all, we…
What’s the Most Fundamental Thing in the Universe?
Posted by Ethan on July 14, 2010 “I do not feel obliged to believe that the same God who has endowed us with sense, reason, and intellect has intended us to forgo their use.” -Galileo Galilei Geez, Ethan, why don’t you take on a bigger question? This question of “fundamental things” has a special meaning to scientists and natural philosophers, going all…
Is the Universe a Giant Hologram?
Posted by Ethan on March 24, 2010 Note: I’m on vacation this week, so here’s one from the vault. This article first appeared on my old website, back in February of 2009. Some days the questions I get are easy, and some days I get questions from our longtime reader, Ben. This past week, there have been reports all over the news…
The Greatest Story Ever Told — 01 — Before the Big Bang
Posted by Ethan on January 8, 2010 The more I examine the universe and the details of its architecture, the more evidence I find that the universe in some sense must have known we were coming. -Freeman Dyson When we look out at our Universe today, we see all sorts of beautiful things throughout space, from galaxies and clusters, distributed roughly evenly…
