Let's Talk Physics

Consider this modified version of the Bell-Dewan-Beran thought experiment: Two spaceships are attached by a rope. They begin accelerating, ...

This was my submission for the recent FQXI essay contest on the role of mathematics and physics. It didn't win a prize but I think it m...

Recently science journalist John Horgan posted an opinion piece called "How Physics Lost Its Fizz" . Following is my response, po...

This is a bit off-topic for my blog but I just find it very interesting. What do people get out of believing in god? Belief in god doesn...

This a perennially confusing question which I attempted to answer on Quora (http://www.quora.com/What-does-the-constancy-of-the-speed-of-lig...

Why do complex numbers feature so prominently in quantum mechanics, when classical mechanics got by just fine without them?  Scott Aarons...

Here is an article lays out pretty clearly the current conventional wisdom about what distinguishes science from non-science, the so-called ...

Nick Bostrom has famously argued that we probably live in a simulated world. Max Tegmark has famously argued that all mathematical objects e...

Recently I was reading Fulvio Melia's book "Cracking the Einstein Code", and I was struck by his discussion of an old (very ol...

Warning, this blog entry devoted to shameless self promotion! I've been working over the past 6 months or so to expand and improve my ...

Why does physics attract so many more cranks than any other field? I don't know, but here's how you can identify them. 1. They cla...

In a nutshell: the multiverse makes it possible for our universe to be described by an beautiful theory. Why does beauty imply a multivers...

Reason 1: In General Relativity, the effects on clock rates and rulers have a concrete cause, namely the gravitational field. It's hardl...

One often hears that Special Relativity is a "Spacetime Theory". Indeed, this is the predominant way to view the theory, and has b...

So, after thinking about the subject for many years, I've written a book on Relativity! It is called "Relativity Made Real", r...

Apologies to my Kindle followers - I just can't post at a rate that justifies selling the blog on Kindle. My goal is not to just relay t...

Things are heating up in the field of dark matter. One interesting idea making the rounds is that the very first stars may have actually bee...

Here's a popular-level online talk which goes over the current state of thinking on the whole fascinating mix of topics relating to blac...

Could it be that springtime is near, not just in Earth's climate (in the Northern hemisphere at least!), but also in experimental partic...

Now here's surprising twist in the string theory story, to say the least... I blogged a little bit the other day about the "Ads/CFT...

I just finished a really good popular physics book, the best I can remember reading for a long time. It is "The Black Hole War", b...

Everyone knows Quantum Mechanics is weird. Many of its principles sound paradoxical. Matter is both wave and particle. Position and veloci...

A cool paper appeared on ArXiV by Erik Verlinde, arguing that gravity should be thought of not as a fundamental force but rather as arising ...

Worrisome-sounding news in the blogosphere today: two scientists (Matthew Choptuik and Frans Pretorius) report computer simulations proving ...

The slowing of moving clocks ("time dilation") is one of the most famous results of Einstein's Special Theory of Relativity. B...

Here's something that surprised me...I guess I didn't pay close enough attention in thermodynamics class.... What's the most e...

Here's an beautiful line of research: look at very distant objects with the best possible telescopes, and see if their images are blurre...

What makes a theory "scientific"? Probably the most widely accepted notion is that it should be falsifiable, i.e., there should be...