Does light have mass?

You're almost entirely correct, but I think you meant to say the general theory of relativity. I google'd it, and I found this page:

http://csep10.phys.utk.edu/astr162/l...y/gravity.html

I could be wrong, but because gravity does affect light (black holes, etc.) there is a force at work there so the general theory would apply.

Actually E=mc^2 is slightly outdated, it never accounted for -mass, so it should be E=(- or +)mc^2
c= the speed of light. fyi they have brought it's speed to 0, I belive SCIAM.com had a detailed article on it... not sure... but I think so.

You have to remember that when searching on the web to check your sources, some may be outdated or "billy bobs super cool home page", normaly howstuffworks.com is a good place to check things out.

Drakain Zeil,
I checked howstuffworks and I didn't see anything on negative mass. Are you sure that it exists? Scaim.com didn't turn up anything either. If you could give a URL, I'd be very appreciative.

I should clarify for those interested. Einstein wrote a papers back in the early 1900s and consolidated them in 1920 and called it Relativity: The Special and General Theory .

I may have crossed the line a bit but the SPECIAL theory describes the motion of particles in relation to the speed of light. The reference of momentum and energy is the Special Theory. Later it was expanded to add gravitation and how it effects the shape of space and the flow of time, that is the general theory. It says space and time or not linear and are intertwined and expanded greatly upon by Steven Hawking in A brief History In Time at a later date.

I was saying that if we could overcome the limitation posed by strict boundaries in the universe, as applied to light speed and our inability to accelerate mass to C, we could reshape time and in reshaping time you are also reshaping space because gravitation would change.

The fact the negative mass could exist doesn't mean much to the Special Theory. We already know there are mass less particles that can go the speed of light. One is a photon and IS light. Even if I entertain the idea that negative mass exists, of which I am not convinced it does; who cares? The theory still applies. If you can accelerate a particle with 0 mass to C then certainly something that weighs less than nothing can reach C and beyond.

It's curious that the mathematical computations supplied by Einstein resulted in anomalies: Black Holes and Gravitational Waves. Some still believe they do not exist and they are purely mathematical mistakes of the original equations used. I say Steven's work is quite evident that a singularity exists. It's even more curious that Einstein himself, thought they were mathematical mistakes and he didn't live to see current observations of blacks holes and the singularities they contain.

That makes much more sense. Obviously you have done more research than me on the topic. Einstein should have put a warning on that paper, "May cause severe headaches!". ;)

I don't know if I put more research into it, only while others had Rock stars and sports stars has childhood heros: mine are as follows in order.... Carl Sagan, Steven Hawking, Albert Einstein, and all the great minds of the classic civilisations. Of course, Bono, Roger Waters, Johnny Bench and others are up there too, alnong with all the great brewmasters of the world. :D

Hey road closed check out "The future of time" its a collection of essays dilivered by hawkings and others at UC Berkly for their head physacist's birthday. I would also sugest "The Universe in a nut Shell" for any of you just getting interested in space-time, its a book by Hawkings that gives a bref overview of the current happings in theorectical physics.

Thanks got the recomendations. Also, the "Brief History in Time" is hard to read. I had to go out and get a math book to comprehend some items. BUT, we (non mathematically gifted) are saved. A couple of years ago, the illustrated "dumbed" down version was released. It's amazing and is called "The Illustrated, brief history in Time"

Oh I forgot someone on my list of top 3, now 4. Issac Asimov. Sure he wrote tones of science fiction, many dealing with the social issues of "what if" robots were made human like. But he also worte essays and books about basic physics that are sort of "physics for dummies" where things are explained with down to earth models.

Good stuff.

The nutshell and future book are much kinder to those of us how had to take liniar algabra twice (defeq killed me.) so don't let the math in history of time scare ypu.

I got the "Future of Space Time" from the library at lunch. Good ****.