Recent content by FeynmanMH42

I don't get this bit. True, you can say that from the wall's frame of reference my velocity changes from 10 metres per second to zero, but can't I say the same for the wall? I can consider myself at rest and the wall's velocity changes from 10 metres per second to zero?

Thanks for the input, but I've had another thought... what about momentum in inertial reference frames? If I'm traveling at 10 metres per second one way, it's fair to say I could consider myself at rest and say the room is traveling at 10 metres per second the other way. Since me and the room...

But you won't know that WIMPs are never to be found unless you wait around for eternity. All the evidence available today points towards the Big Bang - one piece of evidence could falsify it, but so far that has not been found. Some evidence that would support it if found (e.g. WIMPs) hasn't...

Ahh, but the speed of light in a medium is irrelevant. There's no law saying that the speed of light in glass is a universal constant - in fact it's perfectly okay to travel faster than the speed of light passing through a medium, and this can produce...

I was recently having an IM conversation with my friend about the principle of relativity - I'd been reading up on special and general relativity all day. Special relativity is based upon the postulate that all uniform motion is relative, and general relativity extends this to non-uniform...

Ahh, right. So charge is a scalar quantity, then?

2.1 Two objects, A and B, are initially uncharged. A negative charge of 4 nC flows from A to B. What is then the charge on each object? My problem with this is that a) the two objects are uncharged; to me "flow" of charge indicates current - I can understand the two objects becoming charged...

Yes, there could be microscopic organizams on surface. No, but there could have been life in the past. As you can choose more than one option I decided to pick both. I'd say it's a pretty safe bet that there could have been life in the past. It hasn't really had chance to evolve, and...

Terrestrial planets and Jovian planets. :)

Ahh right. By coincidence I was re-reading BHT again today and saw that even SH himself had admitted all the singularity theorems prove is we have to use quantum gravity rather than GR at the beginning.

The biggest "debate" I've seen on these cosmology forums appears to be "did the Universe, time, space and the whole whatevery actually begin with the Big Bang?" or "there is no scientific evidence the Big Bang was the beginning of the Universe, why should we believe it?" I haven't seen a thread...

I thought said celebrity had mathematically proven for his PhD thesis that an expanding universe would have had its beginnings in a Big Bang singularity thus giving space and time a beginning with no "before"?

Hello everyone, can someone clear up these Big Bang problems for me? As far as I know quantum physics is a set of physical laws and rules describing our universe. If so, how can we say the Big Bang sprang from a quantum fluctuation if there was no Universe (and hence no laws of quantum...

Alright, basically you have to think of a song that in some way relates to a planet, star, moon, astronomer, concept, theory, astronomical term, etc. Expect some to be funny. I'll start off: I still haven't found what I'm looking for - U2 - Dark matter/energy Here comes the Sun - The Beatles...

Sorry about ressurecting such an old thread but isn't the planet named Theia?