Recent content by Nasher

Is an atom's nucleus a single particle? Take for example the nucleus of a lithium atom which contains three protons and three neutrons. Do the wavefunctions of these three protons and three neutrons merge together to form a single particle, in the case of the lithium's nucleus, a...

In certain circumstances, when an electron collides with an anti-electron, the interaction produces two gamma photons. The reverse process would be a gamma photon colliding with a gamma photon, such that the interaction produces an electron and anti-electron. A gamma photon is a high...

Na, it is too much fun coming up with such ideas!

High Energy Photon/Curved Space Limit?? Energy curves space. The smaller the wavelength of a photon, the higher its energy. With regards to a high energy photon, Could there be an energy threshold for a photon at which its high energy could curve space to such an extent that the photon...

So, due to universe expansion and the radiation being red-shifted, has this radiation lost energy, since a red photon has less energy than a blue photon? With regard to energy conservation, to what form of energy would this lose in energy have being converted to? Would it be gravitational...

I reckon that idea of parallel universes sounds more like fiction that fact. Of course, since I am not well up in it, that's just my opinion. Maybe theoretical cosmologists can vary the number of dimensions and other variables, which will yield different universes and parallel universes...

Here is a link to a parallel universe... documentary. BBC Horizan - Parallel Universes (44 min 35 sec) http://video.google.co.uk/videoplay?docid=4183875433858020781

A typical star like the Sun is emitting radiation energy. Over a duration, say the star emitted radiation energy, E. This would have required the mass, m=E/(c^2), to be converted to radiation. For the Universe, is the ratio of radiaton energy to mass energy increasing with time?

nrqed, this is straight out of the glossary section of the book, "Universe", 6th ed. by Freedman and Kaufmann... isotropic Having the same property in all directions. homogeneous Having the same property in one region as in every other region.

Thank you all for your feedback... When I think of the big bang, I naively think of these galaxies moving away from some big bang centre point in a sort of spherical space and that the universe expending is like the space getting stretched in the three usual dimension of space. If it was...

Lets get a bit of brain-storming going... What shape is the universe? Is it infinite in all three dimensions of x, y, z ? Is it spherical?

Any suggestions to what the largest anti-matter object would be? Would it be just anti-particles, or would it be anti-hydrogen, or anti-carbon, larger anti-atoms, or multiple anti-atom object, or anti-one_kilogram object, or anti-planet, or antistar, or anti-galaxy, or anti-cluster, or...

I meant... This suggests antistars are not stars going backwards in time from our perspective.

Retrocausality I just find this site about Retrocausality... http://en.wikipedia.org/wiki/Retrocausality It seems to dismiss the idea.

Retrocausality This is a quote from this interesting link about Retrocausality... http://en.wikipedia.org/wiki/Retrocausality It said that Feynman employed retrocausality to provide a proposed model of the positron, electrons moving backward in time would appear to possesses a positive...