Recent content by Islam Hassan

So if I understand correctly, QM prescribes that if a particle exists in the absolute sense, it can be detected somewhere. QM does not extend this logic to the particle's movement being continuous or not. Intuitively, people --and especially laymen-- cannot help wondering whether this is the...

So time is simply relative movement. Unlike gravitational mass vs inertial mass, there is no stand-alone, inertial time measure.

Yes that is understood, and both those processes at the microscopic level involve movement, of sub-atomic particles or anything else. I did not mean movement in a macroscopic sense only.

We only measure time via the relative movement of a standard, agreed reference, a clock for example. If we replaced all instances of "time" in the formulation of SR and GR by "relative motion [ie, of an agreed reference]", would SR/GR remain correct/consistent? Or does SR/GR rely on a deeper...

Thanks Dan, that pretty much sums it up for me!! Theoretical continuous movement is out of the scope of QM due to the uncertainty principle...at least out of the scope of QM as it is formulated today.IH

Thank you Halc...re the electron orbit, that's why I put the word in quotation marks 'orbit'... If QM says nothing about what goes on between measurements, what do physicists speculate about a particle's movement being smooth and continuous or not...if of course they engage in such speculation...IH

Niels Bohr famously said --and I paraphrase-- that QM is an abstract description of nature and that it can only prescribe what we can say about nature rather than what nature is. What does QM say about the movement of a particle? Is this movement positively ascertained to be smooth and...

Yes I have, some time ago and I substantially found nothing. I was intrigued by an article I once read somewhere on the net that said that black holes contained the majority of the mass in the universe, which seemed odd. This question has been on my mind since then...recently I said to myself...

What percentage of the universe’s A) total mass —including dark matter— and B) radiation energy is estimated to reside in: Inter-galactic space covering i) inter-galactic medium and ii) distinct inter-galactic astronomical objects; and Galaxies covering iii) inter-stellar gas clouds, iv) stars...

Wonder why it suddenly gets so much media attention though...is something different this time or people simply didn't do enough due diligence and research?...even CNN is on the bandwagon...slow news day probably...IH

Thanks for the clarification. Is pair production the same as annihilation? Or can annihilation produce a multiple photon burst?IH

Ok, I have read the wiki on pair production...only a single boson is needed to do this. I had thought that annihilation produces many more photons than one, a big burst of photons. Thanks for the feedback. What about the weak interaction though?IH

To take annihilations, their reversal would I believe require a number of sufficiently energetic photons to converge to a single, very precise microscopic location with very precise microscopic timing. Their combined energy must then be exactly equal to the energy need to produce one given...

Thanks for all your answers. Conceivably then, could a supernova explosion develop fully over a span of minutes or hours even? Would there theoretically be an upper limit on this time interval?IH

At the particle interaction level, we cannot distinguish a preferred direction of interaction, an arrow of time as they say. I do not understand this if i) in annihilations, there is a manifest disparity between particles before (massive fermions) and after (photons) an interaction and...