Hi, I'm grateful for all the information I got and I tried to read most of the referenced articles. I think I understood the bound systems (also due to the information in the References).
In post #8, I wrote "If the universe is finite, then I can quote J. Peacock from ref 5 (you indicated)...
Hi, I agree, I stated it too strongly. We came to the subject of virtual particles in this thread because of the discussion on expanding space and the following arguments that there is nothing to expand since space is completely empty. Then I replied that space is filled with a sea of virtual...
Hi, yes I took courses on QFT and have some books at home. So, all other effects such as vacuum polarization, lamb shift, ... can be explained without virtual particles?
Even when the concept of a virtual particles just comes from a representation of some terms in an integral, I prefer to think...
Well, that is the opinion of one author. I'm sure there are many other opinions on this. In https://www.physicsforums.com/insights/misconceptions-virtual-particles/ the author writes that virtual particles "cannot cause anything, interact with anything or affect anything". The Casimir force...
Thanks for the comment (though it does not really answer my previous question).
Of course, this statement does not take into account quantum physics: In quantum field theory space is not empty at all but filled with a vibrant sea of virtual particles. Maybe that in this context, space can...
Let us suppose that the universe is not infinite. This is a valid hypothesis, in view of the fact that we have no experimental evidence that the universe is infinite. In that case, space itself must have expanded (ref Peacock). Then, I ask myself why tightly bound systems do not expand. The...
In fact, we don't really know if our university is infinite. Models can suggest that this is the case, but we will never get experimental proof of this. If the universe is finite, then I can quote J. Peacock from ref 5 (you indicated); "This is most clear-cut in the case of closed universes...
I find your answer highly confusing; In every textbook and article, it is clearly stated that space expands (see also wikipedia ; https://en.wikipedia.org/wiki/Metric_expansion_of_space , "Over time, the space that makes up the universe is expanding "). If space would not have expanded since the...
In the "raisin bread model", the raisins do not expand (as the universe expands). It is often mentioned that the space within gravitationally bound systems, such as galaxies, does not expand. However, I have never heard a good explanation for this. Saying that space in a galaxy does not expand...
Hello guys,
My name is Rudi Van Nieuwenhove. I'm a physicist working in the field of nuclear energy since 1982.
I have a strong interest in the field of relativity and cosmology and made also some publications in this field. The reason for joining this forum is to follow more closely the...