Recent content by jensel

From my tiny understanding: From my understanding you are right but the field itself does not predict the electron as it self. Classical quantum mechanics desribes very well, let's say a single electron. The interaction then is very well described in QFT with respect to SRT. The interaction...

I would like to remove this thread. I did not see the geometry of the galaxies. It is something not to be described in such an easy way. A 1/r^2 rule is only given for a point like mass center. I found out some material, sorry.

Hi, I hope you can help me. I am a physicist but not a researcher and have currently not the time to study many papers about the subject of dark matter. What I would need for deeper thoughts is an expansion in a series of the Newton law for cases where it has been measured that star rotation...

PS: If \dot{a} \sim a we see immediately that it is going a \sim exp(t) which I find natural (without having this calculated, sorr, I shouldn't be that lazy) if we have a linear loss of effective mass.

Well, normally I should delete my last posting because it is not correct to compare a black hole with the universe. As well as I understand there is a big difference between both, let's say type of event horizon. A black hole is gravitating because no mass dissappears within the event horizon...

Thanks for the replies! Would you agree: If there is a cosmological model where the current state of our position is outside the infulence of parts moving > c, outside of any influence, wouldn't this influence the model itself? We are talking about Black "Objects" where normally no information...

Hi, I have one question about the expansion of the universe. Say, that there is a part which is that far away that we can't see it any more more because the speed of light is succeded. Wouldn't this mean that those part of the universe has no more influence on us at all? In ohther words...

I would never say that this thought is new - I just find this point is not teached very well. I found it surprising that a feather falls down the same way as an iron bar, as a child. For me, it was just measured and astonishing and I find "my" little "thought experiment" very convincing. A...

Hi, Something which I never read in a physics book. Let us take a homogeneous gravitational field. Now let's take an appel. Let us watching it falling. Now let's cut it into two pieces. If there would be a very short distance, would we really expect that both pieces now fall slower or...

Hi, Problem seems to be solved. I found this brilliant website (rest in peace Tony, you genius, you helped me a lot!): http://www-users.cs.york.ac.uk/~fisher/mkfilter/ So great... Jens

Hello, Please help me with the following problem. Given a measured signal which has to be smoothed. A lowpass filter has to be applied. The signal is available as measured data (a data file on the hard disk, numerical, not real-time) ( it has to be applied in C or C++). The filter...

I can give myself a first answer. I have a bacic misunderstanding of GRT. Since the velocity of light is a constant the expansion of the universe is not bending the let's say meter-scale but a real expansion. An object real get's farer away from every point in the universe in the long scale...

Hello, I hope you can help me. I thought I have an idea about GRT but I found this about about the basic cosmology. It is a link to a video from Stanford Univerisity. In short words: Susskind seems to confuse coordinates with distance. I can't understand that he seems to talk about defined...

Mass of the Earth and the Newton law that F=m a=-G m M/R^2. In classical physics the acceleration does depend only on the distance to the center of the earth. (This means that the acceleration is on a mountain smaller.) That m does cancel out in this equation is very important, it is unique in...

Got it, Lisa! :smile: And since I have a new theory about spaghetti instead of strings (in combination with a galacticly great 23 dimensional tomato sauce) I may profit some day from this ads, if my book is ready. :wink: