51,813 reputation
232116
bio website
location Greece
age 74
visits member for 3 years, 9 months
seen 54 mins ago

Retired experimental particle physicist.

The picture is a fayum . It looks like aunts and cousins of mine :).


4h
comment If Earth starts moving when attracted by an object, where does the energy come from?
have you checked en.wikipedia.org/wiki/Conservative_force . the answers you have got are on those lines.
6h
comment If Earth starts moving when attracted by an object, where does the energy come from?
yes, that is a correct summary
10h
answered Which nucleus is the most resilient against gamma-induced fission?
1d
comment what kind of wings would a person need to fly?
@Jim , just that people have been wondering about winged flight for a long time
1d
comment what kind of wings would a person need to fly?
One should remember Icarus en.wikipedia.org/wiki/Icarus
1d
revised If Earth starts moving when attracted by an object, where does the energy come from?
clarification after comment
1d
comment If Earth starts moving when attracted by an object, where does the energy come from?
exactly the same thing, you provide the energy with the impulse of the throw , taken from the breaking of chemical bonds in the matter that makes you up, and ultimately from the heat of sun that makes things grow that you eat and have available energy. Again, you-and-the-earth initially accelerate downwards and the tomato upwards: from momentum conservation the available energy is shared. (it is the huge mass of the earth that is confusing you, very little motion is needed to give the same momentum as to the tomato).
1d
answered If Earth starts moving when attracted by an object, where does the energy come from?
2d
answered Is there some special case where a fermion can mediate a force?
2d
comment Gravity - Force or Result?
@CuriousOne except the mathematical beauty of a consistent mathematical frame for all observations, which was the aim that was followed and so physics has progressed the last centuries.
2d
comment Gravity - Force or Result?
@CuriousOne "Force" is a statement of physics semantics. It works at our everyday level and the mathematical models are rigorous within the accuracies of measurement. Take the word "particle" also a classical word and we have not abandoned it at the quantum mechanical level, ( even though it generates great confusion) because it works classically and at the limit where quantum becomes classical it has a definition. The concept of classical force is really abandoned with Feynman diagrams, it is just the continuity that generates the identity.
2d
revised Gravity - Force or Result?
added link
2d
answered Gravity - Force or Result?
2d
answered Surviving collapsing buildings: Which floor maximizes your chances of survival?
Oct
21
comment Dalitz plot for $ \pi \to \gamma (1) + e^+ (2) + e^- (3) $
You are missing a 0 after the pi .AFAIK a Dalitz plot is used to plot data. www2.warwick.ac.uk/fac/sci/physics/staff/academic/gershon/talks/… If you have the decay matrix element you could put it in a monte carlo generator to give points in the dalitz plot.
Oct
20
comment Quantum decoherence and Schrodinger's equation
@CountIblis in my books, a measurement has a probability of having a given value to a variable or a set of variables at time t. This measurement will be one point in accumulating the probability distribution (multidimensional if there are many measured variables) which is the square of the wave function. The probability will come from the correct amplitude.
Oct
20
comment Quantum decoherence and Schrodinger's equation
One cannot measure a unique wave function with one measurement. One can measure the square of the wave function, i.e. the probability distribution, with many measurements accumulated .
Oct
20
comment Is the particle reaction $π^- + p \to K^- + Σ^+$ possible?
wrong signs ? pi+p can go to K+ sigma+ :inspirehep.net/record/6000
Oct
20
comment About the Large Hadron Collider
This is part of the ongoing analysis of LHC data on ATLAS and CMS. example arxiv.org/pdf/1307.2518.pdf
Oct
20
comment Producing photons with same frequency, different amplitude wave
@BenCrowell I am responding to the question, where amplitude is connected with energy , that is why I put the quotation marks. I give the link where a quantum mechanical amplitude is of course defined, in case the questioner is more sophisticatedin physics than the question.