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232116
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location Greece
age 74
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Retired experimental particle physicist.

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


Oct
13
awarded  Good Answer
Oct
13
comment Is it possible to focus the radiation from a black body to make something hotter than that black body?
@Hypnosifl nobody will lose energy as the sun will be getting back the reflected.
Oct
13
awarded  Nice Answer
Oct
13
comment Can neutrons be synthesized purely from protons and electrons?
If by purely you mean only an electron and a proton to join into a neutron, the answer is no. Lepton number will not be conserved in a two input one output situation even ignoring the energetics of the reaction. (see the answer with electron capture)
Oct
13
comment In young's double slit experiment?
have a look at en.wikipedia.org/wiki/… you are missing a parenthesis in your choice (n+.5)pi .
Oct
13
reviewed Approve suggested edit on Does Gravity Really Exist?
Oct
13
comment Does Gravity Really Exist?
@brightmagus He/she is asking an existential question from a physics model , in my books. Forces enertia etc are not real physics, they are definitions constructed from observations, postulates in a sense, for the variables we can define in our dimensions.
Oct
13
answered Does Gravity Really Exist?
Oct
13
comment In young's double slit experiment?
it is true that pi plays a role as the sines and cosines vary from zero to twopi. You should not be "adding" an integer though, since the resulting angle will not be a multiple of pi.
Oct
13
revised Is it possible to focus the radiation from a black body to make something hotter than that black body?
edit after comments
Oct
13
comment Is it possible to focus the radiation from a black body to make something hotter than that black body?
@Hypnosifl No, I am not saying that. One is not increasing total energy or volume of the system. The system is open and one is rearranging the energy depositions.
Oct
12
comment Is it possible to focus the radiation from a black body to make something hotter than that black body?
I think if one set up such a system at 6000 equilibrium, a new temperature would be arrived at because the spot would be equilibrating with the rest of the earth/sun, so even if for a delta(t) it was higher the system will equilibrate. In addition I do not think you are correct that non equilibrium and equilibrium follow at the level you imply. There will be a limiting process in the variables. We would not have the CERN plasma either
Oct
12
comment Is it possible to focus the radiation from a black body to make something hotter than that black body?
But the earth sun is not in a thermodynamic equilibrium. We are not at 6000K ! The problem is not an equilibrium problem. Everything would melt at that point ;).
Oct
12
comment Is it possible to focus the radiation from a black body to make something hotter than that black body?
@Hypnosifl Suppose that one can focus with a parabolic lens enough to go to 2000K on a spot. All one has to do is to use four parabolic lenses on that spot to bring the temperature higher than the 6000. It is a matter of energy which is scalar and additive , it is algebra at this point. We are not talking of focusing the total energy of the sun, just some of it per meter square ( my solar panel example was used to show this, not clearly I guess :( )
Oct
12
answered Is it possible to focus the radiation from a black body to make something hotter than that black body?
Oct
12
awarded  Self-Learner
Oct
12
revised Is the wave-particle duality a real duality?
corrected error
Oct
12
comment Experimentally diminishing random errors for low wavelength UV observations
Well, then use a stronger "telescope". If the noise is coming from the atmosphere this should strengthen the signal to noise.
Oct
12
comment Experimentally diminishing random errors for low wavelength UV observations
Are you focusing the UV with lenses on your detectors? ( I am thinking on the lines of seeing stars in the noise with telescopes)
Oct
11
revised Intuitive explanation of how hadron mass emerges from the strong force
added link