108,633 reputation
4165295
bio website ratsauce.co.uk
location Chester, United Kingdom
age 53
visits member for 3 years, 9 months
seen 17 mins ago

Semi retired old time computer nerd who started programming on a Commodore Pet.

Since I'm also active in the Physics forum I should add that I started as a theoretical chemist, moved into solid state photochemistry and finally worked in industry as a colloid scientist. I only became a full time computer nerd in 1997.


Jun
23
reviewed Approve suggested edit on Why is a Josephson junction important for a SQUID?
Jun
23
revised Why diaphragm in diffraction experiment using electrons is quantum object?
Minor tidying
Jun
23
answered What is the minimum pressure of a medium for which a sound wave can exist?
Jun
23
reviewed Approve suggested edit on What is $l_i$ in The wetted perimeter
Jun
23
reviewed Approve suggested edit on Poynting's Theorem simplified?
Jun
23
reviewed Close Symmetry factor of $n$-point one-loop diagram
Jun
23
comment What is $l_i$ in The wetted perimeter
Can you expand on your question a bit? What sort of systems are you talking about and where did the equation you mention come from?
Jun
23
reviewed Leave Closed Why and how the Universe has (at least) 3 spatial dimensions
Jun
23
reviewed No Action Needed What is the general conditions for non-zero polarization?
Jun
23
reviewed Leave Open Thin Lens Methods and Object Perceived vs Literal Size
Jun
22
comment Why can't a gas be liquified by pressure above its critical temperature?
That's a good question and anyone can give an intuitive explanation of why the liquid gas transition disappears above the critical temperature I would be interested to read it. "Intuitive" is the key word here!
Jun
22
comment Do photons occupy space?
The theory agrees astonishingly well with experiment to an accuracy of 10−6−10−10 for electrodynamics, of 10−1 − 10−4 for the weak interactions and of 1 − 10−2 for the strong interactions." - This quote is from the Nobel prize winning physicist David Gross.
Jun
22
comment Do photons occupy space?
arxiv.org/abs/hep-th/9704139 - "Quantum Field Theory (QFT) is today at a pinnacle of success. It provides the framework for the the standard model, a theory of all the observed forces of nature. This theory describes the forces of electromagnetism, the weak interaction responsible for radioactivity, and the strong nuclear force that governs the structure of nuclei, as consequences of local (gauge) symmetries. These forces act on the fundamental constituents of matter, which have been identified as pointlike quarks and leptons.
Jun
22
reviewed Leave Open Why is the anti-symmetric tensor more important than symmetric tensors?
Jun
22
reviewed Leave Open Why is a Electron negative not both?
Jun
22
revised Why can't a gas be liquified by pressure above its critical temperature?
Improve grammar
Jun
22
comment Do photons occupy space?
Most of the time our calculations using QFT work exceedingly well. In some circumstances, typically strong force calculations at intermediate energies, the calculations are very hard. But even then we can usually do them to reasonable accuracy. Because the maths is hard doesn't invalidate QFT.
Jun
22
comment Why is a Electron negative not both?
There is a related discussion in Rob's answer to the question Do electrons have shape?, and you might be interested to read it. The electron is forbidden from having an electric dipole moment by CP invariance. In fact CP invariance is very slightly violated and the electron is calculated to have a very, very small electric dipole moment.
Jun
22
comment Do photons occupy space?
Yes, "In general we can't solve the Standard Model exactly. We use approximations." seems an excellent summary. But then this is true of most physics beyond undergraduate level.
Jun
22
comment Plank stopping time
@CarlWitthoft: Can you be certain of that?