108,928 reputation
4166295
bio website ratsauce.co.uk
location Chester, United Kingdom
age 53
visits member for 3 years, 9 months
seen 8 hours 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.


Oct
11
comment Can the diffraction/interference pattern behind the slit (double slit) be calculated with Feynman path integrals (QED)?
See also Young's Double Slit Experiment in Quantum Field Theory
Oct
11
comment Center of mass & Big Bang Theory
20 billion years ago? You have a book from the future!
Oct
11
comment Have $2s_{1/2}$ and $2p_{1/2}$ the same energy?
Where did the diagram come from? What system is it referring to?
Oct
11
comment What causes Paulis Exclusion Principle?
Closely related: Is Pauli-repulsion a “force” that is completely separate from the 4 fundamental forces?
Oct
10
comment How big can a cube-shaped planet be?
Also see this paper. The link came from Martin Beckett's answer to Are “broken” planets possible in the real world? though this isn't quite a duplicate of your question.
Oct
10
comment How big can a cube-shaped planet be?
Reading this paper would be a good start.
Oct
10
comment Centre of mass as a function of distance
This question appears to be off-topic because it shows insufficient prior research
Oct
10
comment Centre of mass as a function of distance
Have you done the obvious Google search to see if you can find the answer for yourself?
Oct
10
comment What causes an increase in sound speed in a medium?
@user60180: that depends on what you're asking. The frequency of a sound wave depends on what is generating it. If I play a 1kHz tone on my HiFi then the frequency doesn't change with temperature. However because the speed of sound changes the wavelength will also change in proportion.
Oct
10
comment Does a photon exert a gravitational pull?
@Luaan: I'm reluctant to hedge every answer on GR with the qualification but quantum mechanics might change this. Also note that the stable photon orbit is at $1.5r_s$ not at the event horizon.
Oct
10
comment Did the Cretaceous-Paleogene extinction event cause miniature tidal waves?
At a quick Google I can't find any good links, but I'm 99% sure there is geological evidence for debris caused by tidal waves from the Chicxulub impact. What's more the thickness of the debris layer decreases with distance from the impact point as it should do.
Oct
10
comment Has the gravitational interaction of antimatter ever been examined experimentally?
@Eoin: it would be good to post those links as an answer, maybe with some description of what's in them. Comments are ephemeral and may be deleted. Plus you'd get some rep points - I, at least, would upvote :-)
Oct
10
comment Could anyone show me mathematics of how singularity arises?
Can you give some idea of what research you've already done? For example have you read through the various articles that this search finds
Oct
10
comment Has the gravitational interaction of antimatter ever been examined experimentally?
@Luaan: thanks, I've clarified the wording.
Oct
9
comment Storing a Planet-sized Chunk of Metal Inside a Star
@SamWashburn: even assuming wormholes exist (they almost cetainly don't) putting one end inside the core of a star would be like uncorking a bottle containing plasma at 20 million degrees and 250 billion atmospheres. The result would make a hydrogen bomb look tame.
Oct
9
comment Has the gravitational interaction of antimatter ever been examined experimentally?
@annav: thanks, I've added a link for AEGIS and also for the GBAR experiment.
Oct
9
comment What's the meaning when Kerr-Newman metric's mass is zero?
For the non-charged metric see problem 6 here. The $\mu \rightarrow 0$ limit is just Minkowski spacetime in some rather eccentric coordinates. I would guess that the Kerr-Newman metric will just give the $\mu \rightarrow 0$ limit of the Reissner-Nordstrom metric.
Oct
9
comment How to derive the cigar soliton solution to the Ricci flow equation?
I've suggested a move to the MathSE, but note the existing question Cigar soliton solution.
Oct
9
comment In a column of fluid does density vary?
See the question Hydrostatic pressure - doesn't density vary with depth? for more on the density variation of fluids.
Oct
9
comment What underlying structure/framework defines the charge of an antiparticle or regular particle (specifically a proton)?
@sidewaiise: if I've understood your question correctly it's something that has bothered me too. I've suggested my own question as a duplicate.