113,917 reputation
5176303
bio website ratsauce.co.uk
location Chester, United Kingdom
age 53
visits member for 3 years, 10 months
seen 39 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.


Nov
24
comment Can a ultracentrifuge be used to test general relativity?
@CarlosFreites: which comment? If you mean your second comment asking about the three scenarios then I think that's a different question to the one you asked.
Nov
24
comment Is time dilation a mechanical slowdown only?
See also Is time dilation an illusion?
Nov
24
comment Is time dilation a mechanical slowdown only?
possible duplicate of The real meaning of time dilation
Nov
24
comment Are black holes “Immortal”?
They may not even exist!
Nov
24
comment With what fraction photon quanta emission rate is decreased in the expanding universe?
I've read through this several times, but I'm afraid I still can't work out exactly what you're asking.
Nov
23
comment How does Gravity behave at high energy?
@SachinShekhar: yes it does, but that's just saying the curvature is dependant on the stress energy tensor - kinetic energy appears in the stress energy tensor as a momentum flow or a pressure. To be surprised at this would be like being surprised that increased mass causes increased curvature.
Nov
23
comment Can a quark irreversibly pass though an event horizon?
I saw your later question first, and I think my objections to the later question apply to this one as well.
Nov
23
comment How does Gravity behave at high energy?
@SachinShekhar: unless you consider quantum effects there is no mechanism to change the value of $G$. Quantum effects certainly will change $G$, but of course we have no theory of quantum gravity so we can't say exactly how it would change.
Nov
23
comment Why does hot food give off vapor?
You are seeing water vapour evaporating from the hot potato, and then condensing as it cools to form water droplets.
Nov
22
comment What do we see while watching light? Waves or particles?
@enthdegree: sorry, I couldn't resist :-)
Nov
22
comment Photo-excitation in terms of particle physics
See also What is the Quantum Transition Time for Photon Emission?, which also a duplicate, though a less obvious one.
Nov
22
comment Can all fundamental forces be fictitious forces?
@ACuriousMind: ah yes, now I actually research it rather than relying on a faulty memory I see your point. Thanks, I've updated my answer accordingly.
Nov
21
comment Can all fundamental forces be fictitious forces?
@Christoph: yes, but only if you're prepared to accept extra dimensions.
Nov
21
comment White light is not line specific?
For ordinary glass the change in the refractive index across the visible spectrum is less than 1%. You won't see a beam of white light split much unless your screen is a long way from the prism. I mentioned this in an answer to Can we get the refractive index of a prism by using white light?
Nov
21
comment White light is not line specific?
To clarify, are you saying you did the experiment and when you viewed the red light the pins weren't in line?
Nov
21
comment What is the point of this type of graph? (Projectile)
@Sarabetorrius: the gradient is $2v_0^2/g$. So if you know the launch velocity you can calculate $g$, or if you know $g$ you can calculate the launch velocity.
Nov
21
comment Is there any limit on movement of space itself?
@daniel.sedlacek: the rubber sheet analogy, or your Jello metaphor, are useful for giving a rough idea of how GR works. But they mislead in some important ways. For example they only show curvature of space, but in most cases you and I are likely to encounter curvature of the time coordinate dominates. Anyone seeking to understand how GR really works would be wise to discard the rubber sheet/jello analogy.
Nov
20
comment Is there any limit on movement of space itself?
I think the downvotes are unkind. It seems obvious what Daniel is asking, and quibbling over the use of the word move seems ungracious to me. Instead of downvoting, why not answer and as part of the answer explain why spacetime doesn't move?
Nov
20
comment What is the identity of Dark Matter?
@BenCrowell: wounded, but not dead yet
Nov
20
comment How water and honey behave with increasing pressure?
Oh that Laplace law! No, it's not related to surface tension or the Young-Laplace equation.