108,633 reputation
4165295
bio website ratsauce.co.uk
location Chester, United Kingdom
age 53
visits member for 3 years, 9 months
seen 20 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.


1d
comment Self-replication of gravitons in string theory
The phrase self-replication was used by the IO9.com journalist not by Luboš. It is not a term used by physicists.
1d
comment Self-replication of gravitons in string theory
I don't think the phrase self-replication has any special meaning in physics. Are you asking how string theory removes the divergences when summing the Feynmann diagrams for gravitons?
1d
comment How does EM radition depend on the reference frame?
If you take off in a rocket you know you're accelerating because you can feel the g forces. However if you leap out of the ISS and fall to Earth then you will feel no acceleration even though as viewed from Earth you are accelerating. So we have two cases where you are accelerating but they are fundamentally different. The question is whether an electron accelerates when falling an a gravitational field and I'm not sure anyone knows the answer.
1d
comment How does EM radition depend on the reference frame?
The spacecraft can do what it likes. If the charge isn't accelerating it won't radiate. In special relativity acceleration is absolute so there is no ambiguity about whether the spaceship or the charge is doing the accelerating. In general relativity the question is rather harder.
1d
comment How does EM radition depend on the reference frame?
Only accelerating charges radiate. Charges moving at constant velocity do not radiate.
1d
comment Which wavelength of light can reflect easiest on any material?
See Why glass is transparent?. Although this is specifically about glass it applies to any material.
1d
comment While finding escape velocity, does human mass counts as the mass of Earth?
We've both assumed that the average human is well fed :-)
2d
comment Can anyone tell me what's this equation?
See this article on Sean Carroll's blog
2d
comment What would be the best way to explain color confinement in quarks?
possible duplicate of About free quarks and confinement
2d
comment Why do propellers look like they are moving really slow when they are moving really fast?
This seems a perfectly fair question. Actually I'm surprised it hasn't been asked before, but I can't find a duplicate - a search for aliasing turns up related questions but no duplicates.
2d
comment How is antimatter made?
Making anti-protons is dead easy. Turning them into a cooled collimated beam suitable for use in an accelerator is not at all easy. Although it was done at Fermilab the intensity of the anti-proton beam was far lower than could be (relatively easily) achieved with a proton beam.
2d
comment Why seeing further in “timespace” does not add up?
See Did the Big Bang happen at a point?
Oct
17
comment How to understand “always create before we annihilate, not the other way around”?
In my 2003 edition the quote is at the top of page 64
Oct
17
comment Chaotic behaviour re-obtained in QM
This seems a very broad question. Since you linked the Wikipedia article on Gutzwiller I assume you've also read the article on quantum chaos that the Gutwiller article links. Can you extend your question to explain what aspects of the description of quantum chaos you would like expanded upon? There seems little point is us attempting answers that will inevitably reproduce much of what is already in the Wikipedia article.
Oct
17
comment Uses of Static Electricity
A supercapacitor, like all capacitors, produces a charge separation. The point is that it doesn't transform the energy to another form like, for example, charging a battery where the energy is stored as chemical energy.
Oct
16
comment Advanced Gravitational Waves?
A gravitational field is described by a metric that is a function of one time like and three spacelike coordinates. To look at time dependance you need to choose a coordinate system, express the metric in the chosen coordinate system then look at changes with respect to your chosen coordinate time. However you are free to choose any coordinates you want, and the changes with time will be different in different coordinate systems. Since there is no preferred time there is no preferred reverse time. Your question doesn't have an answer.
Oct
16
comment Is there a null incomplete spacetime which is spacelike and timelike complete?
This paper claims to describe just such a spacetime, however it's behind a paywall.
Oct
16
comment What prevents a star from collapsing after stellar death?
Have you Googled for relevant articles? For example this one on Wikipedia? After reading such articles what precisely are you unclear about?
Oct
16
comment What holds an atom together?
(1) is a duplicate of The Nucleus of an Atom. (2) is a duplicate of several questions. For (3) see the strong interaction. For (4) see preons. For how to ask a question see What counts as sufficient prior research when asking a question?.
Oct
16
comment What holds an atom together?
possible duplicate of The Nucleus of an Atom