Recent content by moving_on

oh I forgot my personal favourite 'random' equation: differentiate the formula for Lense-Thirring w.r.t to c dt. i.e. -2/5 Gmw/sqr(c)R to get -1/5 Gmw/cR Apart from being the wrong sign and god knows what units, the result is a gnat's whisker from the required one (depending on...

Not sure where to put this, but if it's wrong, sorry... I just looked at the Nieto, Anderson paper on arXiv: arXiv:0907.3418 "Earth Flyby Anomalies" Funnily enough, it's about anomalies in the velocity of probes doing Earth flybys! This has hit the scientific news (New Scientist this...

Thanks as ever Dr. C. I'm thinking about the half-wave plate (e.g. 'Observation of a "quantum eraser": a revival of coherence in a two-photon interference experiment': Kwait, Steinberg, Chiao, Physical Review A, Vol 35, No 11) and I need to think more in order to be able to phrase clearly what...

Just a quick question regarding the sources used for investigating entanglement (of photons). There are two types of production method as I understand it: ('Fundamentals of quantum optics and quantum information', Peter Lambropoulos, David Petrosyan, 2006, Springer): Page 242 "In fact...

Anyone listen to BBC Radio 4 this morning (depending where you are in the world!) http://www.bbc.co.uk/radio4/history/inourtime/inourtime.shtml. 'The measurement problem in physics'. Basil Hiley, Simon Saunders and Roger Penrose explaining 'the cat' to Melvyn Bragg (bless him) and Radio 4...

hmm. Can't get hold of the papers even though they are quite old (without paying!). One abstract mentions simply using scattering theory as the basis for correctly calculating the probablility in line with experiment. Couldn't see reading up how that might work. I also read around pertubation...

Thanks very much Dr C., it sounds interesting.

If you're talking about spontaneous parametric down conversion as 'described' by most papers involving Bell test experiments (and Wikipedia), I too would like to know... ... as every one of them describes a single photon 'splitting' into two. What is the actual quantum theoretical description...

'kay... ...that went down well. What about this... ...I get two 'bosons' into a 'space' for which they are too big to 'fit' they conform to Bose-Einstein statistics. ...if I make two 'bosons' from something that was in a 'space' in which they are too big to 'fit' (presuming that...

thanks for the quote daschaich The 'missing antimatter' was also mentioned in Davies book although I did not quite gather from the text that the matter had been so completely settled.

Just flipping through one of my many easy reading books... Paul Davies 'About Time', 1995, Penguin p. 206... '(John) Wheeler proposed that all the electrons in the universe are really one and the same particle, simply bouncing back and forth in time...' 'This offers a neat explanation...

hmmm, maybe neither... ...as photons are bosons, can we use Bose-Einstein statistics? Can we consider an entangled pair of photons as a Bose-Einstein condensate? If we 'push it too hard' it collapses, but will 'reform' if the conditions are amenable.

I am having difficulty understanding why the single rate of detection (as opposed to the coincidence rate) is unaffected during Quantum Eraser experiments. I'm looking at the great Kwait, Steinberg and Chiao paper: 'Observation of a "quantum eraser": A revival of coherence in a two-photon...

Thinking more about this. My understanding is that when you set up a 'polarization by reflection' experiment, it is possible to infer the polarization of the reflected photon based on the angle set for the reflector. Is this about right? (assuming it reflects). What about a 'cat in the box'...

With respect to reflection, can't this 'affect' polarization in certain circumstances? What I mean is 'polarization by reflection'.