Anyone know about "Spooky action at a Distance"?

[SJorgensen]

NPR had an interesting topic today. Quantam physics. Deals with quantam "entanglement"
You can hear the program on NPR's site:
Hope the link works:

javascript:getMedia('TOTN',%20'20-Jun-2003',%203,%20'WM,RM');

Such a strange phenomenon that is provable in experiments. One photon in one place seems to be intimately connected to another photon in a completely different place. Theoretically anywhere in the universe. Turn one and the other turns in the same direction. Cool.
Spence

[Evan]

This is the part that Einstein just could not wrap his head around. He stated "God does not play dice with the universe" and Stephen Hawking said "Not only does He play dice with the universe, he sometimes throws them (the dice) where they can't be seen".

As an example, when an electron is energised to a higher energy state, that is, raised to a higher orbit, when it decays it will give off two photons. They depart in exactly opposite directions. The polarisation of the photons is indeterminate. BUT, if you measure the polarisation of one of the photons then the other photon will assume the opposite polarisation instantly, with no speed of light lag, no matter if they are light years apart. That is the "spooky action at a distance".

Here is one you can try at home:

When light travels through a polarizing filter the filter allows photons of a particular vibratory angle to pass. It does not alter the vibratory angle of the photons. If the filter is a vertical polarization filter then only vertical polarizied photons will pass. Important: this is a quantum effect. It is subject to the laws of probability. If you then place a second filter after the first and the second filter is horizontally polarized there is a zero percent chance that a vertically polarized photon will pass through the second filter. Try this with sunglasses. Not perfect but it will illustrate the effect. Here is the kicker. If you place a third filter between the first and second, angled at 45 degrees then 50% of the light will pass through all three. It is due to how the probabilities add up. It doesn't make intuitive sense and this is why Einstein had so much trouble with it.



[This message has been edited by Evan (edited 06-21-2003).]

[Randy]

Here's a link to an article on quantum entanglement from Wikipedia, a free online encyclopedia:
http://www.wikipedia.org/w/wiki.phtm...nglement&go=Go
(BTW, I recently discovered Wikipedia, and it's quickly become one of my favorite websites.)

[Dave Opincarne]

Scientific American had an article on the phenominon and the research back in '94 or '95. I don't know if I still have the article, I'll look for it but if they have an online index you could check there.

-Dave

[Evan]

If you are interested in the subject I strongly suggest reading the book "Quantum Electro Dynamics (QED)" by Richard Feynman. He had an unusual knack of making the wierd and strange world of quantum mechanics understandable, without having to do the math! Even if you are not really that interested in QED I highly recommend you read "Surely you're Joking, Mr. Feynman?". It is one of the most entertaining books I have ever read. It just doesn't get much better.

[Joel]

"Surely You're Joking, Mr. Feynmen!" is one of my favorite books. I recommend it to all on this site. It is not a science book, but a book about an amazing person and his interesting, once in a lifetime experiences.

[SJorgensen]

Wasn't he the guy who determined it was the gaskets on the Challenger SRB that caused the disaster? Practical thinker, plain talking, smart guy.
Spence

[Joel]

Well, he gets credit for it because he brought it to light. The person who knew and understood, wasn't about to tke credit.
It is all covered in his second book "What do you care what other people think?", also excellent. A good source for what and how the shuttle disaster happened.
"Smart guy" is an understatement. Many people we call genius, are narrow. Their expertise seldom goes far beyond their field. Feynman was broad, and brilliant in virtually everything he was interested in, which was most everything.

[crossthreaded]

Feynman certainly was "broad & brilliant". His is the only book physics book that gave a method where-by you get the pickup chick to go home with you. Hasn't worked for me, but then I'm not a Nobel prize winner.

[jfsmith]

Crossthread,

You will just have to buy a large Tennis Trophy and carry it around with to impress the ladies.

Jerry