CapitalistImperialistPig

A persistent puzzle of quantum mechanics is the emergence of the classical world from its quantum substrate. How is it that the world of everyday experience appears to follow classical rather than quantum laws? This was a mystery to the founders of quantum mechanics, and ultimately they mostly adopted the so called Copenhagen interpretation, which just sweeps the mystery under the rug by declaring that two must be kept separate, pushing all the weirdness into the measurement process. Over the last three decades an alternative interpretation, known as consistent histories or de-coherent histories, introduced by Robert Griffiths and further developed by Roland Omnes, Murray Gell-Mann, and James Hartle, has attracted widespread interest and support. Its great virtue is that it does away with the Copenhagen division of the world into quantum systems and classical measurement apparatus. All get treated on the same quantum mechanical basis. The most mysterious quantum phenomena are those as...

A blogger, this one at least, is a person who can't learn anything without developing an urgent impulse to communicate it. Have you ever wondered how an oxygen concetrator works? (If not, you can safely skip the following) An oxygen concentrator, if you are wondering, is one of those devices you see people with clear plastic tubes in their noses using - recognizable by it's own characteristic raspy breathing - sort of a pssst, pssst, pssst with a period of a few seconds. As its name indicates, it concentrates oxygen from the air and delivers it to the wearer, usually an ill person, but also to some pilots flying at high altitudes. Knowing that air is 78% nitrogen and about 21% oxygen, how does it do that? What difference between the molecules is being exploited to do the separation. This stumped me, so I had to look it up, but if you don't know the answer, try to guess. It turns out to be molecular size. Oxygen atoms, with 8 protons, are about 5% smaller than the 7 prot...

The Plutocracy got most of the Congress it wanted. Let's see what they do with it. There seems to be some stepping back from the apocalytic rhetoric of shutdown... Big tax cuts for the rich and endless deficits seem built in ...

I wanted a bit more space here, since you guys are teaching me a lot. James wrote: The most common states in your Hilbert spaces don't actually live there: such as position and momentum states. Rigged HS combines a nice space (physically realistic - nice and smooth), with your HS, and the nasty (generalised functions usually) dual of the nice guys. James, I don’t dispute your mathematical point, and perhaps I misunderstood it, but when you said that position and momentum states don’t live in the Hilbert space, I assumed that you meant that it was position and momentum eigenstates that didn’t live in the HS. My point was that real physical systems can’t be prepared in position or momentum eigenstates (i.e., with infinitely precise position or momentum) – they are always superpositions with some uncertainty in both position and momentum. Those superpositions, I think, can and do live in the Hilbert space – or am I totally confused on this point? I hadn’t heard of a “rigged Hilbert ...

According to quantum mechanics, physics takes place in Hilbert spaces. Bizarre as this notion might be, we have learned to live with it as it continues to be verified whenever experimentally tested. Surely, this abstract identification of a physical system with a state vector in Hilbert space will eventually be found to be incomplete, but in a presently unimaginable way, which will involve some other weird mathematical structure. That Nature uses the same mathematical structures invented by mathematicians is a profound mystery hinting at the way our brains are wired. Pierre Ramond in Group Theory: A Physicist's Survey.

I see the great green wave rising and Numenor looks doomed - at least to two more years of utter folly.

It has many times been convincingly demonstrated that I have zero talent for languages. Failed attempts to learn Latin, Russian, German, Spanish, and Japanese litter my history. I, however, am also not one to learn very well from my mistakes, so I am once again attempting Spanish. Rosetta Stone (Latin American) is my main tool here, but I also got this cheap beginning Spanish Reader for my Kindle. I am beginning to suspect that it might not be too current, since its Chapter on the US lists the population as 110 million! Also our money includes \$5,\$10, and \$20 gold pieces as well as \$1000 bills. What is cool is the fact that I can set my Kindle Spanish-English dictionary as primary and use it to quickly define words that I don't know, or find the conjugations of irregular verbs. It has been a lesson, however, in the limitations of the Kindle interface. I find the five-way navigation button a bit clumsy. A touch screen please.