h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I never thought I'd see an article on Shrödinger's Cat that was actually accurate or in any way dealing with the facts instead of the popular mythology surrounding the matter...

I'm impressed

Definitely Edited Guide material.

26199

Well it's certainly better thant the other 4 entries (non-approved) the two "best" ones being;

http://www.h2g2.com/A306569
http://www.h2g2.com/A173909

And it seems to tie in with what I learnt on my BSc Physical Science degree (Failed in year 1)

Go for it - not that my opinion counts for muck

Hawke

Here is a nice link to Scientific American who published some nice limericks on the subject:

http://www.sciam.com/2000/0500issue/0500editors.html

Nice article. On the subject, I would argue that the cat does not qualify as an observer (cat eyes aren't THAT sensitive) but the sensing device does.

but since the sensor is measuring a change in the quantum state of an electron and the sensor itself is, supposedly, made UP of electrons, wouldn't the electrons making up the detector be subject to the same quantum rules as the one trapped in the box. and therefore need to be observed just like the 'trapped' electron would?

Hmmm...


Triv.

But besides that, thanks all for paying attention to this forum. I really appreciate it.

Triv (again)

If you took that sort of logic further, you could say that the electrons that carry the information from our eyes to our brains are subject to the same fault, at which point, you could say that nothing in the universe is qualified to be an observer.

And there, my friend, you have come upon the crux of the matter. Schrödinger wanted to proove the idiocy of quantum physics, and that was the next step he came to as well. But then again...quantum physics WORKS, so something must've changed. Search me as to what tho.

Triv

But every potential observor possesses their own universe, do they not? The cat-killing device observes, and in its universe, the waveform collapses. Yet to, say, Tom Hanks, the waveform hasn't collapsed. In fact, if he doesn't know there's such a thing as Schroedinger's cat, that existence is an uncollapsed waveform.
But how do we capture this principle and power a PC with it?

Hmm. Cat powered PCs.

Well, conceiveably you could use an electron as a true/false switch (since that's all a computer is anyway--a machine designed to interpret a long string of 0's and 1's) but i don't know how it'd work. Supposedly, there'd have to be a device inside the computer tha'd be able to collapse the waveform of each electron on way or another, but...

ths is making my brain hurt...
Tom Clancy (of all people) talks about a quantum computer in one of his Op-Center books, but I can't remember which one...it was set in England, I know that.

Triv

I heard about quantum computing in an article in my local newspaper last summer. I think, at this point, that the largest (electron-wise) such computer contains four electrons. Now, I'm sketchy on why the next paragraph is true, but here goes --

Please hang with me. This may be a bit slow; I haven't written this before.

Electronic computers operate with binary code, that is, through on/off switches. Each bit (a switch) has two options; thus, each bit multiplies the previous number of possible binary numbers by two.

To illustrate, the possibilities for progressive amounts of bits:
One bit: (0) (1)
Two: (00) (01) (10) (11)
Three: (000) (001) (010) (011) (100) (101) (110) (111)
And so on. Computer space is reported in bytes, sets of eight bits. A personal computer contains anywhere from under 500 million bytes (such as my eight-year-old computer) to 40 billion (this is with the American system -- that's 40,000,000,000 bytes). That is, 40 gigabytes. But wait! That huge amount of space isn't enough for some databases, programs, and really ripping games. Now we're talking terabytes. Very expensive.

Now remember the multiplicative progression, times two. Also note that RAM -- operating power -- is only under 100 megabytes. Tiny.

Now the interesting part, the part that I can't explain until I do some more reading:
With quantum computers, each new bit SQUARES -- that is, raises to the POWER of two -- the original number of possibilities. Don't ask me how -- that's what I don't know yet. So, with two bits, you still have four possibilities. With three, you have 16. With four, 64. With five, you have to get out a pocket calculator. Now imagine one megabyte. Huge possibilities, eh?

The above phenomenon has something to do with the fact that each electron's spin (the electrons are what's storing these possibilities) is in BOTH directions until it is examined and the waveform collapses. Thus, the world on such a tiny scale follows Schroedinger's cat in an extremely real way.

I suppose I should submit this as an entry.

One last note -- Michael Crichton (who is, arguably, no more classy than Clancy) uses quantum physics to explain his time travel device in the novel "Timeline." I do reccomend reading the book -- it's a great example of Crichton's synthesis of scientific theory and real-world background information.

yes, you SHOULD post that as an entry. Wow.


And I've read timeline, but I always assume that when popular writers talk about stuff like that they just want it to SOUND good.The physics is a secondary concern.

Anyone out there seen "Copenhagen" yet? It's a play on broadway currently that focuses on Neils Bohr. It's supposed to be amazing...

Oh, and speaking of plays, another good one that skirts the boundariesof physics it Tom Stoppard's "Arcadia" or, for that matter, anything Stoppard's ever written.

Triv

Indeed, Crichton's trying to make it all sound good -- which is why he glazes over the fictional part between the slit experiment and the time machine. He doesn't even consider the other implications of the famous two-slit, four-shadow experiment.

Yeah, I found it kinda hard to believe Crichton--he spent so much time explaining the artifice of the time machine in order to make it plausible he missed some of the intricacies. I would've liked to see how he would've dealt with the four shadow experiment, but he's not a science writer, he's a fiction writer. Only the amazingly good can combine the two.

Whenever I read that kind of stuff it seems to me that the author picked up a book on some esotheric realm of physics and thought it'd be good filler for a novel without actually bothering to understand the concepts.

Some people call it 'inspiration', others call it "exploiting a popular idea"

Running out of ideas, maybe?

Triv

He does actually talk to people in the areas of science that he writes about, and considering that he has a bibliography at the end of his book I think you ought to give him a little more credit. Especially since it's fiction, and doesn't have to have any basis in fact.