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

The largest problem I've seen with this theoretical experiment is the fact that the cat itself observes it's own state constantly, and puts quite a large ammount of concern into knowing wether it is alive or dead I might add, thus preventing a cat from exising in a simplistic quantum state (alive and dead) as opposed to the combination of the quantum states of every cat particle that makes it up.

This has bothered me for several years now because I would quite like to make this a practical excersize as I'm not particularly fond of cats and I've partialy worked out some of the difficulty. If you were to set the trigger mechanism up slightly differently to where time was a known variable instead of a range during which the particle might or might not be emmited it would help a bit. To this end I suggest firing a single photon at a 90 degree light splitter at a measurable instant in time and having said photon either trigger or not trigger a device to used to put the cat into the death state.

Now we still have the problem of the cat observing itself and spoiling the state. Were the experiment able to be preformed in a vacuum and with the cat being cooled to absolute zero at the instant when death is in question the cat, theoreticly, could exist in a state of both life and death. Unfortunately cats are quite unable to get on with their normal kitty lives after being subjected to both a vacuum and being cooled to absolute zero, so it would quite definately be in the death state.

If you have any ideas on how to remedy my delima please feel free to let me know.

The solution to your problem is simple, replace the vacuum with a cat box, and replace the proton with some 12 bore shot, use a nice Winchester double barrel shotgun, aim the shot gun and a comfortable angle into the cat box, and activate the trigger mechanism, the lead shot will definately turn the cat in its dead state, hence solving the problem. The beauty of this solution is that the cat will observe pretty much every thing.

The Schroedinger's Cat model, as I understand it, is merely an approximation of the uncertainty principle, meant to explain and (to some degree) make simple the concept.

The point is to make the cat unobservable to people outside the box, therefore rendering us unable to discern whether the cat is alive or dead. The cat is allowed to be aware of its state, just as we are allowed to have some rough idea of where we are and where we're going, and just as an electron (if electrons are self-aware?) are allowed the same rough idea.

Your suggestion of making time a fixed interval doesn't quite sit well with me; as far as I can gather, making time a factor in the experiment would reduce the absolute uncertainty of the cat being alive or dead by restricting the amount of time in which the photon in question could trigger the death-device.

x·v Æ k/m

This is the basic formula for uncertainty, wherein the uncertainty in position (x) multiplied by the uncertainty in velocity (v) is always greater than a constant (k) over the mass of the object in question (m). Time only enters into the equation as a function of the estimated uncertainty in displacement over time. Once a photon is released which may (or may not) trigger the device, time is not an issue, simply probability.

Just a thought process, a hazy one at that; it's 4 AM and I wish the bars here didn't close so bloody early.

Ok, for the first point, the Cat-in-a-box thought experiment was created my Scroedinger (sp?) to point out how ludicrous the idea of superposition of eigenstates is, not to make it simpler to understand.

Secondly, the experiment has been performed, and it was discovered that the cat could in fact be in one of three super-imposed states - in the box and dead, in the box and alive, and the unpredicted result of alive and in the janitor's cupboard - it appears that the janitor didn't like the idea of the poor cat being gassed just to demonstrate something which was supposed to refute, or at least question the ideas it was based on.

Thirdly, I believe that the experiment is in fact possible if it is possible to totally isolate the system containing the cat, rendering it impossible for it to affect the rest of the universe, and vice versa. OK, that's quite difficult to do as well, but it works on the idea that then there is no external indication as to whether the cat is dead or alive, so from your point of view, it is in a superposition state consisting of the eigenstate where the cat is alive, and the one where it's dead, with coefficients depending on respective probabilities. It is interesting to note, that, from the cat's point of view, the rest of the universe also enters a superposition state, which could, for example, be desribed as a sum of the states in which 1) the rest of the universe exists, and 2)it doesn't, or any number of other eigenstate sets. ie, the state of the cat from your point of view is as unknown as the state of the universe from the cat's.

here's how i once wrote it up:

Heisenberg's Uncertainty Principle/Schrodinger's Cat

Couples engaged in a romantic relationship usually have large amounts of physical contact with one another. However, when someone seems near, physically, to them, they begin acting normally again, even if blushing a bit. We therefore see that the couple has a probability wave function associated with them. Whenever an observer goes to see what they're doing, their wave function collapses and becomes a stable state. This is exactly the same concept that is illustrated in the Schrodinger's cat thought experiment. In this case, a cat is placed in a box along with a Geiger counter, a bottle of poisonous gas hooked up to the Geiger counter, and a radioactive particle source. If the source decays and triggers the counter, the poison is released and the cat dies. However, if the source doesn't decay, the cat lives. This is only a thought experiment, and no cats have ever been killed in one of these experiments. However, be that as it may, you have to open the box to see if the cat is still alive. If you do this, however, you collapse the probability waveform into one of two states: either the cat is alive or dead. While the box remains closed, the cat could be either alive or dead, but once opened, the cat has to choose a state. Just the same, the couple in question may or may not be making out, but when approached, they either will or will not be doing so.

The experiment will work for any animal, not just cats - as long as you have a big enough box for whatever animal it is. I think using a cat is bad idea since they have nine lives - this adds extra complications to the experiment.

Well, all lives span a ten-dimensional state space (9 lives + death).

Oooh... I love the Janitors cupboard state. A perfect example of "tunneling".

That thing about the cat and the cupboard-wasn't that in Dirk Gently's Holistic Detective Agency? I thought he just made that up for a joke.

If a cat is shut in a box for a certain amount of time with a radioactive ion etc, and the lid is opened, the cat can be in any of 4 states
1.alive
2.dead
3. furious
4.tunneling out

Terry Pratchett devotes a chapter to Heisenberg Cat(s). It's impossible to tell if there is one or many as a side effect of the experiment. You may have one (it). They are (it is) recognisable by their(its) tendency to get into and out of places that they(it) shouldn't be able.

I believe I have an iteration of the Heisenberg cat. Its ability to tunnel into my bedroom after I've quadruple checked that it is safely sitting on the sofa in the living room before I shut the bedroom door is proof.

He especially likes doing this trick right before I get home from a weekend trip so as to make me feel guilty about the 3 days he pretended to be locked in my bedroom.