LewisWildermuth: What I'm referring to is not what Thai is talking about. He's got a completely wrong and whacked-out interpretation (no offense) of quantum physics, reading all of it from a single article about a controversial issue that cannot be proved / disproved experimentally under current theory, which no scientist would themselves believe. What I'm talking about is the damage that scientifically valid interpretations can do to Christianity.
For example: the idea that a particle lies in quantum superposition of all its possible states, and then collapses randomly to one of those states once its state is measured (the Measurement Principle) is taken by some scientists to mean that we as observers are in fact the ones responsible for "actualizing" the universe around us by making observations. That's the Indian concept of "maya" in modern, humanistic reinvention. That's why I want to go into quantum physics: to look at all this stuff first-hand and see what a Christian theist can make of it.
To Thai: Honestly, you've got the whole article wrong. I'll go into an indepth explanation of the many-universes idea and show you what it really means.
According to quantum physics, at the subatomic scale a particle may have many possible states at once, a phenomenon known as "superposition". For example, electrons have a property called "spin" which can be either "up" or "down". Before we measure an electron's spin, the electron's spin is both up and down. Simultaneously. But then, when we measure the electron's spin (using a device called a Stern-Gerlach analyzer) we will get only one result - either it is spinning up, or it's spinning down. (In technical terms the wavefunction collapses.) The probability of getting this result is random, distributed according to the physical state the system is in.
Another example is that the position of the electron itself may be randomly distributed within the atom, given certain constraints. There is something called an "electron probability cloud" that mathematicians can construct within an atom and where the cloud is more dense there is a greater possibility of finding the electron. It's something like saying that there's a 40% chance that I am in Malaysia, a 20% chance that I am in Singapore, a 2.56% chance that I am in China ... but before you've "measured" my position and found out where I am, I am mysteriously in Malaysia and Singapore and China and ... all at once. That's how an electron behaves in an atom until it has been detected / observed / measured.
The question is: what exactly has the measurement done? If we measured the electron in spin-up, what happened to its spin-down state? If we measured the electron in a particular place, what happened to it everywhere else? The many-worlds interpretation is that at the exact moment of the measurement, the universe split into two: one where the electron was measured in spin-up, say, and the other where the electron was measured in spin-down.
Here's what you need to know about the model:
1. It's an interpretation. The scientists look at the math they get in quantum mechanics and try to come up with some sort of physical rationale for the results they're getting: this is one of them. There are other hypotheses as well, and they all give the same math, so there's no reason to stick to this particular one at the moment.
2. When interpreted properly this isn't even testable. The scientist who just measured spin-up can't open a door, walk out of one universe, and ask the scientist in the next "Hey, did you measure spin-down?" There is no information exchange between the universes and there is no interaction between them. For all practical purposes there is only one universe to everyone who is inside a particular universe.
3. This phenomenon applies only to interactions at a very, very, very small scale of mass and spacetime. We're talking about atomic radius and electronic mass measurements. By comparison, a typical bullet will have at least 6 * 10^22 atoms (0.1 moles of iron; is my estimate on track?), which would amount to something like 10^25 (10 with 25 zeroes after it) times the mass of an electron. On that scale, the uncertainty in measurement of position is probably anywhere within a few picometers - narrower than the breadth of a hair and certainly not enough to save anyone pointing a gun to his or her head.
In the quantum suicide experiment, the scientist may escape death from the gun because the gun is being triggered by a measurement of an event at quantum scale. But in time he will simply age and die, no matter how many deaths he avoids. The aging processes of our body don't occur at quantum scale (as far as I know) and there's no question of there being a universe where all the right reactions magically occur to keep the scientist alive.
It is an interesting thought experiment, though.
(If you want to read further on this, here are a few keywords you might want to use:
"counterfactual definiteness"
"locality" / "violation of locality" / "nonlocality"
"EPR paradox"
"Bell's theorem" / "Bell's inequality"
But be warned that you will probably get hit by a morass of mathematics. This I've posted is quantum mechanics with kid gloves. The real reasoning behind the Many Worlds Interpretation is heavy and deep and I would recommend you go do some extensive reading before jumping to any more conclusions.)
If it's true, then why do you want to fight it?
