So this is going to sound weird, I was looking up Nyan Cat on Youtube and got lost in the different variations of it, one of which includes the Schrodinger's Cat. Now I have seen the term on here before and so got curious about it. I Googled the term and read about it on Wikipedia. Apparently it is a thought experiment dealing with a paradox that has to do with quantum physics, at least that is how I understand it. I am wondering if someone could explain it a little bit better and in terms that I can understand if possible.
I love science and stuff like this does fascinate me, but I have never taken any of the "higher sciences" like physics or chemistry due to my learning disability in math (My math skills are that of third grade level.) I wanted to but the school system is lazy when it comes to dealing with kids with learning disorders.
So please be kind to me, I know many of you are well versed in the sciences and know a lot more than I do and I feel dumb for even asking this.
I'm on Skype: ElmNehmara
A powerful double-lie verbal disinformation bomb
I'm probably going to be horrible at explaining this, but I can give it a try. There are a couple of things you need to understand about quantum physics before you can understand Schrodinger's Cat. Firstly, that particles at a quantum level exist differently when they are observed vs. when they are unobserved. If, say, an electron has not been observed or measured, then in exists in what is called a "superpostion". What this means is that it exists in all possible states at once. Once it has been observed, wave-function collapse occurs and the electron now exists in a single state.
This probably makes no sense, but Schrodinger's Cat actually helps make it more clear. The idea is there is a hypothetical cat in a box. Going by the laws of quantum mechanics, the unobserved cat exists in all possible states, right? So now picture that there is a dish or some sort of dispenser that has poison in it. It is possible for the cat to drink the poison, and once that happens the cat will die. Once possible state for the cat to occupy is being alive, and another is being dead. If it occupies all possible states, then this means that the cat must be both alive and dead at the same time. I can try to clarify it further if you want, or maybe someone else can explain it better than I can. I suck at explanations. ;D
Post by Mlle Antéchrist on Nov 4, 2011 23:10:26 GMT -5
Schrodinger's Cat is a thought experiment dealing with quantum superposition. It's a difficult concept to verbalize, but the simplified explanation (based on my own admittedly amateur understanding of quantum theory; someone please correct me if I get anything wrong) is that a particle exists in all possible states unless observed or measured. In the Schrodinger's Cat scenario, we place a cat in a box with a device that contains a radioactive substance. If a single atom in this substance decays, the device breaks open and immediately kills the cat. Because we can not observe or measure the particles within the box, they exist in all possible states; therefore, the atoms in the substance are considered both decayed and not decayed and the device containing the toxins can be said to be both broken & intact, thus rendering the cat both alive and dead.
An even simpler explanation is that quantum physics is fucking weird.
Post by DarkfireTaimatsu on Nov 4, 2011 23:24:10 GMT -5
Tai explanations: understanding the stupidest ways. =3
You change outcomes by measuring them. That's how magic quantum physics works. Therefore, you don't know if the cat in the box is alive or dead without observing it. Once you observe it, it's one or the other, but without observing, all the possibilities are open. Thus when unobserved, it's both. Tada!
Also, the hotness version:
There once was a unicorn who would shove His rainbows around like a dove "Always I'll be with you And then make-believe with you Harmony, Harmony, oh love"
I thought it was more of a "we can't say what state it exists in because observing it changes the state."
Yes, in the sense that all particles present will fall into a single state once observed or measured.
Also: Something I should have been clearer about is that we're dealing with probabilities in this particular thought experiment, meaning that we design it in such a way that there's a 50% chance that one of the atoms has decayed, opening the device and killing the cat.
Again, this is all based on my own amateur understanding -- it's quite possible that I'm incorrect about any number of aspects.
This is actually a very important point. In order to observe something, something else must interact with it. We find that strange because on the macro scale we have photons constantly bombarding things, so while we personally aren't interacting with the objects we look at the photons are. The smaller you get the more impact this interaction necessary to observe becomes.
At the quantum level this becomes magnified, as you don't have anything smaller than what you're trying to observe to observe with. There is absolutely no way to observe what you want without a large interaction, meaning you drastically change the state of what you're observing when making your observation.
Of course, this doesn't explain quantum superposition, or even mean that you would need quantum superposition for observations to alter what you're observing. This is when you also need to understand the Heisenberg uncertainty principle. I remember my father explaining it in that you can know where something was and when it was there, or you can know it's velocity (it's speed and direction of travel), but never both of those things. This is also not a limitation on our ability to observe quantum stuff, but rather it is a fundamental aspect of quantum stuff.
Of course, the Heisenberg uncertainty principle is only tangentially related to Schrödinger's cat, but it is important for understanding the principles behind the unlucky cat in that box.