The bible is Nielsen and Chuang's Quantum Computation and Quantum Information: http://www.amazon.com/Quantum-Computation-Information-Cambri... See also these resources in Nielsen's blog: http://michaelnielsen.org/blog/writing/
That looks interesting. Does one need to have a background in QM before reading this? If yes, what would you suggest as a good read on basics of QM?
Let me double-check it today, but I think that it introduces the basics of QM. You need to know some linear algebra though.
I've always wanted to study quantum mechanics because of this very "entanglement". Can people please post recommendations on good resources/books on the topic for a person like me having no solid experience with physics(except college level courses)?
I'm extremely ignorant, but I've enjoyed Brian Greene's books and I'm currently reading The Fabric of the Cosmos.
I've no idea how accurate it is or if I'm even understanding it. He could literally flip around the explanation and I'd have no way of verifying. Yet I still find it very satisfying to read.
I have a question. I just went to a source of physical (quantum) randomness http://www.randomnumbers.info/ and I'm giving you a random number between 0 and 10,000 which I've just generated there. Here it goes: 6296. Ok. Now that light cone had finally reached you. And you (neurons in your brain to be precise) are thoughtfully entangled with that random event (outcome), now in your past. Now imagine the following. A f…
1. When you tell me the result 6296, my brain becomes only classically correlated with it, not entangled. The source of randomness (whether you got it through a quantum experiment or not) does not matter here, as I am only receiving the classical information. 2. After I forget it completely, all I can say is that I (my current body) am not correlated with the event --- but there is no reason to think of the event as…
When you say you receive classical information as the outcome of that experiment, what's an example situation in real life when you receive quantum information and do indeed get entangled with it (I mean if at all such a situation ever arises)?
And what if you would move away from that surrounding matter? Or, say launch it away with near light speed, so it would get behind the horizon at some point. How is that situation different from the one in which I've just generated the number and the light cone haven't reached you yet?
> And what if you would move away from that surrounding matter? You can't :) By surrounding matter I meant the rest of your body that isn't neurons, as well as the environment outside your body.
Can't I? What if the state of these poor remaining neurons and the body is scanned, encoded as polarization of a bunch of photons and sent to a receiver far far away? In that case good old environment would definitely end up behind the cosmic horizon.
1. When you tell me the result 6296, my brain becomes only classically correlated with it, not entangled. The source of randomness (whether you got it through a quantum experiment or not) does not matter here, as I am only receiving the classical information. 2. After I forget it completely, all I can say is that I (my current body) am not correlated with the event --- but there is no reason to think of the event as…
> So for my current body, the event never happened, although you might have written the number down and will always remember it. In other words, the past is relative. So where this event would be for you ? In the future? Again? Yes. Past is definitely relative. Special relativity is very specific about that ;)
The event is neither in my causal past (it has no influence over the current state of my body) nor in my causal future (I have no influence on it). It's simply uncorrelated with me. If now you remind me of the number again, it becomes part of the causal past of my (new) body. Analogy: if a dwarf dies in a fortress far far away and you don't hear about it, her death is neither in your past nor in your future. You know nothing about her state: in QM, you would say that your brain and her are in an uncorrelated, product state, something like |dunno><alive|)/2 .
The x stands for \otimes, tensor product.
Is this really new? IANAP, but I clearly remember being taught about the Arrow of Time as a probabilistic/thermodynamical phenomenon even in high school and I also read similar explanations that involved causality and probability theory without refering to quantum entanglement . Is the "quantum" bit even needed there for anything?
Probability theory is how we model the arrow of time, but it's not a physical mechanism by which the arrow of time occurs. The article covers this distinction.
Isn't the classical definition of Arrow of time is from the system with less entropy to a system with more entropy? What is lacking in this definition of Arrow of time that we need to take it to Quantum level?
> And what if you would move away from that surrounding matter? You can't :) By surrounding matter I meant the rest of your body that isn't neurons, as well as the environment outside your body.
Can't I? What if the state of these poor remaining neurons and the body is scanned, encoded as polarization of a bunch of photons and sent to a receiver far far away? In that case good old environment would definitely end up behind the cosmic horizon.
Then you have implemented teleportation and we have new problems to think about!
Probability theory is how we model the arrow of time, but it's not a physical mechanism by which the arrow of time occurs. The article covers this distinction.
Isn't the classical definition of Arrow of time is from the system with less entropy to a system with more entropy? What is lacking in this definition of Arrow of time that we need to take it to Quantum level?
How the entropy spreads on a microscopic level, rather than a statistical one.
I thought it was the second law of thermodynamics that already explained the arrow of time? Well, that and friction?
The second law is an empirical statement. This entanglement based approach is an attempt to understand the underlying physical mechanism that controls the spread of entropy. If this picture is right, the next question is what is the physical process behind entanglement.
Seeing this article is rather bittersweet. I came to a similar conclusion in my college years but I never pursuit it further. Taking Quantum Physics in college was a life changing experience and it reshaped how I viewed the world. I was always obsessed by time and one afternoon it became clear. I explained my variation not as a cup of coffee but a handful of dice. Essentially every tick of time is rolling these dice.…
There's good reason you got the most amount of resistance from physics majors. Intuition won't help you with theoretical physics. The only understanding is that achieved through studying the math in depth. Unless you've developed the formalism (in which case you'd be the subject of this article), you haven't reached any conclusions. Hate to break it to you. There's no such thing as pedagogical theoretical physics- no…
How did you assume I took quantum chemistry in college and was asked by my prof to join his lab without having any math background, or to be the #1 student in my physics class of 300, or was a member of 3 person team that won our state math championship. Not to mention scoring high enough to make it to the chemistry Olympiad, but ultimately being rejected once realizing US citizenship was required....