An entangled quantum state is one which cannot be written as the tensor product of two pure states. Imagine I prepare two objects whose states are quantum-entangled; suppose they either both say ‘0’ or ‘1’, but they can’t disagree, and we don’t know beforehand. We each take an object and go our separate ways.
A day later, I decide to “measure” the state of my object. This basically just means I get to find out whether it says ‘0’ or ‘1’. I find out it says ‘0’. This allows me to deduce that when you measure your object, yours will also say ‘0’.
But this isn’t sending information ‘faster than light’ or ‘instantly’ or anything strange like that. The quantum superposition was between the |0⟩⊗|0⟩ and |1⟩⊗|1⟩ states, and when I measured the state of my object, I “found out” which world I was in. Then, I inferred what you would see if you peeked.
We can construct a classical example of a similar kind of “faster-than-light” inference. Consider a closed system of two objects of equal mass, which were earlier at rest together before spontaneously pushing off of each other (maybe we intervened to make this happen, whatever). We aren’t sure about their velocities, but when we learn the velocity v of one object, we immediately know that the velocity of the other is −v by conservation of momentum. Under these assumptions, the velocity of one object logically determines the velocity of the other object, but does not cause the other object to have the opposite velocity.
(I’m not a physicist, but if you want to learn the math of basic quantum theory, I recommend Nielsen and Chuang)
Interesting. It seems that although entanglement breaking the speed of light is technically untrue, we could make these inferences ‘as if’ they were quicker than the speed of light. Instead of measuring the differences between the states of the two items, we’re able to make that inference instantly. So although it’s not faster than the speed of light, our measurements operate as though they were.
I think my misunderstanding comes from the inability to put this operation into practice. But as per my original argument, if electrons were simply more concentrated waves which behave like particles, determining a full theory of everything that incorporates the quantum is possible. Computing power aside, having these roadblocks in place do not seem sufficient to keep our current theoretical knowledge as is. The most famous example was the conventional wisdom of the ether, which general relativity broke. Ignorance is bliss.
An entangled quantum state is one which cannot be written as the tensor product of two pure states. Imagine I prepare two objects whose states are quantum-entangled; suppose they either both say ‘0’ or ‘1’, but they can’t disagree, and we don’t know beforehand. We each take an object and go our separate ways.
A day later, I decide to “measure” the state of my object. This basically just means I get to find out whether it says ‘0’ or ‘1’. I find out it says ‘0’. This allows me to deduce that when you measure your object, yours will also say ‘0’.
But this isn’t sending information ‘faster than light’ or ‘instantly’ or anything strange like that. The quantum superposition was between the |0⟩⊗|0⟩ and |1⟩⊗|1⟩ states, and when I measured the state of my object, I “found out” which world I was in. Then, I inferred what you would see if you peeked.
We can construct a classical example of a similar kind of “faster-than-light” inference. Consider a closed system of two objects of equal mass, which were earlier at rest together before spontaneously pushing off of each other (maybe we intervened to make this happen, whatever). We aren’t sure about their velocities, but when we learn the velocity v of one object, we immediately know that the velocity of the other is −v by conservation of momentum. Under these assumptions, the velocity of one object logically determines the velocity of the other object, but does not cause the other object to have the opposite velocity.
(I’m not a physicist, but if you want to learn the math of basic quantum theory, I recommend Nielsen and Chuang)
Interesting. It seems that although entanglement breaking the speed of light is technically untrue, we could make these inferences ‘as if’ they were quicker than the speed of light. Instead of measuring the differences between the states of the two items, we’re able to make that inference instantly. So although it’s not faster than the speed of light, our measurements operate as though they were.
I think my misunderstanding comes from the inability to put this operation into practice. But as per my original argument, if electrons were simply more concentrated waves which behave like particles, determining a full theory of everything that incorporates the quantum is possible. Computing power aside, having these roadblocks in place do not seem sufficient to keep our current theoretical knowledge as is. The most famous example was the conventional wisdom of the ether, which general relativity broke. Ignorance is bliss.