3 ms·

If you have a red ball and a green ball, and you put each in a box, and you randomly pick one of the boxes and give the other to your friend, and you travel a t

If you have a red ball and a green ball, and you put each in a box, and you randomly pick one of the boxes and give the other to your friend, and you travel a trillion miles away and open the box, you instantly know what color ball your friend has. This is just classical correlation. Or a more entanglement-like example, you randomly pick a pair of red socks or green socks from your drawer but don't know what you picked. Then put the socks you picked into two boxes and give one box to your friend. If you go a trillion miles away and look at your sock then your friend is guaranteed to have the same color. This isn't quite entanglement or the Bell pair since it's a mixed state, but the same idea of classical correlation holds and so these kinds of "action at a distance" scenarios aren't impossible from a classical perspective.

gus_massa 4y ago
What you are describing is a "hidden variable" theory. They are disproved by the experiments of the Bell's inequality. It's more weird, much more weird. Let's continue with your experiment about the pair of red or green socks. If you and your friend measure if they are red-or-green, both will get the same results. This can be explained with a classical theory. Nobody disagree with that. The weird part is that you can measure if they are 50%red and 50%green! Can I call it yellow? This makes no sense with classical socks and colors, but it makes sense for quantum particles and other properties. But there are two ways to combine 50%red and 50%green, the technical notation is (R+G)/sqrt(2) and (R-G)/sqrt(2), one with a plus and one with a minus. Can I call them good-yellow and bad-yellow? Or you prefer yellow and blue? In one of the experiments, red means vertical and green horizontal, so one of the combinations is a 45° diagonal like this / and the other is a 45° diagonal like this \. You don't need fancy equipment to measure the combinations, it's just a polarizer rotated 45°. Can I call them yellow and backyelow? I prefer good-yellow and bad-yellow because it's more clear that something weird is happening. If you measure red-or-green and your friends measures good-yellow-or-bad-yellow, then the results will not be correlated. If you got "red", your friend has a 50% probability of getting good-yellow and a 50% probability of getting bad-yellow. There is nothing to explain here. If you and your friend measure if they are good-yello or bad-yellow, both will get again the same results. This can be again explained with a hidden variable theory. Both socks "know" what to say if they are asked if they are red-or-green and what to say if they are asked if the are good-yellow-or-bad-yellow. It get's more interesting when you pick more combinations, like 90%red and 10%green. Can I all it orange? And you can pick 10%red and 90%green. Can I call it lemon? If you measure red-or-green and your friends measures orange-or-lemon, then if you got red, your friend will get orange 90% of the time. And there are good-orange, bad-orange, good-lemmon and bad-lemmon. And there are many more shades of orange-yellow-lemon. But this is getting too long. You can have very smart socks that know what to answer for every possible combination of colors. So if you and your friend ask for the same color, whatever it is, both get the same result. The problem is when you and your friend measure many times using the correct shades of orange and lemon. So the results don't agree 0% neither 100%. You can count how many times you get each combination of results, like (red-vs-dark-orange, or green-vs-bright-yellow), and then add and subtract some of them. If you assume the socks can's communicate with the other socks before answering, then the result of the calculation is smaller then some number. But in the experiments disagree. There are some videos with all of this, with a better and longer explanation by MinutePhysics and 3Blue1Brown https://www.youtube.com/watch?v=zcqZHYo7ONs https://www.youtube.com/watch?v=zcqZHYo7ONs and https://www.youtube.com/watch?v=MzRCDLre1b4&t=0s https://www.youtube.com/watch?v=MzRCDLre1b4&t=0s
- d0mine 4y ago
  It reminds me boxes with 3 green/red lights from the workshop "Quantum Mechanical View of Reality" by Richard Feynman https://youtu.be/ZcpwnozMh2U?t=18m20s https://youtu.be/ZcpwnozMh2U?t=18m20s (there is a statement that 3 is the minimum, 2 lights won't work)
wrycoder 4y ago
Berthlmann’s Socks[0] [0] https://en.m.wikipedia.org/wiki/Reinhold_Bertlmann#Bertlmann’s_socks https://en.m.wikipedia.org/wiki/Reinhold_Bertlmann#Bertlmann...

gus_massa 4y ago

What you are describing is a "hidden variable" theory. They are disproved by the experiments of the Bell's inequality. It's more weird, much more weird. Let's continue with your experiment about the pair of red or green socks. If you and your friend measure if they are red-or-green, both will get the same results. This can be explained with a classical theory. Nobody disagree with that. The weird part is that you can measure if they are 50%red and 50%green! Can I call it yellow? This makes no sense with classical socks and colors, but it makes sense for quantum particles and other properties. But there are two ways to combine 50%red and 50%green, the technical notation is (R+G)/sqrt(2) and (R-G)/sqrt(2), one with a plus and one with a minus. Can I call them good-yellow and bad-yellow? Or you prefer yellow and blue? In one of the experiments, red means vertical and green horizontal, so one of the combinations is a 45° diagonal like this / and the other is a 45° diagonal like this \. You don't need fancy equipment to measure the combinations, it's just a polarizer rotated 45°. Can I call them yellow and backyelow? I prefer good-yellow and bad-yellow because it's more clear that something weird is happening. If you measure red-or-green and your friends measures good-yellow-or-bad-yellow, then the results will not be correlated. If you got "red", your friend has a 50% probability of getting good-yellow and a 50% probability of getting bad-yellow. There is nothing to explain here. If you and your friend measure if they are good-yello or bad-yellow, both will get again the same results. This can be again explained with a hidden variable theory. Both socks "know" what to say if they are asked if they are red-or-green and what to say if they are asked if the are good-yellow-or-bad-yellow. It get's more interesting when you pick more combinations, like 90%red and 10%green. Can I all it orange? And you can pick 10%red and 90%green. Can I call it lemon? If you measure red-or-green and your friends measures orange-or-lemon, then if you got red, your friend will get orange 90% of the time. And there are good-orange, bad-orange, good-lemmon and bad-lemmon. And there are many more shades of orange-yellow-lemon. But this is getting too long. You can have very smart socks that know what to answer for every possible combination of colors. So if you and your friend ask for the same color, whatever it is, both get the same result. The problem is when you and your friend measure many times using the correct shades of orange and lemon. So the results don't agree 0% neither 100%. You can count how many times you get each combination of results, like (red-vs-dark-orange, or green-vs-bright-yellow), and then add and subtract some of them. If you assume the socks can's communicate with the other socks before answering, then the result of the calculation is smaller then some number. But in the experiments disagree. There are some videos with all of this, with a better and longer explanation by MinutePhysics and 3Blue1Brown https://www.youtube.com/watch?v=zcqZHYo7ONs https://www.youtube.com/watch?v=zcqZHYo7ONs and https://www.youtube.com/watch?v=MzRCDLre1b4&t=0s https://www.youtube.com/watch?v=MzRCDLre1b4&t=0s

d0mine 4y ago
It reminds me boxes with 3 green/red lights from the workshop "Quantum Mechanical View of Reality" by Richard Feynman https://youtu.be/ZcpwnozMh2U?t=18m20s https://youtu.be/ZcpwnozMh2U?t=18m20s (there is a statement that 3 is the minimum, 2 lights won't work)

wrycoder 4y ago

Berthlmann’s Socks[0] [0] https://en.m.wikipedia.org/wiki/Reinhold_Bertlmann#Bertlmann’s_socks https://en.m.wikipedia.org/wiki/Reinhold_Bertlmann#Bertlmann...