3 ms·

Would this be correct: You take a marble out of the bag without looking and give the bag to your friend. Your friend also take a marble out of the bag without

Would this be correct: You take a marble out of the bag without looking and give the bag to your friend. Your friend also take a marble out of the bag without looking. Both you and your friend now look at your marbles and they will both be the same colour every time. You can't send information this way because you don't know the colour until your friend has already taken a marble too. You cannot do anything with the fact that they are both the same colour unless you can control or know the colour in advance, which you can't. When you look at your marble and see that its red, your friend looks at their marble and sees that its red, all you know is you both have red marbles. The only way to send information would be if you took multiple marbles, looked at them until you found one that's blue (say, the third) and then told your friend to look at the third marble. But since you can't tell your friend to do that without using traditional information sending, you may as well just tell them that the third marble is blue and forego the marbles altogether, you're not sending faster than light information anymore anyway.

abetusk 5y ago
This is, as stated, again classical correlation. Where have you used the fact that the observation of one marble affects the observation of the other? Your above experiment could be done with just a simple bag and two marbles without the need to contort yourself around looking or not looking. Here's an attempt to fix your example: You and your friend each take a marble out of the bag, go very far away from each other and make an agreement to look at the marble at a given time in the future and not before or after. If you look at the marble before or after the agreed upon time, the result will be random. If you both look at it at the exact same time, the marbles will be equal. Maybe you have many bags of marbles so you can do this experiment many times over. You decide to fudge some results by looking at some marbles before or after the agreed up time. You and your friend will see the same marble color for all marbles seen at the agreed upon time and potentially different marble colors for ones that were opened at different times. How do you tell if your friend fudged the result? How does your friend tell if you fudged the result? The marbles have a 50-50 distribution of being red and blue, and the extra probability of it flipping to one color or no if it's fudged is lost in that noise. If you then reconvene and compare notes on what you observed, you can see a very clear correlation of which experiments were fudged and which weren't but now you've done the work of getting in close proximity and destroyed any chance of faster than light communication. I'm not a physicist and I don't have a deep knowledge of this stuff. This is a toy example and may or may not be a valid reduction of quantum entanglement. The above explanation is my current understanding, which could be wrong.
- dkersten 5y ago
  > Where have you used the fact that the observation of one marble affects the observation of the other? Here: "they will both be the same colour every time" > Your above experiment could be done with just a simple bag and two marbles without the need to contort yourself around looking or not looking. They won't be the same colour every time, despite being able to be either colour prior to looking. But ok, I see what you're saying in the attempted fix. Thanks.

abetusk 5y ago

This is, as stated, again classical correlation. Where have you used the fact that the observation of one marble affects the observation of the other? Your above experiment could be done with just a simple bag and two marbles without the need to contort yourself around looking or not looking. Here's an attempt to fix your example: You and your friend each take a marble out of the bag, go very far away from each other and make an agreement to look at the marble at a given time in the future and not before or after. If you look at the marble before or after the agreed upon time, the result will be random. If you both look at it at the exact same time, the marbles will be equal. Maybe you have many bags of marbles so you can do this experiment many times over. You decide to fudge some results by looking at some marbles before or after the agreed up time. You and your friend will see the same marble color for all marbles seen at the agreed upon time and potentially different marble colors for ones that were opened at different times. How do you tell if your friend fudged the result? How does your friend tell if you fudged the result? The marbles have a 50-50 distribution of being red and blue, and the extra probability of it flipping to one color or no if it's fudged is lost in that noise. If you then reconvene and compare notes on what you observed, you can see a very clear correlation of which experiments were fudged and which weren't but now you've done the work of getting in close proximity and destroyed any chance of faster than light communication. I'm not a physicist and I don't have a deep knowledge of this stuff. This is a toy example and may or may not be a valid reduction of quantum entanglement. The above explanation is my current understanding, which could be wrong.

dkersten 5y ago
> Where have you used the fact that the observation of one marble affects the observation of the other? Here: "they will both be the same colour every time" > Your above experiment could be done with just a simple bag and two marbles without the need to contort yourself around looking or not looking. They won't be the same colour every time, despite being able to be either colour prior to looking. But ok, I see what you're saying in the attempted fix. Thanks.