# I Explaining quantum entanglement

#### davidge

Usually, people trying to explain quantum entanglement, uses the scenario where two particles were created and one of them ends up very far away from the other, and then a measurement is made, etc.

The problem I see is that they seem to assume the two particles are classical particles, like two balls. So the very beggining of the explanation seems to be wrong, for this reason. The following video shows the situation I'm describing here.

But the conclusion emerging from such explanation is correct, namely what Quantum Entaglement causes. So, is that explanation okay even that it describes the form of the particles incorrectly?

Related Quantum Physics News on Phys.org

#### newjerseyrunner

For me, it's easiest to explain with math. Not QM math, but regular simple algebra.

If you have two entangled particles, they are described by a single formula: f(x).
Now define one of the particles with a definite value: g(x).
This forces the value of the other particle to be (f-g)(x).

There is nothing else it can be, and no information has to be sent between the particles for it to happen.

#### davidge

I totally agree with you.

The problem arises when you try to explain something that only makes sense with mathematics, to people who have not learned the mathematics. In such case, I wonder if it's better not to talk about the given phenomenum at all.

S

#### sirios

For me, it's easiest to explain with math. Not QM math, but regular simple algebra.

If you have two entangled particles, they are described by a single formula: f(x).
Now define one of the particles with a definite value: g(x).
This forces the value of the other particle to be (f-g)(x).

There is nothing else it can be, and no information has to be sent between the particles for it to happen.
your its mathematics and good but fails in certain situations of the quantum entanglement, it is worth noting that it is not only the property of spin that interweaves but also others such as the wave function and etc ... as several articles recently published. I think a lot of people get confused in this respect.[emoji5]

S

#### sirios

I totally agree with you.

The problem arises when you try to explain something that only makes sense with mathematics, to people who have not learned the mathematics. In such case, I wonder if it's better not to talk about the given phenomenum at all.
I agree

T

#### Thuring

What bothers me is, in the video above, she says that "each ball would be red and blue". I believe she should say "each ball COULD be red or blue". But, this may be a philosophical statement, not allowed on a physics forum ... lol

Also, measurement of an entangled pair doesn't really break the entanglement (collapse), it increases the entanglement of the pair with the measurement system. Collapse is just a simplification.

But, I've been wrong often ...

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#### Strilanc

Normally the channel 'Sixty Symbols' is good, but that particular video is terrible. Don't pay attention to anything it says, particularly the stuff about using entanglement to communicate (i.e. the whole thing).

#### PeterDonis

Mentor
PF discussion should be based on acceptable sources; the video linked to in the OP is not. Thread closed.

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