Does the moon exist when no one is looking at it?

[Pinball1970]

Just a side note because I do not think this has been mentioned yet.
All the physics people will excuse me hopefully, I will try and get this right.

"Does the moon exist if we don't look at it?"
It was Einstein who said the during his debates with the giants of Quantum Mechanics.
This particular one with Niels Bohr.

The issue being that the micro world behaves differently when being observed.
A particle acts like a wave when it is not observed and a particle when it is.
Taking all paths to a detector from a photon emitter or just one.
This is weird enough today so it was to Einstein in the 1920s.

The act of observation assigns specific values.

Decoherence is the explanation usually given but I'll leave it there.

 

[Pinball1970]

Пин, а что такое существование?

That is too general a question for me. I prefer physics to philosophy.

 

[ольга]

Just a side note because I do not think this has been mentioned yet.
All the physics people will excuse me hopefully, I will try and get this right.

"Does the moon exist if we don't look at it?"
It was Einstein who said the during his debates with the giants of Quantum Mechanics.
This particular one with Niels Bohr.

The issue being that the micro world behaves differently when being observed.
A particle acts like a wave when it is not observed and a particle when it is.
Taking all paths to a detector from a photon emitter or just one.
This is weird enough today so it was to Einstein in the 1920s.

The act of observation assigns specific values.

Decoherence is the explanation usually given but I'll leave it there.

Наблюдатель взаимодействует с частицей при наблюдении, поэтому волна и коллапсирует. Это и ежу понятно. Тут нет магии.

 

[ольга]

That is too general a question for me. I prefer physics to philosophy.

Это и есть физика. Мы ведь изучаем физические объекты, т.е. те, которые существуют в нашем понимании. Это основы, которые мы должны понимать, если не хотим построить здание без фундамента.

 

[Pinball1970]

Наблюдатель взаимодействует с частицей при наблюдении, поэтому волна и коллапсирует. Это и ежу понятно. Тут нет магии.

You are fully equipped to understand QM?
Ok.

 

[Pinball1970]

Это и есть физика. Мы ведь изучаем физические объекты, т.е. те, которые существуют в нашем понимании. Это основы, которые мы должны понимать, если не хотим построить здание без фундамента.

"What is existence" to me is philosophy.

 

[ольга]

You are fully equipped to understand QM?
Ok.

Пин, волну, с которой наблюдатель не провзаимодействовал, он просто не увидит.

 

[ольга]

"What is existence" to me is philosophy.

Вы путаете физику и инженерию. Раньше у физиков была степень по философии. Разве сейчас нет?

 

[Pinball1970]

Пин, волну, с которой наблюдатель не провзаимодействовал, он просто не увидит.

There is a lot about QM that is very strange and has kept philosophers and physicists busy since it was discovered. There is nothing obvious about it.
This is why there is not one agreed interpretation of the Theory.

 

[ольга]

There is a lot about QM that is very strange and has kept philosophers and physicists busy since it was discovered. There is nothing obvious about it.
This is why there is not one agreed interpretation of the Theory.

Да она просто не доделанная до конца, эта теория. Вот почему всегда нужно знать основы явлений, а не действовать "методом научного тыка".

 

[Pinball1970]

Да она просто не доделанная до конца, эта теория. Вот почему всегда нужно знать основы явлений, а не действовать "методом научного тыка".

No that is not what this means. The Theory describes the microscopic world in exquisite detail.
The interpretation really is what it actually means.

 

[ольга]

No that is not what this means. The Theory describes the microscopic world in exquisite detail.
The interpretation really is what it actually means.

Она причины не указывает. Т.е. основы.

 

[DaveC426913]

The observer interacts with the particle when observing, so the wave collapses. It's obvious. There's no magic here.

This is not true. It is a popular misconception.

There is no observer required. When article systems interact, they cause the collapse.

The Moon does not exist in a vacuum of particle interactions. It, and the world around it, are all one giant particle system.

If you could isolate indvidual particles and superpose them, you could maintian tha, but it's impossible to do in any macro-scale system.

 

[ольга]

This is not true. It is a popular misconception.

There is no observer required. When article systems interact, they cause the collapse.

The Moon does not exist in a vacuum of particle interactions. It, and the world around it, are all one giant particle system.

If you could isolate indvidual particles and superpose them, you could maintian tha, but it's impossible to do in any macro-scale system.

Дэйв, если у частицы нет наблюдателя, то как тогда вы узнаете, что частица вообще существует?

 

[DaveC426913]

Dave, if a particle has no observer, then how do you know the particle even exists?

Because it's there when I look again. And because other particles are now doing other things that they wouldn't have done if that particle had stopped existing.

 

[ольга]

Because it's there when I look again. And because other particles are now doing other things that they wouldn't have done if that particle had stopped existing.

Мы сейчас говорим о частицах? Разве частица может находиться в одном и том же месте?

 

[DaveC426913]

Are we talking about particles now? Can a particle be in the same place?

We're talking about anything material.

If I look away from the Moon, the tides don't stop. Thus, I know the Moon is still there even if I can't see it.

If I shoot a cue ball a the red ball on a pool table and then look away, when I look back I see that the red ball has, in fact, gone into the pocket. Thus, the cue ball did not cease to exist when I wasn't looking.

If I shoot an proton at a sheet of gold foil, and then look away...
etc.

 

[ольга]

We're talking about anything material.

If I look away from the Moon, the tides don't stop. Thus, I know the Moon is still there even if I can't see it.

If I shoot a cue ball a the red ball on a pool table and then look away, when I look back I see that the red ball has, in fact, gone into the pocket. Thus, the cue ball did not cease to exist when I wasn't looking.

If I shoot an proton at a sheet of gold foil, and then look away...
etc.

И что будет, если вы направите протон на лист золотой фольги?

 

[ольга]

We're talking about anything material.

If I look away from the Moon, the tides don't stop. Thus, I know the Moon is still there even if I can't see it.

If I shoot a cue ball a the red ball on a pool table and then look away, when I look back I see that the red ball has, in fact, gone into the pocket. Thus, the cue ball did not cease to exist when I wasn't looking.

If I shoot an proton at a sheet of gold foil, and then look away...
etc.

Луна никуда не денется, если вы на неё не смотрите, но она никак при этом и не "выглядит". Она "просто гравитирует". Вы когда-нибудь видели, слышали, или нюхали гравитацию? Нет. Это библейское "земля была безвидна и пуста".

 

[DaveC426913]

So what happens if you point a proton at a sheet of gold foil?

Same thing as what what happens to a red ball on a pool table.