Earth's moon

[ydoaPs]

Is it there if no one is looking? after all, probability waves aren't collapsed until one observes the particle. the moon is just a collection of particles, so is it there if no one observes it?

 

on a side note, what is the probability that the moon could suddenly dissapear to the other side of the andromeda galaxy? i suspect it is so close to zero that it is almost infinitely small.

[Cap'n Refsmmat]

I closed my eyes and touched my computer. Nobody else was looking at it. Thus the moon would probably be there too.

[Tesseract]

the moon is just a collection of particles' date=' so is it there if no one observes it?

 

[/quote']

 

So is everything else so no.I pretty sure i can breath but I dont observe the air.

[VendingMenace]

just because a particle is not observed does not mean that it doesn't exist. Indeed, if particles came into existence just when they were obseved then there would have to be a whole lot more energy floating around than there is. All that it means is that a particle exists in a superposision of its quantum states until it is obseved, at which time the particle colapses into a single state.

 

So, things do not rely on observation for their existance -- but they do rely on observation to bring them into a single, definate, state.

 

Of course the consiquences of this also somewhat reast on what you consider "observation" to be. And people have been arguing about this for quite a while now.

[Sayonara]

Unless you consider the tides to be an observer, then "yes", of course it's still there.

[CPL.Luke]

well normally you observe something by shining light on it.

 

I'm pretty sure that the moon is constantly being bombarded by light

[slickinfinit]

In order to answer that u are assuming the observer is infinite? cause as we know us the observers will die in a very short time on a cosmological scale. I think u would have to know the exact number of observers and we have no way present of knowing what is watchin who or how they are watching.I cant see how our existence is needed to varify what would be in all likelyness there even if u were not.

[Ophiolite]

Is it there if no one is looking? after all' date=' probability waves aren't collapsed until one observes the particle. the moon is just a collection of particles, so is it there if no one observes it?

[/quote']If you accept the interpretation of quantum mechanics that requires observation to imbue reality ,then clearly if we all stop looking at it for long enough it will no longer be there. About one or two billion years should be enough. But if anyone takes a sly peek we'll be back to square one.

[slickinfinit]

If you accept the interpretation of quantum mechanics that requires observation to imbue reality ,then clearly if we all stop looking at it for long enough it will no longer be there. About one or two billion years should be enough. But if anyone takes a sly peek we'll be back to square one.

I think that part of qm is selfish in interpreting our life as observers. I believe there are forms of preception beyond our understanding and to sum it up it is the observers that ceases to be and the inert matter or energy stays for the next who peak.Oh ya telescopes see in a range mesured by time so u could see back billions of years ? things are there weather we see them or not lol

[Ophiolite]

Well, I wasn't expressing a view either way. I did say if and you. My wavering thoughts on the correct qm interpretation haven't collapsed into a particular conclusion yet.

 

It seems a little unusual to characterise the observer viewpoint as selfish. If it happens to be the correct one, then it just is.

[ed84c]

I think all observation talk and cats in boxes is a little arrogant on the scale of the human race in the fact that the universe [/i] changes somehow just for us. I think we just dont understand the double slit expo properly yet.

 

 

BTW; the earth has 2 moons, i forget what the other is called.

[Sayonara]

Cruithne.

[Ophiolite]

I think all observation talk and cats in boxes is a little arrogant on the scale of the human race in the fact that the universe [/i] changes [i'] somehow just for us. I think we just dont understand the double slit expo properly yet.

I agree totally with your final sentence. But when that understanding comes, it may turn out that the observer does play a critical role. I have not detected arrogance at the heart of this explanation (though it is evident in many other scientific pronouncements).

 

As another example, it is not arogant to say humans are the most intelligent species on the planet. It is arrogant to say they are the most important.

 

I've always thought Schroedinger's cat was perfectly capable of observing for itself if it was dead or not. (And while we're at it, if you want a real example of arrogance look no further than your average cat; or maybe its just complacent self importance.)

[Gilded]

"BTW; the earth has 2 moons"

 

If it ain't gravitationally bound, I'm not going to call it a moon. >:/ Unless you make me eat plastic forks with chili mustard.

[Sayonara]

If it ain't gravitationally bound, I'm not going to call it a moon. >:/ Unless you make me eat plastic forks with chili mustard.

It is, just not in an elliptical orbit.

 

You orbit-racist

[swansont]

You orbit-racist

 

Keplarian elitist?

[ydoaPs]

ok, say we put it in a giant box so that no radiation can get to it and we magically move it to an isolated part of the universe. does it have an exact position? there is a probability that every one of the particles that compose the moon could suddenly be scattered across the universe. so, how would we know it is there?

[VendingMenace]

does it have an exact position?

no.

 

But of course, it never has an exact position. One of the uncertanty priciples states that we cannot ever know the position and momentum of an object to an arbitrary degree of certainty at the same time. Which would make it seem like we could determine position exactly, however, we know that the moon cannot be moving faster than the speed of light, so we have an upper bound for momentum and hence, a lower bound for how precise we can know the earth's position.

[Cap'n Refsmmat]

Move it again and measure the acceleration and the force. With a known mass of the box, you would be able to determine (with F=ma) the mass of the object inside and tell that it existed.

[ydoaPs]

the question is not, nor ever was, if it existed, but rather "does it exist where it is if nothing observes it?"

[ydoaPs]

nevermind. i found the answer. it is decoherence