If the Big Bang throws you, this surely will. Do you create reality by looking?

[Hayabusa Rider]

http://seedmagazine.com/content/article/the_reality_tests/P1/

The article is from 2008 but AFAIK it's still relevant to our current understanding of "what is".

Too long to copy and paste but interesting reading I think and does a fair job of explaining the situation.

Quantum physics was the one thing Einstein could or would not accept as he was a Realist.

Thoughts after reading?

 

[woolfe9998]

Please explain, in layman's terms, how it is possible that objects have no properties which pre-exist our observation? I understand this to be a feature of quantum mechanics but I don't see any way to truly get it except perhaps in mathematical terms. Is there any way to understand it without the math?

 

[Cerpin Taxt]

Please explain, in layman's terms, how it is possible that objects have no properties which pre-exist our observation? I understand this to be a feature of quantum mechanics but I don't see any way to truly get it except perhaps in mathematical terms. Is there any way to understand it without the math?

Suppose you flip a coin, and you catch it and smack it on the back of your hand, but you do not reveal it. You don't know if it's heads or if it's tails, but you DO know that it is (heads or tails). That is, you know it has to be one or the other.

We used to think quantum particles were like that. We believed that they had a certain polarization, for example, but we just couldn't know which until we looked at it.

Now, they're saying that this isn't the case. They're saying it is meaningless to talk about the polarization before we look at it. The polarization, for all intents and purposes, does not exist.

 

[Paul98]

I don't like the word "Observation" that is used so much, it makes people think that it needs to be some person or animal looking to make the particle do what it does.

 

[woolfe9998]

Suppose you flip a coin, and you catch it and smack it on the back of your hand, but you do not reveal it. You don't know if it's heads or if it's tails, but you DO know that it is (heads or tails). That is, you know it has to be one or the other.

We used to think quantum particles were like that. We believed that they had a certain polarization, for example, but we just couldn't know which until we looked at it.

Now, they're saying that this isn't the case. They're saying it is meaningless to talk about the polarization before we look at it. The polarization, for all intents and purposes, does not exist.

Right, like Shrodinger's Cat. I get that much. I just don't understand how or why it is possible. In the classical world, your coin IS either heads or tails up before you look at it. Quantum mechanics doesn't accord with our observation of the classical world. I don't doubt it one bit. It's just difficult for a lay person to understand it.

It might help to explain what is meant by "observation" in quantum mechanics.

 

[woolfe9998]

I don't like the word "Observation" that is used so much, it makes people think that it needs to be some person or animal looking to make the particle do what it does.

You've explained what it doesn't mean. Now explain what it means.

 

[Cerpin Taxt]

Right, like Shrodinger's Cat. I get that much. I just don't understand how or why it is possible. In the classical world, your coin IS either heads or tails up before you look at it. Quantum mechanics doesn't accord with our observation of the classical world. I don't doubt it one bit. It's just difficult for a lay person to understand it.

It might help to explain what is meant by "observation" in quantum mechanics.

Well, the EPR paradox, coupled with Bell's theorem kinda put us at a crossroads: either locality was false (i.e. some things move faster than light) or realism was false (things don't exist till we look at them). This latest bit of theory and experimentation suggest that it's realism that is false.

 

[Cerpin Taxt]

You've explained what it doesn't mean. Now explain what it means.

In order to "see" a property or characteristic of a subatomic particle, you have to interact with it in some way. For example, to measure position, the particle must collide with a detector. To measure momentum, the particle must past through a magnetic field. (there are other methods, these are just general examples)

You hear about how we cannot know position and momentum simultaneously with precision, and that's because the methods of measuring one aspect are destructive to the original value of the other aspect. To measure position, you must alter the momentum. To measure the momentum, you must alter the position.

 

[woolfe9998]

In order to "see" a property or characteristic of a subatomic particle, you have to interact with it in some way. For example, to measure position, the particle must collide with a detector. To measure momentum, the particle must past through a magnetic field. (there are other methods, these are just general examples)

You hear about how we cannot know position and momentum simultaneously with precision, and that's because the methods of measuring one aspect are destructive to the original value of the other aspect. To measure position, you must alter the momentum. To measure the momentum, you must alter the position.

That actually makes sense. Thanks.

 

[justoh]

That actually makes sense. Thanks.

Yeah, that was concise and well explained. If you can handle a 5 Minute Clip, James Burke also explains this quite well: http://www.youtube.com/watch?v=WcOECH7427w

Short, interesting, and seemingly directly on topic. Episode description:

Points out that studies of the properties of magnetism, electricity, and light have led scientists to the realization that Newtonian physics is inadequate to explain all that they observe. The public, meanwhile,
has continued to concentrate on the technological by-products of science.

Humour me.

 

[woolfe9998]

Yeah, that was concise and well explained. If you can handle a 5 Minute Clip, James Burke also explains this quite well: http://www.youtube.com/watch?v=WcOECH7427w

Short, interesting, and seemingly directly on topic. Episode description:



Humour me.

I did watch that. Thanks. I may check out some of the other Burke segments.

I also watched this Nova piece on quantum mechanics, making it about as simple as it can be for lay people.

http://www.youtube.com/watch?v=STF0moww_zQ

I can follow it pretty well, though this business about quantum entanglement and "spooky action at a distance" is just flat out weird.

 

[justoh]

I did watch that. Thanks. I may check out some of the other Burke segments.

I also watched this Nova piece on quantum mechanics, making it about as simple as it can be for lay people.

http://www.youtube.com/watch?v=STF0moww_zQ

I can follow it pretty well, though this business about quantum entanglement and "spooky action at a distance" is just flat out weird.

I like that Brian Greene guy you linked. He did a show about string theory about 8 years ago or something that was very well done. Both very good at explaining this kind of stuff to people with no math or physics background (like me ), and also very entertaining.

 

[Caravaggio]

Thoughts after reading?

There was a young man who said, God
Must think it exceedingly odd
If he finds that this tree
Continues to be
When there's no one about in the Quad.

(Parody of Bishop Berkeley's philosophy. Still doing the rounds, it seems.)

 

[manimal]

I recommend reading the holographic universe by James pribham I think it was.

The holographic model has always intrigued me since I began to appreciate the golden mean.

 

[soulcougher73]

This stuff makes my head hurt lol

 

[Pulsar]

It's not that difficult a concept.

Before you measure something, it can be any state. So some people like to believe that it exists in both at once (or doesn't exist at all) until it's measured.

Which doesn't really mean shit, because we only care about things which give us feedback. Whether a TV is on, off, or missing from it's shelf doesn't really matter to us unless we're in the same room watching it. Etc.

We don't really car if a cat in the box is dead or alive, unless we're giving it to a favorite relative. In which case you'd probably check, or not keep it in a box to begin with.

It's philosophy. Like a large portion of quantum mechanics (at this point). Newtonian physics are observable. A lot of quantum mechanics are still just best-guess.

 

[piasabird]

I dont have time to take quantum physics. I quit reading after the second page.

This is like asking if there is no light, does color exist?

My son took a lot of physics and calculus and other math classes. Sometimes when we can not measure things we can measur that things are not or their boudaries.

 

[woolfe9998]

It's not that difficult a concept.

Before you measure something, it can be any state. So some people like to believe that it exists in both at once (or doesn't exist at all) until it's measured.

Which doesn't really mean shit, because we only care about things which give us feedback. Whether a TV is on, off, or missing from it's shelf doesn't really matter to us unless we're in the same room watching it. Etc.

We don't really car if a cat in the box is dead or alive, unless we're giving it to a favorite relative. In which case you'd probably check, or not keep it in a box to begin with.

It's philosophy. Like a large portion of quantum mechanics (at this point). Newtonian physics are observable. A lot of quantum mechanics are still just best-guess.

I think what makes it such a difficult concept to grasp is that on the classic level, things do exist and have definite properties whether we're looking at them or not. On the quantum level, things "exist" only as a probability matrix, i.e. a series of possible properties with no definite state, until we observe them. That wouldn't be such a problem if everything in the classical world wasn't made up of quantum units, but it is. It's the lack of congruity between these two inter-related domains which causes me the greatest confusion.

 

[Pulsar]

I think what makes it such a difficult concept to grasp is that on the classic level, things do exist and have definite properties whether we're looking at them or not. On the quantum level, things "exist" only as a probability matrix, i.e. a series of possible properties with no definite state, until we observe them. That wouldn't be such a problem if everything in the classical world wasn't made up of quantum units, but it is. It's the lack of congruity between these two inter-related domains which causes me the greatest confusion.

Except they can't prove the theory because they can't measure it. They can only hypothesize and try to create mathematical proofs.

Einstein thought it was a load of bollocks. What's the point of saying something is in some in-between state? We only care about measured values, observed values, so the whole thought-process that says something can be both at once is stupid.

To quote Einstein on Shrodinger's Cat reduction:

You are the only contemporary physicist, besides Laue, who sees that one cannot get around the assumption of reality, if only one is honest. Most of them simply do not see what sort of risky game they are playing with reality—reality as something independent of what is experimentally established. Their interpretation is, however, refuted most elegantly by your system of radioactive atom + amplifier + charge of gunpowder + cat in a box, in which the psi-function of the system contains both the cat alive and blown to bits. Nobody really doubts that the presence or absence of the cat is something independent of the act of observation.[4]

 

[Hayabusa Rider]

Except they can't prove the theory because they can't measure it. They can only hypothesize and try to create mathematical proofs.

Einstein thought it was a load of bollocks. What's the point of saying something is in some in-between state? We only care about measured values, observed values, so the whole thought-process that says something can be both at once is stupid.

To quote Einstein on Shrodinger's Cat reduction:

You are the only contemporary physicist, besides Laue, who sees that one cannot get around the assumption of reality, if only one is honest. Most of them simply do not see what sort of risky game they are playing with reality—reality as something independent of what is experimentally established. Their interpretation is, however, refuted most elegantly by your system of radioactive atom + amplifier + charge of gunpowder + cat in a box, in which the psi-function of the system contains both the cat alive and blown to bits. Nobody really doubts that the presence or absence of the cat is something independent of the act of observation.[4]

Quantum physics makes predictions validated by repeatable experiments. It is in fact one of the most successful theories in science. If you read the article you would see where Einstein debates Bohr who used Einstein's own theories against him so effectively that he never raised the challenge again.

As far as why we would be interested? Our entire modern world is based on spooky physics.