Need help with Quantum Physics

[StuTheWise]

Hello all!

I'm trying to learn a little more about a particular area of quantum physics. Only problem is, I'm not that bright... so if anybody is able to explain this in "layman's" terms, or point me to a site that does, I'd greatly appreciate it.

The theory I'm after is the one that states nothing exists unless it is observed.

Are there any experiements available that will help me understand this better? I read something about a wall with two holes and a light source shining through it, and something about a cat in a box with a radioactive source and a bottle of poison, but the person explaining it had incredibly bad grammar and I could barely understand what he was talking about.

Remember... I'm a layman, so go easy on me

 

[Luis G]

shit, i wish i still had my chemistry 1 notes, i can't remember much of it.

 

[Camelyn]

(Edited because I'm an idiot.)

Best I could do, in layman's terms:

http://www.flownet.com/gat/QM.pdf

If I had a bit more time to google, I'd do better, but I have to run

Let me know if it helps at all.

 

[chcr]

http://www.lassp.cornell.edu/ardlouis/dissipative/Schrcat.html
http://www.emr.hibu.no/lars/eng/cat/

The cat story You're thinking of is Schroedinger's Cat, from a paper by Erwin Schroedinger in 1935. Here are a couple of links. Schroedingers cat is a fair explanation, at least to how I understand quantum mechanics. See if this explanation helps, it's the one I use. Remember, I am not a physicist, but this is my understanding of the situation. First, physics as we observe it daily does not in any way exist on the quantum level (the level governing subatomic particles). Now, you understand that electrons, protons and nuetrons are actually made up of smaller stuff, I assume. Put simply, this stuff all exists in an indetermihnate state until it is observed. Things exist on a quantum level, they just don't have physical properties until those properties are measured. Camelyn's link is a much better explanation, this is just the short version I use in my head. Einstein thought it was so much hooey, but the theory is fairly well accepted now.

Clear???? It's not even clear to the people who purport to understand it!

 

[HeXp£Øi±]

Baaaaa! We're living tn the second generation of dark ages only this time the church consists of people like hawking who don't know the first thing about physics because they accept math as the gospel when it's not. This is exactly how we end up with worm holes and parrallel universes. These same individuals have once again according to the big bang theory, placed us right smack in the center of the universe. I'm sure the sixteenth century catholic church would be proud.

 

[chcr]

Umm, Hex? We are pretty much in the middle of the observable universe. I do agree that a lot of conventional physicists limit themselves by being conventional and not paying attention to unconventional theories, however.

 

[Luis G]

Baaaaa! We're living tn the second generation of dark ages only this time the church consists of people like hawking who don't know the first thing about physics because they accept math as the gospel when it's not. This is exactly how we end up with worm holes and parrallel universes. These same individuals have once again according to the big bang theory, placed us right smack in the center of the universe. I'm sure the sixteenth century catholic church would be proud.

Math is the gospel, thou, new math theories and laws are needed to understand new theories

 

[HeXp£Øi±]

We are pretty much in the middle of the observable universe.

That's about the most obvious statement i've ever heard.
Nomatter where you are you're always going to be at the center of the 'observable'' universe.
My point is that they continue to date the universe and every time we build a bigger telescope its age gets a little older. Do they actually believe we're seeing the end of the universe? Yes they do and to this day scientists continue to make these ridiculous statements.Duh. These guys are morons. Wait another twenty years and the universe will be 40billion years old. I'm not making this up, i read the periodicals. Astronomy magazine, scientific American, science news, sky & telescope.

Luis i do agree with your statement but i like to think of math as the language of physics only a language that hasn't been fully translated. This is because we really have no idea how the math changes under extreme conditions such as black holes and the like. If you don't understand the language fluently then you will undoubtedly mistranslate the conversation and ultimately theories will abound based upon that conversation and theories upon those that become exponentially inaccurate.

 

[chcr]

Do they actually believe we're seeing the end of the universe?

Sorry Hex, I was being facetious. As you say, I'm afraid some of them do believeve we're seeing the end of the universe. Clearly not all of them do, though. Every time you change the observations, or the rules, there are going to be a certain number of people (among those educated enought to understand, even) who will resist with all their fiber. This happens because they can't believe they could be wrong. Unfortunate, but there it is.

This is because we really have no idea how the math changes under extreme conditions such as black holes and the like. If you don't understand the language fluently then you will undoubtedly mistranslate the conversation and ultimately theories will abound based upon that conversation and theories upon those that become exponentially inaccurate.

Exactly my point, no one understands the language completely yet. Observation is not complete, and unlikely to be in my lifetime.

 

[Camelyn]

Baaaaa! We're living tn the second generation of dark ages only this time the church consists of people like hawking who don't know the first thing about physics because they accept math as the gospel when it's not. This is exactly how we end up with worm holes and parrallel universes. These same individuals have once again according to the big bang theory, placed us right smack in the center of the universe. I'm sure the sixteenth century catholic church would be proud.

Um, OK, call me stupid, but isn't this exactly why they are called "Theories"? Do you propose that until we know with absolute confidence exactly how the world works, from the interaction of galaxies to the interaction of electrons in an atom, we should just keep our mouths shut?? Scientific theory is published not only for the propagation of information, but also in order for it to be proven or disproved, by others. Looking back 100 years, we can giggle at the scientific theories of the time and think "how quaint". But those theories were debunked exactly because they were published, so that anyone willing to do the research could come up with a better one.

You can critique and criticize a scientific theory all you like, but the basis of all science is the ability to question the world around you. But to suggest that it should not be proposed at all is counter to all the scientific method stands for.

 

[HeXp£Øi±]

If only they were taught as theory but the problem is they are taught as fact and people in the scientific world who challenge these theories are the ones being critisized and mocked.

But to suggest that it should not be proposed at all is counter to all the scientific method stands for

What? Who suggested that? Talk about putting words in ones mouth. I'm sorry but it sounds as if you'd have me pity the majority who falsly and against the rules of scientific method apply and teach these theories as fact.
The hawkings of today have much to learn from the einstein's of yesterday.

 

[Camelyn]

If only they were taught as theory but the problem is they are taught as fact and people in the scientific world who challenge these theories are the ones being critisized and mocked.

In all honesty, I haven't been exposed to the presentation of theory as fact that you are talking about. Maybe it's a matter of interpretation. To a layperson, yes, it's easy to confuse scientific theory with fact. But to other scientists, the distinction should be evident. And if one theory is held to be fact above all others, the person who is presenting it as such should have that pointed out to them, firmly. I have seen the mocking attitude you are speaking about, but that’s the way it has always been in the scientific world. Change comes slowly, with checks and balances. The new ideas always sound extreme until they are supported and re-supported one to many times to question. Bad or good, I'm not sure, maybe it's limiting, but it also limits the acceptance the nuttier (well, some anyway ) ideas out there at face value.

What? Who suggested that? Talk about putting words in ones mouth. I'm sorry but it sounds as if you'd have me pity the majority who falsly and against the rules of scientific method apply and teach these theories as fact.
The hawkings of today have much to learn from the einstein's of yesterday.

Nope, never asked you to pity them. Not sure where you got that from, actually. My understanding of the thread of this was that theories that could not be completely proven, because out understanding of the basic concepts was incomplete, should not be presented, for example Hawkings theories, derived from principals we don't fully understand. This was the impression that I got. My point was that its very constructive to disagree, disagree loudly, even. But not to say that these ideas shouldn't be presented because of what we feel may be weak science. Maybe we are saying the same thing? But to present a "theory" as "fact" I also disagree with. I have read Hawking, granted it's been a few years and a few papers ago, but I can't recall getting a feeling of "this is the gospel according to Hawking". Maybe this is why I am not exactly sure I understand the Einstein/Hawking reference?

 

[chcr]

If only they were taught as theory but the problem is they are taught as fact and people in the scientific world who challenge these theories are the ones being critisized and mocked.

Are we still talking about quantum mechanics? Granted, I've been out of school for a very long time (since before there was quantum theory, in fact) and I am merely a well read lay person, but I have never seen anyone present it as other than theory, even Stephen Hawking. He strongly beliieves the theory to be true, but still admits that it is in fact a theory, at least in everything I've ever read. I'll grant you that Stephen Hawking tends to be overrated as a physicist, IMO, but I have never seen him present quantum theory, or even the big bang as fact. You are right about the scientific establishment in general ridiculing anything that is outside accepted forms. This is a problem that is not unique to science, unfortunately.

 

[Camelyn]

Granted, I've been out of school for a very long time (since before there was quantum theory, in fact) and I am merely a well read lay person... [snipped for brevit, not content ] I'll grant you that Stephen Hawking tends to be overrated as a physicist, IMO,

Ditto. I am lay person as far as pure scientific research goes. I have an education that is mostly in the biological, medical technology fields. But, I was weaned on Nova, and I am an avid reader. And I work in a scientific field (yeah, like I could do anything else, geek that I am ).

I agree, he does tends to be overrated, mostly because he was a breath of fresh air at the time in a field that had gone a bit stale. Not that his theories don't have merit, but I think we may have to wait a half century or so to see if he was/is the next Einstien

 

[StuTheWise]

Thanks Camelyn and chcr for the links. I'll save that pdf and bookmark the links so I can read them over when I get a chance.

I'd love to get get a lot more into physics, if only I didn't suck so bad at math. But I'm a big Nova fan myself, so I'll stick with PBS for now. My brain hurts just from thinking about thinking about quantum mechanics!

 

[HeXp£Øi±]

I think we're all lay persons or we wouldn't be wasting time here.

I wasn't speaking wholly of quantum machanics but of many theories in general and one that gets me the most is the big bang theory. Sure the scientific world knows what theory is but ask the common person in the street. It's taught in grammer and high schools and the word 'theory' is used in passing as if it were almost a certainty which it is not.. As if they want it to be accepted as fact. The reason i stress this is because i believe it is extremely important what the common person believe about these subjects. This is where we recieve much of our funding for science. Like i said i read the periodicals, i have for years and there's just something that's not right about how we're teaching scientific method, fact & theory and i'm not the only one.

 

[Camelyn]

I think we're all lay persons or we wouldn't be wasting time here.

I wasn't speaking wholly of quantum machanics but of many theories in general and one that gets me the most is the big bang theory. Sure the scientific world knows what theory is but ask the common person in the street. It's taught in grammer and high schools and the word 'theory' is used in passing as if it were almost a certainty which it is not.. As if they want it to be accepted as fact. The reason i stress this is because i believe it is extremely important what the common person believe about these subjects. This is where we recieve much of our funding for science. Like i said i read the periodicals, i have for years and there's just something that's not right about how we're teaching scientific method, fact & theory and i'm not the only one.

I agree pretty strongly with everything you say here. We aren't actually taught enough science in school to be able to make the distinction between fact and theory, let alone formulate an informed opinion about any given theory. This means that crappy science can be accepted as fact, if it has the right hype, while solid science is rejected as a waste of resources, because the concepts are too difficult to grasp without the right background. I have read articles that poke fun at scientific research, decrying the waste of taxpayers money, without ever digging deeper to find out exactly why this research was conducted. Because they don't know, or care, to ask. A huge part of the problem is education, but another part is that scientists, when they present data and research, direct their comments at other scientists, which flies right over the head of anyone without the right background and education. I mean damn, I have read some articles in Scientific American and Nature that have left me blinking, with a tiny trail of drool trailing from the corner of my mouth. And I like to think of myself as at least informed. Methinks that the scientific community as a whole needs to look into a good PR firm....

And Woohoo! Rock on Nova!

All the geeks in the house, represent!

K, I'll just stop typing now....

 

[HeXp£Øi±]

Some points very well made Camelyn. I've been reading sciam since high school and it has become much more techinal in that short period of time(91). My father told me the exact same thing in fact he said he even quit reading scientific american because he said he doesn't understand it anymore. This guys studied physics & astronomy as a hobby on & off for 40 years and has taken calc as well. It definetely sounds like there's a missing medium within the ranks of communication in the scientific community.

 

[outside looking in]

The theory that nothing really exists until we observe it is related to something called the collapse of the wave function. The wave function is a mathematical description Erwin Schrodinger (of cat's fame) came up with to explain some observations and some theoretical mathematics.

It isn't the only explanation of physics compatible with observation. Another is the multiverse theory which states that each possibility results in a physically real universe, with the 'choice' being the splitting point. As odd as that may sound, it does explain a lot of things quite niceley, such as time travel paradoxes.



Hex... I think your viewpoint is a bit jaded. The big difference between Hawking et. al is that they readily admit that they have no final answers, that they don't know everything, and that they are groping for the truth using the limited knowledge we have acquired. Hardly the same as dark age churches you made an analogy to.

Oh, and perhaps we are at the center of the universe. It depends on the shape of the universe. If it is closed, then calling Earth the center is just as valid as calling any other point the center. Where would you place the center of the surface of the Earth? And many are beginning to think that the uinverse is actually infinite in size, although that is thinking a bit outside the hypercube.

 

[HeXp£Øi±]

Jaded:
1 a : to wear out by overwork or abuse b : to tire or dull through repetition or excess
2 obsolete : to make ridiculous

Well i'm not going to bother arguing your opinion of me. This is exactly what i mean when i say that we're living in another form of dark ages. Independent thinkers/scientists are looked down upon to the point that many feel frustrated and discouraged. Galileo suffered under these conditions granted they were much more extreme.

As far as being the center of the universe in an expanding universe, the idea is positively ridiculous.Why? Because if the expanding universe theory were accurate there would be a massive void at what was once the center. In otherwords everything would be moving away from that point in space. I'm not saying absolutely that the expanding universe theory is inaccurate, only that if it is accurate we're definetely not at the center.