Quantum physics.

PardonTheWait

PardonTheWait

PardonTheWait

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Short version: Explain quantum physics to me

Long version: I would like someone to give me just the vaguest clue what it's about. I have never read any explanation of quantum physics which didn't leave me immediately feeling quite, quite stupid and cause me to give up reading within minutes. I just don't have the faintest hope of understanding any of these explanations, and I honestly doubt I'm alone. I'm not stupid. Not properly anyway.

Can it really be that I'm too stupid to even comprehend the very notion of it? Because right now, I feel like there's a load of other complicated stuff I'd need to understand before I could even begin to comprehend it.

I don't even know what it does! What do people do with quantum physics? What's it for?!

Example: I don't understand mavity in any proper sense, but I know what it is. Makes little things go towards big things, or as far as I'm concerned, makes stuff fall down.

That is as far as I'd like my understanding of quantum physics to go. Is it possible? Help me.
 

Gives quite a good insight. Watch Parts 1,2,3 and 4.

Also don't worry about mavity, even Physicists don't know what mavity is. (Well not fully anyway)
 
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Heh always wondered the same thing, watching that youtube video now, cheers for the link aswell!

But if someone could also explain it here that would be great haha.
 
Quite hard to explain it all, just read Physics books like I do! Many different parts to Quantum Physics and a hell of a lot more theories.
 
I always love that quote, entire human race with all space removed would be the size of a sugar cube. Mind bending.. I love and hate physics at the same time.
 
PardonTheWait said:
Short version: Explain quantum physics to me
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Short answer : Get a degree, PhD and spend the rest of your life researching it and you might manage to scratch 0.01% of it.

PardonTheWait said:
Long version: I would like someone to give me just the vaguest clue what it's about. I have never read any explanation of quantum physics which didn't leave me immediately feeling quite, quite stupid and cause me to give up reading within minutes. I just don't have the faintest hope of understanding any of these explanations, and I honestly doubt I'm alone. I'm not stupid. Not properly anyway.

Can it really be that I'm too stupid to even comprehend the very notion of it? Because right now, I feel like there's a load of other complicated stuff I'd need to understand before I could even begin to comprehend it.

I don't even know what it does! What do people do with quantum physics? What's it for?!
Click to expand...
The CPU your computer is currently working on is designed using quantum mechanics. The laser in your Blueray drive uses quantum mechanics. Mobile phone masts use quantum mechanics. Fiber optics use quantum mechanics. Protein folding for cancer drug research uses quantum mechanics. Your hard drive uses quantum mechanics. Gold is the colour gold because of quantum mechanics (and special relativity as it happens). Obviously nuclear reactors and weapons use quantum mechanics.

It's possible (though the technology is in its infancy) to use quantum mechanics to create uncrackable secure communications, as well as computers which would eat through SSL encryption like an Andrex puppy through wet toilet paper.

PardonTheWait said:
Example: I don't understand mavity in any proper sense, but I know what it is. Makes little things go towards big things, or as far as I'm concerned, makes stuff fall down.
Click to expand...
mavity, currently, doesn't fall under the heading of 'quantum theory', we don't understand mavity on a quantum scale. The other three forces we do understand on a quantum scale. There are various technical reasons why mavity is a problem which, if you hate yourself a lot, I'll go into in detail.

PardonTheWait said:
That is as far as I'd like my understanding of quantum physics to go. Is it possible? Help me.
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If you can be a little more specific I can give a specific answer. Your question is like saying "I want to understand Geography, can someone help?", there's a hell of a lot to it and the only way to give any kind of answer is to be more specific. I've spent the better part of a decade doing it and while I've heard of the majority of major areas of research and even have done some myself most of what appears in the theoretical physics section of ArXiv (which is where 99.9% of current maths and physics research is put) here makes me go "What the **** are you talking about?".

I could give a vague 'all covering' answer but unless you're familiar with differential equations, probability density functions and complex numbers you're not going to follow it unfortunately.
 
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Watch this and let your mind be blown :p




Observing stops it..

Just like how Quantum computers can stop completely at the slightest interference.
 
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I am just wondering, what counts as an observer?
Would someone sitting in the same room count?Or is my understanding as bad as I think it is.
 
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PardonTheWait said:
Short version: Explain quantum physics to me
Click to expand...

Unfortunately the shorter the question, the longer the answer :p.

Long version: I would like someone to give me just the vaguest clue what it's about. I have never read any explanation of quantum physics which didn't leave me immediately feeling quite, quite stupid and cause me to give up reading within minutes. I just don't have the faintest hope of understanding any of these explanations, and I honestly doubt I'm alone. I'm not stupid. Not properly anyway.
Click to expand...

I think to really explain what quantum mechanics is, you need to really ask what science actually does first.

The role of science is to build models, essentially. Consider a simple question: "Why does stuff fall to the ground?" Just calling it mavity isn't really answering the question, that's just putting a name to an unknown phenomenon. Instead, science says it's mavity, and proceeds to describe all the maths related to mavity. Does it say what mavity "is"? Hmm, that's really for you to decide :p. Maths is all we have unfortunately.

That might not sound very satisfying, or complete, but consider everything that science has achieved with mathematical models. Every time you run your computer, you essentially running scientific experiments which ~100 years ago our leading scientists couldn't even conceive. LED displays, giant magnetoresistance (hard drives), transistors etc etc all came about from scribbles of maths on a black board.

So what is quantum mechanics? It's a model, a fantastic model, of all things small. From highly complex maths one can make predictions about the universe to an incredible degree of accuracy (more so with QED and QCD, but let's ignore those for the time being).

At the most fundamental level, quantum mechanics boils down to the idea that everything is probabilistic in nature. In classical mechanics, everything can be known to absolutely perfect precision, if you have good enough measuring equipment. If I say my computer is at position "x", it is always at "x" everytime I measure it.

In quantum mechanics, this isn't the case. If I trap a particle in a small region of space, and proceed to try to measure its position, I will get a number. However, if I repeat the same experiment again, I could get a different number. People talk about waves and dead cats and such like, but really such things follow from this basic principle if you do the maths.

Can it really be that I'm too stupid to even comprehend the very notion of it? Because right now, I feel like there's a load of other complicated stuff I'd need to understand before I could even begin to comprehend it.
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To truly understand quantum mechanics you do need a good grasp of extremely complex maths (in both senses of the word :p). One can make crude analogies but they are just analogies. Anything more difficult than what I said above really needs an understanding of hermitian operators, bra-ket notation and abstract states to get the jist of really. Even after 3 years of doing a physics degree, I still don't know what's going on most of the time :p.


I don't even know what it does! What do people do with quantum physics? What's it for?!
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Everything :). All of chemistry is quantum mechanics, and from that everything you have ever come in contact with is essentially quantum mechanics.

I hope I at least helped a bit :)
 
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"Anyone who is not shocked by quantum mechanics has not understood it" - Niels Bohr (I think)

:)
 
Quantum mechanics is basically the lowest (smallest) level at which our universe works (overly simplified its the cause and effect of millions of tiny bits of energy doing stuff).

Know one really knows what mavity is because we can only really see the effect it has on other objects and not see it directly - the simplest but not necessarily correct explanation is that it is a force that works outside of our universe like the programming in a computer game - you can see the effect the programming has on objects in the game world but you can't see it actually in action itself.
 
It also postulates 11 dimensions, if you want to start moving into string theory. It also looks at different universes as being a membrane and rubbing next to each other or if you really want to go hardcore, have a look at is our universe a hologram:

 
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