Does Quantum Physics Prove there is no such thing as Matter?


by n4esa
Tags: matter, physics, prove, quantum, thing
n4esa
n4esa is offline
#1
Dec1-10, 02:12 PM
P: 4
First off, I'm no scientist or physicist, I don't have a fancy degree, I'm a computer engineer with an absolute fascination with quantum physics and the unknown. I figured there must be some great minds here who can help me make sense of the theories I'm learning.

My understanding so far, is that, at the root of quantum physics, we have discovered that matter (atoms/subatomic particles) does not exist at a single point of space/time until observed. Not sure if I worded that correctly, but is this in fact true? Matter exists everywhere and anywhere simultaneously, until observed, at which point it comes into being once observed.

I've watched videos of scientists taking this theory into mind-bending other theories. Essentially stating that there is no matter at all, since it does not exist until observed, and that it is simply our perception through our brain's senses that makes something 'real'.

If nothing exists until we observe it, then what is reality? Furthermore, our reality is simply eletric signals interpretted by our brain, so even the things we think we observe may not actually exist.

Consider a dream. You can smell, taste, touch, hear, and see things in your dream, and at the time your brain considers these things real. Yet we wake up and realise these things weren't real at all. So how do we know what we observe is really there?

It just boggles my mind and maybe I'm trying to make sense of something that cannot be rationalized. But I find myself asking things like, nobody ever 'observes' my heart, its inside my body, yet it must be there, no? So I know that things must exist even though there is no observer, yet quantum physics is telling me that it doesn't exist.

Am I understanding all of this correctly or should I just stop thinking before my head explodes :)
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torquil
torquil is offline
#2
Dec1-10, 03:29 PM
P: 640
Quote Quote by n4esa View Post
First off, I'm no scientist or physicist, I don't have a fancy degree, I'm a computer engineer with an absolute fascination with quantum physics and the unknown. I figured there must be some great minds here who can help me make sense of the theories I'm learning.
Why, thank you!

My understanding so far, is that, at the root of quantum physics, we have discovered that matter (atoms/subatomic particles) does not exist at a single point of space/time until observed. Not sure if I worded that correctly, but is this in fact true? Matter exists everywhere and anywhere simultaneously, until observed, at which point it comes into being once observed.
Yes, objects are "spread out" with varying degrees. At the instant you measure position, the object is suddenly at one specific position. No, nothing in quantum mechanics says that anything "comes into being" at the moment of measurement. It just changes when you measure. I.e. the measurement influences the system.

I've watched videos of scientists taking this theory into mind-bending other theories. Essentially stating that there is no matter at all, since it does not exist until observed, and that it is simply our perception through our brain's senses that makes something 'real'.
That's probably mostly speculation. Unfortunately, some physicists like to talk about unproven speculative theories as if they were true. All objects exist and are described as wave-functions even when no measurements are being done.

If nothing exists until we observe it, then what is reality? Furthermore, our reality is simply eletric signals interpretted by our brain, so even the things we think we observe may not actually exist.

Consider a dream. You can smell, taste, touch, hear, and see things in your dream, and at the time your brain considers these things real. Yet we wake up and realise these things weren't real at all. So how do we know what we observe is really there?

It just boggles my mind and maybe I'm trying to make sense of something that cannot be rationalized. But I find myself asking things like, nobody ever 'observes' my heart, its inside my body, yet it must be there, no? So I know that things must exist even though there is no observer, yet quantum physics is telling me that it doesn't exist.

Am I understanding all of this correctly or should I just stop thinking before my head explodes :)
Sure you can think about it, but these thoughts are based on assumptions that are not known to be true. In quantum mechanics, things always exist as wave-functions even when they are not observed.
n4esa
n4esa is offline
#3
Dec1-10, 04:59 PM
P: 4
Quote Quote by torquil View Post
Sure you can think about it, but these thoughts are based on assumptions that are not known to be true. In quantum mechanics, things always exist as wave-functions even when they are not observed.
So, how do we measure, or see, or whatever, these wave functions without being part of that measurement ourselves, which as you said basically influences the outcome through observing? I'm not questioning, just wondering if there are experiments done that can prove 'something' is there, without us being involved in the process.

Chopin
Chopin is offline
#4
Dec2-10, 01:56 PM
P: 344

Does Quantum Physics Prove there is no such thing as Matter?


Quote Quote by n4esa View Post
So, how do we measure, or see, or whatever, these wave functions without being part of that measurement ourselves, which as you said basically influences the outcome through observing? I'm not questioning, just wondering if there are experiments done that can prove 'something' is there, without us being involved in the process.
We can calculate the probability that a measurement, if we did one, would result in a certain value. That's what the mathematics of quantum mechanics allows you to do--you can write an equation that can tell you "when I do a measurement, the probability that it will be HERE is 10% and the probability that it will be THERE is 90%", etc.

Then you can make the measurement over and over again (like firing a stream of particles at a screen and seeing where each individual one lands), to see whether your equation gave you the right probabilities. If it did, then the density of particles at each point will correspond to the probability that your equation told you.
n4esa
n4esa is offline
#5
Dec2-10, 04:34 PM
P: 4
Thanks for the great info. I suppose I find it hard to separate what I experience as a human, from a set of mathematic equations that say something is a certain way. When you strictly look at an equation there is no room for error, it either functions or it doesn't. But what the function winds up meaning brings into question all kinds of philisophical theories.

I'm curious then, as a scientist how do you visualize something like quantum physics? I know our human senses aren't really capable of understanding its true meaning, but I mean, I basically look at something, and then I turn my head away so I'm not observing it, does it disappear? does it turn into a big fuzzy ball of nothingness as each atom becomes its wave function?
Chopin
Chopin is offline
#6
Dec2-10, 05:04 PM
P: 344
A big fuzzy thing is probably the closest analogy, but it isn't always a ball. It could have a lot of different shapes--some common ones that you find when dealing with electrons around an atom are dumbbell shapes, rings, and other kinds of lobed structures (read up on atomic orbital shapes if you're interested.)

The equations of quantum mechanics tell you what kinds of shapes are possible for a given situation, and how they change through time. For instance, if an electron is by a proton, the equations will tell you the way in which the proton attracts the electron, and pulls its fuzziness into different shapes. But if you put an electron in empty space, where there's nothing around to attract it, its fuzzy shape will just keep spreading out forever, getting bigger and bigger. After enough time, there really isn't even a well-defined center to the fuzzy cloud anymore, it's nearly the same density everywhere. The electron is still just as real as it ever was, but it doesn't have a well-defined position--like a ripple on a pond after it's expanded out.

Then, when you observe the electron, you "collapse the wavefunction", which means all of a sudden the fuzzy cloud shrinks down to a tiny point. The location of that point is random, but the probability of it being at a certain place is proportional to the density of the fuzzy cloud at that point. So if the fuzzy cloud was very very small, you have a pretty good idea where the measurement will be. But in the case above, where the cloud spread out a great deal, you have very little idea where that point will be--in the most extreme case, every location in the universe could be equally probable.

Finally, once the observation is made, the tiny collapsed fuzzy point starts to spread out again, and after enough time it will once again be very large in size. So if you observe the electron again after only a very short time, the cloud didn't have much time to grow, so you can be fairly sure of where it is. But the longer you wait, the more the uncertainty grows.
n4esa
n4esa is offline
#7
Dec3-10, 01:57 PM
P: 4
Absolutely fascinating. I wish I had this interest when I was younger and could persue formal education on these subjects.

I'm curious, how exactly does one become a quantum physicist? What kind of education background do you need? Can you really make a living in this area of science?

I'm somehow doubting you could bring up Monster dot com and find yourself such an exotic job :) What types of job titles are there in this field?

Also, what's a good starting point for getting more serious about learning these things? Books/courses etc.
Mommabear
Mommabear is offline
#8
Dec8-10, 01:40 PM
P: 1
I also am not a physicist, but would like to ask some questions: Is it more like, the possibility exists for infinite "realities": ie they exist all at once until someone "observes" and then one must be 'chosen' - perhaps because we cannot perceive them all at once or more likely, because by having the observer enter the picture, it changes the equation? Or because we perceive time in a linear fashion, we can only perceive one line of it, when many actually exist?


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