Can someone explain quantum physics?

[Bolero]

It's not brain surgery.

[Cyclone]

To just respond to the bit directed at me. Your teacher would have a fit because you got it all garbled and wrong.

[nightrider]

Oh Gawd, this seems to be the thread of pedanticism.

 

 

Why would he have a fit ? I have merely laid down the ground for the basics. I haven't even mentioned the wave-particle theory yet ! Whereas a lot of people have already given names of Physicists, and Principles. Yet, exactly what are they about ? Huh ? Since no-one really deconstructed it, how can a non-scientist understand what is one theory over another ? How about decoding the basics by going into analogies and layman terms ? I presume if one understands the concepts, then you an use other analogies to explain what you are seeing, rather than quoting directly what can be found everywhere on the Net ! I still think that merits should be given on what I have posted. ! I distinctively stayed away from terminologies which are not easily understood without going into details of theories and principles.

 

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Electrons have no mass. This is true relatively, and on a very basic level of understanding, because Electrons' mass are negligible compared to a proton ! If we're not going to go into an equation definition mode, then does this really matter ? It's what's known at a basic level. From wikipedia:

 

 

 

 

 

 

 

Electron = 9.11 × 10−31 kg

Neutron = 1.6749 × 10-27 kg

Proton = 1.6726 × 10−27 kg

 

 

Source = http://environmentalchemistry.com/yogi/periodic/atom_anatomy.html

 

GCSE/A level = http://www.chemguide.co.uk/atoms/properties/gcse.html#top

 

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The electron does have a mass and it is 511 MeV or 9x10-31 kg as you say. It is not negligible in many scenarios. e.g. if you want to know how much energy a photon must have to produce an e+e- pair you should know the electron mass. If you set it to zero you get the *wrong* anwser.

[Cyclone]

Okay, this is my attempt at decoding it into layman terms of the basic "idea" of it. I can't say theory, since I'm not sure what they are currently.

 

If you cut any object and split it again and again, until you have the smallest particle, you get an atom. You can view an atom by strong microscopes.

grammar, but not so bad so far

 

However, if you split an atom and want to look inside it, I don't think you can see it. Smallest particle inside an atom are (by guess work)

I hope there's no guesswork involved

, electrons, protons, and neutrons. With negative electrical charges, positive electrical charges, and no charges respectively. These particles are the smallest particles known to man

No, just the smallest we can actually see directly

, and it is widely accepted as scientifically true.

it being what?

Its existence are proven by experiments. However, I don't think you can see the electron, proton, or neutron by the most powerful microscope.

 

Now, Quantum Physics is about the interactions of these sub-particles, (if they are indeed particles), inside the proton and neutron. (I think this is right, cos both of these have a mass, whereas an electron has no mass, but just a charge.)

as already explained you've seized on a small part of quantum theory here, it's certainly not the bigger picture though

 

Quantum physics is about how these particles (known as 'quarks' ?) bump into each other, and how they interact to produces the effect that is seen inside an atom. I think theories in this area is still being debated, and scientifically proven. i.e. how fast they are, how they move, when do they move, which direction do they move etc etc etc

Yes a lot of this is still under debate and revision, but like I said you're focussing on a subset of quantum behaviour here, quite a small subset.

[Bago]

The electron does have a mass and it is 511 MeV or 9x10-31 kg as you say. It is not negligible in many scenarios. e.g. if you want to know how much energy a photon must have to produce an e+e- pair you should know the electron mass. If you set it to zero you get the *wrong* anwser.

It is not of importance, and hence it is always mentioned within chemistry as a charge, and not of a particle with X mass. It's always emphasized as 'relative mass'.

 

Anyhow, within physics, it's importance is emphasized on the mass cos you often have to do calculations of F=ma. How strong a force is, depending on how much it weighs ! This is important when you talk of the acceleration of particles. Which is what physics is all about. The mechanics of particles and body. Even though electrons are not exactly solid rounded particles as such. Quatum physics would be something similar. The mechanics of particles within a sub-sub-atomic level.

[nightrider]

It is not of importance, and hence it is always mentioned within chemistry as a charge, and not of a particle with X mass. It's always emphasized as 'relative mass'.

 

Anyhow, within physics, it's importance is emphasized on the mass cos you often have to do calculations of F=ma. How strong a force is, depending on how much it weighs ! This is important when you talk of the acceleration of particles. Which is what physics is all about. The mechanics of particles and body. Even though electrons are not exactly solid rounded particles as such. Quatum physics would be something similar. The mechanics of particles within a sub-sub-atomic level.

 

You may be able to neglect its mass for chemistry but that is an approximation specific to whatever calculation(s) it is they do this for, but in general no one who has a clue about physics claims the mass of the electron is zero.

 

And I already gave you an example where you must know the mass, so your claim you can neglect it for physics is wrong (though there may of course be cases where you can neglect it).

[defstef]

Why would he have a fit ? I have merely laid down the ground for the basics. I haven't even mentioned the wave-particle theory yet ! Whereas a lot of people have already given names of Physicists, and Principles. Yet, exactly what are they about ? Huh ? Since no-one really deconstructed it, how can a non-scientist understand what is one theory over another ? How about decoding the basics by going into analogies and layman terms ? I presume if one understands the concepts, then you an use other analogies to explain what you are seeing, rather than quoting directly what can be found everywhere on the Net ! I still think that merits should be given on what I have posted. ! I distinctively stayed away from terminologies which are not easily understood without going into details of theories and principles.

Planck's re-writing of the Rayleigh-Jeans law (a classical expression for the energy density of a black body emitter which considers work by Josef Stefan and Willhelm Wien) avoided the obvious problems with the latter in terms of its predictions of 'the ultraviolet catastrophe', wherein we would expect the energy density to become infinite at higher frequencies, i.e. the universe would be awash with UV. We know it is not. Planck's reformulation necessarily included a 'fiddle', which meant that energy can only be added or subtracted from a system in discrete amounts - 'quanta' - which is at odds with the classical concept of being able to add or subtract any arbitrary amount. That is the essence of quantum mechanics. I also mentioned one of the first experimental observations that are in agreement with this concept, Einstein's work on the photoelectric effect.

 

While your answers may contain some truths, Bago, you hadn't really answered the question, IMO. If somebody asks, "Can you explain quantum mechanics", then the most simple answer would be that energy can only be given to or taken away from a system in discrete amounts, rather than any old amount. Anything else is superfluous.

When I wrote this, I just knew someone will pick at it. Shall we say, an ELECTROMAGNETIC microscope. So therefore we can 'view' this.

I'm not sure you understood my point here. In fact, I'm not sure I understand you. I was making a point that all our experiences of the world are virtual, even if we see them with our own eyes.

 

{edit: The second point I made should be expressed seperately:} Conventional light microscopes can only resolve down to about 0.2 micrometres (because of the diffraction limit - human beings can't see light less than 400nm and the diffraction limit is half that, 200nm i.e. 0.2 µm) - although the CCD systems in digital cameras can do much better, and respond over a range of frequencies. Try pointing an IR remote at a cheap digital camera, you can actually 'see' the IR (or the CCDs response to it) on the screen. But I digress...

{edit: The Scanning Tunneling Microscopies and Atomic Force Microscopies I mentioned because you had taken the tangential route of talking about microscopes. Both technologies work by a computer-controlled probe interacting with the electron clouds of the constituent atoms of the surface under study. It was probably an unnecessary digression, but I never claimed to be perfect}

Apart from the ability to view it electromagnetically, I don't think (yes, my opinion here) anyone else can view the sub-level below the atomic level ! (Enlighten me if it does exist.) We are only using theories to predict what we see. Do electrons, neutrons, and protons really exist ? Yes, you can prove by experiments that they exist. However, can you prove that the 'matters' (hadron) which makes the neutrons, protons really exist ? If we go beyond this level of particles, then it goes into theory mode, which is, as I understand it, what Quatumn physics were about !

Quantum physics is the best description we have of how energy interacts with matter. See above for a simple explanation.

[nightrider]

Oh Gawd, this seems to be the thread of pedanticism.

 

 

Why would he have a fit ? I have merely laid down the ground for the basics. I haven't even mentioned the wave-particle theory yet ! Whereas a lot of people have already given names of Physicists, and Principles. Yet, exactly what are they about ? Huh ? Since no-one really deconstructed it, how can a non-scientist understand what is one theory over another ? How about decoding the basics by going into analogies and layman terms ? I presume if one understands the concepts, then you an use other analogies to explain what you are seeing, rather than quoting directly what can be found everywhere on the Net ! I still think that merits should be given on what I have posted. ! I distinctively stayed away from terminologies which are not easily understood without going into details of theories and principles.

 

-----------------------------------

 

 

Electrons have no mass. This is true relatively, and on a very basic level of understanding, because Electrons' mass are negligible compared to a proton ! If we're not going to go into an equation definition mode, then does this really matter ? It's what's known at a basic level. From wikipedia:

 

 

 

 

 

 

 

Electron = 9.11 × 10−31 kg

Neutron = 1.6749 × 10-27 kg

Proton = 1.6726 × 10−27 kg

 

 

Source = http://environmentalchemistry.com/yogi/periodic/atom_anatomy.html

 

GCSE/A level = http://www.chemguide.co.uk/atoms/properties/gcse.html#top

 

-----------------------------------

 

 

 

When I wrote this, I just knew someone will pick at it. Shall we say, an ELECTROMAGNETIC microscope. So therefore we can 'view' this. Apart from the ability to view it electromagnetically, I don't think (yes, my opinion here) anyone else can view the sub-level below the atomic level ! (Enlighten me if it does exist.) We are only using theories to predict what we see. Do electrons, neutrons, and protons really exist ? Yes, you can prove by experiments that they exist. However, can you prove that the 'matters' (hadron) which makes the neutrons, protons really exist ? If we go beyond this level of particles, then it goes into theory mode, which is, as I understand it, what Quatumn physics were about !

 

 

 

You have no idea what you are talking about and are just creating confusion. Protons and neutrons are not made of hadrons, they are made of quarks. And yes there is vast amounts of experimental data indicating the existence of hadrons and quarks going back to something like the 1960s or early 70s. This evidence is just as good as evidence for electrons, protons and neutrons.

[defstef]

You have no idea what you are talking about and are just creating confusion. Protons and neutrons are not made of hadrons, they are made of quarks.

Sorry, but protons and neutrons are hadrons, which comprise 3 quarks and the necessary binding bosons in normal matter.

 

{edited for my own stupidity}

[defstef]

Anyway, I'll reiterate:

If somebody asks, "Can you explain quantum mechanics?", then the most simple answer would be that energy can only be given to or taken away from a system in discrete amounts, rather than any old amount. Anything else is superfluous.

 

{edit: ...OK, maybe that last sentence is a little flippant, any QM certainly has some exotic and exciting consequences, many of which it has predicted and which have been verified in the C20th and recent years (Bose-Einstein condensates, tunneling, superposition, entanglement). But, central to the layperson's understanding should be the above concept.}