[jccc]

The explanation for why an electron does not fall into the nucleus comes from a fundamental concept in quantum mechanics: the Heisenberg uncertainty principle. Put simply, it states that you cannot know the position and momentum of a particle simultaneously. More rigorously stated, the product of the uncertainty of the position of a particle (Δx) and the uncertainty of its momentum (Δp) must be greater than a specified value:

ΔxΔp≥ℏ2


Now, as the electron approaches the nucleus, it's uncertainty in position decreases (if the electron is 10nm away from the nucleus, it could be anywhere within a spherical shell of radius 10nm, but if the electron is only 0.1nm away from the nucleus, that area is greatly reduced). According to the Heisenberg uncertainty principle, if you decrease the uncertainty of the electrons position, the uncertainty in its momentum must increase. This increased momentum uncertainty means that the electron will be moving away from the nucleus faster, on average.

Put another way, if we do know that at one instant, that the electron is right on top of the nucleus, we lose all information about where the electron will be at the next instant. It could stay at the nucleus, it could be slightly to the left or to the right, or it could very likely be very far away from the nucleus. Therefore, because of the the uncertainty principle it is impossible for the electron to fall into the nucleus and stay in the nucleus.

In essence, the uncertainty principle causes a sort of quantum repulsion, that keeps electrons from being too tightly localized near the nucleus.

Quantum repulsion? My head is exploding.

Pete,

I googled those answers, not my words.

[PmbPhy]

Quantum Mechanics has absolutely nothing to do with WHY things happen. It is strictly a mathematical method for predicting things by assuming everything to have quantifiable properties, statistically found to be in certain ranges. Why any of it works is NOT the business of QM.

Predicting things is what is meant by explaining why. I used to believe the same thing that you just said but have been tilting the other way recently. For example; using quantum mechanics one can explain the nature of why alpha decay occurs and I recall that it can also predict the lifetime of radioactive nuclei that decay by alpha decay. It'd say that's a why question which has an answer.

You can also say that relativity is a mathematical model to. That doesn't mean you can't explain why moving clocks run slower than stationary ones.

[jccc]

May God have mercy, put a quantum grenade in my head ASAP.

[evan_au]

In fusion reaction, two atoms impact so hard, even two nucleus crashed into one, how come electron escaped from the crash?

Before nuclear fusion is initiated, the Deuterium* gas is heated to somewhere around a million degrees (F, C or K, whatever you prefer...).

At these temperatures, the atoms are completely ionised, so the electrons have already escaped from the nuclei.

When two Deuterium nuclei run into each other with sufficient velocity to overcome their electrostatic repulsion they can approach within 1 femtometer. At these distances, the attraction of the strong nuclear force is greater than the electrostatic repulsion. The two deuterium nuclei can then fuse to form a Helium nucleus.

The electrons have not escaped from this reaction, as they were not present around the Deuterium nuclei at the start of the fusion reaction.

If you cool down the reaction products to room temperature, the plasma will cool into a mixture of neutral Helium atoms and Hydrogen molecules, with the electrons in a cloud around the positive nuclei.

*Sometimes a mix of Tritium & Deuterium is used, but it's easier to explain the D+D=He reaction.

[jccc]

In fusion reaction, two atoms impact so hard, even two nucleus crashed into one, how come electron escaped from the crash?

Before nuclear fusion is initiated, the Deuterium* gas is heated to somewhere around a million degrees (F, C or K, whatever you prefer...).

At these temperatures, the atoms are completely ionised, so the electrons have already escaped from the nuclei.

When two Deuterium nuclei run into each other with sufficient velocity to overcome their electrostatic repulsion they can approach within 1 femtometer. At these distances, the attraction of the strong nuclear force is greater than the electrostatic repulsion. The two deuterium nuclei can then fuse to form a Helium nucleus.

The electrons have not escaped from this reaction, as they were not present around the Deuterium nuclei at the start of the fusion reaction.

If you cool down the reaction products to room temperature, the plasma will cool into a mixture of neutral Helium atoms and Hydrogen molecules, with the electrons in a cloud around the positive nuclei.

*Sometimes a mix of Tritium & Deuterium is used, but it's easier to explain the D+D=He reaction.

Thank you AU. You sound like work closely in this field.

At that high temperature, electron escape away from nucleus attraction force field? Why not escape into it? Is there a force field around nucleus that keeps electrons at certain distance? So no matter how energize electrons can only move outward from nucleus?

Isn't strong force quite mystery? Why gluons glue positive and negative quarks together not electron? Is quark really carries -1/3 or +2/3 charge? Why is add 3 quarks mass is not equal to proton mass? How to measure quarks mass?

What is quantum repulsion? Are you going to hate me? Please don't, it's my head's fault.

[Insentient]

The uncertainty can be explained as follows...We live in a certain dimension of our own consciousness, and our consciousness has a certain limit to what we are able to observe...We know that the universe is not governed by our consciousness, but we are unable to grasp the fact that we are governed by the universe...When we see an electron behave as a particle, it is because that is what the universe needs us to observe, but this does not mean that's what is actually happening. It just means that we asked a question, and had to get a lie for an answer, because if we don't get an answer, it's a lot worse than getting lied to...Every cause needs to have an effect, otherwise we wont be able to function in our consciousness of time...In the grand scheme of things, there are secrets that the universe needs to keep...We are the uncertainty  []

[PmbPhy]

The uncertainty can be explained as follows...

First off, welcome to the forum. It's always nice to see a new member join. In the second place, that is not correct. You're using the term uncertainty incorrectly. The uncertainly in a quantity is really the standard deviation in a physical observable and that's not what you were describing. See:
http://en.wikipedia.org/wiki/Uncertainty_principle

The uncertainty of an observable depends on the state that the quantum mechanical state that the system is in. If uncertainty was what you described then that wouldn't be the case.

Again, welcome to the forum!

[Insentient]

Thanks for the welcome! [] and thanks for the link also.., but the observer effect still holds the position of uncertainty (The position, and velocity of an object can not be quantified at exactly the same time)... well actually they can... It's just the wave length we determine, is actually our wave length, no matter what 'instruments' we use...We are stuck in a dimension 'like fish are stuck in a fish tank'.., and all the Latin symbols only get you so far before the realization occurs that we have enough information to build a 'spaceship' to get us the hell out of here!..Then we find out how the real math works

[lightarrow]

At that high temperature, electron escape away from nucleus attraction force field? Why not escape into it? Is there a force field around nucleus that keeps electrons at certain distance? So no matter how energize electrons can only move outward from nucleus?

The more energy the electrons have, the less they are bound to the nucleus. It's not a force field but Schrodinger equation (solved  []).

They can however interact with a nucleus in the same way as in LHC or other collider: high energy electrons are shooted against nuclei to explore their inside; the more energetic the electron is, the less its (wavefunction) wavelenght is, so it can explore and reveal smaller parts of the nucleus.

So, if you heat up hydrogen atoms at very high temperatures, you will ionize them, the electrons will move even faster, colliding with fast moving nuclei, and at very very high temperatures the electrons will begin to explore the nuclei's inside and to reveal quarks, and to generate new particles, even more exotic and massive and in even more number, in the collisions.

--
lightarrow

[chiralSPO]

jccc, I'm happy to discuss this topic further, but let's do it on this thread only.

[jccc]

If electrons stick to the protons, atoms will become neutral particles. Therefore matter will not form. Nor the universe.

The nature is God. Its creation beyond wonder.

As human, we wonder why? Why is electron and proton, the strongest force source in nature, not stick together within an atom?

I heard of two theories, QM, which I can't understand. The other one, you pretend you don't understand.

[chiralSPO]

Let's say for the moment that there is some negatively charged fluid other than electrons that was attracted to positively charged nuclei. A few questions immediately arise:

1) Why wouldn't the nucleus attract enough of the negatively charged fluid that it would become neutral, and no electrons are needed?

2) Is the entire universe negatively charged, or is there another as-yet-unobserved positively charged something that balances this out?

3) How can this fluid be observed?

If we assume that quantum mechanics is not a good model of the way things work on atomic/molecular scale, then we need to find new solutions for mysteries such as:

1) How do atoms interact to make molecules?

2) What is responsible for the bright line spectra of all the elements? (http://en.wikipedia.org/wiki/Emission_spectrum)

3) When the double slit experiment is performed with beams of electrons, why does it generate an interference pattern?

[jccc]

Let's say for the moment that there is some negatively charged fluid other than electrons that was attracted to positively charged nuclei. A few questions immediately arise:

1) Why wouldn't the nucleus attract enough of the negatively charged fluid that it would become neutral, and no electrons are needed?

2) Is the entire universe negatively charged, or is there another as-yet-unobserved positively charged something that balances this out?

3) How can this fluid be observed?

If we assume that quantum mechanics is not a good model of the way things work on atomic/molecular scale, then we need to find new solutions for mysteries such as:

1) How do atoms interact to make molecules?

2) What is responsible for the bright line spectra of all the elements? (http://en.wikipedia.org/wiki/Emission_spectrum)

3) When the double slit experiment is performed with beams of electrons, why does it generate an interference pattern?

1. The Earth can carry as much sea water as you can supply. The electron's force density/strength is equal to the   fluid density at atom radius.
2. The space is negative charged compare to matter/planet.
3. EM wave needs the fluid to exist.

1. Electron grabbing war is on going all the time.
2. Light is produced by electrostatic force vibrating in the space fluid. Every element has its own set of force density/strength due to their charges.
3. I am not sure yet, but I am sure electron is particle, not wave.

[chiralSPO]

1. The Earth can carry as much sea water as you can supply. The electron's force density/strength is equal to the   fluid density at atom radius.

But water doesn't repel itself. If you think this negative fluid gathers around the nucleus, presumably the effective charge of the nucleus would be less than a naked nucleus in the absence of negative fluid. How would this "electrons floating on sea of negatively charged space" work for heavier atoms, where there is a multiply charged nucleus and many electrons? How much negative space gets pulled close to the nucleus as it is bigger and more positively charged?

2. The space is negative charged compare to matter/planet.

So space is all negative, and matter is 50% positive 50% negative? How much negative charge is there in the space? This doesn't make much sense to me...

3. EM wave needs the fluid to exist.

So all of the experiments that couldn't find the aether are wrong?

1. Electron grabbing war is on going all the time.

2. Light is produced by electrostatic force vibrating in the space fluid. Every element has its own set of force density/strength due to their charges.

That might work as a qualitative description, but it breaks down when we consider the quantitative description. If it were just an issue of force constants (like springs) we wouldn't see the same harmonics as are observed (http://en.wikipedia.org/wiki/Hydrogen_spectral_series)

3. I am not sure yet, but I am sure electron is particle, not wave.

Glad to hear you are able to admit you are unsure about some things, but why are you so sure the electron is not a wave?

[jccc]

1. If there's only one positive change and 10 negative charges in the universe, will the negative charges gather around the positive charge?  Heavier nucleus have more positive charge, form denser space fluid balls, electrons are float at atom radius.

2.Who told you that the universe has same amount positive and negative charges?

3. Could be all wrong, they don't understand that the ether is charged, light speed is not constant, temperature and medium density involved.


1.

2. ??

3. Electron is a charged particle. It turns in EM field. It has mass. EM wave/light is moving force, no mass, no charge. 

[Bill S]

Jccc, somewhere Pete suggested you should read the Haifa Lectures. If you have done that you have probably seen the following:

“A trouble with Bohr’s atomic model is that, according to classical, electromagnetic theory, an accelerating electric charge, as is the case of the orbiting electric charge, must radiate energy away. In this case, the electron could not stay in a fixed orbit; it would spiral into the nucleus of the atom. Thus, such an atom could not be stable. Bohr resolved the problem by postulating that the angular momentum of the orbiting electron must be ‘quantized,’ in units of h/2π(The hint for this quantization may come from the fact that the units of Planck’s constant h are the same as those of angular momentum.) Thus, the classical orbital angular momentum, mvr, of the electron was taken by Bohr to be nh/2πwhere n = 0, 1, 2,…, and where v is the speed of the orbiting electron, and r is its radial distance from the nucleus. Thus, with Bohr’s model of the atom, the electron in a fixed orbit is in a particular energy level of the atom, En, until it would (acausally) ‘jump’ to a different energy level. When this ‘jump’ happens, to a lower energy level, the energy lost by the electron (and therefore the host atom), when it descends to the lower energy level Em, is taken up in the creation of a photon with frequency fnm”.

Does that not answer your question about how the electron avoids spiralling into the nucleus?

[jccc]

Not at all. Orbiting is totally BS.

[PmbPhy]

I think the following quote from QED by Richard Feynman is worth remembering. From page 15

I want to emphasize that light comes in this form - particles. It is very important to know that light behaves like particles, especially for those of you who have gone to school, where you were probably told something about light behaving like waves. I'm telling you the way it does behave - like particles.

Feynman talks about the wave aspects of the photon in his lecture series.

[jeffreyH]

The 'orbit' of an electron must be distributed in all directions. It is still an orbit however. If you think of the solar system model of an atom then an electron approaching the polar region of the proton WILL be able to 'crash' into the proton. This would be happening all the time which it doesn't because matter would not be stable. jccc, you neglect the distribution of the electron charge and the fact that it would not naturally combine with the proton. For a start the wavelengths of the proton and the electron will be different. Only when certain conditions are met can they combine to form a neutron. Some things just have to be accepted because the theory matches experimental evidence. How many people have to tell you this before you decide to believe them.

[jccc]

I'll never believe anything not logical to my mind.

Solar systems are light years apart. Do they share planets?

Those who believe orbiting atom structure should also believe magic.

Still think about photon? Particle wavelength? There's no such thing beside foolish theories.