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Author Topic: Are electrons affected by gravity?  (Read 25039 times)

Offline JP

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gravity and electrons
« Reply #25 on: 09/11/2007 17:51:07 »
There's probably some cosmological reason for believing that gravity affects electrons the same as it does all positively charged and neutral matter.  If electrons were repelled by gravity, then they would be slightly pushed away from all clumps of matter (such as our galaxy) by gravity, while protons and neutrons etc.  This would probably have some measurable consequences in deviation from Newtonian gravity or general relativity, which I don't think have been observed. 

There is some thought that antimatter might be affected by "negative gravity": http://en.wikipedia.org/wiki/Gravitational_interaction_of_antimatter
This might help to explain why there seems to be so little of it in the universe, but this is not a widely accepted view.
 

lyner

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gravity and electrons
« Reply #26 on: 09/11/2007 22:04:10 »
You would need an experiment or observational evidence to take this further. Else it's idle chit chat. (Fun though)
 

Offline Soul Surfer

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gravity and electrons
« Reply #27 on: 10/11/2007 08:07:04 »
The universe just would not work as it does now if electrons responded to gravity differently to protons that's the plain and simple truth.  After the "dark ages"  when the universe consisted mostly of neutral atoms the universe was reionised into a plasma by the first stars it was at that time starting to form major condensations.  If the protons and electrons had at thast time moved in any way differently in the gravitiational field the universe would have developed a charge structure that opposed gravity and prevented objects from condensinf properly into stars and galaxies.  remebe it would only require a small differentiation between the motions of protons and electrons in a gravitiatinal field to crerate very large balancing electrostatic forces over the same range as gravity.

As an aside it is looking like electromagnetic forces did have an effect on the formation of galaxies and that is only just starting to be understood.
« Last Edit: 10/11/2007 08:13:55 by Soul Surfer »
 

Offline thebrain13

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gravity and electrons
« Reply #28 on: 14/11/2007 07:40:26 »
but  electric force is still way stronger than gravity. Protons are still attracted to electrons. The tendency for positive charge to coagulate would only be as strong as gravity is compared to electric force.

I dont really see how it could make a big difference.
 

Offline ManasviMittal

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Re: gravity and electrons
« Reply #29 on: 10/10/2015 11:15:37 »
Van der waals theory says that there is negligible effect of gravity on an electron.
On the other hand, theory of relativity tell us that gravity can effect even light particles. As it happens in a singularity, even light is not able to escape from it. So according to me, i think that gravity effects electrons on a large scale. Now, if electron uses its energy to overcome the effect of gravity, then over a certain period of time and electron should loose all its energy and should fall on the ground due to gravity.
tell me if i'm wrong.
 

Offline alancalverd

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Re: gravity and electrons
« Reply #30 on: 10/10/2015 11:26:32 »
Gravity has exactly the same effect on electrons as it does on any other object with mass, from an electron to a galaxy.
 

Offline lightarrow

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Re: Are electrons affected by gravity?
« Reply #31 on: 10/10/2015 14:16:21 »
Van der waals theory says that there is negligible effect of gravity on an electron.
On the other hand, theory of relativity tell us that gravity can effect even light particles. As it happens in a singularity, even light is not able to escape from it. So according to me, i think that gravity effects electrons on a large scale. Now, if electron uses its energy to overcome the effect of gravity, then over a certain period of time and electron should loose all its energy and should fall on the ground due to gravity.
tell me if i'm wrong.
You're wrong.

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Offline Colin2B

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Re: gravity and electrons
« Reply #32 on: 10/10/2015 14:26:51 »
.... if electron uses its energy to overcome the effect of gravity, then over a certain period of time and electron should loose all its energy and should fall on the ground due to gravity.
tell me if i'm wrong.
If the electron is moving against gravity it will not lose energy, but the energy will be converted, firstly to potential energy and then as it falls into kinetic energy in the opposite direction.
This would work in a vacuum but in air the range of an electron is usually less than 2m.
 

Offline ManasviMittal

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Re: Are electrons affected by gravity?
« Reply #33 on: 10/10/2015 14:28:53 »
Van der waals theory says that there is negligible effect of gravity on an electron.
On the other hand, theory of relativity tell us that gravity can effect even light particles. As it happens in a singularity, even light is not able to escape from it. So according to me, i think that gravity effects electrons on a large scale. Now, if electron uses its energy to overcome the effect of gravity, then over a certain period of time and electron should loose all its energy and should fall on the ground due to gravity.
tell me if i'm wrong.
You're wrong.

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How am I wrong?
« Last Edit: 10/10/2015 14:32:29 by ManasviMittal »
 

Offline Thebox

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Re: Are electrons affected by gravity?
« Reply #34 on: 10/10/2015 14:40:52 »
If electrons are influenced by gravitational force, then how is the Earth able to emit a magnetic field?



http://www.nasa.gov/feature/goddard/nasa-measuring-the-pulsating-aurora
« Last Edit: 10/10/2015 15:31:35 by Thebox »
 

Offline jeffreyH

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Re: Are electrons affected by gravity?
« Reply #35 on: 10/10/2015 17:08:23 »
The form of the energy taken from the electron is kinetic energy. Kinetic energy and the wavelike nature of the electron are closely related. Because of this wavelike nature the electron can never be at rest on the ground. Unless it happens to be part of a static electric charge. However an electron as part of a molecule which makes up a solid CAN rest on the ground. If it is simply a gas molecule then it is less likely to remain at rest. There is something about the wavelike nature of the gas molecule that prevents this. What that something is I don't know. For solids the wave is not free to move in a straight line path. the waveform of particles in a solid are linked together within atoms and molecules which prevents this from happening. Unless of course some external force is applied.
 

Offline lightarrow

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Re: Are electrons affected by gravity?
« Reply #36 on: 10/10/2015 20:28:02 »
How am I wrong?
Totally  :)
A longer answer would require to write an entire encyclopedia.
Write one single statement at a time, at least.

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Offline MolonLabe

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Re: Are electrons affected by gravity?
« Reply #37 on: 11/10/2015 11:00:33 »
  However an electron as part of a molecule which makes up a solid CAN rest on the ground.

Please set me right here, but I understood that electrons bound to molecules in a solid were in some kind of constant state of motion around the nucleii. I know that the analogy of planets orbiting a sun is far too primitive, but I find it hard to imagine how any such electron could be described as at rest.
 

Offline evan_au

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Re: Are electrons affected by gravity?
« Reply #38 on: 11/10/2015 11:21:27 »
Quote from: ManasviMittal
Van der waals theory says that there is negligible effect of gravity on an electron.
Please describe which one of Van der Waals' theories imply this (and why)?
 

Offline alancalverd

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Re: Are electrons affected by gravity?
« Reply #39 on: 11/10/2015 11:42:59 »
I know that the analogy of planets orbiting a sun is far too primitive, but I find it hard to imagine how any such electron could be described as at rest.


Analogies and imagination are, alas, worthless. You have to start with the world as it is, then build a mathematical model that describes and predicts what you see. Whilst the Bohr atom is historically interesting, and the electron shell model is useful for inorganic chemistry (at least in gases and liquids), only a quantum orbital probability model describes and predicts all the observed properties of atoms and molecules.   
 

Offline MolonLabe

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Re: Are electrons affected by gravity?
« Reply #40 on: 11/10/2015 12:16:45 »
I know that the analogy of planets orbiting a sun is far too primitive, but I find it hard to imagine how any such electron could be described as at rest.


Analogies and imagination are, alas, worthless. You have to start with the world as it is, then build a mathematical model that describes and predicts what you see. Whilst the Bohr atom is historically interesting, and the electron shell model is useful for inorganic chemistry (at least in gases and liquids), only a quantum orbital probability model describes and predicts all the observed properties of atoms and molecules.   

I'm not sure how to respond to that, given that only yesterday I had to defend the concept of using maths to explain something. I was asking for an explanation as to how an electron could be stationary, given, as you say, that only a quantum orbital probability model is satisfactory.

 

Offline alancalverd

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Re: Are electrons affected by gravity?
« Reply #41 on: 11/10/2015 14:17:09 »
The quantum orbital probability model describes the distribution of electrons in atoms and molecules. Free electrons in vacuo behave as individual particles with charge -1 and mass 0.008 that can be made to move at pretty much any speed you want, including backwards, so there's no problem creating a stationary electron. Would such a thing be useful, I wonder? I think not, though Millikan's oil drop experiment measured the charge on a stationary body carrying one surplus electron. 

There's no problem describing your motion if you are standing still in the middle of a field, but the equation would look quite different if you were caught up in a tornado or a moving crowd.   
 

Offline MolonLabe

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Re: Are electrons affected by gravity?
« Reply #42 on: 11/10/2015 14:47:35 »
Because of this wavelike nature the electron can never be at rest on the ground. Unless it happens to be part of a static electric charge. However an electron as part of a molecule which makes up a solid CAN rest on the ground.

The quantum orbital probability model describes the distribution of electrons in atoms and molecules. Free electrons in vacuo behave as individual particles with charge -1 and mass 0.008 that can be made to move at pretty much any speed you want, including backwards, so there's no problem creating a stationary electron.

This is what I was querying, because your response looks to me like a direct contradiction to the other post I quote here.
 

Offline alancalverd

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Re: Are electrons affected by gravity?
« Reply #43 on: 11/10/2015 16:01:24 »
Read the first post carefully. It's clumsily expressed but basically tautologous: an electron cannot be at rest unless it is static.... I'd agree with that.
 

Offline jeffreyH

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Re: Are electrons affected by gravity?
« Reply #44 on: 11/10/2015 16:58:54 »
I would go with Alan's view if I were you. He is a professional.
 

Offline MolonLabe

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Re: Are electrons affected by gravity?
« Reply #45 on: 11/10/2015 19:47:36 »
The quantum orbital probability model describes the distribution of electrons in atoms and molecules.
Read the first post carefully. It's clumsily expressed but basically tautologous: an electron cannot be at rest unless it is static.... I'd agree with that.
I would go with Alan's view if I were you. He is a professional.

Perhaps I'm missing something here, but I can't go with anybody's view until they express it. Surprisingly, I had read the post very carefully. It included "However an electron as part of a molecule which makes up a solid CAN rest on the ground." This did not seem compatible with the statement "The quantum orbital probability model describes the distribution of electrons in atoms and molecules." I was hoping for some clarity.
 

Offline jeffreyH

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Re: Are electrons affected by gravity?
« Reply #46 on: 11/10/2015 19:55:59 »
The whole molecular system as a unit can rest on the ground as a solid. In which case the electron cannot be considered on its own. It also depends upon what you mean by 'rests'. That is more a macroscopic representation which will not apply in the microscopic domain.
 

Offline MolonLabe

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Re: Are electrons affected by gravity?
« Reply #47 on: 11/10/2015 20:04:30 »
The whole molecular system as a unit can rest on the ground as a solid. In which case the electron cannot be considered on its own. It also depends upon what you mean by 'rests'. That is more a macroscopic representation which will not apply in the microscopic domain.

Ah - ok. That clear's up my bafflement. Thanks.
 

The Naked Scientists Forum

Re: Are electrons affected by gravity?
« Reply #47 on: 11/10/2015 20:04:30 »

 

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