Physical challenge question about electrons

[neoaspilet11]

Re: challenge question ..

Hello Guys,
I think this is the same thing as the gravity problem. we know exactly the gravitational interaction of objects, how the gravitational field behaves around an object, but nobody knows waht causes them! even NEwton said that he is afraid he may never find an answer to waht causes the gravity. Einstien left a theory that gravity is cause by curvature of object in space etc, but not the field.

In the e field question. It is similar. we know exactly how electrons behave in electric fields - e.i we can compute the forces betwen electrons, etc. But we may never know what causes for its field to exist.

I think when we ask things at the fundamental level, causality may not be logical at all. because our reasoning will fall into a chicken - and - egg - age - old dilemma.

In my own opinion, if the e - field is generated by the electron, then Mr Cool is right, it must have an energy source! Maybe that infinitessimal decrease of electron mass converted to energy is the source. we should not forget the the electron is moving at all times! maybe its its kinetic energy is converted to to useful form to create its field. (This is a wild idea.)

Thanks

 

[irfan1]

Re: challenge question ..

The problem arises from considering the electron as an isolated quantity. In addition, saying "electron is always radiating energy to sustain the electric field" is completely an unphysical. This statement is not correct. Moreover, one should be careful about the notion of "fields". The physically observable quantities are not the fields.

 

[pengboy]

Re: challenge question ..

i really confused by you guys.

First by classical physics theory:

if it is a isolated electron in its own universe with nothing else (i am saying the electron will not interact with anything else), then the electron already posess the E-field. there is no radiation. it is a static field. there is no power flowing.

if you are talking about creating a electron, then you input the energy to create the field.

Second, we all know the electron is moving randomly and in a atom it is called electron cloud.

if we are using Maxwell equation in the classical form, the electron is radiating.

but it is not right, acording to quantum theory, the electron is in a stable state and it will not iradiate.

Added after 15 minutes:

just curious to what type of reponse i would get if i were to ask:

"from where does the electron get its energy such that it can poor out electomagnetic fields CONTINUOUSLY for the entire life of said electron?"

think before you post, its not an easy answer.

Mr.Cool

"from where does the electron get its energy such that it can poor out electomagnetic fields CONTINUOUSLY for the entire life of said electron?"

It is not a correct argument. first, the electron already posess the field. if we do a integral for the energy stored in the infinite space, we will have a finite value which is all the E-field energy that one electron posses.


so the electron does not pour out energy or absorb energy after it is created.

a static E-field by itself means no power flowing around.

we need both E-field and M-field to define a power flowing or called Pointine Vector.

 

[Mr.Cool]

Re: challenge question ..

wow, these are some awesomely thought provoking posts! well done everyone.

neoaspilet11,
everything you said is the bases of why i posted to begin with! ha. what you said is the "accepted norm" of our scientific elite community. my personal belief, we can do better than that. 100 years ago, perhaps this status quo was acceptable. we are now beyond that. or more correctly, we SHOULD be beyond that. the chicken and the egg.. so aggrivatingly true!! but i challenge this

irfan1,
not necessarily. you can consider an electron all by itself and the issue would still be a valid thought experiment. of course, in reality, it is impossible to have an electron all by itself - even in vacuum. i recognize the difficulty in using the term field. when one measure the charge of the electron one measure the field and not the electron at all! the physically observalbe IS the field because that is what i can measure with an oscilliscope. perhaps i could even measure the mass of the electron itself with sensitive enough equipment. what came before the field (the source) is what i can NOT measure, and therefore would be labeled "unphysical" by your terms, or non-observable as i have previously used (they are the same meaning to me).

pengboy,
my response to your post is a bit longer.

if it is a isolated electron in its own universe with nothing else (i am saying the electron will not interact with anything else), then the electron already posess the E-field. there is no radiation. it is a static field. there is no power flowing.

you were correct about everything except "there is no radiation". it is still radiating, there is just nothing near bye to interract with it. when a tree falls in the forest does it make a sound? of course... it is the laws of physics that determins if a sound is made - not the presence of a human.

if you are talking about creating a electron, then you input the energy to create the field.

i am not talking about creating an electron, which is akin to creating energy. as posted previously, i assume the electron is already existing in space and THEN i go and consider how it works.

It is not a correct argument. first, the electron already posess the field. if we do a integral for the energy stored in the infinite space, we will have a finite value which is all the E-field energy that one electron posses.
so the electron does not pour out energy or absorb energy after it is created.

if your hypothesis is correct then your argument is correct. however, i do not believe that ALL the energy of the electron is contained by the integral. quite simply, when the electron's field interracts with some electromagnetic force that OTHER force will impart a BEMF on the original electron's field. this is faraday's law? anyway, it is well understood in physics and accepted. we simultaneously accept that the original electron's field charge "e" is always of the same magnetidue even when some other BEMF is working against the field! yet how can this be? if a BEMF is working against the original field AND the original field never diminishes... from where is this mystical replenishing energy come from?

we need both E-field and M-field to define a power flowing or called Pointine Vector

now you are getting into the nitty-gritty. actually, the power flow equation is quite a bit longer. yes it includes pointings energy flow S = E X B, but also other terms & expressions. (Dirac spells this nicely in his book). the other terms have no known physical meaning, in real practical circuits, as we know them today, we observe and measure only S = E X B. this is why when you crack open ANY electrical engineering text book you will find only a discussion on pointing's energy flow.

but this doesn't mean that Dirac's other terms are non-existant! only that they do not appear relavent when discussing power flow. their effects are too small, are negligable. this is how the other terms in Dirac's equation appears, but does not necessarily mean they are!

truely, the interesting part about Dirac's EM wave equation is the fact that it is a symmetrical equation! too bad he never discussed "with what is the equation in symmetry with?". but that's OK, we'll do that discussion here

Mr.Cool

 

[nec4b]

Re: challenge question ..

Hi everybody!

If you have an electron in vacum all alone than there actually is no E field. E field is just a tool for easier understanding and calculation. There is no field to be maintained at any time. The fact is that charged particles interact with each other by a electromagnetic force. And you need at least two particles to get any action. It's the same with gravity. If you have two bodies of mass in space, they will start moving toward each other without an energy input.

best regards

 

[jfkaz]

Re: challenge question ..

But by observing the electron, haven't you effected it. Schroedingers Cat, Was the electron affected by the observation. Could another force be at play, and what about dimensional influences M theory, string theory or maybe another unknown influence, dark matter perhaps.

 

[Mr.Cool]

challenge question ..

hehee.. when a tree falls in a forest, does it make a sound?

Mr.Cool

 

[treehugger]

Re: challenge question ..

hehee.. when a tree falls in a forest, does it make a sound?

Mr.Cool

consider this:

take an electron isolated in the vacuum. it is like "no body around here; so do i have a field or not, even I dont know" and so on. anyway. now i'll make a series of assumptions:
think of this electron fixed in space. somehow do not allow it to move.
now all of a sudden bring a lonely second electron and put it close to the first one, and fix it. do not allow it to move.
now my question is: do they exert a force on each other?
they cannot exert force on each other in this setup because if they did, then that would violate the principle that information cannot be carried faster than light.
so i conclude that an electron in vacuum does not posess a field.
now i wonder if my argument is flawed.

to speak about a field in my setup you need a differential amount of motion in one of these electrons. that would trigger the radiation of a photon, and the momentum of the photon will be responsible for the repulsion of the two electrons.
[/b]

 

[Lord Loh.]

challenge question ..

I guess from nowhere. They are quantum fluctuations.

 

[Mr.Cool]

Re: challenge question ..

if the electron where truely alone in vacuum then yes, it wouldn't know that it had a field.

an Efield needs CHARGED MASS to interact with. i am not aware if that charged mass must also be in motion. ?

when two magnets are placed near each other, they do not need to be in motion to feel the repulsion effect.

so, i would answer YES they do exert a force on each other.

be careful with trying to define the electron. all text books define the electron's field by placing a "point charge" somewhere in face and calculating the force on that charge. but this is akin to looking up a word in the dictionary and then finding that same word in the definition!! this is NOT a definition...

but here we are getting away from the original question. how is the electron in symmetry with its environment if it appears to be totally one sided (gives off efield never absorbs????).

Mr.Cool

 

[eogotenks]

Re: challenge question ..

Electrons are charged particles. That is, they carry an electric charge. For this reason, they are influenced by electric fields. More precisely, they are accelerated in an electric field.

Since the mass of an electron is so very small compared with objects of ordinary experience, electrons are accelerated to very high velocities even by electric fields of only a few volts [per meter].

For example, the electrons in orbit in an atom have been accelerated through an electric field of only a few volts created by the positively charged nucleus as they 'fall' into the atom and are captured in orbit. Just these few volts are enough, due to the extremely small mass of the electron [mass of the electron is = 9.10938 x 10-31 kg], to result in the electron attaining orbital speeds that, in some cases, may be an appreciable fraction of the speed of light.

Put another way, the fact that electrons usually seem to travel at very high speeds is not, as one might otherwise think, an indication of great energy.

It is because the mass of the electron is so small that its speed will be very great even when the electron has absorbed only a very small amount of energy.

To be more precise, for a non-relativistic particle, the speed v is given by


v = sqrt(2E/m)


, where E is the kinetic energy and m the mass of the particle. As you can see, if m is very small, v may be very large for a modest energy E.

 

[treehugger]

Re: challenge question ..

when two magnets are placed near each other, they do not need to be in motion to feel the repulsion effect.

so, i would answer YES they do exert a force on each other.

...

but here we are getting away from the original question. how is the electron in symmetry with its environment if it appears to be totally one sided (gives off efield never absorbs????).
Mr.Cool

i will respond by saying that magnet is in no motion but electrons are in motion which are responsible of magnetic effect. indeed it is obvious that if electrons were in no motion, there would be no magnetic effect. i carry this point further and state that if charges are in no motion then there would be no electrostatic effect. but that does not contradict with previous ideas since a differential amount of motion is enough for a charge to interact with its environment.

of course my argument cannot be verified experimentally, however, i find your symmetry argument valuable and i think my suggestion somewhat resolves the problem. there is no giving off a field without a reason, and indeed there is no field of an isolated charge in vacuum. when an electron has a motion (an acceleration) then the symmetry is disturbed and hence the reason for giving off a so-called field.

 

[aryajur]

Re: challenge question ..

Some of my thoughts are:

First of all if we consider an electron in an atom, it is moving, but according to the quantum theory it does not radiate electromagnetic fields as long as it is in a particular energy level. But I guess we are more interested in a stationary electron sitting in Vaccum and just having its electric field around it.
For this case, the only way we know the electron has a electric field is by getting a test charge near it and then detect the field due to the force it produces on the test charge. So in a way when we detect the field we detect it using the energy we supply to bring the point charge closer to the electron.
The field is just a representation of the electromagnetic force at a distance which is considered as one of the 4 fundamental forces. Now going deeper, I don't know how physicist are trying to explain the causes of the 4 fundamental forces, maybe string theory or something.
But I guess the key point is that electric field is the mathematical representation of the force at a distance (the electromagnetic force) and that force is only visible when a test charge is brought close. So when there is no test charge no force on anything and no energy dissipated. So it requires no energy to maintain the "electric field".

 

[Basil]

Re: challenge question ..

you are entirely correct about electric fields. they are not properly defined (yet) in common text books. actually, if you read the "definition" you find that the electric field defines itself.. which of course is wrong.
...
Mr.Cool

No mistery in this definition of field: a field is a property in the space caused/produced by something.

A charge causes/produces an electrical field
A mass a gravitional field

The property of the space is measurable and is proportional to the cause (generally linear).

 

[Mr.Cool]

challenge question ..

treehugger, i like your posting. i'll have to think on it for a while.

what immediately came to mind is relativity. lets say you have 2 electrons in motion, traveling in parallel at exactly the same speed, with NO other fields in interaction *(hypethetical to make understanding easier)*.

relative to one another, both electrons are "not in motion", so would there exist "no electrostatic effect" ?

Basil, there is great mystery!! even your own statement "a field is a property in spaced caused by something" umm.. that is the point of this thread. what is the source of the field? cause & effect. in your next statement, "a charge causes an electrical field" they are one and the same. again, i point the analogy of looking up a word in the dictionary and finding the definision is the same word! doesn't make any sense.

aryajur, a novel try. again, i have to disagree if only on the premise that there is NEVER a case when there is no other charge to interact with. even in vacuum there are trillions of charges in the smallest of volumn of space. how does an electron avoid this? it can't.

Mr.Cool

 

[aryajur]

Re: challenge question ..

aryajur, a novel try. again, i have to disagree if only on the premise that there is NEVER a case when there is no other charge to interact with. even in vacuum there are trillions of charges in the smallest of volumn of space. how does an electron avoid this? it can't.

Mr.Cool

I thought we just wanted 1 isolated charge in vaccuum , but if we assume many charges interacting then also the whole thing makes sense because if there are so many charges the forces that set up will do the work and finally neutralize the system by either pushing the charges to infinite distance or by combining. If something prevents this then that will be the source of evergy to maintain this.

 

[Basil]

Re: challenge question ..

...

Basil, there is great mystery!! even your own statement "a field is a property in spaced caused by something" umm.. that is the point of this thread. what is the source of the field?

The source of the field is the charge or the mass.

cause & effect. in your next statement, "a charge causes an electrical field" they are one and the same. again, i point the analogy of looking up a word in the dictionary and finding the definision is the same word! doesn't make any sense.

I agree dictionaries are unuseful because circular loops.

But the history of these concepts is: 1) first humankind discovered fields (many isolate magnetic an electrical experiments) and 2) then made a complete description of them (Maxwell) and 3) then at the beginnings of the XX century where explained via electrons (charge). Carged particles are conceptually so independent of fields the some prominent physics died before to believe in electrons. The point is charges exist independently from fields so dictyoinary analogy doesn´t aply.

If you ask how is charge changes the space stablishing electrical properties in any point sorrounding the charge I can't answer. Is this "The Mistery"?.

During the flat earth age most of people used to negate the world was round because "why the ships and water doesn't fall?" There was something there that caused everything to be sticked to a round planet. May be now to pursue trying to know what is going on between the charge and the field will show even a more oustanding thing than Newton discovered.

Personally I'm not as much interested in physics as when I were young. For me now the most interesting discoveries are comming from many "soft" sciences and I hope they will help to avoid the evil lone hyperpower dominance nevertheless most people of that country is travelling faster than ligth to religious fundamentalism. But from the same part of this planet we have got many good stuff like www.edge.org so, I'm optimist anyway.

 

[xaris106]

Re: challenge question ..

my opinion(and others`):
an electron alone in the vaccum does not "posesses" or "creates" an electric/magnetic field.this is because it has nothing to interact with.if you want to measure its field you must interact with it.so if its alone it does not loose energy in that matter.
now if you bring somehow anothel electron "near" it, they will interact by applying electromagnetic force,one of the fundamental forces.
now what exactly is that?
scientists(e.g ritchard feynman,nobel prize 1963) say that the carrier of the electromagnetic force is the photon.the photon carries momentum and energy from one electron to another for the time of the interaction.
(so if i`m an electron sitting around lonely and suddently see another electron, i will go like "go, my photons!!! go!!!")
these photons are called virtual photons because we can`t measure or see them A virtual photon is absorbed from the second electron almost immidiatelly after its is emmited from the first and vise versa.
The odd thing is here.
the virtual photons DO NOT obey the conservation of energy law.They are covered from the uncertainty law of quantum pshysics.that is, the photon returns the surplus energy "dE" in the very small time fragment it "lives".This amount of time is smaller of the boundary time set by the uncertainty law ,"dt", witch also sets the maximum allowed energy surplus dE=h(barred)/dt.
so again it does not loose energy.

I don`t know if that solves things,or makes it worse but maybe we can redifine the question to:
why, if i`m an electron (or any charged particle), i go berserk sending photons when i see one of my kind?why there are fundamental forces?

 

[Basil]

Re: challenge question ..

my opinion(and others`):
an electron alone in the vaccum does not "posesses" or "creates" an electric/magnetic field.this is because it has nothing to interact with.if you want to measure its field you must interact with it.so if its alone it does not loose energy in that matter.
....
I don`t know if that solves things,or makes it worse but maybe we can redifine the question to:
why, if i`m an electron (or any charged particle), i go berserk sending photons when i see one of my kind?why there are fundamental forces?

So, according to that vision the field doesn´t exist when it is not needed, the field (an abstraction which doesn´t mean more the 'interaction') appear when it's needed, i.e. when has to be measured.

I believe things exist even when nobody measures them.

We can always say "The moon behaves as a measuring device and because that exists the earth gravitatory field" but I prefer to save the aditional issue (the moon measures) and just believe the Earth has a gravitatory field given by

k*M/r²

no matter the moon is or is not there. And because the field equation has M, earth mass I say the mass produces a field, meaning that if M=0 (no mass) there is no field. Like I say the potential V produces the current I acording to Ohm's law.

 

[xaris106]

Re: challenge question ..

i think a field is a human creation to make things and computations easier.i don`t think it exists.it is there to describe how much force and in what range will be acted in a proper object from the source.it does not describes how that force will be applied.it`s a tool to calculate (present or future) interractions.So, if you imagine a lone electron and its field you are actually trying to explain what will happen if an other charged particle comes into range (virtual photon range?).how this force is applied is described by quantum mechanics (and theory).it is said that this force is (virtual)photon exchange.So if there is no other electron, there is no exchenge, hence no force,no "field".if a lone eletron emmited photons it would lose energy, and in the lowest energy state it does not want to do that.
now gravitational force is described by the general theory of relativity.mass actually bents timespace and the "force" we see it is actually normal "no force" movent in the bended timespace(i don`t know if i`m totally correct on this).
the gravity field is there with the same purpuse as above.
so we have 2 theories one describing the gravity force(relativity)and one describing the other forces(quantum theory).
the problem is we can`t unify the 2 theories for the time being,and that is what scientists work to(superstring theory?).The good thing is when we apply these theories(even simplified) we get good results and now you are reading this on a human created electron powered machine.