Thales Posted August 17, 2004 Posted August 17, 2004 But does inertial mass change enough to be taken into consideration? Particularly when trying to account for the orbitals 'chaotic' motion. Would it also effect the whole gravity of the situation? When something accelerates and gains mass, does it also have a greater gravitational infleunce? If an electrons position around the atom is so disordered how do we measure it? What if its velocity is so high it 'looks' like its going slow(think about chopper blades at certain speeds)?
Aeschylus Posted August 17, 2004 Posted August 17, 2004 The fact electrons have mass dictates they have radius, be it very very small. Keebs is correct. A dimensionless particle with a mass would create a singularity. Wrong. You simply cannot talk about elemnatry particles cretaing singularities as not enough is known The particles position however is what, to me, is more undefined. Even if it is moving at speed c or close too then it would increase its mass, meaning its rest mass may be much much smaller than we interpret it. Is it possible that the electron is more 'smeared' across the atom than in a stable 'orbit'. Clearly the particle will not have a defintie postion most of the time, but you still cannot use this to assign it a radius. We can be certain that our value for the elctrons mass is correc within experimentla error. The idea of the majority of an atom being empty space still doesn't sit well with me, even after years of physics. Though experimentally we can only ever put an upper limit on the radius of an electron, in the standard model electrons are point particles, infact the standard model gets into trouble if they are not. This is because if electrons are not point particles they will be subject to Lorentz-Fitzgerald contraction which will have a definite and noticeable effect and also I beleive it would violate gauge invariance.
swansont Posted August 17, 2004 Posted August 17, 2004 The only reason an electrons size would be arbitrary is because of the wave-particle duality of the electron. But the electron particle has a definite size. Dirac theory has the electron as a point particle; no structure. Every experiment of which I am aware that measures the size is consistent with zero. You can't state that a dimensionless particle will create a singularity until you have come up with a theory of quantum gravity.
Thales Posted August 17, 2004 Posted August 17, 2004 But gravity varies at a rate of [math]1/r^2[/math] so doesn't that mean if r is effectively shrunk to zero and there is still a mass contained inside that radius don't you create an infinite curvature of space-time?
fuhrerkeebs Posted August 17, 2004 Posted August 17, 2004 The measured magnetic moment of a free electron yeilds a radius 3.86607 x 10-13 meters. This also leads to the correct magnitude of the electron spin and the measured compton wavelength. A point particle electron doesn't.
fuhrerkeebs Posted August 17, 2004 Posted August 17, 2004 We just can't tell what shape the electron is...
pulkit Posted August 17, 2004 Posted August 17, 2004 But gravity varies at a rate of [MATH]\frac{1}{r^2}[/MATH] so doesn't that mean if r is effectively shrunk to zero and there is still a mass contained inside that radius don't you create an infinite curvature of space-time? This leads to the dirac delta function, its quite a frequent situation when you have inverse square dependence.
swansont Posted August 17, 2004 Posted August 17, 2004 But gravity varies at a rate of [math]1/r^2[/math'] so doesn't that mean if r is effectively shrunk to zero and there is still a mass contained inside that radius don't you create an infinite curvature of space-time? [math]1/r^2[/math] is from a classical gravity equation. Electron size is quantum mechanics. Danger, danger, Will Robinson!
swansont Posted August 17, 2004 Posted August 17, 2004 The measured magnetic moment of a free electron yeilds a radius 3.86607 x 10-13[/sup'] meters. This also leads to the correct magnitude of the electron spin and the measured compton wavelength. A point particle electron doesn't. Under what assumptions? Do you have a link for this?
Encrypted Posted August 17, 2004 Posted August 17, 2004 What about photons?? I have heard that they can exert pressure, so therefore they must be having mass. And if they have mass then they are matter, correct??? ______________ 32.22.7.11.2.9.42.31.22< Decode that...
swansont Posted August 17, 2004 Posted August 17, 2004 Photon momentum is E/c. The have no rest mass.
paganinio Posted August 20, 2004 Posted August 20, 2004 i have been wondering 'whether fire is matter or energy' for years, this thread is relative StarCraft comes to mind(that's a video game) in StarCraft, PHOTON CANNON shoots 'PHOTON', it looks like energy more than matter because when the assault is over, we ain't able to find the 'PHOTON' any more, if it's matter we must be able to find the 'PHOTON'.
paganinio Posted August 30, 2004 Posted August 30, 2004 i suggest this thread: Do photons have mass or not? http://www.mrfixitonline.com/readTopic.asp?PostingId=1634904
Thales Posted August 30, 2004 Posted August 30, 2004 I don't think StarCraft is a valid scientific reference.
Sorcerer Posted August 30, 2004 Posted August 30, 2004 For starters, its been said that photons have energy, but they aren't energy....... what else do they have that seperates them?? Photons have mass, but no rest mass..... how can u have a photon at rest? I've been told that all matter is comprised of energy, but that photons do not make up matter.... yet I have also been told that when matter and antimatter annihilate they produce radiation.... I always thought radiation was photons. So since matter produces photons and has mass, how can matter not be made from photons...... and how can it have mass if it is. Wouldnt the speed of light be the same even if photons did have mass.... it would just mean that things with less mass could go faster.... but since we cant observe them (cause they r travelling faster than c) they don't exist..... is this tachyons? Wouldn't it be impossible to measure the weight of a photon, since it would require a perfect scale, a huge ammount of photons a way of quantifying them and an exact measure of the weight of a vaccuum(which apparently has energy, and hence mass). Plus the ability to account for undetectable annomalies such as neutrinos which could be there too. As u can see I am tearing my hair out, and I don't go in for the classical 1 liner posts....... sorry if I confused u too.
TheProphet Posted August 30, 2004 Posted August 30, 2004 And they are indeed quantized. Mr Feaynman himself taut that at his lessons! ANd Yes Radiation is Photons. all sorts of electromagnetic(mechanic? *ach* waves are photons aswell!
Sorcerer Posted August 30, 2004 Posted August 30, 2004 And they are indeed quantized. Mr Feaynman himself taut that at his lessons! ANd Yes Radiation is Photons. all sorts of electromagnetic(mechanic? *ach* waves are photons aswell! Right, and that quantum depends on their wavelength, this is energy and as such is proportional to mass as in e=mc^2.... however photons don't have mass.... or no rest mass...... so its called momentum.... is this just an elaborate pseudonym.... I mean how can a photon ever be at rest???? ie if a photon were at rest wouldn't it cease to exist. The point I was trying to make with photons being radiation, is that when a matter and antimatter pair annihilate, they exactly cancel out and produce photons..... as such I would infer that photons make up the matter, however since photons have no mass then how did they make up something that does have mass. Perhaps I have oversimplified, or wherever I read this oversimplified..... apparently the theory goes there is a Higg's boson, and this interacts with neutrinos (also supposedly being 0 mass btw) which somehow produce the force called gravity........ so I guess the model of antimatter/matter annihilation must also contain bosons and neutrinos..... do these fall into the category of radiation? Btw I don't like the idea of wave particle duality, I don't care what people tell me I like to think for myself.... nowhere in the double slit experiment does it rule out the possibility that photons are wavefronts and that all light travels as waves, I think that it is only the interaction of a wave with matter that allows us to quantise the wave front and give it a measure of energy.... this does not seem to me to need to be visualised as a discrete entity... it is merely the causal result of the wave interaction. Bah u probably think Im an egghead..... but I have way more questions than answers... and my ideas are in no way mainstream.
TheProphet Posted August 30, 2004 Posted August 30, 2004 Bosons, Neutrinos: Nah, acording to our View of radioation itäs just POhotons... Momentum is energy that has a direction! No direction or Speed Then no momentum! So that photons have only momentum means actually what u point out! Photons are also energy exchannge particles: So when u anihiliate a Electron positron pair u get energy = Photons! Whom does really like the Particle-Wave Duality? Honestly? ANd i just love answers that simply state: Well it's due to the particle wave duality!.. *argh*
swansont Posted August 30, 2004 Posted August 30, 2004 ANd Yes Radiation is Photons. all sorts of electromagnetic(mechanic? *ach* waves are photons aswell! All photons are radiation, but not all radiation is photons.
5614 Posted August 30, 2004 Posted August 30, 2004 yes, i think TheProphet meant that: photons = radiation however there are many different forms of radiation... (photons being one of many)
TheProphet Posted August 30, 2004 Posted August 30, 2004 Well of course there are other forms Swansont, as you already know of, like Beta and Alfa! Alfa is Helium atoms and Beta is Hydrogen. Shure some more obscure too!
swansont Posted August 30, 2004 Posted August 30, 2004 Well of course there are other forms Swansont, as you already know of, like Beta and Alfa! Alfa is Helium atoms and Beta is Hydrogen. Shure some more obscure too! Betas are electrons. Alphas are Helium nuclei.
Flak Posted August 30, 2004 Posted August 30, 2004 I don't think StarCraft is a valid scientific reference. LOL
TheProphet Posted August 30, 2004 Posted August 30, 2004 Betas are electrons. Alphas are Helium nuclei. *arghhh** my memory isn't making much use to me right now...
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