Electromagnetic radiation and gravity

[Mild mannered]

I've read loads on gravity and light - QED etc and enjoyed all of it - though still frustrated that so much is still in doubt / unknown.

One thing that recurs again and again is the similarity between these two subjects.

They travel at the same speed and such - now mostly the connections/similarities might turn out to be spurious but still they are interesting.

A particle is highly radioactive (more massive than a/another less radioactive particle) and has greater gravity. We accept this obvious connection.

My thought / question was:

If you get equal and opposite forces and if all particles have an anti particle - can elctromagnetic radiation / light that radiates out from atoms have gravity as its anti - whatever - because clearly it is focused inwards and would balance the effect of the outward going radiation.

Are light (all electromagnetic radiation - not just visible light) and gravity opposite ends of the same spectrum?

+/Light - -/Gravity

Also - we accept that magnetism is bi-polar but say that gravity is mono (directed inwards) - and that all electromagnetism raidiates (outward)

Lastly - I was imagining a particle sitting in space - motionless to a given frame of reference- it is spitting out radiation because it is a highly radioactive particle. Would it not move about? (equal and opposite forces) or does the radiation come out so evenly that it stays motionless - (I don't beleive this is posssible)

Rather I beleive that the raditaion is counter balanced by an inward facing -force (gravity)

PS:

If Gravity is the -wave of electromagnetism then if we could reverse the electromagnetism somehow (like in an implosion - but to the nucleus) would we get + gravity (anti gravity)

I'm sure I'm wrong somewhere but was intrigued enough by the seeming interconnections to ask.

[Matthew]

As to gravity and electromagnetism being connected there is almost no doubt. But how? Its the unified field theory, or the theory of everything, that we are looking for. As such we don't have a theory that explains how gravity and electromagnetism can interact (except for gravity bending light, but thats as far as it goes). These theories would take into account every one of the 4 forces (electromagnetism, gravity, the strong force, and the weak force).

[Mild mannered]

Originally posted by matthew@Oct 27 2004, 09:09 AM
As to gravity and electromagnetism being connected there is almost no doubt. But how?

Thanks for the reply Mathew -

Anybody else got uptodate answers / theories on this - I'm not taking an electric universe stance (I don't think) there are a lot of debates on the site on this already - but it's this anti-particle/wave idea that intrigued me

If Gravity is the symetry of electromagnetic waves (and I believe in a supersymetric universe) then it is a reverse sign wave and should be flowing backward in time also (or would it?)

- how would you best look for gravity as an anti particle rather than the conventional plus particle we are looking for?

[antoniseb]

Originally posted by Mild mannered@Oct 26 2004, 09:15 AM
Lastly - I was imagining a particle sitting in space - motionless to a given frame of reference- it is spitting out radiation because it is a highly radioactive particle. Would it not move about? (equal and opposite forces) or does the radiation come out so evenly that it stays motionless

Hi Mild,

If a particle is highly radioactive, you are either talking about an atomic nucleus, or a fundamental particle with a half-life. In either case, when it gives off some kind of radiation, whether it be gamma-rays, electrons&neutrinos, neutrons, alpha particles, or something else, there will be a recoil. Momentum is conserved. When this happens, the particle is changed, and is perhaps less radio-active, or not radioactive at all.

In any case, the gravitational attraction that a single Uranium nucleus has is *very* small, and can for most purposes be discounted altogether.

While there are some ways that light and gravity can be compared, there doesn't, at the moment, seem to be a practical way to say that they are two parts of the same thing, unless that thing is everything-in-the-universe.

[GOURDHEAD]

As to gravity and electromagnetism being connected there is almost no doubt. But how? Its the unified field theory, or the theory of everything, that we are looking for. As such we don't have a theory that explains how gravity and electromagnetism can interact (except for gravity bending light, but thats as far as it goes).

You continue to ignore the Shmoo field at your peril!!

[wstevenbrown]

Much gets made of the fact that the equations are so similar. It is more the case that our perceptions are similar, and the equations reflect our approach, our allowed ways of knowing. In general, FORCE = CONSTANT X CHARGE X CHARGE divided by DISTANCE^2. If the force is gravity, the charge is mass, and the constant is only there to make sure the units come out right. BUT-- all of the forces other than gravity are so-called gauge theories. That is, the force that is felt is the result of the exchange of particles between the interacting bodies (usually considered only two at a time).

Even though gravity is classed as a force, it is too different from the other forces to fit comfortably in the same theoretical framework. For one thing, it only attracts. Trying to make repulsive gravity (other than in social situations) requires a negative mass, and as far as we know, that can't happen in this universe-- even antimatter has positive mass. Also, whatever the gauge particle is for the gravitational force, we have never detected it. We may not be equipped to detect it; some of its quantum numbers (read dimensions) may be those that we don't participate in.

Photons, on the other hand, are the gauge particles of the electromagnetic force, the means of communication between two bodies carrying electric 'charge'.

We have got a pretty good handle on what 'mass' is-- it's energy divided by c-squared, which gives us well-behaved dimensions of measurement. For the electromagnetic force, try to figure out exactly what the dimensions of 'electric charge' are, so that the dimensions come out right.

The point of the comparison is this: gravitation and electromagnetic force have more differences than similarities. Direct comparison isn't comparing apples and oranges, it's more like comparing alligators to alligator pears. When we reason too far by analogy, we may become mystics. Thanks for your patience-- I get a little sententious, sometimes. S.

[Guest_Mild Mannered]

Originally posted by wstevenbrown@Oct 27 2004, 03:30 PM
Photons, on the other hand, are the gauge particles of the electromagnetic force, the means of communication between two bodies carrying electric 'charge'.

Thanks for your patience-- I get a little sententious, sometimes. S.

No worries wstevenbrown - thanks for your excellent and thoughtful input

This kind of question requires a great deal of patience!!!

If the Gravity (gauge) particle is negative - and is time reversed also how would we try to observe it - surely all the usual ways would be meaningless - as you say we would be ill equipped to ever see it.

I take your point about seeming similarities and how dangerous that is though - but everything else in the universe is so inticately interlinked and Gravity is connected to mass so maybe these apples and pears are more similar in fact than we currently perceieve

Thoughts anyone?

[Guest]

Originally posted by antoniseb@Oct 27 2004, 01:59 PM
there will be a recoil. Momentum is conserved. When this happens, the particle is changed, and is perhaps less radio-active, or not radioactive at all.

Thanks Ant

Can we (do we) observe this recoil or does it go inward - if it does then it could be the gravity particle / wave we are looking for - certainly it would be proportional in the same way we'd expect gravity and would vary as the particle radiated energy / lost mass.

You say the gravity for a Uranium particle would be very small - as far as I know it is a very weak force we are looking for.

Not that I know much about all this - I really don't - I was just wondering at the connections

Oops - just realised that I don't think I'm logged in (typing from home now) sorry

And thanks again

Gourdhead, Hi

Forgive my ignorance

What's a Shmoo field?

Mild

[antoniseb]

Originally posted by Guest@Oct 27 2004, 04:19 PM
Can we (do we) observe this recoil or does it go inward

I don't know what you mean by go inward.

There's nothing magical about this. It is the same kind of recoil you feel if you are holding a gun when the bullet is fired from it.

For example, if you have a a Radon-222 nucleus floating in space. It will emit an alpha particle [two protons and two neutrons] on average 3.8 days after it was created. This means, after the alpha decay, there will be a rapidly moving alpha particle going one way, and a less-fast moving Polonium-218 nucleus going the other.

This alpha particle has an energy of 5.59MeV which in MKS units is about 9x10^-13 Joules, and a mass of about 6.6x10^-27 kilograms.

Since KE = 0.5mv^2 we can divide both sides by m and get v-squared = 6.8x10^13. So the velocity of the alpha particle is about 8.3 million meters per second.

Momentum is conserved, so the momentum of the alpha particle must be equal and opposite the momentum of the Polonium nucleus [in the rest frame of the original Radon nucleus], So the Polonium nucleus will be travelling at about 150 thousand meters per second [(4/218) the velocity of the alpha].

This is the recoil. It took nothing more than some easy first year physics to calculate it.

[Mild mannered]

Originally posted by antoniseb@Oct 27 2004, 05:24 PM
I don't know what you mean by go inward.

Momentum is conserved, so the momentum of the alpha particle must be equal and opposite the momentum of the Polonium nucleus [in the rest frame of the original Radon nucleus], So the Polonium nucleus will be travelling at about 150 thousand meters per second [(4/218) the velocity of the alpha].

This is the recoil. It took nothing more than some easy first year physics to calculate it.

Thanks again Ant

I know I have a problem expressing what I mean but what I meant by inwards was that when there was a recoil - nicely worked out by your 1st year physics which was way beyond me as I never got that far! - there might be an excess of energy not quite accounted for and that nature being the clever bookkeeper she is would apply that energy in some way to cancle the equations.

I was supposing that that would be Gravity. By inwards I meant (like an implosion)back into the nucleus - so it would be the cause of attraction to other atoms.

Gravity is essentially a sucking / attracting force (as I understand it) and I always wondered how if it was doing this work conservation of energy was maintained as I don't believe it is truly energy for free.

If it is a negative force to electromagnetic radiation and balanced by a small excess from that neat (but maybe not exact) recoil would this be a good balancing of natures "books"?

As I'm at great pains to point out I have very little expertise at this and was just wondering.

i'm sure the explanation you gave is satisfactory and correct but that leaves us with wondering what Gravity actually is and where it's energy is conserved?

(at least it leaves me wondering and scrathing my aching head at very odd hours of the morning&#33

Mild(ly confused) :blink:

[StarLab]

And this is where I come in.

Gravity is not a force.
Oh, and a photon carries energy. I'm not sure whether it has volume. I think that might help.

And there's got to be a threshold, because gravity and electromagnetism are the same force, except one is geometrically flat and the other is geometrically volumized.

And, in a field devoid of gravity, everything is spread out evenly. With gravity, things can exist in clumps. That threshold I just talked about is the threshold that separates these two concepts; and I think that threshold can be expresed mathematically: velocity (electromagnetism) x frequency = acceleration (gravity)

And this is where I leave you.

[zephyr46]

I though that alpha particles were the emmision of a proton, and betas were electrons. Named after the order of there discovery.

And if gravity waves do exist, they could be likened to seismic wave, that can be expressed in the EM spectrum as the force they exert?

Explorers Map of the Electromagnetic Spectrum

This is the most thorough treatment I have seen, it still leaves out gravity This Encyclopedia Britanica entry suggests that Gravity can be described as a radiation. My question is, arn't we talking about a gentle giant of a siesmic wave?

My other feeling is that our evidence for gravity is in motion itself, electricity is an electron carried on a gravity wave, thus we get the feild the distribution of electrons on a gravity wave, though it may appear stationary, we must keep in mind that stationary to us is an orbit of 65,000 mph (105,000 kph) around the sun, 250 kps around our galaxy. So feilds are in motion as well.

I always feel nausious ( :blink: ) when I think about the speeds and Earth/Sun center of gravity. Like a big showride.

[Mild mannered]

Originally posted by StarLab@Oct 28 2004, 06:20 PM
And this is where I come in.

Gravity is not a force.

And there's got to be a threshold, because gravity and electromagnetism are the same force

?
Hi Starlab - thanks for yuur input - not too up on on the volume issues but i'm pretty sure it's [gravity] either a force or not - can't be both. (though I remain Heisenberg-ly uncertain&#33

Or did I read you wrong?

zephyr46

Hi and thanks also -

And if gravity waves do exist, they could be likened to seismic wave, that can be expressed in the EM spectrum as the force they exert?

I like this idea of spectrum and seismic description.

I will be starting two new threads - questions regarding gravity later and one concerns this (kind of)

Mild

[StarLab]

Or did I read you wrong?

Actually, yes, you did.

I should have said

gravity and electromagnetism are the same thing

instead of...

gravity and electromagnetism are the same force

[Mild mannered]

Originally posted by StarLab@Oct 29 2004, 03:32 PM

gravity and electromagnetism are the same thing

Are they? (I don't know)

I know they are similar but not the same as electromagnetism has polarity unlike Gravity.

[ferg.c.]

If Gravity and EM radiation are the same thing then why don't we all go weightless in the middle of the night?!?!?!?!?
Sorry if this is a bit sarcastic but come on guys I'll drag you about with my standard lamp from IKEA! I don't think so!
Ferg h34r:

[StarLab]

One thing I like to ponder:

Attractions between gravity sources is just a natural "falling-in" based on bends and distortions in spacetime, whereas electrical or magnetic phenomenon are drawn towards each other because of "charge." That's always confused me.

[Mild mannered]

Originally posted by StarLab@Oct 30 2004, 04:40 PM
One thing I like to ponder:

Attractions between gravity sources is just a natural "falling-in" based on bends and distortions in spacetime, whereas electrical or magnetic phenomenon are drawn towards each other because of "charge." That's always confused me.

Star mate,

Not that I'd argue with the folding in off space time stuff - ever - but if that's all it is then why do fall down hill so to speak - this folding in is directional. I'm looking basically for why.

Ferg mate - hey I buy at Ikea too - it's where I get most of my theories (no surprises there&#33

I agree - Gravity is different to electromagnetic radiation but also I think very closely connected. Someone please help - the doctors are coming...

[zephyr46]

I like to think of gravity as mass, as the combination of the polarity. All matter is made up of positive and negative charge, the combined attraction is not as strong due to the repulsion, but take a human for example, and the Earth, there is a lot of Protons and electrons that combine to keep us on the ground. ( I could be very wrong though :unsure: )

It shares the Inverse Square Law with light and other radiation and feilds.

If I have any understanding, then gravity is the basic magnetic force, and the magnetic feilds are the loose effects of free protons and electrons.

This should maybe be in alternative theories.

I am still trying to understand neutrons, one discription is that of a combined Proton and Electron, this explains the mass and neutral electrical charge, but gives rise to the strong force. If this were the case, then it should also explain gravity, which it doesn't quite the opposite, it creates the theoretical partical, the Gravaton.

This hyperphysics explains the current theory as I understand it, based on the strength of the identified forces.

[StarLab]

Zephie, mate, you're losing yourself. You were fine when going over protons and electrons, but then you got high when talking about neutrons. Lemme pitch in.


Neutrons have nothing to do with gravity. Neutrons are simply what balance the atom. Thousands of particles can orbit a proton, but the neutron is largely responsible for keeping the protons and electrons locked together. That's why heavier elements fall apart due to neutronic weaknesses and instability. The strong force governs the nucleus until the weak force pulls it apart (and here, size does matter.)

Although, neutrons certainly add a bit of weight, and when protons and electrons are all but absent or absorbed, the neutrons can squeeze together into a neutron star, hence the name.

I, too, like to think of gravity as mass (and acceleration, of course.)

[zephyr46]

Table of Baryons

Gives the rest mass of a Proton as 938.3 MeV/c^2
and the rest mass of a Neutron as 939.6 MeV/c^2

and

rest mass of an Electron as 0.511 MeV/c^2

I had read in a chemistry dictionary that description, that a neutron was a combined proton and electron, but the mass just isn't there.

Interesting, about the postron electron collision resulting in two gamma rays.

[StarLab]

Well, particle + antiparticle = pure energy

Any thoughts about the idea that matter and energy are the same thing? Like, what makes them different? What's this "thing" that they're the same versions of?

[zephyr46]

If you collide to gamma rays do you get a postitron electron pair?

I wouldn't be suprised if there is something else undected going on, smaller particles, peaces of quarks maybe.

[StarLab]

No. Gamma rays cannot be "turned" into another form of energy, unless condensed...and I'm not sure that even that is possible, since pure electromagnetic radiation is a form of heat energy, which is that energy known as entropy, thus following one of those thermodynamical laws.

[Mild mannered]

Originally posted by StarLab@Nov 1 2004, 04:13 AM
Any thoughts about the idea that matter and energy are the same thing? Like, what makes them different? What's this "thing" that they're the same versions of?

That must be one of the most important questions in physics!

Answers on a postcard please...

Drifting into alternate theories for a second.

The lowest common denominator that is present in all things is the base form of energy that the original 1st nano-second of the universe coughed up. And that's what I think it was - Time - the original energy - without it there would never have been a universe for any other energy to exist in - then space/time - then space/energy/time - then space/energy/matter/time - (our time) ( Joke: Hammer time - for those old enough to remember&#33

Sorry for the drift - this was only a question at the start

Thanks for your continuation of the thread guys - very interesting speculation

[rahuldandekar]

Matter and energy have a very interesting relation between them. But I don't know if particle physics explains it too- infact, they are searching for a higgs boson to explain mass. But matter - how is energy converted into matter? Who explains that?

Talking about gravity and elctromagnetism, the fundamental difference lies in two things - mass and charge, and the relative strength. Thus, gravity and electromagnetism are definitely not the same, atleast in a low energy world. Not unless a unified theory is found connecting the two.

[Mild mannered]

Originally posted by rahuldandekar@Nov 1 2004, 09:59 AM
But matter - how is energy converted into matter?

This is a very interesting - but different question - why not start a new thread? - I'd certainly like to read the answers

Mild

[ferg.c.]

It shares the Inverse Square Law with light and other radiation and feilds.

Hi zephyr,
This is a bit spurious, like saying that cheese is like Andromeda is like my big toe because it's made of matter. It's probably easier to name the things that don't follow the inverse square law with regards to thier effect at various distances than those who do! We are looking for more specific connections.
Don't fall into that trap!
Cheers
Ferg.