Jump to content

Recommended Posts

Posted

When a photon is absorbed by an atom, does the atom lose some of its mass? Or does it keep its mass, as the electron hasn't left the atom, but just jumped to a higher energy level?

The atom gains mass if it absorbs a photon and no particles are ejected.

Could something with a mass travel at the speed of light, or is that scientifically impossible?

Not possible. The energy required tends to infinity as v approaches c.

I am still hung up on how a particle like object can travel in a wave like fashion, without having any charge or mass. Does light still move as a wave in a vacuum?

It's not a particle traveling as a wave. It's something that displays properties of both.

Posted

Is it not also the case that its wave aspect is everywhere? In which case it is not travelling.

 

Is this correct?

 

If it is, then the problem seems much greater than can be solved by fiddling around with ideas about masses and charges.

Posted

One question. If a photon moves at c, and therefore cant have mass, then does that also mean that if it moves at c, it cant have energy? As energy, mass and c are all part of the same equation.

 

If the mass is 0...

E=mc2

= 0 x (3 x 108 ms-1)2

E= 0?

 

Or, if a photon IS 3 x 108 ms-1

And there is NO mass. Then is the equation:

E = (3 x 108 Ms-1)

 

I am very lost.

 

Note: 2 represents "squared"

E=mc2 simply says their is a ratio between energy and mass.

Photons being the transmitters of energy.

Posted

Light being made up of charges would give it a dipole moment. We don't observe this.

I don't follow, why must light have a dipole moment if it were made up of charges?

 

And isn't that rather a large step from, light does not have a dipole moment, therefore light is not made up of charges?

Posted

I don't follow, why must light have a dipole moment if it were made up of charges?

 

That's what happens when you have two charges with fixed separations, as appears in the model. It was claimed to be "like a magnet."

 

 

And isn't that rather a large step from, light does not have a dipole moment, therefore light is not made up of charges?

 

All you need is one failure of a model, but if you want more, light is also massless.

Posted (edited)

That's what happens when you have two charges with fixed separations, as appears in the model. It was claimed to be "like a magnet."

 

 

All you need is one failure of a model, but if you want more, light is also massless.

Because an electron has mass, and light does not, does not necessarily mean that the two cannot be made of the same substance.

 

To show that the model is a failure, would require the inclusion of how an electron acquires the property of mass, and show that this would also give light the property of mass - therefore showing that the model is flawed.

 

Can that be done?

Edited by robinpike
Posted

Because an electron has mass, and light does not, does not necessarily mean that the two cannot be made of the same substance.

 

To show that the model is a failure, would require the inclusion of how an electron acquires the property of mass, and show that this would also give light the property of mass - therefore showing that the model is flawed.

 

Can that be done?

 

 

In this sort of case we apply occam's razor - rather than try to explain why two entities composed of the same material either do or do not have, rather than explain why we have a mysteriously disappearing dipole, rather than etc... we go for the simple explanation; light is not composed of a combination of charged particles. And until there is observational evidence that requires (or even hints at) something that the simple model does not cover we will stick to that simple model.

Posted

In this sort of case we apply occam's razor - rather than try to explain why two entities composed of the same material either do or do not have, rather than explain why we have a mysteriously disappearing dipole, rather than etc... we go for the simple explanation; light is not composed of a combination of charged particles. And until there is observational evidence that requires (or even hints at) something that the simple model does not cover we will stick to that simple model.

 

I agree with the principle of using Occam's Razor - but I disagree with your conclusion using it...

 

Having electrons and light made of the same substance is a much simpler mechanism than the suggestion that electrons and positrons create something different, i.e. light - and then having created this different substance, themselves disappear.

 

By the way, the reason why Occam's Razor applies, is because it is vastly more likely (just on a statistical basis) that we are in a universe that has simple mechanisms at its fundamental level, than a universe that has complex mechanisms at its fundamental level.

Posted

Because an electron has mass, and light does not, does not necessarily mean that the two cannot be made of the same substance.

 

To show that the model is a failure, would require the inclusion of how an electron acquires the property of mass, and show that this would also give light the property of mass - therefore showing that the model is flawed.

 

Can that be done?

 

The Higgs has been discovered. Does that count? Anything comprised of electrons can't be massless.

 

Photons are not deflected by electric or magnetic fields.

Photons are spin 1. Composite particles have multiple angular momentum states. There's also the possibility of multiple internal energy states. Neither of these are seen.

Posted

The Higgs has been discovered. Does that count? Anything comprised of electrons can't be massless.

 

They didn't say that photons are made of electrons..

 

Photons are not deflected by electric or magnetic fields.

 

Neutrons can be deflected by electric or magnetic fields?

Posted

They didn't say that photons are made of electrons..

 

Someone in this thread did.

 

Neutrons can be deflected by electric or magnetic fields?

 

Yes. Neutrons have a magnetic moment.

Posted (edited)

The Higgs has been discovered. Does that count? Anything comprised of electrons can't be massless.

 

Photons are not deflected by electric or magnetic fields.

Photons are spin 1. Composite particles have multiple angular momentum states. There's also the possibility of multiple internal energy states. Neither of these are seen.

 

I re-posted this thinking it didn't go in - not realising that the post was then moved to the Physics section.

 

So please reply to it in that section... thanks

 

The discovery of the Higgs is evidence, so yes, I agree it may count, as it was something predicted by theory.

On reading the Wikepedia explanation of how the Higgs mechanism gives mass to particles, it is very complicated.

I have a few questions:

Does the Higgs field give particles inertia, i.e. is that what giving mass to a particle, means?

If so, how the does the Higgs field avoid giving a particle continuous inertia that slows it down continuously?

And how does the Higgs field give a particle inertia according to Relativity, as presumably, a moving particle is not moving in its own reference frame, and so what reference frame is the Higgs field in when it interacts with a particle?

Edited by robinpike
Posted (edited)

The Higgs has been discovered. Does that count? Anything comprised of electrons can't be massless.

 

Photons are not deflected by electric or magnetic fields.

Photons are spin 1. Composite particles have multiple angular momentum states. There's also the possibility of multiple internal energy states. Neither of these are seen.

above post got duplicated

Edited by robinpike
Posted

I agree with the principle of using Occam's Razor - but I disagree with your conclusion using it...

 

Having electrons and light made of the same substance is a much simpler mechanism than the suggestion that electrons and positrons create something different, i.e. light - and then having created this different substance, themselves disappear.

 

By the way, the reason why Occam's Razor applies, is because it is vastly more likely (just on a statistical basis) that we are in a universe that has simple mechanisms at its fundamental level, than a universe that has complex mechanisms at its fundamental level.

 

Occam's razor is better applied to human explanations of physical phenomena rather than the phenomena themselves. Of two competing explanations of a single concept, in the absence of other factors, the most simple is to be preferred; it is not correct to say that the simplest concept is the most likely

Posted

Occam's razor is better applied to human explanations of physical phenomena rather than the phenomena themselves. Of two competing explanations of a single concept, in the absence of other factors, the most simple is to be preferred; it is not correct to say that the simplest concept is the most likely

 

However, when it comes to creating a universe, it is reasonable to expect simple universes to be created far more often than complicated ones.

 

If there is a simple way to create atoms and life, and there is a complicated way to create atoms and life, then it is far more likely that our universe is a version of the simple one.

Posted

However, when it comes to creating a universe, it is reasonable to expect simple universes to be created far more often than complicated ones.

 

If there is a simple way to create atoms and life, and there is a complicated way to create atoms and life, then it is far more likely that our universe is a version of the simple one.

It might be nice to expect straightforward and aesthetically correct foundations, to impose our concepts of statistically likelihood and human ideas of simplicity/complexity on the universe - but there is no need for that to actually be the case.

If you want to know the way nature works, we looked at it, carefully, that's the way it looks!

 

You don't like it..., go somewhere else!

 

To another universe! Where the rules are simpler, philosophically more pleasing, more psychologically easy.

Richard Feynman

The Sir Douglas Robb Lectures, University of Auckland, 1979

Posted (edited)

 

It might be nice to expect straightforward and aesthetically correct foundations, to impose our concepts of statistically likelihood and human ideas of simplicity/complexity on the universe - but there is no need for that to actually be the case.

Richard Feynman

The Sir Douglas Robb Lectures, University of Auckland, 1979

 

True, but ironically, it is easier to think of complicated explanations than simple explanations.

 

So, if you arrive at a complicated explanation, it is worth thinking about it some more to see if there is a simple explanation - for if there is - then that is far more likely to be how our universe works.

Edited by robinpike

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.