Relativity and its demerits.

[ovi issac]

It is wrong indeed becoz it only mentioned that photon has dual nature though having zero mass explain it in view of enistines concept 

Be amicable dear that is only way to reach conclusion 

[mistermack]

As far as I'm aware, the equations of relativity relating to rest mass apply to particles at rest, ie, in the rest frame that is co-moving with the particle. 

I think that for a photon, there is no such rest frame available. 

[swansont]

15 minutes ago, ovi issac said:

It is wrong indeed becoz it only mentioned that photon has dual nature though having zero mass explain it in view of enistines concept 

It has a dual nature because everything at the quantum level has a dual nature.

It's Einstein, not enistine.

40 minutes ago, ovi issac said:

I am claiming that eneisteins theory was lacking few concepts like relative mass of something that had zero mass OK u explain it 

It also doesn't explain evolution. Theories have limits. Relativity is not a theory that purports to explain the nature of photons.

Having said that, Einstein did deduce the nature of the mass-energy relationship, and from that we can find that E² = p²c² + m²c⁴
A massless photon has E=pc, which is consistent with classical EM 

[ovi issac]

4 minutes ago, swansont said:

It has a dual nature because everything at the quantum level has a dual nature.

It's Einstein, not enistine.

What about debronglie lambda =h/ MV it is not applicable at quantum level only hahaha 

7 minutes ago, swansont said:

It has a dual nature because everything at the quantum level has a dual nature.

It's Einstein, not enistine.

It also doesn't explain evolution. Theories have limits. Relativity is not a theory that purports to explain the nature of photons.

Having said that, Einstein did deduce the nature of the mass-energy relationship, and from that we can find that E² = p²c² + m²c⁴
A massless photon has E=pc, which is consistent with classical EM 

Nice but where from the apparent mass of massless quantity can evolve 

[swansont]

Just now, ovi issac said:

What about debronglie lambda =h/ MV it is not applicable at quantum level only hahaha 

deBroglie.

lambda = h/p

p=mv is only applicable for object with rest mass, and deBroglie's equation applies to everything. You just only notice it at the quantum level. (One does not noticeably diffract when walking through a doorway, for instance) 

[ovi issac]

3 minutes ago, ovi issac said:

What about debronglie lambda =h/ MV it is not applicable at quantum level only hahaha 

Nice but where from the apparent mass of massless quantity can evolve

4 minutes ago, ovi issac said:

What about debronglie lambda =h/ MV it is not applicable at quantum level only hahaha 

Nice but where from the apparent mass of massless quantity can evolve 

Every thing at quantum level has dual nature but photon is nothing at all but energy as having no rest mass so what about that do u mean energy on quantum level behaves as particle 

3 minutes ago, swansont said:

deBroglie.

lambda = h/p

p=mv is only applicable for object with rest mass, and deBroglie's equation applies to everything. You just only notice it at the quantum level. (One does not noticeably diffract when walking through a doorway, for instance) 

Nice then if it is applicable for quantity having mass then do u mean energy behaves as particle 

2 minutes ago, ovi issac said:

Nice then if it is applicable for quantity having mass then do u mean energy behaves as particle 

We cannot measure the lapse between transition between two dual behavior of photon as it is so rapid we pretend that both natures exist simultaneously

And at highest density point it has particle nature and energy nature at threshold value density ... Energy for compression is obtained from the energy associated with its particle nature 

[studiot]

32 minutes ago, ovi issac said:

It is wrong indeed becoz it only mentioned that photon has dual nature though having zero mass explain it in view of enistines concept 

Be amicable dear that is only way to reach conclusion 

No, it is you who is wrong.

The photon does not have dual nature.

The photon is a particle.

But light has dual nature since aspects of the behaviour of light are consistent with wave theory and with not particulate theory.

By the same token, some aspects of light are only consistent with particulate theory.

And we call those particles that observe this behaviour, photons.

 

I am disappointed that when I pointed out the only maths equation you have quoted so far (in your opening post) is incomplete and you are completely silent on that subject.

 

[ovi issac]

If photon is mass less then it is only energy ... If we say it has particle nature then we shud say energy has particle nature ... Then every kind of energy shud have particle nature 

3 minutes ago, studiot said:

No, it is you who is wrong.

The photon does not have dual nature.

The photon is a particle.

But light has dual nature since aspects of the behaviour of light are consistent with wave theory and with not particulate theory.

By the same token, some aspects of light are only consistent with particulate theory.

And we call those particles that observe this behaviour, photons.

 

I am disappointed that when I pointed out the only maths equation you have quoted so far (in your opening post) is incomplete and you are completely silent on that subject.

 

Where was that incomplete bro I am not wrong ... OK let u explain dual nature how it is possible for zero mass quantity 

But I am not denying its dual nature but trying to explain its existence 

Dear f is free energy associated with every particle in nature .. It is new term not preworked one that is why u r confused 

[studiot]

3 minutes ago, ovi issac said:

Where was that incomplete bro I am not wrong

Since you can't seem to read either your own writing or mine let me try again

6 minutes ago, studiot said:

I am disappointed that when I pointed out the only maths equation you have quoted so far (in your opening post) is incomplete and you are completely silent on that subject.

I have underlined the part of my post where I told you just exactly where that incomplete bro lies.

[ovi issac]

U meant equation is incomplete 

[studiot]

2 minutes ago, ovi issac said:

U meant equation is incomplete 

That is exactly what I did say.

From what I can see you do understand reasonably good English, you just aren't prepared to use it.

Don't you think that is rude to other members here?

[ovi issac]

And f is free energy not fruquency 

 

1 minute ago, studiot said:

That is exactly what I did say.

From what I can see you do understand reasonably good English, you just aren't prepared to use it.

Don't you think that is rude to other members here?

But where u found I am feeble in English 

Have u found any correction in my content I posted initially 

[studiot]

2 minutes ago, ovi issac said:

And f is free energy not fruquency 

 

But where u found I am feeble in English 

You have already been told that 'u' is not a word in any English dictionary.

[ovi issac]

I am well in English but yaar it seems u r not well prepared to understand physics 

Being Indian u is short form of you

48 minutes ago, mistermack said:

As far as I'm aware, the equations of relativity relating to rest mass apply to particles at rest, ie, in the rest frame that is co-moving with the particle. 

I think that for a photon, there is no such rest frame available. 

Nice dear that is what I was trying to say sofar and if rest frame for photon doesnt exist then how to explain its relative mass 

[Strange]

1 hour ago, ovi issac said:

Photons are masless but apparent mass can be defined only for those particles having definite rest mass ...

Why?

1 hour ago, ovi issac said:

what about term particle nature of photon ... Explain it 

It simply describes the fact that light is quantised; i.e. either the whole photon is absorbed or nothing. It doesn't mean they are little balls. 

[studiot]

 

Several members have told you useful things that anyone genuinely interested in Physics would wish to know or, if they did already know, then simply say a friendly 'yes I have come across that' or wording to that effect.

 

You either ignore these things that are said to you in good faith or argue with them.

Is that a good strategy?

[Thorham]

What do mass and massless actually really mean? Can't you just say that photons belong to a class of particles that behave one way, while things like protons are part of a class of particles that behave in another way?

Just thinking out loud

Edited September 18, 2017 by Thorham

[mistermack]

1 hour ago, ovi issac said:

Nice dear that is what I was trying to say sofar and if rest frame for photon doesnt exist then how to explain its relative mass 

But in your OP you said that if something doesn't have rest mass, it doesn't exist. I don't see how you derived that conclusion.

Something moving at the speed of light can't have rest mass, but it doesn't follow from that that it doesn't exist. It just means that the equations for rest mass don't apply to it. It can still have energy, and hence exist, as a result of it's momentum. Momentum that is not the product of mass and velocity, but still momentum.

[geordief]

2 minutes ago, mistermack said:

But in your OP you said that if something doesn't have rest mass, it doesn't exist. I don't see how you derived that conclusion.

Something moving at the speed of light can't have rest mass, but it doesn't follow from that that it doesn't exist. It just means that the equations for rest mass don't apply to it. It can still have energy, and hence exist, as a result of it's momentum. Momentum that is not the product of mass and velocity, but still momentum.

How would one calculate the momentum of a particular quantity of light if one is not using the  formula involving mass and velocity? (not being argumentative ,I genuinely have not studied this)

[Silvestru]

41 minutes ago, Thorham said:

What do mass and massless actually really mean? Can't you just say that photons belong to a class of particles that behave one way, while things like protons are part of a class of particles that behave in another way?

Well we already have these classes called Bosons and matter particles called Fermions (quarks, and leptons).

This is a bit confusing because while photons and gluons have 0 mass, the Z and W bosons have mass.

[mistermack]

5 minutes ago, geordief said:

How would one calculate the momentum of a particular quantity of light if one is not using the  formula involving mass and velocity? (not being argumentative ,I genuinely have not studied this)

Nor I, so don't quote me. I think momentum equals it's energy divided by the speed of light. So it's going to be tiny. But still enough to change the course of an asteroid over time, with enough hits from photons.

[ovi issac]

34 minutes ago, mistermack said:

But in your OP you said that if something doesn't have rest mass, it doesn't exist. I don't see how you derived that conclusion.

Something moving at the speed of light can't have rest mass, but it doesn't follow from that that it doesn't exist. It just means that the equations for rest mass don't apply to it. It can still have energy, and hence exist, as a result of it's momentum. Momentum that is not the product of mass and velocity, but still momentum.

Yes dear energy does exist independently however mass doesn't exist independly . means mass less particles may contain energy but can not exhibit particle characteristics 

[Silvestru]

3 minutes ago, ovi issac said:

means mass less particles may contain energy but can not exhibit particle characteristics 

Also not true
https://en.wikipedia.org/wiki/Wave–particle_duality

http://photonterrace.net/en/photon/duality/

[mistermack]

9 minutes ago, ovi issac said:

Yes dear energy does exist independently however mass doesn't exist independly . means mass less particles may contain energy but can not exhibit particle characteristics 

I don't get what you mean by independently.  Also, what particle characteristics do you mean? You have matter particles and you have bosons. A photon is a boson, it won't have the same characteristics as a fermion. 

[swansont]

3 hours ago, ovi issac said:

Nice then if it is applicable for quantity having mass then do u mean energy behaves as particle  

Energy is a property of things. So no, energy does not behave as a particle. Electrons do, though. The have energy and momentum. They also behave like waves.

38 minutes ago, ovi issac said:

Yes dear energy does exist independently however mass doesn't exist independly . means mass less particles may contain energy but can not exhibit particle characteristics 

And yet they do, which is perfectly consistent with the theories that predict such behavior. Again, if you want to call this into question, you need to show where experiment does not conform with theory. For example, if photons had mass, they would not travel at c. Yet there is no experimental evidence that this is the case.