Photons and mass

[Michael Kieth Adams]

First of all. Please forgive any spelling problems.  I suffer from severe cataracts and often have trouble seeing the keyboard of my iPad.  Here is an idea I have had and wondered if it has any merit.  What if a photon both does and does not have mass.  Maybe a sort of Schrödinger cat type of thing.  Light is a particle and a wave depending on how you look at it. What if it is actually both and neither at the same time!?!   A photon of light can transfer momentum, can a wave of light do the same?    I am sure I am making all kinds of mistakes in logic here but what if momentum, instead of being a property of an object moving through space was actually a property of space time when it associates with mass.  I’m probably saying the same thing two different ways, but what if I’m not?  We try to put everything in its correct box but some things won’t stay, ie light, photon, wave.  Maybe the problem with Newtonian slash quantum physics is less actual and more an exercise in perspective?!?

[saac]

We generally talk about the rest mass and the relativistic mass of the photon. The rest mass, as the name implies, is the mass of the photon if it were brought to rest (not really possible). The relativistic mass is the mass of the photon in motion from which it has a derived momentum. It is the rest mass that can be shown (in theory) to be zero following electromagnetic theory  while the momentum of the photon is given by p = h λ , where h is  Plank's constant and λ is the wavelength.  I'm not totally sure but I think there have been some experimental calculations of a non rest mass on the photon, perhaps somebody will confirm.  In any respect I don't think there is any doubt that a wave can transfer momentum. As for perspective, the trouble is we either use a label which has an existing meaning (wave, particle) or we invent a completely new word for the property.  I'm not sure either has any benefit over the other tbh. 

Jim 

Edited October 15, 2023 by saac

[andrew s]

This gives the experimental rest mass as less tha 10^-48 kg.

The photon is the most enigmatic of quantum particles.  

From a quantum field theory perspective it is a localised excitation of the field. However,  its location is impossible to measure, most states of the field don't have any meaningful number of photons and it's very difficult to create single photon states!

I could go on.

Regards Andrew 

Edited October 15, 2023 by andrew s

[andrew s]

Incorrect post removed

 

Edited October 15, 2023 by andrew s

[saac]

The Crookes Radiometer is a device with an interesting history of what it purported to demonstrate regarding light and exchange of momentum.  Turns out like that other physics toy curio, the drinking bird, the explanation owes more to heat transfer.  It's an interesting device to generate discussion on the nature of light anyway. 

https://en.wikipedia.org/wiki/Crookes_radiometer

 

Jim

[Michael Kieth Adams]

Thank you.  A photon moves at the speed of light.  I cannot imagine it being anything like normal matter.  It moves too fast.  What if it is not really matter at all but an artifact of an electric wave and a magnetic one at right angles to each other?  I feel that we may be putting things in the wrong boxes.  Might a photon be a kind  of wave front. acting like a particle rather than an actual one?

[Michael Kieth Adams]

I’d like to really thank everyone.  I have cataracts which cannot be treated at the present time, and thanks to rhabdomyelitus, covid 19, and congestive heart failure I am having to learn to walk again at seventy three.  Thank you for taking my mind off things!

[andrew s]

6 hours ago, Michael Kieth Adams said:

 an artifact of an electric wave and a magnetic one at right angles to each other?

In essence that is exactly what it is. 

However, the connection between light and normal matter is demonstrated by pair production where a high energy gamma ray can produce an electron positron pair. 

Similarly,  a particle and its anti-particle can annihilate to photons.

Regards Andrew 

[andrew s]

6 hours ago, saac said:

The Crookes Radiometer is a device with an interesting history of what it purported to demonstrate regarding light and exchange of momentum.  Turns out like that other physics toy curio, the drinking bird, the explanation owes more to heat transfer.  It's an interesting device to generate discussion on the nature of light anyway. 

https://en.wikipedia.org/wiki/Crookes_radiometer

 

Jim

That was my incorrect post 😊

Solar sails are the only macroscopic example I can come up with.

Regards Andrew 

[Michael Kieth Adams]

XThanks Andrew.  It sounds as if we are talking about basically energy and matter as conditions of each other,  the  “ matterness”  of a photon might have todo with how we observe it.  Do we change its  nature when we measure it?  I’m writing this about three am.  Right now, ideas float around me like clouds in the sky, or vultures flying.  Because of my cataracts vultures will disappear in an otherwise normal appearing sky and reappear out of the clear blue elsewhere.   I can’t help feeling that we are often looking at the universe with cataracts invisibly blocking our vision here and there.  Have you heard of the plans to send tiny light sails towing tiny instrument packages to our neighbor stars?  All powered by photons!   Be well my friends.  Mike

[saac]

I'm presently revisiting Prof Lucie Green's wonderful book which explores and describes  the mechanics of the Sun and the processes that keep it shining.  The book is titled, 15 Million Degrees A Journey To The Centre Of The Sun, it really is captivating and highly recommended. In one of the early chapters she describes the improbable journey that photons must take in order to reach the sun's surface.   Notwithstanding the phenomenal speed in free space, she describes how, at the depths of the radiation zone, the photon's passage through the dense plasma is painstakingly slow, impeded by interactions with electrons  (Thomson scattering). With each interaction and scattering event she suggests that a photon may travel as little as 1 mm before being scattered again and as likely in a backward direction!  The photon's total journey time on its improbable walk to the surface taking some 170,000 years.  In contrast, neutrinos just glide past, at the speed of light,  without any interaction at all, and continue to pass through Earth in a similar way.  I guess the photon's passage through the radiation zone of the sun in many ways resembles the time prior to the so called "cosmic dawn" before recombination and the transparency of the universe. It certainly is an enigmatic particle for sure  as @andrew s said earlier. 

Jim 

Edited October 16, 2023 by saac

[Michael Kieth Adams]

We humans truly do not see very well.    If the production of a photon or a neutrino are both possibilities  light may be an expression of the energy in the electric and the magnetic waves.    What keeps photons photons as they bounce around the inside of the sun?    Why do they not break down to particle and antiparticle?    There must be some process that limits or prevents this.   Light slows down in different mediums, maybe the speed of light in plasma does not allow  energy levels high enough to produce  particles and antiparticles.  If not then shouldn’t the energy of the interior of the sun indicate particle and antiparticle  collision?  I’m going to stop here.    This is fun!

[andrew s]

25 minutes ago, Michael Kieth Adams said:

Why do they not break down to particle and antiparticle?    There must be some process that limits or prevents this

They have to be energetic enough to produce pair production. Then they can cause a star to collapse into a super nova see here

Regards Andrew 

Edited October 16, 2023 by andrew s

[iantaylor2uk]

16 hours ago, andrew s said:

This gives the experimental rest mass as less tha 10^-48 kg.

The photon is the most enigmatic of quantum particles.  

From a quantum field theory perspective it is a localised excitation of the field. However,  its location is impossible to measure, most states of the field don't have any meaningful number of photons and it's very difficult to create single photon states!

I could go on.

Regards Andrew 

I'm pretty sure people have fired single photons at double slits to show that photons only interfere with themselves (rather than other photons) to create the well known diffraction pattern associated with the wave like behavior of photons.

[andrew s]

2 hours ago, iantaylor2uk said:

I'm pretty sure people have fired single photons at double slits to show that photons only interfere with themselves (rather than other photons) to create the well known diffraction pattern associated with the wave like behavior of photons.

Indeed they have. They are dilute beams so that on average only one photon goes through at a time. The beam is not a single photon state in the sense I intended. 

Regards Andrew 

PS It might be worth adding for those less familiar with the topic that a single photon doesn't make an interference pattern.  It just makes a localised "hit". You have to pass a large number of single photon throught for the pattern to appear in line with the quantum perdition. Or better still prediction . Thanks @MalcolmP.

 

Edited October 16, 2023 by andrew s

[MalcolmP]

2 hours ago, andrew s said:

collapse into a super nova see here

Thanks, very interesting link.

1 hour ago, andrew s said:

for the pattern to appear in line with the quantum perdition.

Nice typo ! Some would certainly call quantum phy. to be the Road to Perdition
 

[saac]

41 minutes ago, MalcolmP said:

Thanks, very interesting link.

Nice typo ! Some would certainly call quantum phy. to be the Road to Perdition
 

I wouldn't be so kind  

Jim 

[andrew s]

2 minutes ago, saac said:

I wouldn't be so kind  

Jim 

Oh you engineer. Remember we would not be here but for quantum mechanics.  Classical atoms are unstable.

Regards Andrew 😌

[saac]

19 minutes ago, andrew s said:

Oh you engineer. Remember we would not be here but for quantum mechanics.  Classical atoms are unstable.

Regards Andrew 😌

Yes but they don't know that until we go and put a label on them   

Jim

[Michael Kieth Adams]

Thanks for my introduction to quantum perdition!   I have long contended that the universe depends on how it is perceived.  Point of view is vital.  Shroedingers cat told me so.