Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: allan marsh on 12/06/2014 19:08:23

Title: What is the smallest?
Post by: allan marsh on 12/06/2014 19:08:23
What is the smallest particle that can exist before its properties cease it to become considered as a particle?
Title: Re: What is the smallest?
Post by: chiralSPO on 12/06/2014 19:13:29
what do you mean by smallest? A photon is a particle with zero mass--it's hard to get "smaller" than that...
Title: Re: What is the smallest?
Post by: allan marsh on 12/06/2014 19:35:11
My radiometer questions thar!
Title: Re: What is the smallest?
Post by: JP on 12/06/2014 20:53:52
My radiometer questions thar!

If your radiometer is questioning things, maybe it's time to get a non-sentient radiometer?
Title: Re: What is the smallest?
Post by: jccc on 13/06/2014 02:00:56
what do you mean by smallest? A photon is a particle with zero mass--it's hard to get "smaller" than that...

How come any particles has zero mass? Dose some particles have negative mass?

How to accelerate something with zero mass? F=ma, m=0, therefore, a=0.

Where photons come from and go to? What's the mechanism?  Thanks.
Title: Re: What is the smallest?
Post by: PmbPhy on 13/06/2014 04:45:31
Quote from: allan
What is the smallest particle that can exist before its properties cease it to become considered as a particle?
There is none. The term particle has two meanings. The first makes the term subjective since in this definition an object is called a particle when its size is small compared to the size of all other objects in the scenario and small compared to the characteristics of the gradient of the field the object is in. The second definition of particle defines it as having no dimensions whatsoever. Think of a sphere with zero radius and you can all that a particle. Many particles exist that fit this latter definition such as electrons, photons, neutrinos etc.

Quote from: jccc
How come any particles has zero mass?
They really don’t. He was talking about proper mass which is the value m that appears in the relationship

E2 + (pc)2 = m2 c4

The mass you’re thinking of is the m that appears in the relationship

p = mv

Quote from: jccc
Dose some particles have negative mass?
None have ever been observed in the lab or in nature or even theoretically.

Quote from: jccc
How to accelerate something with zero mass?
They can’t be accelerated. They are created moving at the speed of light and they will always move at the speed of light so long as they exist.

Quote from: jccc
Where photons come from and go to? What's the mechanism?  Thanks.
For example; if an atom is in the excited state and it transitions to a state of lower energy it will emit a photon. That’s one way they are created in lasers. Also when charged particles are accelerated radially they emit an intense beam of photons which is called synchrotron radiation
http://en.wikipedia.org/wiki/Synchrotron_radiation
Title: Re: What is the smallest?
Post by: allan marsh on 13/06/2014 22:07:40
We after all that discussion you can explain superposition and entanglement.
I wait. .... In time!
Title: Re: What is the smallest?
Post by: PmbPhy on 13/06/2014 23:56:47
We after all that discussion you can explain superposition and entanglement.
I wait. .... In time!
What does that have to do with my response and this thread? If you want to discuss those things then it's best to start a new thread rather than taking over this thread for your own purpose.