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mite
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Can we find massless particles at rest? and why?
Have a read of the similar threads listed below.mite said:Can we find massless particles at rest? and why?
This is wrong. Firstly, you agree that SR requires that a massless particle travel at c. In other words, physics currently predicts that all massless particles must travel at c. So can you now see the problem with asking physics to predict what would happen if we had a massless particle that didn't travel at c?mite said:Thanks for replying
I understand massless particles travel at light speed & we cannot have massless particles at rest.
but if we just consider we have a massless particle at rest & suppose we apply a small force on it.
As massless particle wouldn't oppose being accelerated so its velocity will keep on increasing to infinite speed but ofcourse special relativity doesn't allow that.
So these massless particles reaches the ultimate speed possible the speed of light.
Is this right or wrong?
Hootenanny said:This is wrong. Firstly, you agree that SR requires that a massless particle travel at c. In other words, physics currently predicts that all massless particles must travel at c. So can you now see the problem with asking physics to predict what would happen if we had a massless particle that didn't travel at c?
Hootenanny said:This is wrong. Firstly, you agree that SR requires that a massless particle travel at c. In other words, physics currently predicts that all massless particles must travel at c. So can you now see the problem with asking physics to predict what would happen if we had a massless particle that didn't travel at c?
matheinste said:Hello all
Just a thought. Are we perhaps a bit hung up about mass. We have particles that lack other properties such as charge, spin etc. so why can't we have particles with no mass. We tend to think of mass as something that everything real has, but why? Is it just another property that something may or may not have?
Matheinste.
paw said:I think the problem with this is that as mass approaches zero the force required to achieve a given acceleration also approaches zero. In fact in the limit as mass --> 0 no force at all is required to achieve any acceleration, including infinite acceleration.
As soon as we accept infinite acceleration we have to accept the baggage that goes with it. For example, we'd have to accept infinite velocity because, under infinite acceleration a particle would attain infinite velocity in an infinitely short time. Since we don't observe massless particles moving infinitely fast I think we just have to accept that massless particles can only travel at c.
matheinste said:Hello paw.
I have no problem with photons having zero mass or zero mass particles having to travel at c. I was just getting a bit off topic. I understand your point.
Matheinste.
kev said:It is easy to see in this diagram that infinite acceleration corresponds to a constant velocity of c from the point of view of an inertial observer.
Massless particles are subatomic particles that have no mass. This means that they do not have any physical weight or volume. They are also known as massless particles because they travel at the speed of light, which is the maximum speed possible in the universe.
According to the theory of relativity, mass and energy are equivalent. Massless particles, such as photons, have no mass because all of their energy is in the form of electromagnetic radiation. This is why they can travel at the speed of light, as they have no physical mass to slow them down.
No, massless particles cannot be at rest. As they have no mass, they must always travel at the speed of light. This means they are constantly in motion and cannot be at rest in the traditional sense. However, they can be in a state of relative rest, where they are stationary relative to another object traveling at the same speed.
Massless particles play a crucial role in the study of physics, especially in the field of quantum mechanics. They help us understand the fundamental nature of particles and their interactions, and have been key in developing theories such as the Standard Model. They also have practical applications, such as in technology and medicine.
Massless particles, being particles of light, interact with matter through the electromagnetic force. This means they can be absorbed, reflected, or refracted by matter, depending on the properties of the material. For example, photons (massless particles of light) are absorbed by the retina in our eyes, allowing us to see.