Does Light Have Infinite Mass When Traveling at the Speed of Light?

In summary, this equation states that if an object has a mass greater than zero, then its total energy must also be greater than zero. This is because E=MC^2, which cannot be broken down without resulting in an infinite mass. photons have a relativistic mass, which is not infinite, and 0/0 is not defined.
  • #1
demosthenes_001
13
0
I recently heard something very interesting. For mass to go light speed, it must be infinite. It can be proved by breaking apart E=MC^2.
 
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  • #2
I highly doubt it.
 
  • #3
demosthenes_001 said:
For mass to go light speed, it must be infinite.


Even if it could, how could such a discovery in any way be significant?
 
  • #4
On the contrary, for something to go light speed, its (rest) mass must be 0.

You may be thinking that, if an object with non-zero mass could go at light speed, according to the transformation formula, its mass would be infinite. What that does is prove, since there is no such thing as "infinite mass", that it is not possible for something with non-zero rest mass to go at light speed.
 
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  • #5
Exactly! :biggrin:
 
  • #6
demosthenes_001 said:
I recently heard something very interesting. For mass to go light speed, it must be infinite. It can be proved by breaking apart E=MC^2.


Simply because it's singular in the point v=c,the formula
[tex] m_{SR}=\frac{m_{0}}{\sqrt{1-\frac{v^{2}}{c^{2}}}} [/tex]

cannot be used
This one can and it yields the correct results within the framework of SR
[tex] E^{2}=m_{0}c^{4}+p^{2}c^{2} [/tex]

Try to make rest mass infinite and see that the total energy is also infinite.Ergo,unphysical situation.

Daniel.
 
  • #7
[tex] m_{SR}=\frac{m_{0}}{\sqrt{1-\frac{v^{2}}{c^{2}}}} [/tex]
according to this formula... anything that travels with speed of light will have infinite mass...

but light also travels like a matter... and so light(matter) obviously travels at the speed of light... doesn't it imply that light(as a matter) has infinite mass?
 
  • #8
No. Anything traveling at light speed has zero mass (m0).
 
  • #9
yeah that is the rest mass... and light is never at rest
so isn't talking about the other mass a little more practical?
and 0/0 still is infinite right? so the other mass is infinite...
doesnt that mean that when light falls on me... i should be blown (no pun intended)?

PS: as you can judge by my no. of posts, i am new to this world... sorry if i sound stoopid or dumb...
 
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  • #10
rahuld.exe said:
yeah that is the rest mass... and light is never at rest
so isn't talking about the other mass a little more practical?
A better term than rest mass is invariant mass.
and 0/0 still is infinite right?
No, it isn't.
so the other mass is infinite...
No, it isn't.

That equation you used does not apply where m0 = 0 or v = c. (As was pointed out in this thread over 6 years ago!)
doesnt that mean that when light falls on me... i should be blown (no pun intended)?
No, the energy and momentum of light are related by the second equation in post #6, which gives you: E = pc. Neither the energy nor momentum of light is infinite.

If you wanted to define the 'relativistic' mass of a photon, it would be E/c2, which is also not infinite.
 
  • #11
hmm... thank you for clearing it out!
what is 0/0 anyway? not defined?
 
  • #12
rahuld.exe said:
hmm... thank you for clearing it out!
what is 0/0 anyway? not defined?
Not defined.
 
  • #13
thank u!
 
  • #14
rahuld.exe said:
[tex] m_{SR}=\frac{m_{0}}{\sqrt{1-\frac{v^{2}}{c^{2}}}} [/tex]
according to this formula... anything that travels with speed of light will have infinite mass...

but light also travels like a matter... and so light(matter) obviously travels at the speed of light... doesn't it imply that light(as a matter) has infinite mass?

It's better to think of and use only one formula which is valid for all <particles> from special relativity.

[tex] E^{2}=m_{0}c^{4}+p^{2}c^{2} [/tex]

With operators instead of scalar functions, this formula holds valid in quantum specially-relativistic theories as well. That's where the photons come from.
 

What is infinite mass?

Infinite mass is a theoretical concept in physics that suggests an object could have a mass that is infinitely large. This would result in an object having an infinite amount of inertia, making it impossible to accelerate or move.

Can anything travel at the speed of light?

According to Einstein's theory of relativity, nothing with mass can travel at the speed of light. The speed of light is considered to be the maximum speed at which energy or information can travel in our universe.

What happens to an object's mass as it approaches the speed of light?

As an object approaches the speed of light, its mass increases according to the theory of relativity. This increase in mass is known as relativistic mass and it becomes infinite at the speed of light.

Is it possible for an object to have infinite mass and travel at the speed of light?

This is currently a topic of debate and research in the field of physics. While the concept of infinite mass and light speed is theoretically possible, it has not been proven to exist in our universe.

What are the implications of infinite mass and light speed?

If an object were to have infinite mass and travel at the speed of light, it would violate the laws of physics as we know them. It would also have significant implications for our understanding of the universe and the fundamental principles of physics.

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