What Happens to Mass as it Approaches the Speed of Light?

In summary, as an object approaches the speed of light, its mass increases and it becomes more difficult to accelerate further. This phenomenon is known as relativistic mass or apparent mass, and it is a result of Einstein's theory of special relativity. As an object gets closer to the speed of light, its mass approaches infinity, making it impossible to reach the speed of light itself. This increase in mass also causes time dilation and length contraction, leading to many fascinating consequences for objects traveling at high speeds.
  • #1
teetar
35
0
Pretty straight-forward, I'm just curious. My current level and understanding of physics has lead me to believe that as an object accelerates it's mass becomes higher and if it were to be able to reach the speed of light it would get infinite mass. I believe this currently, however, two of my friends have denied this statement saying that, rather, an object's mass will become zero when it reaches the speed of light. I'm just wondering if I'm correct or if they are. If they're correct, is it just a simple misunderstanding, or mistake on my part, or is it that I don't understand physics to the correct level to attempt to understand this yet?

Thanks for anyone who can respond to this, and please have a nice day!
 
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  • #2
It is a very common misconception that an object's mass changes at its speed increases. The term "mass" refers to "rest mass", which is the mass the object has in its own inertial frame. This never changes. That, along with the fact that an object with mass cannot reach the speed of light, means that your question is a nonsensical one. Any object with mass cannot reach the speed of light so we cannot say what will happen "if" it did.
 
  • #3
teetar said:
Pretty straight-forward, I'm just curious. My current level and understanding of physics has lead me to believe that as an object accelerates it's mass becomes higher and if it were to be able to reach the speed of light it would get infinite mass. I believe this currently, however, two of my friends have denied this statement saying that, rather, an object's mass will become zero when it reaches the speed of light. I'm just wondering if I'm correct or if they are. If they're correct, is it just a simple misunderstanding, or mistake on my part, or is it that I don't understand physics to the correct level to attempt to understand this yet?

Thanks for anyone who can respond to this, and please have a nice day!

In addition to what Drakkith has stated:

1. The "mass" that you know is what we term as the rest or invariant mass. This mass doesn't change. So both you and your friends are mistaken. Do I get to win the bet, if any?

2. If you are invoking this thing called "relativistic mass" then read this first

https://www.physicsforums.com/showthread.php?t=642188#post4106101

Zz.
 
  • #4
Thanks guys! I'm sorry I posted this here, I should've looked into it more to find an answer, I obviously need to learn more :P
 
  • #5
Here's an answer from another perspective. Suppose that instead of you being "stationary" and the object zooming past you at a speed approaching warp 1, it is the object that is "stationary," and it is you who are zooming past the object at a speed approaching warp 1 (in the opposite direction). I think you will agree that your motion as a passive observer cannot affect the mass of the object in any way (after all, you are not even coming close to contacting it). Yet from your perspective, it is the object that is zooming past you. So, either way, its mass can't change.
 
  • #6
Drakkith said:
Any object with mass cannot reach the speed of light so we cannot say what will happen "if" it did.

Please explain. Light as a wave carries energy, and energy is equivalent to mass, right?
 
  • #7
vanceEE said:
Please explain. Light as a wave carries energy, and energy is equivalent to mass, right?

No it is not. Read the Relativity FAQ!

That question is also off topic to what the OP is asking. Either ask this elsewhere, or better yet, read the numerous other threads and our FAQ that have addressed this.

Zz.
 
  • #8
ZapperZ said:
Read the Relativity FAQ!

Please send link. Thank you
 
  • #9
vanceEE said:
Please send link. Thank you

ko5t.jpg


Zz.
 
  • #10
teetar said:
Thanks guys! I'm sorry I posted this here, I should've looked into it more to find an answer, I obviously need to learn more :P

Nonsense, it's a perfectly valid question to ask. Why else would this forum exist if not to help people?
 

1. What is the theory behind mass changing as it approaches the speed of light?

The theory behind mass changing as it approaches the speed of light is known as Special Relativity, which was developed by Albert Einstein in the early 1900s. This theory states that as an object's speed increases, its mass also increases. This is due to the fact that energy and mass are interchangeable, and as an object's speed increases, its energy also increases, thus increasing its mass.

2. Does this mean that an object's mass becomes infinite at the speed of light?

No, an object's mass does not become infinite at the speed of light. According to Special Relativity, an object's mass will approach infinity as its speed approaches the speed of light, but it will never actually reach infinity. This is because as an object's mass increases, so does the amount of energy required to accelerate it, making it increasingly difficult to reach the speed of light.

3. How does this affect the behavior of an object as it approaches the speed of light?

As an object's mass increases, its acceleration decreases. This means that as an object approaches the speed of light, it requires more and more energy to increase its speed even by a small amount. This results in the object's speed approaching but never reaching the speed of light.

4. Can any object actually reach the speed of light?

No, according to Special Relativity, no object with mass can reach the speed of light. As an object's mass increases, the amount of energy required to accelerate it also increases, making it impossible to reach the speed of light. Only particles with no mass, such as photons, can travel at the speed of light.

5. What are the real-world implications of mass changing as it approaches the speed of light?

The concept of mass changing as it approaches the speed of light has significant implications in fields such as particle physics and space travel. It has been observed in particle accelerators, where particles are accelerated to near the speed of light, and their mass increases accordingly. In space travel, it means that the closer an object gets to the speed of light, the more energy it requires to increase its speed, making it incredibly difficult to travel at such high speeds.

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