Is It Possible for Anything to Truly Move at the Speed of Light?

In summary, the conversation discusses the concept of reaching the speed of light, and whether it is possible to travel at exactly c or 99.999...% c. It is explained that mathematically, these are equivalent, and the problem lies in the physical impossibility of infinite acceleration. The conversation also touches on the idea of imposing a limit on speed and the concept of infinity.
  • #1
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I know it is impossible(for now:wink:), but if we use the mathematical proofs that any non-zero number with a finite decimal notation has a counterpart with trailing 9's. So, unless that is not always true, then wouldn't anything moving at 99.999...% (supposing we reach that somehow)the speed of light be actually moving at c? Remember the proofs, 0.9999...=1

Correct me please, something is definitely not right.

regards,
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  • #2
The problem is physical not mathematical. In order to get to the speed of light you need infinite acceleration.
 
  • #3
Fragment said:
I know it is impossible(for now:wink:), but if we use the mathematical proofs that any non-zero number with a finite decimal notation has a counterpart with trailing 9's. So, unless that is not always true, then wouldn't anything moving at 99.999...% (supposing we reach that somehow)the speed of light be actually moving at c? Remember the proofs, 0.9999...=1

Correct me please, something is definitely not right.

regards,
Fragment
Yes, 0.9999...= 1. Therefore you cannot travel at either c or 99.999...% c. They are just different ways of saying the same thing.

Your question is precisely the same as "I know it is impossible to go at c, but suppose we used the letter a and let a= c. Wouldn't anything going at a be actually moving at c?"
Yes, and that is why you cannot travel at c or a?
 
  • #4
Thank you for your explanation HallsOfIvy, learning is the greatest experience:biggrin:

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  • #5
On second thought, where do we impose the limit of speed when getting close to c? It is common knowledge that 99.999... extends to infinity, but what is infinity -1? Where do we put the limit? In other words what is the fastest one could go? Going at 99.999...%c implies infinite energy required, so where must we stop, supposing we had an energy source equal to infinity -1?:uhh: Hopefully I was clear.

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  • #6
You never stop accelerating. You just keep on getting closer and closer to c, approaching it more and more slowly.
 
  • #7
A few points. One is that 0.9999... and 1.0000... are two different ways of writing the exact same number. (Like Halls of Ivy said). In this way they are no different than 1/2 and 0.5 are.

The other is that (infinity minus one) is not a number.
 
  • #8
Of course not, it was just an example to try to explain what I meant, sorry about the sloppiness. I guess that's a good way to think about it, you keep accelerating more and more slowly, never reach c, but use up more, and more energy. Thanks for all the clarifications!
 

What is the speed of light?

The speed of light is approximately 299,792,458 meters per second in a vacuum. This is the fastest speed at which energy and information can travel in our universe.

Can anything travel faster than the speed of light?

According to our current understanding of physics, nothing can travel faster than the speed of light. This is due to the fact that as an object approaches the speed of light, its mass increases exponentially, making it impossible for anything with mass to reach or exceed the speed of light.

How is the speed of light measured?

The speed of light is measured using a variety of techniques, including the use of lasers, satellites, and specialized equipment such as interferometers. These methods involve measuring the time it takes for light to travel a known distance, and then using that information to calculate the speed of light.

What is the significance of the speed of light?

The speed of light is a fundamental constant in our universe and has many implications in physics. It is used in theories such as Einstein's theory of relativity and is crucial in understanding the behavior of light and other electromagnetic radiation. It also plays a role in various technologies, such as telecommunications and space travel.

Why is it not possible to travel at the speed of light?

As mentioned earlier, as an object approaches the speed of light, its mass increases exponentially, making it impossible for anything with mass to reach or exceed the speed of light. Additionally, the amount of energy required to accelerate an object to the speed of light is infinite, making it physically impossible to achieve.

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