# Hey, how predictable is a frame of reference going faster than c?

• KillaMarcilla
In summary, the conversation discusses the concept of faster than light travel and the existence of tachyons. The speaker is starting an introductory quantum physics class and wonders if it is possible to travel faster than light without breaking the rules of special relativity. There is debate among experts on whether tachyons, objects that would move faster than light, would cause the quantum vacuum to decay. Some theories, such as string and brane theories, include tachyons, but it is uncertain if they are a real possibility.

#### KillaMarcilla

Yo, d00dz, I'm just starting an introductory quantum physics class, so this'll probably be childishly foolish to some of you, but the risk of sounding childish has yet to stop me from saying something on the internet

It seems like the transformations of special relativity just break down at speeds greater than or equal to c, so that maybe if you somehow happened to get to a speed faster than light without needing to go through the energetic asymptote in your way, you might be all set to go around faster than light as long as you want, until it comes time to skip down back below c

Or is there some way of verifying the impossibility without relying on empirical observations from down here, of the method of faster than light travel wherein one skips past c?

For some reason, any Physics book I've had so far has said that there's no way I could understand tensor analysis, and therefore couldn't possibly even begin to have any grasp of general relativity..

Objects that would move faster than c would have imaginary masses (that is multiples of the square root of minus one). They have a name, tachyons. They are not forbidden in relativity itself, but experts on quantum field theory say the existence of tachyons would cause our quantum vacuum to decay, and we're all going to die! I don't know, some string and brane theories have tachyons in them so maybe they aren't the end of the world after all.

Well, the equations we've come up with so far would say they'd have imaginary masses and whatnot, but how likely do you think that really is? Would stuff like that really have to be the case?

## 1. How is the speed of light defined?

The speed of light is defined as the maximum speed at which all matter and information in the universe can travel. In a vacuum, this speed is approximately 299,792,458 meters per second.

## 2. Can anything travel faster than the speed of light?

According to the current understanding of physics, it is not possible for anything to travel faster than the speed of light. This is due to the theory of relativity, which states that the speed of light is a fundamental constant and cannot be surpassed.

## 3. What is a frame of reference?

A frame of reference is a set of coordinates and axes used to describe the position and movement of an object. It is used to measure the relative motion of an object in relation to a specific point or observer.

## 4. How is the speed of a frame of reference calculated?

The speed of a frame of reference is calculated by measuring the distance traveled by the frame of reference over a certain period of time. This can be done using tools such as a stopwatch or a speedometer.

## 5. What happens if a frame of reference exceeds the speed of light?

It is not possible for a frame of reference to exceed the speed of light. According to the theory of relativity, as an object approaches the speed of light, its mass increases and it requires an infinite amount of energy to accelerate it further. Therefore, a frame of reference can never reach or exceed the speed of light.