emily asked in Science & MathematicsPhysics · 2 months ago

# How is it possible that in theory, nothing can travel faster than light?

Why is there a max speed? How was that decided? There must be something or someone, some time, that can build or create something that can travel fast than light, right?

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• 1 month ago

The closer an object gets to the speed of light the greater its relative massive it becomes. This is given by the formula: m = γm0, where γ = 1/ √(1 − v2/c2).

Thus as you approach the speed of light the relative mass of an object approaches infinity. Since it would take an infinite amount of energy to accelerate an infinite mass and there isn't an infinite amount of energy in the universe, superluminal speed is impossible for a massive object.

• D g
Lv 7
2 months ago

NASA decided it it's in there with Nada voting on the LAW of gravity

• 2 months ago

According to the theory, the mass of an object will increase the faster it travels. When it reach light speed, its mass will reach infinity. That is why it is not possible to reach light speed.

• Tom
Lv 7
2 months ago

Imagine two cars running 60mph on the highway, side by side---Relative to each other the cars are motionless. despite the 60 mph highway speed.

If one of the cars veers a bit, at an angle, then there is relative speed between the vehicles.  The greater the veer, the greater the relative speed between the vehicles.

Assuming the highway speed is constant, the maximum RELATIVE speed at a veer of 180 degrees is 120 MPH---any more veer, and the relative speed DECREASES as the angle wraps around.----So we have a system where relative speed is limited to 120mph.

I real life, We can think of the highway speed as TIME ( which Time, in RL ,can be thought of as a motion, inherent in ALL matter in the direction of the 4th dimension)

So EVERYTHING around us, in this 3D  universe is moving in the same direction and Same speed--- in the direction of a FOURTH dimension. (which we can't comprehend)  This speed is constant and a mathematical function of light speed (somewhat slower) We call this motion the flow of TIME

So any motion we see in our 3D world is RELATIVE and a function of a change of the ANGLE of veer of time flow in the 4th dimension.  We see as 3 D movement-----The greater the angle, the greater the speed.  So there IS an angle where the RELATIVE speed is at Maximum--Light speed.  ---Just like the two cars on the highway---but with a couple of dimensions added.

In RL though, The maximum veer angle is 90 degrees, because any more veer and the other object would go BACK in time---so you cant go faster, in a RELATIVE sense, no  than  the veer angle will let you--Light speed (c).---Beyond that the speed effectively goes down--------A bit strange, because you have other dimensions in play, so it is not as straight forward as with the cars on the highway,___but the idea is the same.  The time constant remains the same just as the car speed is the same, but relative speed based on veer angles has its limits because of this.

Also, note that in the car case, the car that veers away "drops back" on the road from the other even though they still move 60mph on the highway  (relative speed is slower)--This shows why moving objects Drop back in TIME relative to each other if they are moving.---The same in RL, any moving object moves a bit back in time relative to others. As it's time flow is at an angle to you--so you can see why we have time dilation too.

Yes, there are other factors in play, increase in mass, etc. (because of the dimensions), but you can see the principle why relative speeds have a limit.---Any FTL ship would have to employ a "Physics" shortcut" that shortens space distance or increases the time constant, to get more relative speed than c.

• 2 months ago

It is not a matter of building a better engine for a spacecraft. It is impossible in principle to go at the speed of light or faster. This is a law of physics. It is derived from the theory of relativity. When to apply a force to an object, is momentum increases. Usually this means it's speed increases. But near the speed of light, mass increases instead of speed. It would take an infinite force to reach the speed of light. This is a fact. There is no way around it.

• garry
Lv 5
2 months ago

simple light is measure from earth , its speed is altered by the atmosphere and dust in the air , in space there is no atmosphere to slow light down , we measure its earth speed not the spare speed . simple isnt it ,

• 2 months ago

If you push something faster and faster its mass increases causing it to become harder to push.  If you were able to push it at light speed, it would become infinitely massive.

• Anonymous
2 months ago

darpa invented a warp engine .

• 2 months ago

No, nobody can build such a thing.  The postulate that light speed is the maximum speed came out of Maxwell's equations along with various experimental results.  The theory of special relativity that arose from Einstein's postulates has been proven to be sound, in that it affects the calculation of the trajectories of interplanetary travel.  So our spacecraft would not have correctly landed on Mars and Venus if we had not used Einsteinian relativity as part of the calculation.

• Pearl
Lv 7
2 months ago

cause god made it that way