The theoretical max. speed in deep space

[Faux Carnival]

Hello,

Isn't the theoretical max. speed in deep space unlimited? There is no friction. Therefore, any energy we add to the spacecraft will increase its speed. So can't the speed of light be reached?

Thanks.

 

[tiny-tim]

Hello Faux Carnival!

Isn't the theoretical max. speed in deep space unlimited? There is no friction. Therefore, any energy we add to the spacecraft will increase its speed. So can't the speed of light be reached?

(hmm … i thought pf had an faq on this, but i can't find it )

first, we add momentum, not energy (force times time = change in momentum)

second, yes we can keep adding momentum, and the speed will keep increasing , but it will never quite reach c

(momentum = mv/√(1 - v²/c²) -> ∞ as v -> c)

 

[Faux Carnival]

Hello Faux Carnival!


(hmm … i thought pf had an faq on this, but i can't find it )

first, we add momentum, not energy (force times time = change in momentum)

second, yes we can keep adding momentum, and the speed will keep increasing , but it will never quite reach c

(momentum = mv/√(1 - v²/c²) -> ∞ as v -> c)

Thanks for your reply. I was thinking of kinetic energy. They seem to be the same thing anyway.

But my thinking is not flawed, right? In space, accelerating from 30,000 to 31,000 km/h is the same thing as accelerating from 50,000 to 51,000 km/h?

 

[tiny-tim]

In space, accelerating from 30,000 to 31,000 km/h is the same thing as accelerating from 50,000 to 51,000 km/h?

Nope!

The latter involves slightly more change in momentum … mv/√(1 - v²/c²) … than the former.

And so the latter takes slightly more force (technically, impulse) than the former.

And the closer you get to the speed of light, the greater the difference!

 

[alphy]

Hello,

Theoretical maximum speed in deep space is a complex concept that is still being explored and debated by scientists. While it is true that deep space does not have any friction, there are still other factors that limit the speed of spacecrafts. These include the amount of energy needed to accelerate the spacecraft and the limitations of current propulsion technologies.

Additionally, according to Einstein's theory of relativity, the speed of light is the ultimate speed limit in the universe. This means that no object, including spacecraft, can ever reach or exceed the speed of light. While it is possible to approach the speed of light, it would require an infinite amount of energy, which is not feasible with our current technology.

It is also important to consider the effects of time dilation at high speeds. As an object approaches the speed of light, time slows down for that object relative to an observer. This means that even if we were able to reach the speed of light, time would essentially stop for the spacecraft, making it impossible to travel any further.

In conclusion, while the theoretical maximum speed in deep space is still being explored, it is unlikely that we will ever reach the speed of light or have unlimited speed in deep space. However, continuous advancements in technology and scientific research may bring us closer to understanding and potentially surpassing our current limitations.