/sci/ - Science & Math

[Anonymous No.1002077]

good day /sci/

here's a question for you:
Suppose that I am running at the speed of light (300,000,000 km/s) and I throw a ball with a constant velocity equal to the speed of light (assume the ball does not fall due to gravity) What will happen?

PS I'm not trolling. My friend and I argued about it for an hour.

[Anonymous No.1002109]

Firstly, to run at the speed of light you require infinite energy.

If you were using infinite energy to move that fast, where is the energy coming from to throw something forwards?

If you were some magical being who could run that fast, and you threw a normal ball, it would decelerate so quickly it would simply tear through your body with infinite force.

[Anonymous No.1002110]

It's basically like asking "what happens when an unstoppable force meets an immovable object?"

It doesn't work in our model of physics, so how do we describe it with our model?

[Anonymous No.1002113]

Also it's 300,000,000 metres per second, you're a factor of 1000 out.

[Anonymous No.1002114]

Ball's velocity = c,
De rien

[Anonymous No.1002122]

>914232

[Anonymous No.1002132]

Its really a moot question with no answer physics can provide.
1. It takes an infinite amount of energy to travel at the speed of light which you can never have.
2.Assuming you could get that fast you wouldn't be able to accelerate the ball as that would cause the Lorentz Factor to be >1 which if used in the equations would cause a square root of a negative number, which would mean imaginary numbers become involved then. I'd go to the effort of explaining what all of this stuff was but you can just google it as its late where I am.

TL;DR Physics can't explain it as its physically impossible.

[Anonymous No.1002136]

> Suppose that I am running at the speed of light.
You can't.
> I throw a ball with a constant velocity equal to the speed of light.
No, you don't.

[Anonymous No.1002137]

Suppose an object A is moving with a velocity v relative to an object B, and B is moving with a velocity u (in the same direction) relative to an object C. What is the velocity of A relative to C?

v
u -------> A
-------> B
C w
----------------->

In non-relativistic mechanics the velocities are simply added and the answer is that A is moving with a velocity w = u+v relative to C. But in special relativity the velocities must be combined using the formula

u + v
w = ---------
1 + uv/c2

[Anonymous No.1002144]

>>1002137
final answer was screwed up. here is the formula:

u + v
w = -----------
1 + uv/c2

[Anonymous No.1002150]

>>1002144
FUCK YOU FORMATTING PROBLEMS!

u + v
--------- = w
1 + uv/c2

[Anonymous No.1002152]

Due to relativistic length contraction, if you travel at the speed of light, there is effectively no 'forward' for you to throw the ball into. All of the universe is 'infront' of you, is zero distance away.

[Anonymous No.1002164]

>>1002136
>>1002132
>>1002110
This is the answer OP physics can't explain it as its a question with no answer. You might as well as ask what the elf that lives under your bed does for a hobby.

[Anonymous No.1002165]

>>1002136
> "Suppose." it's a theoretical question.

[Anonymous No.1002169]

>>1002152

While this is true, this is not the answer that the OP wanted.

here is the answer:
W is relative speed of ball. U is speed of spaceship from 3rd observer. V is speed of ball from reference of spaceship.

<math>w = (u + v)/(1+(uv)/c)</math>

[Anonymous No.1002177]

>>1002113
OP here yeah sorry my bad.

>>1002169
>>1002152
>proceed and elaborate.

[Anonymous No.1002190]

>937300

[Anonymous No.1002195]

Question to all you folks out there.

If I accellerate down a very long ruler whilst holding a clock, will I at some point reach and pass the speed of light according to measurements taken from the ruler and the clock?

If so, what speed was I really travelling when I reached the apparent speed of light?

[Anonymous No.1002236]

>>1002177
Here is the website i used for the formulas (since i can't remember them off the top of my head). http://www.xs4all.nl/~johanw/PhysFAQ/Relativity/SR/velocity.html..

Basically, it all depends on your point of REFERENCE! For example, you can't just have a ship traveling at .9999 times the speed of light, something has to OBSERVE you going .99999 times the speed of light.

Lets call the velocity of the spaceship relative to, say, earth 'u', okay? And lets call the velocity of the ball relative to the spaceship 'v', okay?

Ordinarily the velocity of the ball relative to the earth would be u + v (lets call this velocity value 'w'), and that makes sense for things that go much less than the speed of light. But if you add u and v together you get w=1.9998, or something that goes faster than the speed of light.

But this can't happen. And long story short a bunch of scientists created a new, relativistic formula for finding relativistic speed. If you want to velocity of the ball relative to the earth you need to follow this formula:
w = (u+v)/(1 + (u*v)/c).

That is the answer.

So if the speed of the spaceship from the earth is .9999 times the speed of light, and the speed of the ball from the spaceship is also .9999 times the speed of light. Then (using the formula) the speed of the ball from earth will be .999999995 times the speed of light.

[Anonymous No.1002241]

>>1002236
And by a bunch of scientists i mean Einstein.

[Anonymous No.1002254]

>>1002152
>>1002236
>>1002169

I'll consider these. Thanks anons!

[Anonymous No.1002271]

If it takes energy to travel at the speed of light, THEN HOW DOES LIGHT TRAVEL AT THE SPEED OF LIGHT? DOES LIGHT HAVE INFINANT ENERGY?

[pascal !n5Z3VuZapw No.1002445]

>>1002271
something to do with mass

[Anonymous No.1002453]

>>1002271
Light has no mass, therefore requires no energy.

[Anonymous No.1002465]

>>1002271
Furthermore, in a vacuum, light can't help BUT move at the speed of light