What would happen to someone travelling at c

with a jet engine you can travel many times faster than sound. if you want to travel faster than light, make a gravity engine.

skaught said:
But, hypothetically, if you reached c, your mass would become infinite.
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shouldn't the mass only become infinite if you travel at infinite speed? light doesn't travel at infinite speed, so why would the mass would become infinite?
 
shouldn't the mass only become infinite if you travel at infinite speed? light doesn't travel at infinite speed, so why would the mass would become infinite?
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The relevant formula is:

$$m = \frac{m_0}{\sqrt{1-(v/c)^2}}$$

where m_0 is the rest mass, c is the speed of light, and v is the speed of the object.

See what happens when you put v=c.
 
Yorda said:
with a jet engine you can travel many times faster than sound. if you want to travel faster than light, make a gravity engine.



shouldn't the mass only become infinite if you travel at infinite speed? light doesn't travel at infinite speed, so why would the mass would become infinite?
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Also, at c time stops. So distance is travelled instantaneously. In effect this is infinite speed.
 
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are you trying to tell me that light travels instantaneously? That doesn't seem right...
 
Also, at c time stops. So distance is travelled instantaneously. In effect this is infinite speed.
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It's a bit more complicated than that.

Take that spaceship again. Somebody looking at it flying past at close to the speed of light would say that time on the spaceship is running extremely slowly. On the other hand, a person on the spaceship would say that time for the "stationary" observer is running extremely slowly.

Both observers would measure the speed of light at the usual value c = 3 x 10^8 m/s, regardless of whether we're talking about light inside or outside the spaceship.

The person outside does NOT see the spaceship cover distance instantaneously; that person sees the spaceship cover distance according to its speed, same as usual.

The person inside the spaceship sees the universe shrunk in the direction of motion of the spaceship, so things in the outside universe seem to be closer together. The speed of the spaceship is unchanged, so for the person inside, they can complete a given journey faster, simply because there's less distance to cover at the same speed.

Notice: There is nothing in this explanation that equates the speed of light to "infinite speed".
 
James R said:
$$m = \frac{m_0}{\sqrt{1-(v/c)^2}}$$

where m_0 is the rest mass,
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o_0 sorry, i'm not so good at math

James R said:
Take that spaceship again. Somebody looking at it flying past at close to the speed of light would say that time on the spaceship is running extremely slowly.
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i doubt i would be able to see it fly by me. gun bullets only travels like 0.1 km/s, and i can hardly even see them.
 
James R said:
The relevant formula is:

$$m = \frac{m_0}{\sqrt{1-(v/c)^2}}$$

where m_0 is the rest mass, c is the speed of light, and v is the speed of the object.

See what happens when you put v=c.
Click to expand...

Yorda said:
o_0 sorry, i'm not so good at math
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I believe the base of this equation would be 0;

$${\sqrt{1-(c/c)^2} = {\sqrt{1-(1)^2} = {\sqrt{1-1} = \sqrt0$$

And I don't know about you but $$\frac{m_0}{0}$$ doesn't seem like it would have a very rational answer, I can't divide by 0 can you?
 
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11parcal said:
I believe the base of this equation would be 0;

$${\sqrt{1-(c/c)^2} = {\sqrt{1-(1)^2} = {\sqrt{1-1} = \sqrt0$$

And I don't know about you but $$\frac{m_0}{0}$$ doesn't seem like it would have a very rational answer, I can't divide by 0 can you?
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That is precisely why massive objects cannot travel at the speed of light. Their relativistic mass increases without bound as their velocity approaches the speed of light. The relativistic mass of any massive object will exceed the rest mass of the universe as a whole at some subliminal speed. Every last bit of energy in the universe would need to be transferred to the object to get it to that velocity -- and it would still be traveling at a less than the speed of light.
 
11parcal said:
I believe the base of this equation would be 0;

$${\sqrt{1-(c/c)^2} = {\sqrt{1-(1)^2} = {\sqrt{1-1} = \sqrt0$$

And I don't know about you but $$\frac{m_0}{0}$$ doesn't seem like it would have a very rational answer, I can't divide by 0 can you?
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Yorda said:
yes, i can divide by 0. for example:

0/0=0
4/0=0
0/4=0
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So then $$\frac{m_0}{0}= 0$$ meaning if I reach light speed I lose all mass? As i said you CANNOT divide by 0.
 
Think again.

If you have a number and you divide it by a much smaller one, what do you get? What happens if the divisor approaches zero?
 
I realize that if you really wanted to see how many times zero went into another number you would receive infinity as a response i'm not sure what Yorda was thinking...
 
Mike Honcho said:
Also, at c time stops. So distance is travelled instantaneously. In effect this is infinite speed.
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That said the length of the universe would contract in front of you so that the universe would, from your perspective, be crushed into a plane in your direction of travel.

As for conservation of mass, the real rule is conservation of energy, remembering that E=mc[super]2[/super]. Lets say you start out on your journey at 1000 m/sec relative to the Earth, and every minute you turn on your rockets to increase your speed by another 1000 m/sec. You will find that each marginal increase in speed takes more energy than the one before it did. The speed increase is always the same, 1000 m/sec but the energy needed to achieve that increase gets larger and larger. The energy needed to make that last jump, to c itself, would require an infinite amount of energy.

The law of conservation of mass/energy is not violated because, to achieve c, you'd need an inexhaustible supply if energy. Infinite energy has infinite mass, since m=E/c[super]2[/super].

Photons and certain other particles do not require that much energy because they are massless (i.e., if you could stop one, it would have zero mass). The mass they appear to have in actual practice is really just the mass that accumulates due to their energy.
 
11parcal said:
So then $$\frac{m_0}{0}= 0$$ meaning if I reach light speed I lose all mass?
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i don't know, but photons move at lightspeed and it is said that they don't have any mass.

11parcal said:
I realize that if you really wanted to see how many times zero went into another number you would receive infinity as a response
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zero would go zero times into another number. because no matter how many times you add zero to a number, it's always zero.

Pandaemoni said:
4/0 = 0?
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think about this:

4/-1 = -4
4/-0.80 = -5
4/-0.50 = -8
4/-0.25 = -16
4/-0.10 = -40
4/-0.001 = -4000
4/-0.0001 = -40,000
4/-0.00000001 = -400,000,000

there is very little difference between 0.00000001 and -0.00000001, but there's a very big difference between positive 400,000,000 and negative 400,000,000.

so how can you say that 4/0=positive infinity? obviously the answer can't be neither positive or negative which means that the answer is zero, because zero is neutral.
 
You're both wrong. It does not equal anything (not 0, it just doesn't have an answer).
 
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