# Speed of light ideas

1. Aug 13, 2010

### Caelus

if you have an idea on how to exceed the light barrier please post.

2. Aug 13, 2010

### Staff: Mentor

Move to a universe where relativity theory doesn't apply.

3. Aug 13, 2010

### Caelus

The reason that light speed is "imposable" is because this faster it goes the more mass it has and therefore the harder to accelerate. but if you fired an object at earth it would accelerate at 9.8 m/s regardless of an increase in mass. so if scientists got a particle up to 99.999999ect percent of the speed of light and fired it at a large enough planet it would, theoretically, reach or pass the speed of light!

4. Aug 13, 2010

### Caelus

good idea I sould try that!

5. Aug 13, 2010

### Pengwuino

Why do you assume acceleration caused by planets do not comply with relativity? You can influence a massive particle traveling extremely close to the speed of light in any number of ways yet still it won't reach the speed of light.

6. Aug 13, 2010

### Staff: Mentor

7. Aug 13, 2010

### darkhorror

Even if you are going 99.9999% the speed of light away from the earth. You could accelerate to that large planet in the same direction you are moving at 100m/s^2 for a long time. But you wouldn't go faster than the speed of light when compared to earth. you would just get closer to the speed of light when compared to earth.

8. Aug 14, 2010

### Caelus

but if you're moving tward earth at 99.999999999 percent of light speed woulden't (asuming you had enough time) you accelerite at 9.82 m/s regardles of your velocity or mass and therefore excede the speed of light. Am I missing somthing?

9. Aug 14, 2010

### Pengwuino

Like I already said, the 9.8 m/s^2 acceleration is a classical approximation that does not work at relativistic speeds.

10. Aug 14, 2010

### Integral

Staff Emeritus
Yes, you are missing something. A basic understanding of relativity.

11. Aug 14, 2010

### DrGreg

In special relativity, although all observers agree whether an acceleration is zero or not, they disagree on the value of a non-zero acceleration. So someone travelling at 99.999999999% of light speed towards Earth could measure an acceleration of 9.82 m/s2, but someone on Earth would measure the same acceleration to be almost zero, and getting smaller.

If you tried to accelerate at 9.82 m/s2 relative to Earth, the faster you go the more energy you need, and you'd run out before you reached light speed. (Also you would measure your own acceleration to be enormous and would get crushed to death.)

12. Aug 15, 2010

### zara90

Photons have zero mass, which is why they travel at the universe's prescribed maximum speed. Anything with mass can only travel a fraction of c. It doesn't matter how massive something is, it would take an infinite amount of energy to accelerate it to the speed of light. Remember that energy and mass are equivalent via the currency exchange of c-squared, and any object travelling at 99.9999% of c becomes extremely massive as well. When something is travelling that fast, it has accumulated a lot of energy and thus its effective mass is much higher. That's why asteroids that are small fractions of the Earth's size can wipe us out completely simply because gravity can propel them to incredible speeds, in which they pick up vast amounts of energy and then if they strike the Earth, the effect is that much greater. Another example is a coiled up jack in the box weighs slightly more than one that is just hanging out of the top.

13. Aug 15, 2010

### Passionflower

No it would not, in fact the coordinate velocity of such a particle would decrease for such speeds.

14. Aug 15, 2010

### James S Saint

Last edited by a moderator: Apr 25, 2017
15. Aug 15, 2010

### espen180

Last edited by a moderator: Apr 25, 2017
16. Aug 15, 2010