Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

Traveling at the speed of light...

Joined
Aug 25, 2007
Messages
2,007
Points
63
Also, I can't read the title of this thread without thinking of Freddie Mercury singing "I'm traveling at the speed of light"

 





Joined
Jun 12, 2010
Messages
341
Points
0
an example of mass moving at the speed of light using your traing theory...

1 train car has an engine strong enough to move it at the speed of light... but the drag created getting it to the speed of light would equal over 1 million attached a cars all needing their own engines, all creating their own drag.

michael

air resistance isnt relevant in a vaccuum situation. the thing that stops an object getting to light speed is relativistic mass increase. it can have effectively infinite kinetic energy and still not get there:
proton_energy2.jpg
 
Joined
Dec 23, 2008
Messages
3,948
Points
63
i never stated in vaccum. also space is not clean. there is microscopic floating debris. this would creat a "drag" if you will.

michael
 
Joined
Aug 25, 2007
Messages
2,007
Points
63
i never stated in vaccum. also space is not clean. there is microscopic floating debris. this would creat a "drag" if you will.

michael

And still irrelevant to the idea of anything with positive mass traveling at or above the speed of light.

Even in a perfect vacuum (which doesn't technically exist in reality, you're right, but this is all a thought experiment, so we're allowed), it still won't work, and not because of any frictional or drag force. We can approach the speed of light, but not reach it. If I'm not mistaken, the fastest "objects" we've every produced are protons in the LHC, and even those are still a full 3 m/s slower than the speed of light.
 
Joined
Jun 7, 2010
Messages
36
Points
6
Any idea that has anything moving at the speed of light other than photons themselves is irrelivant. It CANNOT happen, so it should never be considered.

If you had a train moving at 99% the speed of light, and then you have someone on the train running forward at 2% the speed of light, you would see his time slowed down just enough so that relitive to you, he was traveling at just under the speed of light.

Its called time dilation. Time will ALWAYS slow down for somthing you see traveling at close to the speed of light just enough so that you view it traveling at under the speed of light.
 
Joined
Oct 24, 2009
Messages
1,173
Points
48
@Leapold; IMO, it's good to keep an open mind. Science is always moving forward, showing that nothing is impossible. In 1950 you'd be looked at funny for mentioning a 1W blue laser that fits in your hand now thousands of collectors, buisinesses, and intoxicated idiots are buying them for 200$. You might be right, you might be crazy, please don't state opinion as fact. :)
 
Joined
Jun 7, 2010
Messages
36
Points
6
@wood
I'm quite sure everything i stated is fact. If not, please correct me.
 
Joined
Jun 12, 2010
Messages
341
Points
0
im pretty sure that, despite time dilation, that the speed of an object must remain in the constant factor in distortion due to speed, otherwise it becomes meaningless. so if you see an object going fast, time dilation wont actually slow down its speed, or suddenly it isnt going as fast. i think in the case you described, the object would appear to not be going as fast to you because length contraction will reduce the distance it is covering in unit time.

edit: actually that probably is just an alternative way to the same conclusion lol
 
Last edited:
Joined
Jun 7, 2010
Messages
36
Points
6
Anything that can be measured will adjust so that the object is not exceeding the speed of light. Whether it be length, time, mass, w/e. The traveler will still see himself going at the same speed, but when i see him, his time is slowed down. So therefor his speed is slowed down.
 
Joined
Dec 23, 2008
Messages
3,948
Points
63
Anything that can be measured will adjust so that the object is not exceeding the speed of light. Whether it be length, time, mass, w/e. The traveler will still see himself going at the same speed, but when i see him, his time is slowed down. So therefor his speed is slowed down.


this is where imagination comes into play.
 
Joined
Jun 7, 2010
Messages
36
Points
6
Physical Reality - Mathematics of Relativity

This is a link to the derivation of the time dilation and length contraction equations, and why mass increases with velocity and more.

It's a great thing when you derive these for yourself and prove facts with simple observations using mathematics.

If you find a flaw in the mathematics or logic behind these equations, please point it out to me.

Einstein, Albert. 1920. Relativity: The Special and General Theory
Also, a link to Einstein's book, 'Relativity, The Special and General Theory.' An amazing book that will tell you everything you need to know about Relativity.
 
Joined
Jun 7, 2010
Messages
36
Points
6
Physical Reality - Mathematics of Relativity

This is a link to the derivation of the time dilation and length contraction equations, and why mass increases with velocity and more.

It's a great thing when you derive these for yourself and prove facts with simple observations using mathematics.

If you find a flaw in the mathematics or logic behind these equations, please point it out to me.

Einstein, Albert. 1920. Relativity: The Special and General Theory
Also, a link to Einstein's book, 'Relativity, The Special and General Theory.' An amazing book that will tell you everything you need to know about Relativity.
 

dnar

0
Joined
Jun 7, 2010
Messages
608
Points
0
One of the benefits of traveling greater than the speed of lights is that red traffic signals would not appear red.

Something else to consider, we know what the speed of sound is, but what is the sound of speed?
 

Razako

0
Joined
Mar 17, 2006
Messages
4,301
Points
113
Ok what happens if you have two objects going in opposite directions at near the speed of light? Will they effectively be traveling apart faster than the speed of light?
 
Joined
Jun 7, 2010
Messages
36
Points
6
Imagine we both have clocks. I am traveling west at 99% the speed of light relative to a 3rd person right in the middle of us. You are going east at 99% the speed of light relative to this person as well. This person will view both of us doing just as i stated, but when i turn around and look at you, i will see your clock running extremely slowly. That way, you will only be able to travel infinitely close to the speed of light.

The closer and closer you get to the speed of light relative to me, the slower your clock will run forcing you to obey the 300,000,000 m/s speed limit.

Think of it this way, you may be going 198% the speed of light if time dilation did not happen. But since once second for me will be .1 seconds 'i did not calculate this' for you, you will only be able to go so fast relative to me.

Sorry if this is not very clear, i am rushed for time. When i get to work ill try and make a better analogy.
 
Joined
Aug 25, 2007
Messages
2,007
Points
63
Imagine we both have clocks. I am traveling west at 99% the speed of light relative to a 3rd person right in the middle of us. You are going east at 99% the speed of light relative to this person as well. This person will view both of us doing just as i stated, but when i turn around and look at you, i will see your clock running extremely slowly. That way, you will only be able to travel infinitely close to the speed of light.

The closer and closer you get to the speed of light relative to me, the slower your clock will run forcing you to obey the 300,000,000 m/s speed limit.

Think of it this way, you may be going 198% the speed of light if time dilation did not happen. But since once second for me will be .1 seconds 'i did not calculate this' for you, you will only be able to go so fast relative to me.

Sorry if this is not very clear, i am rushed for time. When i get to work ill try and make a better analogy.

A better analogy is needed, because your thought experiment violates the law that light speed is constant in all, and regardless of, all frames of reference. If 2 clocks are heading in opposite directions, both at 99% of the speed of light, no information can be made to travel from one to the other, so there's no way for you to ever see what his clock is doing. An observer on one ship can never see the clock on the other ship or know how fast it's ticking.

Also, your analogy shows one of the reasons faster-than-light-speed, or even equal-to-light-speed, travel beaks down in the math. Try to calculate the time dilation for your example, 198% of the speed of light, and you'll see that you can't do so with real numbers.

An interesting note to add though, is that time dilation is actually a testable facet of relativity. It has been tested many times, and with the availability of consumer-affordable atomic clocks nowadays, you can even test it yourself. Because of where we are and the available velocities we have for tests, gravitational time dilation is a much bigger factor than velocity time dilation, but you can still test time dilation, in general all by yourself.
 




Top