Guest bundamba Posted March 29, 2003 Share Posted March 29, 2003 I have no idea where this post belongs, but here goes. If a car was travelling at the speed of light, and it turned on its headlights, would light project in front of the car? Link to comment Share on other sites More sharing options...
spacemanspiff Posted March 29, 2003 Share Posted March 29, 2003 i'm going to say yes. but i'm not a physicist. Link to comment Share on other sites More sharing options...
Dave Posted March 29, 2003 Share Posted March 29, 2003 Originally posted by bundamba I have no idea where this post belongs, but here goes. If a car was travelling at the speed of light, and it turned on its headlights, would light project in front of the car? relative to what? Link to comment Share on other sites More sharing options...
fafalone Posted March 29, 2003 Share Posted March 29, 2003 The speed of light is constant for all reference frames, so if the reference frame was moving at c, light would still move at c relative to that frame. Link to comment Share on other sites More sharing options...
blike Posted March 29, 2003 Share Posted March 29, 2003 in other words, yes Link to comment Share on other sites More sharing options...
EvilMind Posted March 29, 2003 Share Posted March 29, 2003 yep, regardless of your frame of reference, light travels at c. this post should belong under relativity by the way Link to comment Share on other sites More sharing options...
Ryoken Posted March 30, 2003 Share Posted March 30, 2003 hmmm... now you are a stationary object observing that car traveling at c. But how fast would the light from the car's headlights be traveling from your refrence frame? Assuming that there are no absticles such as planets, just you, the car and the car's light. Link to comment Share on other sites More sharing options...
fafalone Posted March 30, 2003 Share Posted March 30, 2003 c. always c. Link to comment Share on other sites More sharing options...
Ryoken Posted March 30, 2003 Share Posted March 30, 2003 so you would see the light from the headlights not moving past their point of origin because the car is moving at C? Link to comment Share on other sites More sharing options...
fafalone Posted March 30, 2003 Share Posted March 30, 2003 no, you would see them moving at c. Link to comment Share on other sites More sharing options...
Ryoken Posted March 30, 2003 Share Posted March 30, 2003 Now lets begin the immentent discussion of C and time. What would happen to a particel if it were to be accelerate to C? I have a vague idea which is certainly incorrect, thus whats YOUR opinion? Link to comment Share on other sites More sharing options...
fafalone Posted March 30, 2003 Share Posted March 30, 2003 Couldn't accelerate to c through conventional means because it would require infinite energy. Link to comment Share on other sites More sharing options...
Radical Edward Posted March 31, 2003 Share Posted March 31, 2003 if you travel at c you get unpleasent infinities in the lorentz transforms. Link to comment Share on other sites More sharing options...
Luminous Posted July 18, 2005 Share Posted July 18, 2005 I guess its like asking, "what if you were going in a car going X mph and fired a bullet out the window ahead of you that was going at the same speed. Link to comment Share on other sites More sharing options...
swansont Posted July 18, 2005 Share Posted July 18, 2005 I guess its like asking, "what if you were going in a car going X mph and fired a bullet out the window ahead of you that was going at the same speed. No, you could actually answer that, given enough information. The original question can't be answered, because the car could never go at c. Link to comment Share on other sites More sharing options...
Littleman Posted July 18, 2005 Share Posted July 18, 2005 The original question can't be answered, because the car could never go at c. Why could the car never be able to go at c? Link to comment Share on other sites More sharing options...
LCD Posted July 18, 2005 Share Posted July 18, 2005 as something approaches the speed of light its mass increases, (right?) thus requiring more energy to move, at c its mass is infinate, as is the energy required to move it. Light can do it because it has no mass. Link to comment Share on other sites More sharing options...
DQW Posted July 18, 2005 Share Posted July 18, 2005 If a car was travelling at the speed of light, and it turned on its headlights, would light project in front of the car?In the ground-frame (to an observer on the ground) : NOIn the car-frame (to an observer in the car) : YES Link to comment Share on other sites More sharing options...
MetaFrizzics Posted July 18, 2005 Share Posted July 18, 2005 The measurement of the 'speed of light' is an illusion caused by an incomplete understanding of the phenomenon being 'measured'. The 'speed of light' does not conform to normal definitions and expectations of a 'speed'. Link to comment Share on other sites More sharing options...
DQW Posted July 18, 2005 Share Posted July 18, 2005 The measurement of the 'speed of light' is an illusion caused by an incomplete understanding of the phenomenon being 'measured'. Pray, elaborate ! An "incomplete understanding" on whose part ? What is this illusion, and how does it come about ? And going a step further, what is the true speed of light, according to you ? "Phenomena" are detected or observed. "Quantities" are measured. "Phenomena" can not be measured. Link to comment Share on other sites More sharing options...
swansont Posted July 19, 2005 Share Posted July 19, 2005 as something approaches the speed of light its mass increases, (right?) thus requiring more energy to move... Depends on your definition of mass (i.e you are discussing relativistic mass, and all that implies), but the observer never sees that his own mass has increased, in his own frame. Link to comment Share on other sites More sharing options...
LCD Posted July 19, 2005 Share Posted July 19, 2005 why not? that doesn't make sense to me. how would mass be relative to who is observing it? Link to comment Share on other sites More sharing options...
swansont Posted July 19, 2005 Share Posted July 19, 2005 why not? that doesn't make sense to me. how would mass be relative to who is observing it? If you use E=mc2, then the mass (relativistic mass) is dependent on the total energy, the value of which depends on your frame of reference. (it's one reason not to use that and use the invariant value instead, but that's a separate discussion) Link to comment Share on other sites More sharing options...
gisburnuk Posted July 20, 2005 Share Posted July 20, 2005 Light from the car would certainly not be able to project forward! Why are most of the members saying 'yes'? Light has a velocity constancy which basically means that light has a speed limit. For instance: if I was travelling on a coach at 30 mph and I throw a ball at 5 mph towards the drivers direction, then the overall speed of the ball would equal to 35mph. Light cannot gain any extra velocity unlike the ball described earlier. On what foundation do you think time dilation is based upon? Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now