Light Speed question

[lukman]

A man is traveling near C, he is having a great time dilation. An observer on the ground is observing if the man is on collision with a meteor in 1hour if the man did not alter his course. <br /><br />Well, 1 hour is more than enough time we supposed, but 1 hour for the observer is 3 second for the speeding man. Time dilation has make him so slow, he cant avoid the meteor, can this be true?<br /><br />Other than infinite mass, infinite energy to travel at light speed. Attemp to increase speed to near C, time dilation slow down everything, even the Core 3 Trio processor in the ship will run at the speed of vacum tube computer. Everything run slower, the engine run slower, then the ship will fall back to previous speed. True?<br /><br />So, the only way to travel FTL will be warping space opposite the way universe unwarping space and accelerates away. <div class="Discussion_UserSignature"> </div>

 

[SpeedFreek]

If the traveller is more than 1 light hour from the observer on the ground, the collision will have already happened before the observer sees the ship on the collision course.<br /><br />For an observers 1 hour to equal the travellers 3 seconds means the relativistic change factor is 1200, and this occurs at a speed of 0.9999996c. Travelling at this speed, it is <i> almost </i> irrelevent how long he has to react, as the amount of energy required to alter his course even a little at this speed is absolutely enormous.<br /><br />Time dilation and length contraction go hand in hand. So what is to blame for him nor having enough time to react? Is it the fact he only has 3 seconds, or the fact that at 0.9999996c the distance to the meteor shrinks from almost a light-hour to 3 light seconds?<br /><br />The traveller does not notice time slow down, to him the computer still runs at full speed. There is just less time for things to happen in. The engine does not run slower, so the ships velocity is unaffected. But distances get shorter at that speed.<br /><br />I cannot understand your statement about FTL travel. Why are people so obsessed by FTL travel, which is theoretically impossible? Time dilation means if you can get close to the speed of light a journey takes a lot less time for the traveller than it seems to an observer. At the speed you are talking about, 0.9999996c, a journey of 5 light years would only take a few days.<br /><br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>

 

[gone_fishin]

Here is a hypothetical situation. <br />Two men are on two planets 51 light years from each other. In this situation both men are 50 years old and will die when they are exactly 100 years old. <br />If either of them took a light speed flight to the others planet they would get there too late to meet because the non traveler would die on his 100th birthday.<br /><br />Now if they BOTH got on a light speed ship and met halfway they would only be a few months older when they met and a few months older when they returned to their home planets.

 

[why06]

<blockquote><font class="small">In reply to:</font><hr /><p><font color="yellow">Why are people so obsessed by FTL travel, which is theoretically impossible?<p><hr /></p></font></p></blockquote><font color="white">- The passion flows from a river called DENILE. <br /><br /></font> <div class="Discussion_UserSignature"> <div>________________________________________ <br /></div><div><ul><li><font color="#008000"><em>your move...</em></font></li></ul></div> </div>

 

[SpeedFreek]

Yes as Tigerbiten said, <i> at </i> lightspeed, if they both made the journey it would be instant for both of them.<br /><br />At just below lightspeed, you are indeed correct according to special relativity.<br /><br />But we must never forget the lag caused by the speed of light in our observations. Your situations are correct, but the <i> frame of reference </i> is important. It is important to aspects of your hypothetical situation.<br /><br />In the first part of your situation, where only 1 man makes the journey, you imply the 2 men are trying to meet. Are you implying they know each other? Does man X know that man Y is 50? If so, we need to know how! <img src="/images/icons/wink.gif" /><br /><br />If they communicate with each other at the speed of light, 1 message takes 51 years. How do these men know each other then?<br /><br />Part 2 of your situation, where they both travel, is also true, but again, how do they know they are meeting each other?<br /><br />I know it's all hypothetical, but it's important to know which frame of reference we are in when we are contemplating these things. <img src="/images/icons/smile.gif" /><br /><br />For instance, as another hypothical situation which mirrors yours:<br /><br />Man X leaves planet X and travels to planet Y, which is 51 light years away. At the speed of light, his journey is instantaneous.<br /><br />He arrives as soon as he leaves. He is still 50 years old and meets Man Y who is <i> the same age, </i> 50 years old. But to man Y it looks like man X's journey has taken 51 years.<br /><br />Indeed, man Y thinks man X has been making this journey since before man Y was born! All his life so far, he has been waiting for man X to arrive, and when he does, lo and behold, they are the same age.<br /><br />Man Y doesn't understand time dilation and wonders how man X could be born a year after he started his journey!<br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>

 

[lukman]

Ok, the traveller wont feel the time dilation, he sees his computer and the engines are running accordingly, but observer can see if the traveller is very slow, if say that the observer also can see that all inside the ship, the computer and the engine is running very slow, but yet the ship is still travel very fast, i am confused. <div class="Discussion_UserSignature"> </div>

 

[SpeedFreek]

Yes, special relativity and time dilation <i> do </i> seem counter-intuitive, for sure!<br /><br />It is simpler to look at the end result and work backwards doing the maths, than to do thought experiments involving observation of the traveller by the observer (or vice versa!) during the journey. The main reason for this is that, according to special relativity, time dilation is <b> symmetrical </b> between inertial frames of reference!<br /><br />What this means is, when travelling at a constant speed due to inertia, both people see the other slowed down by the same amount! So how can they end up aging at different rates?<br /><br />It seems the key to all this is in the non-inertial part of the journey. The observer, watching from his planet, is <b> always </b> in an inertial frame of reference (his planets movement is governed by inertia only). Whereas the traveller has to accelerate to lightspeed and decelerate again. During the acceleration/deceleration phases of the journey, the traveller is in a non-inertial frame of reference, and this must be what accounts for the time dilation.<br /><br />But seeing as it is impossible for either person to see the other one instantly as their observations are always limited to the speed of light, the thought experiment suddenly gets very complicated! <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>

 

[why06]

So at the speed of light you cover more space in less time.<br /><br />Does time always pass at the same rat no matter what so that even if you cover more time you are still moving at the same speed.<br /><br />I always thought about time and space as inter woven, but perhaps I was wrong. I just don' understand how the two can be connected and yet time flows the same. Why would time move slower. if you cover more of it faster.<br /><br /><font color="yellow">Can you even cover more time FASTER?....<br /><br />... Im confused <img src="/images/icons/tongue.gif" /></font> <div class="Discussion_UserSignature"> <div>________________________________________ <br /></div><div><ul><li><font color="#008000"><em>your move...</em></font></li></ul></div> </div>