Here's a questions I've had for a long time about time dilation:<br /><br />Assuming a journey of one million light-years, would a spacecraft travelling at relativistic speeds (let's say 99.99% of <em>c</em>) need components that last the dilated time (Several decades/centuries) or components that would last one million years?<br />
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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Here's a questions I've had for a long time about time dilation:Assuming a journey of one million light-years, would a spacecraft travelling at relativistic speeds (let's say 99.99% of c) need components that last the dilated time (Several decades/centuries) or components that would last one million years? <br /> Posted by baulten</DIV></p><p> </p><p>Time will pass normally in your frame of reference. The components on your craft will also experience the same 'normal' passage of time. </p><p>The million years would only be observed by something outside your frame of reference, but testing on the components would reveal they have only aged decades/centuries despite a million years having passed.</p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'> Time will pass normally in your frame of reference. The components on your craft will also experience the same 'normal' passage of time. The million years would only be observed by something outside your frame of reference, but testing on the components would reveal they have only aged decades/centuries despite a million years having passed. <br />Posted by derekmcd</DIV></p><p>This means if something breaks to will be quite difficult to order the part.<img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-sealed.gif" border="0" alt="Sealed" title="Sealed" /></p><p><br /><br /> </p> <div class="Discussion_UserSignature"> </div>
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>This means if something breaks to will be quite difficult to order the part. <br /> Posted by origin</DIV></p><p>By the time the order is recieved, the technology will be outdated. </p><p> </p><p>Wait... doesn't that happen today, too? </p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>
Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>This means if something breaks to will be quite difficult to order the part. <br />Posted by origin</DIV><br /><br />Just get Chuck Norris, he'll take care of it for you <img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-cool.gif" border="0" alt="Cool" title="Cool" /> <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">Techies: We do it in the dark. </font></strong></p><p><font color="#0000ff"><strong>"Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That's relativity.</strong><strong>" -Albert Einstein </strong></font></p> </div>
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Here's a questions I've had for a long time about time dilation:Assuming a journey of one million light-years, would a spacecraft travelling at relativistic speeds (let's say 99.99% of c) need components that last the dilated time (Several decades/centuries) or components that would last one million years? <br />Posted by baulten</DIV></p><p>derekmd's response is essentially correct. Your components need only last the shorter period of time. What happens is this. You, in the spacecraft will experience only the shorter period of time, while an observer on the Earth would experience nearly one million years of time. However, that observer on the Earth would observe that you in the spacecraft had traveled a distance on one million light years. You in the spacecraft would have experienced a length contraction, (calculated via the Lorentz transformation in a similar manner to the time transformation) and have traveled a far lesser distance.</p><p> This phenomena is verified experimentally by the behvior of the mu meson which is created high in the atmosphere by collisions with cosmic rays and penetrate far deeper streak than would be explained by knowledge of its known speed and half life. Because it is traveling so fast, it experiences a lesser time than is seen by an observer in the reference frame of the Earth, and thus lives longer than might be expected if the effects of special relativity were ignored. <br /></p> <div class="Discussion_UserSignature"> </div>
Okay, I got it. I was relatively certain that this was the case, but I read a few articles that sounded otherwise, which was why I asked. Makes perfect sense, again, thanks.
Replying to:<BR/><DIV CLASS='Discussion_PostQuote'> This phenomena is verified experimentally by the behvior of the mu meson which is created high in the atmosphere by collisions with cosmic rays and penetrate far deeper streak than would be explained by knowledge of its known speed and half life. Because it is traveling so fast, it experiences a lesser time than is seen by an observer in the reference frame of the Earth, and thus lives longer than might be expected if the effects of special relativity were ignored. <br /> Posted by DrRocket</DIV>Doc, are there more documented instances of interaction between matter traveling at relativistic speeds and matter that's not, at scales larger than just particles'? <div class="Discussion_UserSignature"> </div>
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Doc, are there more documented instances of interaction between matter traveling at relativistic speeds and matter that's not, at scales larger than just particles'? <br /> Posted by nimbus</DIV></p><p>Ejected matter from hypernovae that reach these relativisitic speeds are simply too highly energized and hot to accomplish any kind of bonding. Atoms (likely ionized) will probably be the heaviest particles you see in nature achieving these speeds. </p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Doc, are there more documented instances of interaction between matter traveling at relativistic speeds and matter that's not, at scales larger than just particles'? <br />Posted by nimbus</DIV></p><p>That rather depends on what you have in mind. All speeds are relativistic, some are just more relativistic than others. There have been experiments involving the so-called twin paradox. In those experiments two atomic clocks were synchronized and one flown about on an airplane and then brought back to the "stationary" clock. As predicted, the clock flown on the airplane showed slightly less elapsed time than the stationary one. The "paradox" arises by observing that the "stationary" clock is seen to be in motion by the clock on the plane, and the resolution is that the plane must start, stop and turn and therefore is accelerating and not an inertial reference frame.</p><p>I know of no experiments involving significant solid masses at speeds approaching c. The energy involved in producing such a situation would be very large indeed. I believe that there are observations in the astronomical community of large quantities of gasses moving at very high velocities due to explosions of stars or emissions from pulsars or some such. But those phenomena involve enormous energies and diffuse matter. No pitcher throws a baseball anywhere near that fast.</p> <div class="Discussion_UserSignature"> </div>
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>No pitcher throws a baseball anywhere near that fast. <br /> Posted by DrRocket</DIV></p><p>Depends on your frame of reference <img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-laughing.gif" border="0" alt="Laughing" title="Laughing" />. Batters in a slump might argue with ya. </p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>
Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Depends on your frame of reference . <br />Posted by <strong>derekmcd</strong></DIV><br /><br />That was going to be my response to the intial question ... a millions years measured by who ? (or is it whom ?? <img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-tongue-out.gif" border="0" alt="Tongue out" title="Tongue out" /> ) <div class="Discussion_UserSignature"> <p>-----------------------------------------------------</p><p><font color="#ff0000">Ask not what your Forum Software can do do on you,</font></p><p><font color="#ff0000">Ask it to, please for the love of all that's Holy, <strong>STOP</strong> !</font></p> </div>
Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>That rather depends on what you have in mind. All speeds are relativistic, some are just more relativistic than others. There have been experiments involving the so-called twin paradox. In those experiments two atomic clocks were synchronized and one flown about on an airplane and then brought back to the "stationary" clock. As predicted, the clock flown on the airplane showed slightly less elapsed time than the stationary one. The "paradox" arises by observing that the "stationary" clock is seen to be in motion by the clock on the plane, and the resolution is that the plane must start, stop and turn and therefore is accelerating and not an inertial reference frame.I know of no experiments involving significant solid masses at speeds approaching c. The energy involved in producing such a situation would be very large indeed. I believe that there are observations in the astronomical community of large quantities of gasses moving at very high velocities due to explosions of stars or emissions from pulsars or some such. But those phenomena involve enormous energies and diffuse matter. No pitcher throws a baseball anywhere near that fast. <br /> Posted by DrRocket</DIV><br />This brings up an interesting question. Could the paradox you speak of be used to find a fixed stationary reference point in space? <div class="Discussion_UserSignature"> </div>
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>This brings up an interesting question. Could the paradox you speak of be used to find a fixed stationary reference point in space? <br />Posted by vitalstatistic63</DIV></p><p>No. The paradox is not really a paradox. In fact, the basic tenet of the theory is that it is absolutely impossible find any "fixed" reference frame. <br /></p> <div class="Discussion_UserSignature"> </div>
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>No. The paradox is not really a paradox. In fact, the basic tenet of the theory is that it is absolutely impossible find any "fixed" reference frame. <br /> Posted by DrRocket</DIV></p><p>Or, conversely, the universe has an infinite number of fixed reference frames without giving preference to any of them.</p><p>And the non-paradox is that both statements are correct despite seemingly different answers. </p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>
<p>So say I want to travel 1 light year in a year. I hop into my spaceship and burn enough fuel to accelerate to the speed of light and travel for a year my time. Ok, I know its always going to appear to take more than a year to travel a light year for anyone who didn't travel with me no matter what is happening in my own time frame. What percentage of the speed of light would I have been traveling relative from where I left from and how long would the journey have taken in their time? Is there any sudden effect apparent when I cross that (speed of light) barrier, am I suddenly relativistic? </p>
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>So say I want to travel 1 light year in a year. I hop into my spaceship and burn enough fuel to accelerate to the speed of light and travel for a year my time. Ok, I know its always going to appear to take more than a year to travel a light year for anyone who didn't travel with me no matter what is happening in my own time frame. What percentage of the speed of light would I have been traveling relative from where I left from and how long would the journey have taken in their time? Is there any sudden effect apparent when I cross that (speed of light) barrier, am I suddenly relativistic? <br />Posted by kg</DIV></p><p>You cannot actually travel at the speed of light in any reference frame. Only massless particles, such as a photon can do that. Photons experience no time at all. Special relativity provides a factor to relate the passage of time in one frame to the passage in another that is moving at a constant velocity relative to the first. That factor is called gamma. This article will explain how it works.</p><p>http://en.wikipedia.org/wiki/Special_relativity</p><p> </p> <div class="Discussion_UserSignature"> </div>
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>You cannot actually travel at the speed of light in any reference frame. Only massless particles, such as a photon can do that. Photons experience no time at all. Special relativity provides a factor to relate the passage of time in one frame to the passage in another that is moving at a constant velocity relative to the first. That factor is called gamma. This article will explain how it works.http://en.wikipedia.org/wiki/Special_relativity <br />Posted by DrRocket</DIV></p><p>Well that's interesting I was going to write an essay on "Time Dilation" myself with out researching it even,</p><p>but time is relevant thing to us . I only check in occassionally didn't know it was being updated myself .</p><p>I am glad though . Much better I think . All these sites are updating to say in the least.<img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-cool.gif" border="0" alt="Cool" title="Cool" /></p> <div class="Discussion_UserSignature"> <font size="3" color="#339966">E To The Square</font> </div>
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>So say I want to travel 1 light year in a year. I hop into my spaceship and burn enough fuel to accelerate to the speed of light and travel for a year my time. Ok, I know its always going to appear to take more than a year to travel a light year for anyone who didn't travel with me no matter what is happening in my own time frame. What percentage of the speed of light would I have been traveling relative from where I left from and how long would the journey have taken in their time? Is there any sudden effect apparent when I cross that (speed of light) barrier, am I suddenly relativistic? <br /> Posted by kg</DIV></p><p> </p><p>You have to figure in length contraction, too. Considering you can't travel at the speed of light, let's go with 99% of C. An outside observer would see you travel 1 ly and take a little over 1 year to get there. You would experience only about 52 days according to your clock and due to length contraction, your odometer would read having only traveled 1/7 of a light year's distance. So, in your example having traveled one year at 99% C, you would have traversed 7 light years distance due to length contraction. If you were traveling at 100% C, you could be everywhere instantly without experiencing the passage of time. Weird, but true.</p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'> You have to figure in length contraction, too. Considering you can't travel at the speed of light, let's go with 99% of C. An outside observer would see you travel 1 ly and take a little over 1 year to get there. You would experience only about 52 days according to your clock and due to length contraction, your odometer would read having only traveled 1/7 of a light year's distance. So, in your example having traveled one year at 99% C, you would have traversed 7 light years distance due to length contraction. If you were traveling at 100% C, you could be everywhere instantly without experiencing the passage of time. Weird, but true. <br />Posted by derekmcd</DIV><br /><br />Now I'm confused...</p><p> I thought I could travel as fast as I wanted in my own frame of reference. Say I never heard of Einstein or relativity. I build a rocket that contains enough fuel to accelerate so many Gs for so many days to bring me up to C (ok, I understand that this isn't practice). So I light the fuse, climb in and blast off! In my own frame of reference won't I burn up my rocket fuel and accelerate at the force for the time I calculated? When you say "traveled at 99% C" I'm not sure if you mean my reference frame or that of the place I left from. In my example above won't I be traveling much less than 99% C in the frame of the place I left?</p>
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Now I'm confused... I thought I could travel as fast as I wanted in my own frame of reference. Say I never heard of Einstein or relativity. I build a rocket that contains enough fuel to accelerate so many Gs for so many days to bring me up to C (ok, I understand that this isn't practice). So I light the fuse, climb in and blast off! In my own frame of reference won't I burn up my rocket fuel and accelerate at the force for the time I calculated? When you say "traveled at 99% C" I'm not sure if you mean my reference frame or that of the place I left from. In my example above won't I be traveling much less than 99% C in the frame of the place I left? <br />Posted by kg</DIV></p><p> I think that in what most people would call their reference frame, a frame attached to you, you would be at rest. But in that reference, or in any reference frame, nothing travels faster than light. (And to you guys that want to bring up tachyons, I will point out that there is no evidence whatever that they exist.) In the frame of the place that you left you will be traveling 0.99 c. In your own frame you are not moving at all, everything outside of your frame is moving.</p><p>I'm not sure what mean by hypothesising that you "never heard of Einstein or relativity." The theory seems to be correct, so you will not see anything traveling faster than light. Now, if you intend to say that if you apply Newton's theory of mechanics that you can predict that an object will travel faster that light if you apply a force for a long enough period of time, then yes that is true. And the explanation is that Newtonian mechanics is wrong. It supplies good predictions only when speeds are not close to the speed of light.<br /></p> <div class="Discussion_UserSignature"> </div>
Both observers would recognize that .99% C was achieved and both would agree that the astronaut only aged 1/7th of a year. What they would not agree on is the actual travel time and distance measured even though the destination was the same. Intuitively, the astronaut would know that he traveled a full light years distance and his buddy watching him from afar aged a year, but the readings in his craft would indicate that he, physically, did neither. And both observations would be correct.<br /> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>
<p>The whole time relativity thing makes one wonder why we would bother to attempt travel to any star system. Consider the following according to the Time Dilation Theory (TDT) as I have seen it mentioned here.</p><p>Ship travels to Alpha Centauri, just 4.5 Ly distant. Spends 5 years there and returns to earth. Total trip time should be around fifteen years give or take a year or so. But not according to TDT which would have the crew returning when those of us here would be at least 300 years old. This seems to make the idea of a round trip confusing at best. Crews who might think they are getting an advantage by approaching light speed yet returning to earth 300 years into the future.</p><p>And of course, tho I refer to it as theory, tests have shown it may well be fact and some here might argue that it is indeed fact. I would imagine this is why many in the scientific community regard interstellar travel as impractical if not impossible. Some would say impossible.</p><p>Project the single Alpha Centauri scenario across several star systems with round trips being made between them and earth. Confused crews arriving at earth hundreds of years in the future...arriving possibly when their space agencies and governments are long gone.</p><p>If one wonders what my point is, it may be that its hard to accept TDT as fact because of the ensuing confusion that would almost surely result from crews arriving at far future points in human history. This would almost certainly end up making interstellar travel as one way colonization affair.</p> <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>
<p><strong>"Ship travels to Alpha Centauri, just 4.5 Ly distant. Spends 5 years there and returns to earth. Total trip time should be around fifteen years give or take a year or so. But not according to TDT which would have the crew returning when those of us here would be at least 300 years old. This seems to make the idea of a round trip confusing at best. Crews who might think they are getting an advantage by approaching light speed yet returning to earth 300 years into the future."</strong></p><p>When you say "approaching light speed", let's use 99% to make it a fairly drastic effect. Total travel time for your astronaut would be actually 4.2ly each way totalling 8.4ly distance traveled to an observer on earth. Including the 5 years downtime at Alpha Centauri, that astronaut would have only aged ~6.2 years during his mission. The mission control team here on earth would have aged ~13.5 years. </p><p><strong>"And of course, tho I refer to it as theory, tests have shown it may well be fact and some here might argue that it is indeed fact."</strong></p><p>It is, indeed, fact. It is a direct consequence of moving through space and has been proven with absolute certainty. It's not even a theory using the scientific definition of theory. GPS satellites require their clocks to be calibrated in order to function properly due to time dilation. </p><p><strong>"I would imagine this is why many in the scientific community regard interstellar travel as impractical if not impossible. Some would say impossible."</strong></p><p>Definitely not impossible. Impractical, yes, but only because we can't even come close to approaching the requisite speeds necessary to complete a trip in a single life time. Time dilation benefits both the astronaut and mission control simply because things get done faster. The gaps in lifetimes between the two only become severly distorted when the travel time is extreme. The closer you get to the speed of light, the effect of time dilation grow exponentially. Let's say at 99.999% and 1000ly round trip travel distance, Mission Control ages just over 1000 years, but the astronaut only ages ~4.5. At only 99%, Mission Control only ages ~1 extra year, but the astronaut now ages ~136.5 extra years. </p><p> </p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>
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