Notices
Results 1 to 45 of 45

Thread: Relavtivity

  1. #1 Relavtivity 
    Forum Freshman
    Join Date
    May 2008
    Location
    Cairo
    Posts
    59
    If a train" X" is moving at 400 km/hour in relation to the earth ,Inside the train there is a similar object "Y" moving with 400 km/hour.
    So the object "Y" is moving at 800 km/hour in relation to the earth , if we repeat this system for several times , Could we get the speed of light ??

    I mean , It's not feasible , but can any one say it's impossible ??!


    Reply With Quote  
     

  2.  

    Related Discussions:

       

    • #2 Re: Relavtivity 
      Forum Masters Degree SuperNatendo's Avatar
      Join Date
      Dec 2007
      Location
      Nashville, TN USA
      Posts
      505
      Quote Originally Posted by raed
      If a train" X" is moving at 400 km/hour in relation to the earth ,Inside the train there is a similar object "Y" moving with 400 km/hour.
      So the object "Y" is moving at 800 km/hour in relation to the earth , if we repeat this system for several times , Could we get the speed of light ??

      I mean , It's not feasible , but can any one say it's impossible ??!
      speed of light measured from train going 400 km/hour = 299 792 458 m / s

      speed of light measured from train going 400 km/hour inside another train going 400 km/houre = 299 792 458 m / s

      in other words, yes, we can say it, it is impossible.

      now, as for actually warping space-time in the vicinity of the train to give the illusion that you somehow traveled faster than the speed of light, yes, that is possible.


      "It's no wonder that truth is stranger than fiction. Fiction has to make sense." - Mark Twain
      Reply With Quote  
       

    • #3 Re: Relavtivity 
      Forum Radioactive Isotope mitchellmckain's Avatar
      Join Date
      Oct 2005
      Location
      Salt Lake City, UTAH, USA
      Posts
      3,112
      Quote Originally Posted by raed
      If a train" X" is moving at 400 km/hour in relation to the earth ,Inside the train there is a similar object "Y" moving with 400 km/hour.
      So the object "Y" is moving at 800 km/hour in relation to the earth , if we repeat this system for several times , Could we get the speed of light ??

      I mean , It's not feasible , but can any one say it's impossible ??!
      Relativity modifies the calculation you are makin with the following formula

      v = (v1 + v2)/(1+ v1 v2 / c^2)

      so for example your trains gives

      (400 km/hour + 400 km/hour)/(1+ (400km/hr)^2/(1079252850km/hr)^2)

      Since 1,079,252,850 km/hr is the speed of light in km/hr

      To the precision of a typical calculator this will just give 800km/hr

      But if your trains are going 400,000,000 km/hr the result will NOT be 800,000,000 km/hour

      (400,000,000 km/hour + 400,000,000 km/hour)/(1+ (400,000,000km/hr)^2/(1079252850km/hr)^2) is equal to 703,380,674 km/hr

      With this formula any two velocities will add up to less than the speed of light.
      See my physics of spaceflight simulator at http://www.relspace.astahost.com

      I now have a blog too: http://astahost.blogspot.com/
      Reply With Quote  
       

    • #4  
      Forum Masters Degree SuperNatendo's Avatar
      Join Date
      Dec 2007
      Location
      Nashville, TN USA
      Posts
      505
      Quote Originally Posted by mitchellmckain
      v = (v1 + v2)/(1+ v1 v2 / c^2)

      so for example your trains gives

      (400 km/hour + 400 km/hour)/(1+ (400km/hr)^2/(1079252850km/hr)^2)

      Since 1,079,252,850 km/hr is the speed of light in km/hr

      To the precision of a typical calculator this will just give 800km/hr

      But if your trains are going 400,000,000 km/hr the result will NOT be 800,000,000 km/hour

      (400,000,000 km/hour + 400,000,000 km/hour)/(1+ (400,000,000km/hr)^2/(1079252850km/hr)^2) is equal to 703,380,674 km/hr

      With this formula any two velocities will add up to less than the speed of light.
      I thought the equation was:

      V = (V1 + V2)/1 + ((V1 + V2)/(C^2))

      So shouldn't that be (400 km/hr + 400 km/hr)/(1 + (400 km/hr + 400 km/hr) / (1079252850km/hr^2))

      ?

      Also Mitchell, I'm running into a paradox here.

      Lets Say I'm trying to get to Barnard's Star, that is 6.0 light years away. I leave earth at what earth sees as 0.99% the speed of light. Now, at this speed, earth sees me shortened lengthwise at about 7 times, and my clocks moving about 7 times slower. To them, when I stop at Barnard's Star, a little more than 6 yrs have passed, but they know that on the ship, the clocks and my aging are just about 11 months older than when I left earth.

      Now, From my perspective, time is going by as normal, but everything outside my ship appears to be shortened lengthwise at about 7 times, and the orbit of the earth around the sun is going 7 times slower. The shorter distances allowed me to get to Barnard's Star at about a years worth of time. As I watched the earth orbit the sun during my trip, the earth appeared to be taking 7 times as long to orbit as it used to. By the time I reach Barnard's Star, It appears that the earth has only advanced about 11 months. However, knowing that the light is taking 6 yrs to get to me, I know the clocks on earth say it has been 6 yrs and 11 month since I left even though it seemed like it only took me 11 months to get there.

      When I turn around and head back to earth, I watch as my home planet seems to rotate the sun the equivalence of 22 months over the combined time of my trip, yet the people on earth are supposedly 13 yrs and 10 months older?

      How does this make any sense whatsoever?
      "It's no wonder that truth is stranger than fiction. Fiction has to make sense." - Mark Twain
      Reply With Quote  
       

    • #5  
      Moderator Moderator Janus's Avatar
      Join Date
      Jun 2007
      Posts
      2,242
      Quote Originally Posted by SuperNatendo

      I thought the equation was:

      V = (V1 + V2)/1 + ((V1 + V2)/(C^2))

      So shouldn't that be (400 km/hr + 400 km/hr)/(1 + (400 km/hr + 400 km/hr) / (1079252850km/hr^2))

      ?
      I don't know where you got that equation from, but it is not the correct one for velocity addition
      Also Mitchell, I'm running into a paradox here.

      Lets Say I'm trying to get to Barnard's Star, that is 6.0 light years away. I leave earth at what earth sees as 0.99% the speed of light. Now, at this speed, earth sees me shortened lengthwise at about 7 times, and my clocks moving about 7 times slower. To them, when I stop at Barnard's Star, a little more than 6 yrs have passed, but they know that on the ship, the clocks and my aging are just about 11 months older than when I left earth.

      Now, From my perspective, time is going by as normal, but everything outside my ship appears to be shortened lengthwise at about 7 times, and the orbit of the earth around the sun is going 7 times slower. The shorter distances allowed me to get to Barnard's Star at about a years worth of time. As I watched the earth orbit the sun during my trip, the earth appeared to be taking 7 times as long to orbit as it used to. By the time I reach Barnard's Star, It appears that the earth has only advanced about 11 months. However, knowing that the light is taking 6 yrs to get to me, I know the clocks on earth say it has been 6 yrs and 11 month since I left even though it seemed like it only took me 11 months to get there.

      When I turn around and head back to earth, I watch as my home planet seems to rotate the sun the equivalence of 22 months over the combined time of my trip, yet the people on earth are supposedly 13 yrs and 10 months older?

      How does this make any sense whatsoever?
      There seems to be quite a bit of confusion in your post. A lot of it stems form confusing what you see happening on Earth and what you determine is happening on Earth.

      To find what you determine what is happening on Earth according to you, you use the Time dilation formula:

      T = T`/sqrt(1-v²/c²).

      To find what you see happening on Earth you use the Relativistic Doppler effect formula:

      f = f`* sqrt((1-v/c)/(1+v/c))

      One thing to note is that v is positive for velocities of objects moving away from each other and negative for objects approaching each other.

      For the Time dilation formula, this doesn't make any difference because v is squared, but for the Doppler shift formula it does matter.

      Taking your problem for example

      Using time dilation, you would determine that the Earth aged at 1/7 the rate you do on the outgoing trip. Thus if you aged 10.26 mo., the Earth will have aged 10.26/7 = 1.47 mo (Not 6 yr/7 = 11 mo.)
      This is how much the Earth has aged according to you.

      Using Dopper shift, you would see the Earth age at 1/14 the rate you do. Thus you will see the Earth age 10.26/14 = .7328 mo.

      On the return trip, you will determine by time dilation that the Earth will again age 11/7 = 1.57 mo. (Yes, I know, 1.57 + 1.57 mo = 3.14 mo., and the Earth's total accumulated during the trip should be 12.12 yrs, but we'll come back to that later on.)
      Using Doppler shift you will see the Earth age at a rate of:

      sqrt((1-(-.99c)/c)/(1+(-.99c/c)) = 14 times you do. This is 10.26*14 = 154 mo. = 11.97 yrs.

      Add this to the .7328 mo aged during the outbound trip and you get 12.03 yrs. (the difference between this and the 12.12 you should get is due to accumulated rounding error.

      Thus while you age 1 year 8.5 mo., you see the Earth age 12 yrs 1.5 mo. during the trip. No paradox.


      Now, back to that 11+ year difference between what the you have determined by time dilation that Earth has aged and what it has actually.

      The problem is in what happens during the period when you slow down and turn around to return to Earth. During this period, you are no longer in a single inertial frame, And thus the standard time dilation formula and rules can not be applied. Instead, you must use the rules for an accelerated frame. And to cut to the chase, these rules will have you determining that during this period of acceleration on your part, the earth will have aged some 11 yrs 10+ mo.


      So, to recap: Doppler shift gives you what you will see.

      Time dialation gives you what you will determine. (after all light signal delay times have been accounted for.)
      "Men are apt to mistake the strength of their feelings for the strength of their argument.
      The heated mind resents the chill touch & relentless scrutiny of logic"-W.E. Gladstone


      Edit/Delete Message
      Reply With Quote  
       

    • #6 Re: Relavtivity 
      Suspended
      Join Date
      Apr 2008
      Posts
      2,176
      Quote Originally Posted by SuperNatendo
      Quote Originally Posted by raed
      If a train" X" is moving at 400 km/hour in relation to the earth ,Inside the train there is a similar object "Y" moving with 400 km/hour.
      So the object "Y" is moving at 800 km/hour in relation to the earth , if we repeat this system for several times , Could we get the speed of light ??

      I mean , It's not feasible , but can any one say it's impossible ??!
      speed of light measured from train going 400 km/hour = 299 792 458 m / s

      speed of light measured from train going 400 km/hour inside another train going 400 km/houre = 299 792 458 m / s

      in other words, yes, we can say it, it is impossible.

      now, as for actually warping space-time in the vicinity of the train to give the illusion that you somehow traveled faster than the speed of light, yes, that is possible.

      You cannot warp space. Space is just a place for matter. It has no charge, and there is nothing to effect.

      You can create electrical fields that will move matter, change its structure/shape, or change its density, matter that is in space.

      But I see no effect on space that would even fall into the realm of science.

      Sincerely,


      William McCormick
      Reply With Quote  
       

    • #7  
      The Doctor Quantime's Avatar
      Join Date
      Jun 2007
      Location
      United Kingdom
      Posts
      4,546
      To say your all 'qualified' it doesn't give me much faith seeing that you all disagree with each other about the equations. Plus. McCormick, what the heck are you talking about?

      You cannot warp space. Space is just a place for matter. It has no charge, and there is nothing to effect.
      Space is spacetime and thus warps due to mass, thats plainly obviously been proven many years ago with the eclipse as the first. Why would space have charge and by nothing to effect what are you reffering to? We all know there is such a thing as permeability of space, varying constants in different types of space. Don't we live in Minkowski space at the moment?

      You can create electrical fields that will move matter, change its structure/shape, or change its density, matter that is in space.
      Yes, spacetime can do that as well, aka gravity being curved spacetime whats your point?

      But I see no effect on space that would even fall into the realm of science.
      Space is everything along side time as the same entity, space is everything with time. How can space not fall into the realm of science, space-time after all is the base of all science.


      To answer your question as simply and innocently as possible:

      Every new addition of speed will be percieved in numerous ways, so theoretically each observor at every 400 kph would take more or less time to see that one object at 1c. There would be many different observation points to observe with many different time differentials and thus a different time dilation near light speed occuring for each unique observor. So yes we could reach the speed of light, but I'm not sure if that which is seen to be travelling at 1c will be seen by everyone to be travelling at 1c, that especially includes the last 400kph.

      But why not, yes.
      "If you wish to make an apple pie from scratch, you must first invent the universe". - Carl Sagan
      Reply With Quote  
       

    • #8  
      Forum Radioactive Isotope mitchellmckain's Avatar
      Join Date
      Oct 2005
      Location
      Salt Lake City, UTAH, USA
      Posts
      3,112
      Quote Originally Posted by SuperNatendo
      I thought the equation was:

      V = (V1 + V2)/1 + ((V1 + V2)/(C^2))

      So shouldn't that be (400 km/hr + 400 km/hr)/(1 + (400 km/hr + 400 km/hr) / (1079252850km/hr^2))
      Try a google of >relativity velocity addition< if you don't believe me.


      Quote Originally Posted by SuperNatendo
      Also Mitchell, I'm running into a paradox here.

      Lets Say I'm trying to get to Barnard's Star, that is 6.0 light years away. I leave earth at what earth sees as 0.99% the speed of light. Now, at this speed, earth sees me shortened lengthwise at about 7 times, and my clocks moving about 7 times slower.
      Correct... well it is not actually seeing... it is acutally what they calculate must be the case when they take into account that the light they see you by is traveling at 1079252850km/hr.


      Quote Originally Posted by SuperNatendo
      To them, when I stop at Barnard's Star, a little more than 6 yrs have passed, but they know that on the ship, the clocks and my aging are just about 11 months older than when I left earth.
      .8658 years or 10 months and 12 days older, yes.


      Quote Originally Posted by SuperNatendo
      Now, From my perspective, time is going by as normal, but everything outside my ship appears to be shortened lengthwise at about 7 times, and the orbit of the earth around the sun is going 7 times slower. The shorter distances allowed me to get to Barnard's Star at about a years worth of time. As I watched the earth orbit the sun during my trip, the earth appeared to be taking 7 times as long to orbit as it used to. By the time I reach Barnard's Star, It appears that the earth has only advanced about 11 months.
      Correct. HOWEVER, this all changes when you start slowing down in order to stop at Barnard's Star or turn around to go back. While you are slowing down you would "see" (or calculate) that the earth is going around the sun extra fast in order to catch up so that by the time you stop at Barnard's Star you find that the people on earth are completely correct and that over 6 years passed on the earth while only 10.4 months passed for you.


      Quote Originally Posted by SuperNatendo
      When I turn around and head back to earth, I watch as my home planet seems to rotate the sun the equivalence of 22 months over the combined time of my trip, yet the people on earth are supposedly 13 yrs and 10 months older?

      How does this make any sense whatsoever?
      Accelerating back to 99% of the speed of light again you would calculate that the clocks on earth are going 7 times slower than your own, BUT while you were accelerating you calculate that the earth went around the sun, equivalent to the passage of 5.2 years so that when you get there 10.4 months later a total of 6.06 years will have passed on earth during your return trip.

      In order to really understand relativity you MUST understand the relativity of simultaneity. That is the key to EVERYTHING.



      Quote Originally Posted by 425 Chaotic Requisition
      To say your all 'qualified' it doesn't give me much faith seeing that you all disagree with each other about the equations. Plus. McCormick, what the heck are you talking about?
      Nobody who is qualified is disagreeing about equations. (Hint: SuperNatendo, while intellegent and well spoken, has presented no reason for us to consider him "qualified"). And I don't think either I or Janus is going to be able to help you with McCormick. I don't even try to understand him.


      Quote Originally Posted by 425 Chaotic Requisition
      You cannot warp space. Space is just a place for matter. It has no charge, and there is nothing to effect.
      Space is spacetime and thus warps due to mass, thats plainly obviously been proven many years ago with the eclipse as the first. Why would space have charge and by nothing to effect what are you reffering to? We all know there is such a thing as permeability of space, varying constants in different types of space. Don't we live in Minkowski space at the moment?
      In addition, if you don't call, the length contraction that squashes 6 light years down to only .857 light years in the direction you are moving when you travel at 99% of the speed of light, warping space, then I REALLY don't know WHAT warping space could mean otherwise!
      See my physics of spaceflight simulator at http://www.relspace.astahost.com

      I now have a blog too: http://astahost.blogspot.com/
      Reply With Quote  
       

    • #9  
      Forum Professor
      Join Date
      Apr 2007
      Location
      In the circuitous haze of my mind
      Posts
      1,028
      On the other hand, the observer on the platform sees the back of the train moving toward the point at which the flash was given off, and the front of the train moving away from it. This means that the light flash going toward the back of the train will have less distance to cover than the light flash going to the front.
      http://en.wikipedia.org/wiki/Relativity_of_simultaneity

      But then wouldn't this mean that if you were the back wall of the train, you would see light moving faster at you than it normally would? Isn't this impossible, to see light moving faster than c?

      Why would earth appear to move slower while traveling away form it? I thought that through time dilation everything would appear to move faster. What about an object perpendicular to you while traveling at high speeds away from earth? Would this objects time rate appear to go by slower?
      Of all the wonders in the universe, none is likely more fascinating and complicated than human nature.

      "Two things are infinite: the universe and human stupidity; and I'm not sure about the universe."

      "Great spirits have always found violent opposition from mediocrities. The latter cannot understand it when a man does not thoughtlessly submit to hereditary prejudices but honestly and courageously uses his intelligence"

      -Einstein

      http://boinc.berkeley.edu/download.php

      Use your computing strength for science!
      Reply With Quote  
       

    • #10  
      Moderator Moderator Janus's Avatar
      Join Date
      Jun 2007
      Posts
      2,242
      Quote Originally Posted by Cold Fusion
      On the other hand, the observer on the platform sees the back of the train moving toward the point at which the flash was given off, and the front of the train moving away from it. This means that the light flash going toward the back of the train will have less distance to cover than the light flash going to the front.
      http://en.wikipedia.org/wiki/Relativity_of_simultaneity

      But then wouldn't this mean that if you were the back wall of the train, you would see light moving faster at you than it normally would? Isn't this impossible, to see light moving faster than c?
      No, that's the whole point. Everyone measures light as moving at c with respect to themselves. Thus any observer anywhere on the train would "see" that the flash starts at the center of the Train, travels at c with respect to the train and strikes the back of the train and the front of the train simultaneously. Conversely, any observer anywhere on the platform or embankment will "see" the flash start at the middle of the train, travel at c with respect to the platform and hit the back of the train before the front of the train. Ergo, relativity of Simultaneity; Events that are simultaneous for observers on the train, are not simultaneous for observers on the embankment.


      Why would earth appear to move slower while traveling away form it? I thought that through time dilation everything would appear to move faster.
      Two reasons:
      1. Doppler shift
      2. Time dilation. There is no absolute frame of rest in Relativity, Thus every observer is "at rest" as far as he is concerned. To an observer in the ship, it is the Earth that is moving away from him, and the Earth that undergoes time dilation.
      A good rule of thumb in SR:
      Time dilation always happens to the "other guy".
      What about an object perpendicular to you while traveling at high speeds away from earth? Would this objects time rate appear to go by slower?
      If the object has a velocity with respect to you, yes.
      "Men are apt to mistake the strength of their feelings for the strength of their argument.
      The heated mind resents the chill touch & relentless scrutiny of logic"-W.E. Gladstone


      Edit/Delete Message
      Reply With Quote  
       

    • #11  
      Forum Professor
      Join Date
      Apr 2007
      Location
      In the circuitous haze of my mind
      Posts
      1,028
      So then the light traveling towards the front of the train appears, or does go slower than it should be going through adding c to the velocity of the train? Essentially then light cannot go c+v1, so it eliminates the v1 by moving v1 slower and therefore ends up at c again....causing it to appear to get to the right forward side slower.
      Of all the wonders in the universe, none is likely more fascinating and complicated than human nature.

      "Two things are infinite: the universe and human stupidity; and I'm not sure about the universe."

      "Great spirits have always found violent opposition from mediocrities. The latter cannot understand it when a man does not thoughtlessly submit to hereditary prejudices but honestly and courageously uses his intelligence"

      -Einstein

      http://boinc.berkeley.edu/download.php

      Use your computing strength for science!
      Reply With Quote  
       

    • #12  
      Moderator Moderator Janus's Avatar
      Join Date
      Jun 2007
      Posts
      2,242
      Quote Originally Posted by Cold Fusion
      So then the light traveling towards the front of the train appears, or does go slower than it should be going through adding c to the velocity of the train? Essentially then light cannot go c+v1, so it eliminates the v1 by moving v1 slower and therefore ends up at c again....causing it to appear to get to the right forward side slower.
      OR, you can simply conclude that the speed of light is independent of its source.
      "Men are apt to mistake the strength of their feelings for the strength of their argument.
      The heated mind resents the chill touch & relentless scrutiny of logic"-W.E. Gladstone


      Edit/Delete Message
      Reply With Quote  
       

    • #13  
      Suspended
      Join Date
      Apr 2008
      Posts
      2,176
      Quote Originally Posted by 425 Chaotic Requisition
      To say your all 'qualified' it doesn't give me much faith seeing that you all disagree with each other about the equations. Plus. McCormick, what the heck are you talking about?

      You cannot warp space. Space is just a place for matter. It has no charge, and there is nothing to effect.
      Space is spacetime and thus warps due to mass, thats plainly obviously been proven many years ago with the eclipse as the first. Why would space have charge and by nothing to effect what are you reffering to? We all know there is such a thing as permeability of space, varying constants in different types of space. Don't we live in Minkowski space at the moment?

      You can create electrical fields that will move matter, change its structure/shape, or change its density, matter that is in space.
      Yes, spacetime can do that as well, aka gravity being curved spacetime whats your point?

      But I see no effect on space that would even fall into the realm of science.
      Space is everything along side time as the same entity, space is everything with time. How can space not fall into the realm of science, space-time after all is the base of all science.


      To answer your question as simply and innocently as possible:

      Every new addition of speed will be percieved in numerous ways, so theoretically each observor at every 400 kph would take more or less time to see that one object at 1c. There would be many different observation points to observe with many different time differentials and thus a different time dilation near light speed occuring for each unique observor. So yes we could reach the speed of light, but I'm not sure if that which is seen to be travelling at 1c will be seen by everyone to be travelling at 1c, that especially includes the last 400kph.

      But why not, yes.

      Space does not change. It is emptiness. It is filled with matter and free electrons. Matter can be effected. However you cannot effect space.

      You can bend, twist, crush, disassemble/explode, shrink, and expand matter, however the space remains the same.
      Doing those things to matter may cause light or other rays to act strangely. Somehow scientists started to associate the light gases of space with space itself. They are totally two different things. Just more poor science.

      There is just nothing in pure space. Space is a three dimensional area. You cannot effect it. You can fill it, you can nearly empty it. But that is about it.

      I would have to listen to an argument that the matter creates the space. Only because I cannot leave the Universe to find out. However I do not believe so. I highly suspect that space is self supporting.

      Gravity does not cause light to bend. The structure, different density gases, around the sun created by gravity causes the light to bend. Two very different things. One very poor science the other reproducible without a planets gravity field.



      Sincerely,


      William McCormick
      Reply With Quote  
       

    • #14  
      Forum Professor serpicojr's Avatar
      Join Date
      Jul 2007
      Location
      JRZ
      Posts
      1,069
      Quote Originally Posted by William McCormick
      Space does not change... However you cannot effect space.
      How do you know? Where's your proof?
      Reply With Quote  
       

    • #15  
      Forum Masters Degree SuperNatendo's Avatar
      Join Date
      Dec 2007
      Location
      Nashville, TN USA
      Posts
      505
      OK, I don't think I understand the relativity of simultaneity as explained by the lightning thing. The person on the train who sees the lightning, sees the light traveling from the front of the train and from the back of the train at the same speed, however, since he is moving towards the front lightning strike, the light from the front strike hits his mirror first, while the second strike appears to happen afterwards. This is because from his frame of reference, the two events are not occurring at the same time, the simultaneous event only happens in the frame of reference of the observer on the ground.

      I just don't understand this occurrence, I mean, if this is true, someone observing the big bang from a different frame of reference might actually see everything happening simultaneously, while we, being in a different frame of reference, think it all happened in succession.

      I really wish I could grasp this better. It just makes me appreciate Einstein for figuring this out, if it were me I would have thought something was a little bit off in my brain!

      Also, I heard the example of the train and the tunnel. The train, from the frame of reference of someone on the ground, appears to be really short. There is a tunnel up ahead, that due to the shortness of the train, appears as though you can close both ends of the tunnel and trap the train, yet according to people on the train, the outside world is very short and there is no way the train could fit its front and back in the tunnel at the same time.

      All of this also ties mass in with your speed, which is why a particle that travels at the speed of light would have infinite mass, unless its rest mass began at 0.

      Crazy stuff, but I won't give up until I understand it.

      P.S. Yeah, I was wrong about my equation, You both had it right, I am new at the math behind the theory, I am just an amateur "scientist", just very interested in the rules of the universe is all, Trying to learn as much as I can.
      "It's no wonder that truth is stranger than fiction. Fiction has to make sense." - Mark Twain
      Reply With Quote  
       

    • #16  
      Suspended
      Join Date
      Apr 2008
      Posts
      2,176
      Quote Originally Posted by serpicojr
      Quote Originally Posted by William McCormick
      Space does not change... However you cannot effect space.
      How do you know? Where's your proof?
      Look at light passing through hot gas of different densities. It is bent, distorted. It is just different density gas, causing a lens effect.

      You do not need gravity to create this.

      Sincerely,


      William McCormick
      Reply With Quote  
       

    • #17  
      Forum Professor serpicojr's Avatar
      Join Date
      Jul 2007
      Location
      JRZ
      Posts
      1,069
      No, you misunderstood my question. I don't care how you explain certain observable phenomena. I'm asking how you know that space is immutable.
      Reply With Quote  
       

    • #18  
      Suspended
      Join Date
      Apr 2008
      Posts
      2,176
      Quote Originally Posted by serpicojr
      No, you misunderstood my question. I don't care how you explain certain observable phenomena. I'm asking how you know that space is immutable.

      There is nothing to effect. That is what space is.


      Sincerely,


      William McCormick
      Reply With Quote  
       

    • #19  
      Forum Professor serpicojr's Avatar
      Join Date
      Jul 2007
      Location
      JRZ
      Posts
      1,069
      Quote Originally Posted by William McCormick
      There is nothing to effect. That is what space is.
      This is an assumption. You have to show that space behaves this way. You haven't given any evidence that it does.
      Reply With Quote  
       

    • #20  
      Forum Radioactive Isotope mitchellmckain's Avatar
      Join Date
      Oct 2005
      Location
      Salt Lake City, UTAH, USA
      Posts
      3,112
      Quote Originally Posted by SuperNatendo
      I just don't understand this occurrence, I mean, if this is true, someone observing the big bang from a different frame of reference might actually see everything happening simultaneously, while we, being in a different frame of reference, think it all happened in succession.
      The order of all events is not relative. Consider these two examples

      Example 1: Planet A is 10 light years from planet B, according to the people on planets A and B. According to observer C a particular lightning strike on planet A occurs 5 years before a particular lightning strike on planet B.

      Example 2: Planet A is 10 light years from planet B, according to the people on planets A and B. According to observer C a particular lightning strike on planet A occurs 15 years before a particular lightning strike on planet B.

      The relativity of simultaneity only applies to example 1.

      In example 1: An observer D going at a different velocity could conclude that the two lightning strikes happened at the same time or in the opposite order. The only limitation is that no observer can see one lightning strike ocurring before the other by 10 years or more.

      In example 2: Every observer no matter what their velocity would always conclude that the strike on planet A occurs before the strike on planet B by an amount of time that must be 5 years or more.



      Quote Originally Posted by SuperNatendo
      Also, I heard the example of the train and the tunnel. The train, from the frame of reference of someone on the ground, appears to be really short. There is a tunnel up ahead, that due to the shortness of the train, appears as though you can close both ends of the tunnel and trap the train, yet according to people on the train, the outside world is very short and there is no way the train could fit its front and back in the tunnel at the same time.
      Let consider what the people on the train would see. They would see the guy at the gate in front would shut the gate just before the train reached it, then of course the train would crash into the front gate but since nothing can travel faster than the speed of light, nothing can stop the other end of the train from entering the tunnel and when it does, anyone alive on the train would see the guy at that gate shut his gate.



      Quote Originally Posted by SuperNatendo
      All of this also ties mass in with your speed, which is why a particle that travels at the speed of light would have infinite mass, unless its rest mass began at 0.
      There is no such thing as infinite mass. Only massless particles move at the speed of light and in fact must always move at the speed of light. Particles with mass will always move at less than the speed of light.
      See my physics of spaceflight simulator at http://www.relspace.astahost.com

      I now have a blog too: http://astahost.blogspot.com/
      Reply With Quote  
       

    • #21  
      Forum Radioactive Isotope mitchellmckain's Avatar
      Join Date
      Oct 2005
      Location
      Salt Lake City, UTAH, USA
      Posts
      3,112
      Quote Originally Posted by Cold Fusion
      So then the light traveling towards the front of the train appears, or does go slower than it should be going through adding c to the velocity of the train? Essentially then light cannot go c+v1, so it eliminates the v1 by moving v1 slower and therefore ends up at c again....causing it to appear to get to the right forward side slower.
      Light going from one side to the other always does so at the speed of light for every observer whether on or off the train. Every observer also sees the light leave one end of the train before arriving at the other end of the train. What is different depending on the observer is the frequency and wavelength of the light, the length of the train and the time it takes for the light to travel from one end to the other.
      See my physics of spaceflight simulator at http://www.relspace.astahost.com

      I now have a blog too: http://astahost.blogspot.com/
      Reply With Quote  
       

    • #22  
      Alc
      Alc is offline
      Forum Freshman
      Join Date
      Jan 2008
      Posts
      21
      In terms of the whole space being immutable thing.
      Personally i don't beleive it to be immutable. If you consider, we dont know the actual shape of the universe, plus if the universe itself exists in the same space from which it began which is point zero.

      The accepted shape of our universe right now, is a 3-dimentional elipse.

      Take the earth, if you were to travel in a straight line around the equator, you would eventually arrive at the point which you departed from.

      Apply this to the shape of our universe, if you were to travel to another galaxy, or infact any other point of the universe, it is assumed that you would travel around the side of the elipse, so travelling in a straight line would eventually take you back to the same point as before.

      Which brings me to my point, The fastest way to cross from one point to another on any 3 dimensional shape is straight through the middle, in a straight line. The displacement of your travel is less than your total distance in this case...

      And assuming that all of the universe exists on the outer surface of the elipse, that leaves little to imagine, inside the elipse is nothing, no space, light, mass, basically a void. which means since theres no matter and no change, there is also no time at all there and theoretically no physical distance.

      Travelling from one point in the universe to another would be instantanious, if you could actually leave the universe and travel "around it".

      In my opinion this theory backs up the idea that no energy is ever lost form the universe and is only converted, if the universe wasnt self contained in itself eventually all the energy omitted away from the universe would dissappear into nothingness forever... and eventually the universe would die out.

      Just my view on it not really sure if its all provable what i just said, but its a nice thought
      Reply With Quote  
       

    • #23  
      Suspended
      Join Date
      Apr 2008
      Posts
      2,176
      Quote Originally Posted by serpicojr
      Quote Originally Posted by William McCormick
      There is nothing to effect. That is what space is.
      This is an assumption. You have to show that space behaves this way. You haven't given any evidence that it does.

      The definition of space is an area of some x,y,z proportion or infinite proportion because we cannot measure it. It has no charge no particles or anything else. It is total lack of anything. By all definitions that I know of.

      Although in its pure form it has never actually existed to my knowledge, it has or was always thought of in these terms, of being a vast emptiness.

      Then poor scientists who like to write a lot, started misunderstanding the awesome simplicity of the basic building blocks rather then to do the leg work to understand the effect of structures, on ambient radiation.

      One confusion lead to a rumor and then to another confusion and before you know it you have about 70 particles all of them in actuality electrons being called different names, and given properties that can be demonstrated by the electron.

      The definition says that space may or may not contain objects.



      Sincerely,


      William McCormick
      Reply With Quote  
       

    • #24  
      Forum Radioactive Isotope mitchellmckain's Avatar
      Join Date
      Oct 2005
      Location
      Salt Lake City, UTAH, USA
      Posts
      3,112
      Quote Originally Posted by mitchellmckain
      Example 1: Planet A is 10 light years from planet B, according to the people on planets A and B. According to observer C a particular lightning strike on planet A occurs 5 years before a particular lightning strike on planet B.

      Example 2: Planet A is 10 light years from planet B, according to the people on planets A and B. According to observer C a particular lightning strike on planet A occurs 15 years before a particular lightning strike on planet B.
      By the way... To give you some of the terminology, the interval between the two lightnings strikes in example 1 is called a space-like interval and the interval between the two lightnings strikes in example 2 is called a time-like interval. How do I know? Because in example 1 the distance of 10 light years is greater than the time separation of 5 years, and because in example 2 the time separation of 15 years is greater than the distance of 10 light years. A time-like interval in one inertial frame will be a time-like interval in all intertial frames. A space-like interval in one inertial frame will be a space-like interval in all intertial frames.

      Oh and so the relativity of simultaneity only applies to the order of events separated by space-like intervals.
      See my physics of spaceflight simulator at http://www.relspace.astahost.com

      I now have a blog too: http://astahost.blogspot.com/
      Reply With Quote  
       

    • #25  
      Alc
      Alc is offline
      Forum Freshman
      Join Date
      Jan 2008
      Posts
      21
      Quote Originally Posted by William McCormick

      The definition of space is an area of some x,y,z proportion or infinite proportion because we cannot measure it. It has no charge no particles or anything else. It is total lack of anything. By all definitions that I know of.

      One confusion lead to a rumor and then to another confusion and before you know it you have about 70 particles all of them in actuality electrons being called different names, and given properties that can be demonstrated by the electron.
      Your definition of space isn't incorrect... but its too vague, you wrote your definition as if you knew exactly what exists in it, and EVERYTHING that does.
      A more accurate definition would be "An unmeasurable/infinite expanse in which everything exists." Although it isnt entirely accurate.

      This definition does not once imply that space itself is nothingness, just because everything such as our sun and our planet are "floating" in space, doesnt mean that space is nothing, maybe just something we cant yet notice, for example, Water can also contain things which arent water..... (not sure if anyone gets my point on that one).

      And as to the assumption of the different particles all being electrons but given different names, what proof do you have? some of these particles are smaller than an electron itself and have no charge at all (neutrinos) even though they were hard to proove.....

      Give me some proof that these particles indeed are all electrons and do all show the exact properties of electrons then i might consider it remotely possible... but until then it seems like its a very disprovable theory.
      Reply With Quote  
       

    • #26  
      (Q)
      (Q) is offline
      Forum Isotope (Q)'s Avatar
      Join Date
      May 2005
      Posts
      2,650
      Quote Originally Posted by William McCormick


      The definition of space is an area of some x,y,z proportion or infinite proportion because we cannot measure it. It has no charge no particles or anything else. It is total lack of anything. By all definitions that I know of.
      The definition of space is simply the distance between two objects, Billy.
      Religious Fundamentalist Club - Member #1.
      Reply With Quote  
       

    • #27  
      Suspended
      Join Date
      Apr 2008
      Posts
      2,176
      Quote Originally Posted by (Q)
      Quote Originally Posted by William McCormick


      The definition of space is an area of some x,y,z proportion or infinite proportion because we cannot measure it. It has no charge no particles or anything else. It is total lack of anything. By all definitions that I know of.
      The definition of space is simply the distance between two objects, Billy.
      Actually the distance between two objects is the distance between two objects. We often call it space. However space is three dimensional.
      Area is two dimensional. Linear distance is a single dimension.

      Someone mentioned that water can have contaminates and that is true. However water is not space. Water is an object. Space is space. And has nothing in it. It can do nothing, it can change nothing.

      Once something is in space, you can effect the object in space, you can splash the water. Filter the contaminates out of the water. However you cannot change the space.

      Sincerely,


      William McCormick
      Reply With Quote  
       

    • #28  
      Alc
      Alc is offline
      Forum Freshman
      Join Date
      Jan 2008
      Posts
      21
      You say we space cannot change anything or is nothing.... but space is still a new thing for us, maybe it is nothing, maybe there is more than meets the eye, who knows, until we can proove it either way, its unfair to assume.
      Reply With Quote  
       

    • #29  
      Forum Professor serpicojr's Avatar
      Join Date
      Jul 2007
      Location
      JRZ
      Posts
      1,069
      William, what (Q) is saying is that we can quantize space by considering distances. For example, from distance we can develop area and volume. If you do a mathematical analysis of three-dimensional spaces with distances, you'll learn that your usual old Euclidean space is only one of many options. So you cannot assume that we live in Euclidean space. Furthermore, you cannot assume that the "shape" of space does not vary with time. You have to show these things. You have yet to do so.
      Reply With Quote  
       

    • #30  
      (Q)
      (Q) is offline
      Forum Isotope (Q)'s Avatar
      Join Date
      May 2005
      Posts
      2,650
      Quote Originally Posted by William McCormick

      Actually the distance between two objects is the distance between two objects. We often call it space. However space is three dimensional.
      Area is two dimensional. Linear distance is a single dimension.
      No Billy, space is the distance between two objects.
      Religious Fundamentalist Club - Member #1.
      Reply With Quote  
       

    • #31  
      Suspended
      Join Date
      Apr 2008
      Posts
      2,176
      Quote Originally Posted by (Q)
      Quote Originally Posted by William McCormick

      Actually the distance between two objects is the distance between two objects. We often call it space. However space is three dimensional.
      Area is two dimensional. Linear distance is a single dimension.
      No Billy, space is the distance between two objects.
      That is a slang usage. Railing guys use it. I do it myself. It is wrong though for a highly technical discussion of space itself. In the railing business we say the spacing is going to be to code, 3.5 inches apart.

      But it is actually and technically the distance between the balusters.

      Because space implies three dimensions.

      Sincerely,


      William McCormick
      Reply With Quote  
       

    • #32  
      Moderator Moderator
      Join Date
      Jun 2005
      Posts
      1,621
      Hmm, you are all terribly confused here.

      First part is easy. "Space" in the mathematical sense has nothing, absolutely nothing to do with "space" in the Star Trek sense. Here's a couple of simple examples; the real line R<sup>1</sup> is a 1-space, as is the circle S<sup>1</sup>. The real plane R<sup>2</sup> is a 2-space, as is the 2-sphere S<sup>2</sup>. Notice that the superscripts (which are not powers!) merely tell us how many numbers we need to uniquely determine a point in the space in question

      Now consider spacetime. It is conventional to model this as a mathematical 4-space, as defined above; specifically it is said to be a 4-manifold. What does this mean?

      Well, without going into too much detail, it means that spacetime can be fully described by an abstract set of 4 coordinates, under the condition that, at least locally, spacetime is indistinguishable from the 4-plane R<sup>4</sup>.

      Notice the "at least locally" qualifier here. Roughly speaking, this means that, even though spacetime may be locally "flat", in the Euclidean sense, there is no requirement that it should be globally so. This is elementary geometry - it also accords with intuition; I think of my back yard as being flat, even though I know it's a part our global planet

      Einstein's trick, and it was a brilliant one, was to prove that the global "non-flatness" of the 4-manifold called spacetime is a consequence of the presence of energy and matter fields.

      Noticing that, if we allow ourselves to think of gravity as being "energy", which seems unwise on balance, we would have a highly non-linear theory of gravitation. Our man brilliantly side-stepped that one with his field equations.
      Reply With Quote  
       

    • #33  
      Forum Freshman
      Join Date
      Jun 2008
      Posts
      18
      William McCormick, What observations and experiments led you the model of physics you currently subscribe to?

      Did you ever figure out the fundamental difference between magnetic and gravitational attraction? And that odd mathematical oddity that seems to indicate a difference between electrostatic effects and the effect of gravity between particles of the same type?

      Have you observed light significantly bending it's trajectory around in space where no observable gravity wells exist? After-all, these space-gasses certainly shouldn't have absolutely even density across space, we should be able to observe significant lensing effects around the outer parameter of nebulae, since space-gasses are of higher density gradients there than around fully condensed planets and singularities.

      What exactly IS gravity anyhow, given your elennnnnnnnnnnnnnnnnnnnnnnnnnnnctron-based model? Would it be some sort of isolated effect of a mono-polar omnidirectional electric field that somehow attracts the very same mono-polar omnidirectional electric field that all other particles just happen to generate for no obvious reason?


      The current model of physics may not be perfect, but the ones who came up with it at least gave good reasons as to why they think the way they do.. Citing phenomena that at least has SOME form of passable experimental grounding to back up their science-fiction novels.
      Reply With Quote  
       

    • #34  
      Forum Masters Degree SuperNatendo's Avatar
      Join Date
      Dec 2007
      Location
      Nashville, TN USA
      Posts
      505
      William McCormick is a sad case of someone being taught wrong and not having the ability to adapt his knowledge based on new findings. As far as I have gathered in this forum with him it appears that, due to some of the things he has said, he learned from German text books from the 40's or 50's that were inhibited by their refusal to accept Einstein's theories based on the fact that he was jewish. I may be wrong, but based on the encyclopedias and textbooks he has posted scans of I think I'm on track.

      In any case, after getting off-topic apace and time are unavoidably connected. The difference between two objects traveling through space at different speeds gives them both different frames of reference. Sometimes, an event that is simultaneous in one frame is not simultaneous in another frame. The faster an object travels, the shorter it appears to someone in a different frame. From one frame looking to another, it appears as time has slowed down for the object being observed from both points of view. This is relativity at its core.
      "It's no wonder that truth is stranger than fiction. Fiction has to make sense." - Mark Twain
      Reply With Quote  
       

    • #35  
      Forum Freshman
      Join Date
      Jun 2008
      Posts
      18
      Didnt German physicists from the 40's once postulate the idea that space was actually a solid, and matter was a manifestation if cavities in space, like swiss cheese? I think they wanted at one time to bounce radio waves off the walls of space that surrounded Earth, to spy on the other side of the world.. I thought that was kinda funny the first time I read it.


      At any rate.. I'm done hijacking this thread. my apologies.
      Reply With Quote  
       

    • #36 how;s it with speed of light being absolute 
      Forum Freshman
      Join Date
      Jun 2008
      Location
      Poland
      Posts
      38
      Let's suppose that an observer goes with speed of 1 km/s and he travels in opposite direction than beam of light which travels at 300 k km/s.
      What is then the speed of light of the light's beam relative to the observer:

      300 ths km/s or 300 001 km/s?
      Reply With Quote  
       

    • #37  
      Suspended
      Join Date
      Apr 2008
      Posts
      2,176
      Quote Originally Posted by cryptonic26
      William McCormick, What observations and experiments led you the model of physics you currently subscribe to?

      Did you ever figure out the fundamental difference between magnetic and gravitational attraction? And that odd mathematical oddity that seems to indicate a difference between electrostatic effects and the effect of gravity between particles of the same type?

      Have you observed light significantly bending it's trajectory around in space where no observable gravity wells exist? After-all, these space-gasses certainly shouldn't have absolutely even density across space, we should be able to observe significant lensing effects around the outer parameter of nebulae, since space-gasses are of higher density gradients there than around fully condensed planets and singularities.

      What exactly IS gravity anyhow, given your elennnnnnnnnnnnnnnnnnnnnnnnnnnnctron-based model? Would it be some sort of isolated effect of a mono-polar omnidirectional electric field that somehow attracts the very same mono-polar omnidirectional electric field that all other particles just happen to generate for no obvious reason?


      The current model of physics may not be perfect, but the ones who came up with it at least gave good reasons as to why they think the way they do.. Citing phenomena that at least has SOME form of passable experimental grounding to back up their science-fiction novels.

      The earth is bombarded by electrons moving very fast. But slowed from dark normal outer space radiation, to speeds that inflict gravity, by the dielectric gases around earth. The earth itself accelerates the electrons from the far side of the planet, so that they are moving to fast to impart a repulsion to your feet and entire body to equalize the ambient radiation from above.

      When you slow this ambient radiation more, or enough you get a bomb. Even from small rather seemingly harmless materials.

      There is no such thing as attraction. When someone can explain attraction I will take the multi subatomic particle scientists seriously. Universal Scientists won the battle, they showed conclusively that attraction force does not actually exist in this universe. And cannot.

      They allowed multi particle scientists to demonstrate attraction to the total embarrassment of the multi particle scientists, they could only make retarded hand motions and hugging motions.

      But stupid law makers need stupid people to lead. Or visa versa.

      However repulsion does exist and can be demonstrated and explained.

      Sincerely,


      William McCormick
      Reply With Quote  
       

    • #38  
      Suspended
      Join Date
      Apr 2008
      Posts
      2,176
      Quote Originally Posted by SuperNatendo
      William McCormick is a sad case of someone being taught wrong and not having the ability to adapt his knowledge based on new findings. As far as I have gathered in this forum with him it appears that, due to some of the things he has said, he learned from German text books from the 40's or 50's that were inhibited by their refusal to accept Einstein's theories based on the fact that he was jewish. I may be wrong, but based on the encyclopedias and textbooks he has posted scans of I think I'm on track.

      In any case, after getting off-topic apace and time are unavoidably connected. The difference between two objects traveling through space at different speeds gives them both different frames of reference. Sometimes, an event that is simultaneous in one frame is not simultaneous in another frame. The faster an object travels, the shorter it appears to someone in a different frame. From one frame looking to another, it appears as time has slowed down for the object being observed from both points of view. This is relativity at its core.
      Einstein believed in time travel. He had to leave Germany if he wanted to practice science and be take seriously.

      I have heard others here say things about time travel that makes you wonder if they have ever even looked at what they are, and where they are, and what their actions are.

      Time travel is about as silly as wishing for the tooth fairy. Yet it sells. So does the tooth fairy.

      Time travel belief is a sickness of the mind from what I have seen of its poor logic and obvious removal of the individual from the equation. It is almost like you don't or didn't exist, if you think you can travel back in time. It just shows a lack of responsibility for your actions. And poor science.


      Sincerely,


      William McCormick
      Reply With Quote  
       

    • #39  
      Forum Masters Degree SuperNatendo's Avatar
      Join Date
      Dec 2007
      Location
      Nashville, TN USA
      Posts
      505
      Quote Originally Posted by wienertakesall
      Let's suppose that an observer goes with speed of 1 km/s and he travels in opposite direction than beam of light which travels at 300 k km/s.
      What is then the speed of light of the light's beam relative to the observer:

      300 ths km/s or 300 001 km/s?
      299 792 458 m / s

      This is the speed, no matter what speed the observer is going, the light is ALWAYS going 299 792 458 m / s

      If he is going 100 000 000 m / s , the light is still traveling 299 792 458 m / s compared to him.
      "It's no wonder that truth is stranger than fiction. Fiction has to make sense." - Mark Twain
      Reply With Quote  
       

    • #40 so how quickly? 
      Forum Freshman
      Join Date
      Jun 2008
      Location
      Poland
      Posts
      38
      Quote Originally Posted by SuperNatendo
      Quote Originally Posted by wienertakesall
      Let's suppose that an observer goes with speed of 1 km/s and he travels in opposite direction than beam of light which travels at 300 k km/s.
      What is then the speed of light of the light's beam relative to the observer:

      300 ths km/s or 300 001 km/s?
      299 792 458 m / s

      This is the speed, no matter what speed the observer is going, the light is ALWAYS going 299 792 458 m / s

      If he is going 100 000 000 m / s , the light is still traveling 299 792 458 m / s compared to him.
      It is a speed of light, OK. But if I and someone else go in opposite directions with 10 km/h speed each then the distance between us gets larger by 20 km/h. You say it's not the same with light, do you?
      Reply With Quote  
       

    • #41 Re: so how quickly? 
      Moderator Moderator Janus's Avatar
      Join Date
      Jun 2007
      Posts
      2,242
      Quote Originally Posted by wienertakesall
      It is a speed of light, OK. But if I and someone else go in opposite directions with 10 km/h speed each then the distance between us gets larger by 20 km/h. You say it's not the same with light, do you?
      Even at 10 kph, the difference would not add up to 20 kph but:

      (10 kph + 10 kph)/(1+ 10kph*10kph/(1,079,252,849 kph)^2)

      Where 1,079,252,849 kph is the speed of light.

      Which turns out to be just a tiny bit less than 20 kph.
      "Men are apt to mistake the strength of their feelings for the strength of their argument.
      The heated mind resents the chill touch & relentless scrutiny of logic"-W.E. Gladstone


      Edit/Delete Message
      Reply With Quote  
       

    • #42 Relativity. 
      Suspended
      Join Date
      Jul 2008
      Posts
      31
      The concept of relativity indicates that as you approach the speed of light, things act very weirdly (to put it simply). You can add up velocities, but this is only in classical mechanics. However, when the velocities approach the speed of light, you cannot add them up. Here is an example of this:

      Imagine that you are driving south, on a road. Someone else is driving north, on the other lane, and they have their headlights on. As you pass them, will the lights appear to be coming faster than the speed of light? The answer to this is no. Let us get back to the trains.

      The speed of the trains seem to be approaching the speed of light, but the smallest train will take infinite amount of energy to actually obtain such a speed. As objects reach enormous speeds, their velocities don't actually seem to increase, but their mass increases exponentially. When this occurs, it takes more and more energy to approach the speed of light. To accelerate the smallest train to 400 kilometers per hour, the largest trains would require too much energy, rendering the whole process impossible, an intriguing thought. Because the mass of the smallest train is eventually so large, the entire system would fail. Considering this, you will realize that such a process is not only impossible practically, but impossible in theory also. However, the idea that you thought of leads into murkier topics. Here are some things that involves relativity.

      Remember the headlight situation. This involves another queer property of relativity. This has to do with time dilation. As an object reaches enormous speeds, the time of the object seems to slow down. This is, of course, only to the observer. The person or object that actually is in the object will feel that time is at a normal pace. Therefore, a clock will be ticking more and more slowly as you approach the speed of light. But say you were on a train moving 273,000,000 mps. Then people on the outside would appear to be moving excessively slowly. Time dilation, however, has generated the false feeling that you can go back in time.

      To go back in time then, we would assume that we must go past the speed of light. Seeing that time dilation makes time stop (to the observer) at the speed of light, then to go above, the only logical answer would be that you would go back in time. This is true, but going past the speed of light is impossible.

      All of this info was presented in a similar way to Carl Sagan's cosmos. This old show is the most remarkable presentations that I have ever seen, and it is a great place to learn more things. I also got this stuff from various sources. I will form a separate thread called "Weird Stuff" in physics. This info may have errors, of which I would gladly accept any corrections. I am an amateur scientist after all!
      Reply With Quote  
       

    • #43 Re: Relativity. 
      Forum Radioactive Isotope mitchellmckain's Avatar
      Join Date
      Oct 2005
      Location
      Salt Lake City, UTAH, USA
      Posts
      3,112
      Quote Originally Posted by Duelix
      The concept of relativity indicates that as you approach the speed of light, things act very weirdly (to put it simply). You can add up velocities, but this is only in classical mechanics. However, when the velocities approach the speed of light, you cannot add them up. Here is an example of this:
      Wrong. You can add up velocities but you must add them using the formula that Janus just used. For small velocities this is practically the same as regular addition but when the velocities get near the speed of light it is not like regular addition because two velocities less than the speed of light will always add up to a velocity less than the speed of light and if one of the velocities is the speed of light then the result will be the speed of light no matter what the other velocity is.

      (10 kph + 1,079,252,849 kph)/(1+ 10kph*1,079,252,849 kph/(1,079,252,849 kph)^2)

      = (10 kph + 1,079,252,849 kph)/(1+ 10kph/1,079,252,849 kph)

      = 1,079,252,849 kph(10 kph + 1,079,252,849 kph)/(1,079,252,849 kph + 10kph )

      = 1,079,252,849 kph

      Quote Originally Posted by Duelix
      The speed of the trains seem to be approaching the speed of light, but the smallest train will take infinite amount of energy to actually obtain such a speed. As objects reach enormous speeds, their velocities don't actually seem to increase, but their mass increases exponentially.
      Well that depends on what you want to call mass. If you are talking about an innate property of a thing then you are talking about rest mass and this does not change. Frankly I think this relativistic mass that you are talking about is an invented quantity with too little usefulness to be worth the confusion it creates, for it is more intuitive to keep the energy of motion as a separate quantity rather than including it in a mass that is purely relative.


      Quote Originally Posted by Duelix
      To go back in time then, we would assume that we must go past the speed of light. Seeing that time dilation makes time stop (to the observer) at the speed of light, then to go above, the only logical answer would be that you would go back in time. This is true, but going past the speed of light is impossible.
      There is nothing sensible about any of this except your last phrase: "going past the speed of light is impossible". But we can do even better. Regardles of the inertial frame of the observer, massless objects always travel at the speed of light, and objects with mass always travel at less than the speed of light.
      See my physics of spaceflight simulator at http://www.relspace.astahost.com

      I now have a blog too: http://astahost.blogspot.com/
      Reply With Quote  
       

    • #44 Re: Relativity. 
      Suspended
      Join Date
      Apr 2008
      Posts
      2,176
      Quote Originally Posted by mitchellmckain
      Quote Originally Posted by Duelix
      The concept of relativity indicates that as you approach the speed of light, things act very weirdly (to put it simply). You can add up velocities, but this is only in classical mechanics. However, when the velocities approach the speed of light, you cannot add them up. Here is an example of this:
      Wrong. You can add up velocities but you must add them using the formula that Janus just used. For small velocities this is practically the same as regular addition but when the velocities get near the speed of light it is not like regular addition because two velocities less than the speed of light will always add up to a velocity less than the speed of light and if one of the velocities is the speed of light then the result will be the speed of light no matter what the other velocity is.

      (10 kph + 1,079,252,849 kph)/(1+ 10kph*1,079,252,849 kph/(1,079,252,849 kph)^2)

      = (10 kph + 1,079,252,849 kph)/(1+ 10kph/1,079,252,849 kph)

      = 1,079,252,849 kph(10 kph + 1,079,252,849 kph)/(1,079,252,849 kph + 10kph )

      = 1,079,252,849 kph

      Quote Originally Posted by Duelix
      The speed of the trains seem to be approaching the speed of light, but the smallest train will take infinite amount of energy to actually obtain such a speed. As objects reach enormous speeds, their velocities don't actually seem to increase, but their mass increases exponentially.
      Well that depends on what you want to call mass. If you are talking about an innate property of a thing then you are talking about rest mass and this does not change. Frankly I think this relativistic mass that you are talking about is an invented quantity with too little usefulness to be worth the confusion it creates, for it is more intuitive to keep the energy of motion as a separate quantity rather than including it in a mass that is purely relative.


      Quote Originally Posted by Duelix
      To go back in time then, we would assume that we must go past the speed of light. Seeing that time dilation makes time stop (to the observer) at the speed of light, then to go above, the only logical answer would be that you would go back in time. This is true, but going past the speed of light is impossible.
      There is nothing sensible about any of this except your last phrase: "going past the speed of light is impossible". But we can do even better. Regardles of the inertial frame of the observer, massless objects always travel at the speed of light, and objects with mass always travel at less than the speed of light.

      Who taught you that you cannot go past the speed of light? Did they even bother to try? Or did they sit and discuss time travel, (Going back and fixing their cowardice magically).

      Speed of light was done. No one was interested in the speed of light, or the things we claim to want publicly.

      Kennedy claimed to want to go to space. The truth was he hated the space program. He hated the people that could pull it off.

      We can pull off anything, however it will just lead back to a confrontation with law makers.

      What would law makers do in a society lead by real technology? What would their purpose be?


      Sincerely,


      William McCormick
      Reply With Quote  
       

    • #45 Re: Relativity. 
      Forum Radioactive Isotope mitchellmckain's Avatar
      Join Date
      Oct 2005
      Location
      Salt Lake City, UTAH, USA
      Posts
      3,112
      Quote Originally Posted by William McCormick
      Who taught you that you cannot go past the speed of light? Did they even bother to try? Or did they sit and discuss time travel, (Going back and fixing their cowardice magically).

      Speed of light was done. No one was interested in the speed of light, or the things we claim to want publicly.

      Kennedy claimed to want to go to space. The truth was he hated the space program. He hated the people that could pull it off.

      We can pull off anything, however it will just lead back to a confrontation with law makers.

      What would law makers do in a society lead by real technology? What would their purpose be?
      The problem is what does it mean to say you cannot exceed the speed of light? I understand what this means and you do not. You seem to think that this is some sort of speed limit like you have on the highway and that is not what it means at all. THERE IS NO SPEED LIMIT. Relativity imposes absolutely no limitations of speed, for you can get to whatever destination you head towards as fast as you like, providing you expend enough energy to do so. There may be other problems with doing this but relativity is not any such problem. Instead, what relativity and this statement concerning the speed of light is talking about, is the structure of space and time. It would be better for you to say that you don't get it than to produce all this background noise of babble about limitations and science fiction ideas.
      See my physics of spaceflight simulator at http://www.relspace.astahost.com

      I now have a blog too: http://astahost.blogspot.com/
      Reply With Quote  
       

    Bookmarks
    Bookmarks
    Posting Permissions
    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •