# Paradoxial Computer - Tachyons **URL:** \ **Category:** Factual Questions\ **Created:** [July 18, 2003, 2:25am UTC](https://boards.straightdope.com/t/paradoxial-computer-tachyons/189289 "2003-07-18T02:25:04Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Second](https://avatars.discourse-cdn.com/v4/letter/s/9e8a1a/32.png) [@Second](https://boards.straightdope.com/u/Second)\ **Post date:** [July 18, 2003, 2:25am UTC](https://boards.straightdope.com/t/paradoxial-computer-tachyons/189289/1 "2003-07-18T02:25:04Z")
This was not written by me, but a friend at another board. My knowledge on the subject is very limited. From what I understand, which may be wrong, you can not travel back in time as it would violate causality. Is what he is describing possible? I understand anything with rest mass can never go faster then c, and if you could time would stop, the universe would be seen as a infinitesimal point. And you would be at every point is space simultaneously. But I _think_ I remember reading here that if you could go faster then c you would go backwards in time. As nothing can go at c, but going faster is possible. So if tachyons do exist does time go backwards for them? And if so would it ever be possible use them in a controled manner? Here is what was posted at the other board: > [@](#): > > All forms of energy can do work. > > Tachyons: are particles, that act just like photons and electrons, but the difference is, these travel FASTER than ‘C’. Ill put the time principle in a simple form. Imagine a wave, call it time, as speed increases, time waves more and more. the wavyness indicates THE SPEED AT WHICH TIME TRAVERSES. That is the property of Tachyons. > > A paradox for those of you (lil’d) who dont know is an impossibility that cancels itself out. you go back in time and kill your mother before you were born, you were never born, you couldnt have gone back in time if you never existed and therefore couldnt have killed your mother, youve commited a paradox. An Impossibility, got me? > > Since a tachyon is a form of energy, and works similiarly to Electron. and Photon. I assume it can be used in the same way. If not, i apologize, but theoretically, a Computer made using tachyons as a energy form would be faster then time. the application you perform on the computer would work so fast it would go backward in time, therefore appearing before you executed it. An impossibility. A paradox, and a computer built such would ba a Paradoxial Computer. ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [July 18, 2003, 2:38am UTC](https://boards.straightdope.com/t/paradoxial-computer-tachyons/189289/2 "2003-07-18T02:38:40Z")
> [@](#): > > \*Originally posted by Second \* > \*\*But I _think_ I remember reading here that if you could go faster then c you would go backwards in time. As nothing can go at c, but going faster is possible. So if tachyons do exist does time go backwards for them? And if so would it ever be possible use them in a controled manner? \*\* It is true that nothing with rest mass can travel at or above light speed. In addition to the reasons you posted add that you would have infinite mass upon reaching light speed (hence there is not enough energy in the entire universe to get you there as you’d need infinite energy). However, if for fun you speculate on travelling faster than c then the math insists that time move backwards for the traveller. Tachyons are only a theoretical particle at this point and have never been obeserved. Physics can speculate on them but I think few physicists believe such a creature exists. If it did one implication is that the tachyon can never go _slower_ than light speed. How you would handle such a thing is beyond me. You might generate them (if they exist) but using them opens you to paradoxes as you can now violate causality. ---
**Author:** ![CuriousCanuck](https://avatars.discourse-cdn.com/v4/letter/c/d2c977/32.png) [@CuriousCanuck](https://boards.straightdope.com/u/CuriousCanuck)\ **Post date:** [July 18, 2003, 4:18am UTC](https://boards.straightdope.com/t/paradoxial-computer-tachyons/189289/3 "2003-07-18T04:18:47Z")
> [@](#): > > \*Originally posted by Whack-a-Mole \* > \*\*Physics can speculate on them but I think few physicists believe such a creature exists. If it did one implication is that the tachyon can never go _slower_ than light speed. How you would handle such a thing is beyond me. You might generate them (if they exist) but using them opens you to paradoxes as you can now violate causality. \*\* Once upon a time people thought if you sailed too far from shore you would fall off the end of the world. Once upon a time people thought that no person would ever set foot on the moon. Imagine what would happen if everyone thought along accepted norms. We need the freaks out there thinking of the “impossible”. Otherwise I might not be able to have my VR helmet and 5000 naked women TV channel universe someday. 🙂 ---
**Author:** ![John\_Kentzel-Griffin](https://avatars.discourse-cdn.com/v4/letter/j/ccd318/32.png) [@John\_Kentzel-Griffin](https://boards.straightdope.com/u/John_Kentzel-Griffin)\ **Post date:** [July 18, 2003, 5:24am UTC](https://boards.straightdope.com/t/paradoxial-computer-tachyons/189289/4 "2003-07-18T05:24:45Z")
If you have an object going faster than light from point A to point B in one inertial reference frame, then there will be other frames where the object is simultaneously at A and B, and still other frames where it’s at point B before it is at point A.