Tachyons, hypothetical sub-atomic particles which travel faster than light, once attracted a lot of publicity yet we do not hear much discussion of them today. Whatever happened to tachyons?

An artist's impression of the Fomalhaut system, some 25 light years from the Sun. Could tachyons take us there? (Image credit: NASA)

An artist’s impression of the planet Dagon in the Fomalhaut system, some 25 light years from the Sun. Could tachyons take us there in less than 25 years? (Image credit: NASA)


Over a century ago, Albert Einstein anticipated odd things happening on a spaceship travelling at speeds close to that of light (roughly 300 000 km/s) and impossible things happening when travelling at more than the speed of light. It is not necessary here and now to go into why this should be, but these predictions are enough to convince much smarter people than me that the speed of light is a fixed, fundamental speed limit in the Universe and that no material objects can ever attain or exceed this crucial speed.

However some theoretical physicists have gone for a walk on the wild side by speculating on the possible existence of particles of matter which always travel faster than light, avoiding the complications of acceleration past the cosmic speed limit. Physicist Gerald Feinberg even gave them a name, tachyons (from the Greek takhus, meaning “fast”, and the English ”-on”meaning “elementary particle” (yes, really)). There is a history of particle physics predicting the existence of theoretical particles needed to fill gaps in our knowledge which are later discovered to be real, neutrons being the classic example. Could this happen with tachyons?

If they existed tachyons would be really, really bizarre things. For example they would always be moving faster than light, dropping to less than 300 000 km/s would be as impossible for them as exceeding this speed is to us. Stranger still, their mass would be imaginary. “Imaginary” is used in its mathematical sense, meaning a multiple of the square root of -1, whatever that may mean in the real world. Not only that, adding kinetic energy to a tachyon would make it slow down, but it would take infinite energy to drop its velocity down to the speed of light! Conversely, a tachyon shedding energy would continuously accelerate. This leads to a subtle argument against tachyons existing.

Cerenkov Radiation glows in the coolant/moderating water of the Reed Research Reactor. (image credit: United States Nuclear Regulatory Commission)

Cerenkov Radiation glows in the coolant/moderating water of the Reed Research Reactor. (image credit: United States Nuclear Regulatory Commission)


Cherenkov radiation (also, and more correctly, known as Čerenkov radiation) emission occurs when charged particles pass through a medium at a speed greater than the velocity of light in that medium. For example, the speed of light in water is about three-quarters of its speed in free space. Beta particles emitted in an operating nuclear reactor whizz though the surrounding water at speeds exceeding this (but still lower than the speed of light in free space), and Cherenkov radiation is produced as a by-product, appearing as an eerie blue glow. Assuming tachyons are electrically charged (and this is an assumption, there is no evidence either way), as they move though space they would continuous lose energy as Cherenkov radiation emission. As tachyons losing energy accelerate, they would get faster still, give off yet more Cherenkov radiation, accelerate more and so on. Basically this feedback loop would mean that by now any tachyons would be travelling at almost infinite velocity and the whole Universe ought to be filled with the blue glow of their passing. Obviously we have never observed anything like this.

(Update: physicist Ethan Siegel argues that tachyons moving through a vacuum would not generate Cherenkov radiation, going on to state that “tachyons don’t emit Čerenkov radiation unless they move slower-than-light in a medium!”)

As a final piece of weirdness, tachyons would propagate backwards in time, being destroyed before flying around space until they were created. This implies signals sent with tachyons could be received before they are transmitted, either opening up a Pandora’s Box of paradoxes (what lazy TV writers call “wibbly-wobbly timey-wimey stuff“) or conclusively proving the whole idea of tachyons as physically real objects to be hopelessly unfounded.

Physicists played around with the concept of tachyons in the 1960s through to the mid-70s, and a few performed experiments to detect tachyons in cosmic ray showers. The idea was that ultra high-energy cosmic ray particles collide with air molecules in the upper atmosphere creating a secondary shower of billions of daughter particles, some of which can be detected with ground-based instruments.  Possibly tachyons could be also be created in these high altitude (about 20 km overhead) collisions, and would obviously race ahead of their slower than light siblings. Some of the tachyons could be observed as detection events some 60 microseconds or so ahead of the main secondary shower (which is composed of particles moving at just under the speed of light).  In 1973 two Australian researchers, Roger Clay and Philip Crouch, claimed successful detection of a tachyon but no one has ever been able to duplicate this result, and Clay has subsequently concluded “No positive evidence has been found using conventional scintillation detectors for producing a tachyon signal”. Experiments to create tachyons in collisions with particle accelerators at Amhearst College and Brookhaven National Laboratory (both in the USA) also drew blanks.

After the flurry of scientific interest in the early to mid-1970s,the existence of tachyons was looking unlikely, nevertheless tachyons spread rapidly (how else?) to the pages of science fiction. Beams of tachyons were used to make telephone calls between the stars. Mighty starships leapt across the galaxy and still got back home in time for tea thanks to the Tachyon Drive (to non-aficionados of science fiction I should explain that in SF a space propulsion device is always called a ‘drive’). At the press of a button, a Tachyon Drive seems to convert all the matter of a spaceship, its cargo and passengers painlessly and instantaneously into tachyons so they can shoot off into the deep black at superluminal speed and then be transformed back into ordinary matter again at journey’s end. This process seems remarkably easy and trouble-free; presumably it is all done by magic. A less often used alternative Tachyon Drive is the Tachyon Rocket concept (which I remember only from Joe Haldeman‘s 1974 classic The Forever War) where a relatively conventional space vehicle is accelerated to high but subluminal speeds by ejecting an exhaust of tachyons.  The most important fictional treatment of tachyons is Gregory Benford’s Timescape (1980) which was not an epic space opera, rather it told two interlinked earthbound stories.  In 1998 British scientists attempt to use tachyons to send a message into the past warning of an ongoing environmental catastrophe, while in 1962 an American physicist is puzzled by “noise” in the data from an experiment and he begins to wonder if this could be some kind of received transmission. It is a fine book which was very well-received at the time but is sadly rather forgotten now.

What if the radio SETI folk have it wrong and all those alien supercivilisations are chatting away on a tachyonic communications network? What if we build the first tachyon detector and it rings? (Image credit: NASA, ESA, K. Sahu (STScI) and the SWEEPS science team)

What if the radio SETI folk have it wrong and all those alien supercivilisations are chatting away on a tachyonic communications network? What if we build the first tachyon detector and it rings? (Image credit: NASA, ESA, K. Sahu (STScI) and the SWEEPS science team)


Do tachyons exist? Unlike neutrons, tachyons are not actually required to exist by any physical theory and indeed their existence would raise more problems than it would solve (special relativity would be wrong for a start- which would be kind of awesome). Although it is possible to describe them mathematically it would appear certain that tachyons do not exist in the real Universe. Little has been written about them in scientific publications recently apart from some fevered speculations in 2011 when CERN researchers thought they had observed neutrinos moving faster than light, results later found to be in error. Beyond science, tachyons still show up all the time in streams of technobabble in comics and TV shows. More distressingly, “tachyon healing” is advertised as a New Age lifestyle therapy and even as an alternative medical treatment for real illnesses. I have read some of the rationales and product descriptions on sites advertising this sort of junk and found only scare-mongering nonsense, aimed at extracting money from the unwell or anxious, proving that while space has a speed limit, there are no limits to folly and dishonesty.

(article by Colin Johnston, Science Communicator)


Steve · November 12, 2019 at 01:42

Given that it seems clear that tachyons would require the same kind of “energy” (i.e. approaching infinite) to slow down to the speed of light that tardyons require to speed up to the speed of light, what would the “rest state” of tachyons look like? Would they be everywhere at the same instant?

    Steve · November 12, 2019 at 01:50

    To frame it differently, as a tachyon acquires more energy does the universe around it expand?

Millensut · March 21, 2019 at 18:42

Really appreciate you sharing this article.Really looking forward to read more. Awesome.

Jeff · September 7, 2018 at 15:52

If they travel back in time wouldn’t they only be visible at the beginning of time?

Akash p · June 21, 2018 at 15:17

Can tachyon emmit radiation or something which can be useful

John · June 19, 2018 at 13:31

I am no expert .i am just a carpenter with a unquenchable thirst for answers. Tachyons travel faster than the speed of light essentialy going back in time ,so they travel back before they were created .think i just solved it

    Seth Ernest · October 1, 2018 at 01:41

    technically no the particles them self’s can’t go back in time by them selves. while the particles are traveling faster then light they require a host to guide them. they can’t just say ooh lets travel to the world cub series and watch the cubs win the first time or let’s see who the president is going to be in 50 years. it just doesn’t work like that. and let’s say that the particles do have a host somehow the host would have to be traveling at mach 874530.145773 to achieve that and that’s impossible the host would die before that speed was achieved. oh and john if you read this reply ever I just hope you know that tachyon particles are hypothetical dark energy and energy could never be destroyed or created just morphed into something new.

      Lindsey Filler · December 27, 2018 at 02:39

      If I am understanding correctly, you’re saying that there must be another particle that can go faster than light and also go back in time to guide them. How would this host know to guide this tachyon? Why does it needs a host? The tachyon can be a responsible little particle and time-travel by itself.

Goldtree St Bach · December 18, 2017 at 21:44

If tachyons did exist, then Unified Field Theory would follow at once,
since, relative to hyper-light particles, light would behave like a graviton.

Anthony Rodgers · April 17, 2017 at 09:35

My apologies ahead of time if I sound childish by going off of hearsay, but I was discussing tachyons with my friend (he tends to be incredibly smart about these things) and he tells me that an area where tachyons are/would be found is at the event horizon of a black hole. According to him, this is due to the odd effects that tachyons have on spacetime, combined with the time dilation that occurs at the event horizon of a black hole. Can someone experienced in this field please explain? Also, if my friend is correct, should we not be looking to black holes for evidence of tachyons?

Thank you in advance.

Frederic Artus Nieto · August 25, 2016 at 09:54

A simple way (maybe) would be to point a detector towards a black hole, with a polarization filter (or any device allowing the passage of only parallel particles). It would allow to see if particles are escaping from its vicinity, or even if these are generated by it.
i am not certain how to detect a tachyon, but annihilating it with its antiparticle may be feasible. but it’s all just speculation. The possible usages of tachyons are astounding and are quite worth investigation. It could allow mars settlers to have real time internet.

If soemone wanted to prove the existence of tachyons, what would be the appropriate process? (assuming the scientific method is known and used)

Aaron · July 22, 2016 at 14:47

Just a thought, wouldn’t a kind of tachyon-fermion symmetry solve a lot of these problems? For instance, we (fermions) see our clocks run slow as we approach the speed of light; what if tachyons also saw this, their clocks speeding up again as they approach infinity, as ours do when we approach zero? A similar idea to the Cherenkov solution mentioned above. Thanks for the article either way!

Alok · May 27, 2016 at 12:37

Can a human use tachyon to achieve a speed which is grater than the speed of light?

    admin · May 27, 2016 at 13:16

    Dear Alok, please read the article again and your question ought to be answered.

Ernst Wall · April 23, 2016 at 23:50

You can use a negative mass tachyon ( the imaginary mass model was abandoned as useless ) to derive the magnetic moment of the electron, which is the Bohr magneton. See Sections 1 and 7 of the web page, http://www.tachyonmodel.com. Everything on this web page agrees with experiment and is quite extensive. It all had its origin in this negative mass tachyon model. Finally, in a paper at the end I show that time travel is impossible. It is all published in a number of papers as well as a book, The Physics of Tachyonics. Hadronic Press, 1995.

    admin · April 25, 2016 at 10:10

    Dear Ernst, thank you for your comment. You say that

    the imaginary mass model was abandoned as useless

    but I think you are overstating this. The accepted imaginary mass of tachyons is predicted by special relativity and to the best of my knowledge there is no reason to assume that this is not the case.

      Ernst Wall · May 8, 2016 at 02:53

      Dear Admin:

      First of all, thank you for publishing my comments. Also, your return comment was certainly very appropriate.

      My harsh statement about the imaginary mass tachyon was made with great reluctance, but I had no choice. I do not like criticizing other people’s work, and this is especially so with Bilaniuk, Deshpande, and Sudarshan, who derived the imaginary mass model in the first place in 1962, over 50 years ago. They have earned a rightful and significant place in the history of physics because they made it respectable to talk about breaking the light speed barrier. In that sense, they certainly made my work possible.

      If I had been in their place at that time, I might have made the same assumptions they did.

      However, the issue here was that I had no choice but to make that unpleasant statement not because of them, but because the imaginary mass tachyon has become like a religious icon for many people to the exclusion of all other possibilities.

      As a result, many readers would immediately turn off when they saw the use of a negative mass. I was even put on a “crank list”, as best as I can tell, because I had the temerity to use a negative mass tachyon when “everyone knows that tachyons can only have imaginary masses.”

      This is made with all due respect to your comment about it being the “accepted imaginary mass of tachyons”. In fact, I especially appreciate your open mindedness in publishing my remarks in spite of your disagreement over the tachyon mass. That is quite rare!

      There was one case, however, where the imaginary mass model was useful, and that was the case where Recami and Mignai showed that an imaginary mass tachyon would manifest itself as a negative mass (gravitationally repulsive) at subluminal velocities. it was published in Rivista Del Nuovo Cimento 4,209 (1974) . Beyond that, there is absolutely nothing.

      ( In fact, I owe Recami and Mignani a specific citation in my web page. I cited their work in my original derivation of the Bohr magneton model. )

      Beyond their work, I cover in some laborious detail why the concept of the imaginary mass tachyon needs to be reconsidered in Section 11 of my web page.

      To summarize one objection to the imaginary mass model very briefly: In the subluminal domain, particles and atoms interact primarily via electromagnetics. In the superluminal domain, any particles there would move faster than the electromagnetic fields, and so interaction with photons is questionable at best. Hence, simply extending special relativity to the superluminal domain, as logical as it seems at first, is generally questionable. However, as stated above Recami and Mignani did have a success with their derivation of the negative mass.

That Guy · April 15, 2016 at 23:18

I’ve been thinking about the idea of FTL particles for years, and I came to this conclusion, what if the speed of light isn’t the speed limit? There are meny experiments showing that as speed increases so does mass, but there could be an energy level were you can break through the light barrier. If an abject managed to break this speed there could be a completly different reality behind, a possibility of FTL versions of all the elements. For example, take a supernova, supernovas produce massive amounts of energy, if for some reason one particle managed to absorb all that energy it could possibly turn into a tachyon. As for Cherenkov radiation, it might only be something that happens below the speed of light. Now try to prove that there could be no energy level that could create a tachyon, there may only be a few thousand in existance but this theory does make some sence. We have not observed the effects of near light speed travel enough to deny this theory just yet.

jamarr · February 13, 2016 at 06:38

Ok so I agree with everthing.But theres one thing that’s not quite fond of this.What if tachyons are real.Maybe they just move too fast theres no mathematical theoretical Solving in this.Maybe everything is being done wrong.Maybe the amount of caculations they would have to count wouldn’t be possible,well to us.So I think they are real,its just that they don’t seem real because of how fast they move and I don’t think it could be calculated.

    jamarr · February 13, 2016 at 06:41

    Wait.it will be going back in time when it was created like the website says.What if that’s why they cant be found.Its being regenerated to another existance

aeodh · February 11, 2016 at 12:19

I didn’t read all comments here so don’t know if anyone mentioned this before:
If the tachyons are massless, i.e. their imaginary rest masses are zero, then some of the problems disappear. Some people have now essentially confirmed the existence of streams of such particles. I am thinking of constructing a tacyonic anti-telephone using them. It’s a bit of a technical challenge – the list of electronic parts we’re making/sourcing is growing as the tests go on. Everything is rather as predicted by Einstein & co., though. So as with EPR he was right with his reduction an absurdum, only like quantum spooky action at a distance, tachyonic beams are also part of nature, it seems.

    VoiceOfReason · May 24, 2017 at 19:47

    What you are describing violates several fundamental aspects of modern physics. First, tachyons as described here (not the modern definition), cannot be massless without violating Lorentz invariant theory. The total energy of the equation has to be real, so if the tachyon is massless, it breaks the equation, as you would end up a numerator of zero, leaving the total energy of the particle at zero. A massless particle, such as a photon must have positive energy in order to exist (obviously).

    Second. There is a very real thing in modern physics called a tachyonic field that has imaginary mass. They’re actually a pretty important piece of the standard model. These are referred to in physics as simply tachyons and are where tachyon particles would come from just as any other fundamental particle arises from it’s associated field. The problem is, with any standard fundamental particles, their fields are at a local minimum potential energy. Tachyons (the field not the particle) are at a local maximum and are unstable as a result. Any quantum fluctuation that could cause a local excitation, and create a tachyon (the particle not the field) causes the field to collapse to it’s local minimum potential energy and it ends up emitting a boring old Higgs Boson. This is called tachyonic condensation.

    In short… The problems that you are referring to may disappear, but you arrive at new ones (darn you, universe). Sorry to break the bad news as it sounds like you’ve already started spending money on your magic phone, but you’re not going to be able to break the universe with your causality violating machine.

    I wouldn’t mind seeing some of your math though, or the sources for the statement “some people have now essentially confirmed the existence of such particles.” The identity of “some people” would be pretty interesting. Or your circuit board designs, or descriptions of your test procedures.. Tachyonic beams.. All of it really. Sounds like a good time.

      Donald Wood · August 22, 2018 at 16:53

      I am someone who reads a lot of material that I refer to as “physics for morons”.

      One curiosity is C’ at different intervals in the age of the universe. Has it always been the same speed? Will it always be the same speed?
      Is C’ a function of the size limit of the universe at any time we find it?
      So if the universe expands to such a place where all that is left are massless particles like photons and perhaps gravitons, will there be a change in that speed?

      So…if there was ever a time or ever will be a time when C is different than we find it today…is there a so-called “tachyonic time spread”…product, difference or some? This being the case…does it make sense to keep them in the discussion?

Vaibhav Marwaha · January 31, 2016 at 15:39

Sir i am a student of 9th grade.But very much excited about space traveller.Sir i have a question if tychons are objects which travell faster than light and massless objects can travel faster than light then what si the difference between a tychon and a massless object.Pls get it to me as soon as possible.

    admin · February 1, 2016 at 10:59

    Dear Vaibha, thank you for a very interesting question.

    Some particles have a rest mass of zero as you correctly pointed out, photons would be examples. However they have non-zero, positive energies and momenta and are limited to moving at the speed of light. Any mathematical description of tachyons indicates that their mass is imaginary (in the mathematical sense, meaning a multiple of the square root of -1). This seems to be the crucial difference.

    Gowtham · November 10, 2018 at 06:08

    If massless object is faster than the light,like
    photon then we canbuse it for time travel as like tychons.if tychons
    are didnt exist can anyone clarify that

Kelvin · January 27, 2016 at 15:42

It surely helped. Thank you
I am still cracking my head on string theory though

Kelvin · January 17, 2016 at 09:26

thanks for clarifying, quite helpful.
what is tachyonic condensation?

    admin · January 18, 2016 at 09:35

    Dear Kelvin, thanks for your question. I had not encountered the term “tachyonic condensation” before so I’ve learned something too. It seems that some applications of string theory predict situations when the energy density in a volume of space losing energy could become not just less than zero but actually become a complex quantity (that is the energy includes an imaginary component which is a multiple of the square root of -1). I understand that this is not expected to occur in reality and thus is a problem with the theory! It is called tachyonic condensation because the mass density in this volume would be partially imaginary like the mass of tachyons, there is no faster than light motion expected.

    I hope that this has helped you.

gene · January 10, 2016 at 05:18

Additional addendum At the start of the big bang,any particles formed would have enough energy to approach the speed of light where mass gravity could be strong enough to condense them down to mini black holes. As energy cooled this could not happen and only matter as we know it would form.

gene · January 10, 2016 at 05:08

addendum Possible explanation for non locality of light photons. When 2 photons are entangled they share the same wave function. At the speed of light time stops. hence, any communication between the 2 photons occurs instantly. Appreciate any sensible reply.Thanx

gene · January 10, 2016 at 04:53

Can it be that allan guths inflation theory would allow for the ability of matter, antimatter or tachyons to exist in a super luminal universe? Also if this is so, couldn’t the gravity from their mass pull on our distant galaxies producing what is known as “dark energy”?

Kelvin · January 7, 2016 at 16:52

if photons are “massless” how can pair production, for instance an electron and positron which both have masses, be possible from a photon as in accordance with Dirac’s theory?

    admin · January 8, 2016 at 15:18

    Dear Kelvin, I apologise for my loose use of language. Photons have no rest mass but have energy which has a mass equivalence. In pair production the masses of the pair of particles is equivalent the energy of the photon which gives rise them.

    Thanks for me giving the chance to clarify that.

Gian M · December 31, 2015 at 05:29

So I wont even pretend I understand half of whats written down I actualy sort of stumbled on to the article but I found it very interesting. One question though: I have to asume that not having mass would be the reason for these theoretical particles not crashing in to things and destroying everything it comes in contact with. That said, how WOULD these particles even be useful if they are “ghosts”?

    admin · January 4, 2016 at 11:44

    Dear Gian, thank you for your question. “Massless” particles are indeed useful, for example all forms of electromagnetic radiation, including light, radio, X-rays and so on, are composed of particles called photons which have a rest mass of zero. The mass itself is unimportant is these cases , it’s more how they interact with everything else.

      Akash p · June 21, 2018 at 15:20

      Can tachyon emit radiation

Kelvin · December 26, 2015 at 23:02

I am a great fan of all this,my belief which my be wrong ( I’m just an overzealous high school student), is that if tachyonsexist they are from another universe that is parallel to ours but its timeline is opposite to ours,hence any particle from that universe is a tachyon to us . it is true special relativity is a universal law and the properties of tachyons (v>c) would violet al this ..but what I think they don’t at all since they can never be slower than c just like a bradyon can never be faster than c..hence in some respect special relativity is not violeted what differs is the direction of the timeline ( which is why they are believed to go back in time) . in summary all I’m saying is that the special theory of relativity for parallel universes is such that for universe 1 vc..all as a result of opposite timeline direction.

Kelvin · December 26, 2015 at 22:57

I am a great fan of all this,my belief which my be wrong ( I’m just an overzealous high school student), is that if tachyonsexist they are from another universe that is parallel to ours but its timeline is opposite to ours,hence any particle from that universe is a tachyon to us of thia universe. it is true special relativity is a universal law and the properties of tachyons (v>c) would violet al this ..but what I think they don’t at all since they can never be slower than c just like a bradyon can never be faster than c..hence in some respect special relativity is not violeted what differs is the direction of the timeline ( which is why they are believed to go back in time) . in summary all I’m saying is that the special theory of relativity for parallel universes is such that for universe 1 vc..all as a result of opposite timeline direction.

sarah · December 10, 2015 at 07:46

hey so im really interested in tachyons and I’m doing a science project on them and I’m not sure what i can/do for the experiment. does anyone have any ideas?

Joram Arentved · November 16, 2015 at 22:00

Continued, Colin. A Danish Week Magazine claimed that These German Sci.’s achieved
that what, They could get, was that there would be A Warp+, (classified), also The Calif.’s, why on Earth do Both keep on hiding their separate info from The Science World, even Us Both etc.? ‘J.A.’ (I’ll admit that my future labourally hangs by an undeserved thread that’s just not MY obligation at all that I can concentrate on, what such a big conflict problem is, (selfish Danes, liars).

Brian Klock · October 18, 2015 at 19:18

It should say “square ROOT of -1” rather than just “square of -1”. Kind of important to get that correct …

    admin · October 19, 2015 at 08:22

    Dear Brian, thank you, I’ve fixed that!

Draphen · October 7, 2015 at 08:20

Would this not also be a key to unlimited self sustaining energy as well if we somehow found a way to harness tachyons?

    admin · October 7, 2015 at 08:40

    Dear Draphen, I’m not sure myself if we could harness their energy but it might be a possibility. Sadly tachyons do not seem to exist!

Dakota T. · August 14, 2015 at 18:53

Can someone please explain how this idea can be refuted or proven:

We keep looking to smaller and smaller scales to find Tachyons- what if the problem is we are looking in the wrong direction- so to speak. What if the Tachyon is merely the “vessel” that houses our universe. A black hole can be simply releasing/transferring excess mass into the 4th dimensional space our universe (as a whole) is held in- just to be sucked up again by another passing “vessel (tachyon)” to be used as fuel for making the light (or frame) that it leaves behind in the realm of 4th dimensional space time. Drainage of mass would have to occur in order to keep our vessel moving FTL- a natural cosmic checks and balances system. If 4th dimensional space is balanced -/+ matter ( = nothing we can see with our senses a.k.a the origin of the bang itself a.k.a god particles) then it’s possible to think our vessel and it’s contained masses are causing “dimensional friction” which results in the “collection” of kinetic energy/ fuel (matter after the balance is broken so we can perceive it) which is needed to produce the light to make the “frames” of space time. This kinetic energy/ fuel (perceivable matter) inside the vessel builds up so much so that it needs to constantly release the excess to maintain perfect cruising speed- which allows it to move FTL and allows the “frames” of space time to be made in the first place.

Thank you in advance,

Dakota T.

    Frederic Artus Nieto · August 25, 2016 at 08:31

    tachyons would be a very inefficient fuel to a vessel, as the vessel would only be propulsed with equal energy the the loss the tachyons endure.

    you have a misconception of 4 dimensional space, imagine we are flattened and we live on the surface of a volume. we are not a plane of some sort, with time being the fourth dimension. As space time curves, it curves into the 4th dimension.

    FTL can only be obtained in two ways with the current:
    space compression (alcubierre drive): imagine a paddleboat with space instad of water
    space folding: imagine a wormhole.

    tachyons with positive imaginary mass cannot be used to time travel as their speed is between c and positive infinity. you need negative mass particles to time travel, for traditional ones and tachyons.

    the most likely thing to happen when you time travel, is you shift into a parallel reality where you did time travel. it is not created, it merely exists.

    Time goes backwards too, but that is due to the uncertainty principle, it is easier to converge to states than to diverge… imagine teleportation: you get teleported but the original is not destroyed, who are you? both is the answer, but subjectively it is uncertain, unless you are the merged parts of the future you-s.

Jon lensherr · August 8, 2015 at 02:13

Tachyons are subatomic particles with imaginary mass. Since they always move faster than light we would not be able to see them. After it has passed by we would be able to see two images of it which is called an after image or a “speed mirage” if you will. One effect of a tachyon is that it’s speed increases when it’s energy starts to decrease. They are also forbidden from slowing down below c because infinite energy is required to reach the barrier. Also if tachyons one day are found and they used them to go back in time then it will violate causality and find a worse way to fill in time once you change it

Romir Srivastava · July 13, 2015 at 16:37

What if tachyon uses its own type of energy source that is unknown to us and what we call energy is just like weight to it. Like if I’m running with a bag I’ll run faster without the bag. So if tachyon is me and the bag is energy it will all make sense.

    Romir Srivastava · July 13, 2015 at 16:43

    The energy I’m referring to is electricity or just as we call energy.

Nithin thankachan · June 24, 2015 at 13:17

It is the sub atomic particle of an atom .it is faster than light but it have mass. It is a imaginary substance

Joram Arentved · May 16, 2015 at 03:33

Have A Good Solstice, Colin. If The Tachyons don’t exist, my own theorisation is just an issue on which, I (still) don’t know, if I can ‘deny ‘testifying(!!)” to being happy to find out whatever ALTERNATIVE chance to find out, if The T. Travels ARE possible, greetings,
J.A., (email address removed -ADMIN), I suppose, you know a little about, what German Scientists like Their California ‘Colleagues’ did on Sat. The 9th June of 1998?

greg · May 12, 2015 at 04:42

i meant quantum entanglement. since information is transfered simultaneously from one particle to the other, yet both particles are free to roam around and do what ever particles do where ever they are. even if one particle is say one side of a galaxy and the other is on the other. on a side note.. their is one other place where you can find crazy speeding particles too, they move increadibly fast, yet take years and years to leave and that is in a sun.

    Andrew · May 25, 2015 at 05:38

    To Greg,
    Yes, it could be that, maybe.

greg · May 11, 2015 at 14:52

what about quantum duality? would that help solve the problem as i understand it, it is possible to change the state of one particle and the twin also changes state at the same time, do tachyons infur this state?

jamie phillips · April 10, 2015 at 19:39

hello I thoroughly enjoyed the article is is very informative but I do have to question if we could observe the resulting blue light described if the tachyon particles energies also travel faster than light. perhaps the light emission would be in a different spectrum beyond visible light as the characteristics of the particle already seem to be outside the natural law of physics we have to observe their theoretical existence only by the proposed effect on our universe so perhaps it is best that they remain a theoretical mystery

    admin · April 14, 2015 at 06:42

    Dear Jamie, thanks for your comments. Cherenkov radiation is always composed of high-energy photons which mean the visible part of the radiation will be at the blue end of the spectrum (some of it would be ultra-violet and even X-ray and gamma radiation too).

David · April 6, 2015 at 00:56

Just a layman shot, all things considered.
Color, does not exist in the absence of light.
If Tacs, move faster than the speed of light, would that
not, leave them in the dark? So to speak.
Even, at a collisional point, would not evidence be blind (in search of a “colored” proof)?
A collision, beyond the speed of light, would manifest. So, how can you see something,
that’s in the dark?

Just a question.

    admin · April 9, 2015 at 08:22

    Dear David, thanks for your question. The concept of colour would be meaningless to tachyons as not only would they move faster than light but they would be smaller than the wavelength of visible light. Even if they exist, we will never see them.

John · February 5, 2015 at 12:26

Back in the 70s I had a thought about tachyons, but could not get anyone to listen. It was triggered by a line in a physics textbook about transferring momentum between particles.

I had read Feinberg’s Feb. 1971 Scientific American article back in high school, and immediately thought that if a tachyon had a negative time ordering state, it would transfer momentum in the direction it appeared to be moving in to an observer, and, of course, to the particle it hit. That ment the particle would move toward the source of the tachyon, not in the direction the tachyon was moving in.

That was the most difficult point to understand. Tachyons transfer momentum toward their source.

It was therefor an obvious thought that tachyons may explain gravitation; that a temporary reversed tachyon was a graviton. So I explored the concept.

Its a long story, but one of my conclusions was that tachyons with real energy and negative time ordering ( very fast moving to keep it simple, or read Tolman, 1917) are indeed gravitons.

There Is a great deal more, but it’s all apparently far too much when coming from a non scientist.

    Lar Bear · November 18, 2015 at 22:03

    Sorry, I was just very interested in the discussion so I was thinking…Would you have to find a way to emit Tachyons directed away from the back of the spacecraft for the particles (which were hit by the Tachyons) to transfer momentum to the spacecraft from which they emerged? No need to answer since I don’t really understand this at your level.

    Frederic Artus Nieto · August 24, 2016 at 16:28

    this is quite an interesting thought, but with the recent discovery of gravitational waves it seems those move as fast as the speed of light, thus wronging that claim of being a parent to gravitons. On gravity, my knowledge is not very good, but i think space is the counterbalance to matter and energy in the equation:
    outside existence there is nonexistence. there cannot be existence without it being balanced back to being non existent on average. the only think we know exists more close to matter and energy is space, thus the observation… but i am uncertain as it relies on too many assumptions, and possibly not physically based observations (existence and nonexistence).

    tachions would be extremely usefull if discovered, but cannot be used to communicate back in time, as it would require negative momentum. infinite speed is the limit of the tachion and thus can only be used for instant interstellar communication. Unless you consider an epoch being relative to the origin combined with the LY it would take a photon to reach.

    another interesting thought in another comment was that tachyon would be created in pairs, and could be only destroyed by such. could these be the origin of quantum fluctuation? could we detect tachyon by creating them?
    an appropriate experience would be to create high energy at two distant points, pointed at each other and observe the result in the middle, (one of each pair would get lost) high energy is required to be able to discern them from quantum fluctuation and other phenomena.

    I am very likely wrong, but logically it sticks together, and am looking forward to be contradicted.

Maria Agosto · November 18, 2014 at 17:46

In layman’s terms… WOW!

Rishabh Tripathi · October 18, 2014 at 01:47

I feel that these tachyons are a part of the enormous energy the big bang had. As previously specified that these tachyons have huge amount of energy and travel back in time. And its been said that the big bang is itself the start of space and time and its irrelevant to question some thing before that. This tells that the end point for tachyons is the big bang.

Themistoklis · September 17, 2014 at 18:03

Hi Colin,
I added your sites link on my web sites toolbar.

I am asking if you could do something similar to it.

Best Regards

    admin · September 18, 2014 at 09:41

    I’m sorry, but we can’t do that.

Themistoklis · September 15, 2014 at 04:33

Tachyons do exist.

We got a big problem with Tachyons.
We are not within their source, we are within their path!
The [Black Holes] are not an empty space at all. Astronomically; it is a great amount of matter packed into a very small area.
The reason of their Black color is simply the fact related to their extremely high gravitational pull that, besides [Hawking’s Radiation*] and Tachyons, even the light can’t escape.
[*According to Mr. Hawking, Black Stars emit Radiation too, but despite our extended capabilities
and technology we can spot no Radiation leakage].
Think of a Star ten times more massive than the Sun, squeezed into a sphere approximately the diameter of Chicago.
The result is a gravitational field so strong that only particles with greater velocity than light [Tachyons]
can escape.
The Black Stars [because it’s about Stars, not Holes], are not infinite, the loss of Tachyons results on their destruction after several trillion of years.
Tachyon particles that accelerate faster than the light are common on Stars with extremely high gravitational influence such as the Black Stars.
Nuclei system, Solar winds, CME’s, X Ray emissions and Flares that do not exceed the speed of light, are common on Stars the type of our Sun and Red Dwarfs.
Tachyons first proposed by Physicists Bilaniuk,
Deshpande and George Sudarshan in their 1962 paper
“Meta Relativity,” published in the American
Journal of Physics.
Right after that, Arnold Sommerfeld and Gerald Feinberg got involved.
Some Physicists state that, if Tachyons really exist, the principle of Special Relativity most be false, although this is not prudent.
The existence of Tachyons may very well be feasible and realistic from a Quantum Physics point of view, in order to solve, fill up the blanks and troubleshoot major issues within.
It was difficult to discover, isolate and produce Neutrons and will be harder to do as well with Tachyons.
We have to meet their source, to learn, understand the process and the mechanism of the creation.
Australian Physicists Roger Clay and Philip Crough, on 1974 claimed successful detection of Tachyons.
They set up an Array of (5 one-meter-square plastic scintillators and photomultipliers), arranged in a square of 30 m side to detect their showers.
Their experiment indeed detected Tachyons [Particles with a velocity greater than light].
I certainly believe that, Tachyons could finally explain dark matter.
The next step is to isolate Tachyons and find out if they are charged particles.
This energy is what will allow us, to perform intergalactic communication, and later on, explore our neighborhood efficiently.
Below is George Surdashan’s statement about the God’s particle.
(God’s particle is blasphemy.
What is so special about this particle?
Conversions from energy to matter and from matter to energy, takes place all the time.
All this talk about the particle giving mass is nonsense, but talked about with a certain amount of certainty.
It is a mis-statement, bad physics and bad use of language too.
There are a lot of things that are talked about with great certainty.
In America, Republicans have this opinion about creating wealth – they say the rich give money to the world, whereas we know that it is the rich who take away the money.)
Well, the God’s particle (it’s Higgs particle actually], today has been a reality. Mr. Hawking again on his statement about the God’s particle declares that physics would be far more interesting, if the God’s particle had not been found, and that the particle will destroy the (Universe). Although, in many ways, we exist because of it.

    admin · September 16, 2014 at 13:34

    Please see the article again. Tachyons have never been detected, Crouch and Clay no longer claim to have observed them.

      Themistoklis Liardakis · September 17, 2014 at 00:58

      Thanks for your advice. I was not aware about it.
      On their statement, they declare detection of particles with
      a velocity greater than the speed of light.
      It’s a fact that photons can’t escape the gravitational influence
      of the Black Stars. Also, it’s a fact that Black Stars are not infinite.
      Hence, Particles that escape the Black Stars gravitational influence
      must be much faster than photons.

      Themistoklis (Theodore Lar) · May 24, 2019 at 22:14

      Australian Physicists Roger Clay and Philip Crough, on 1974 claimed successful detection of Tachyons, using scintillators and photo- multipliers, but after a few years recalled.
      Although, they were partially right, because what they detected with their Scintillators was the Tachyons enfeeblement, which is the Cosmic Rays.
      Tachyons enfeeble to Cosmic Rays after certain amount of distance from their source and up on confrontation with another Spectral type of Star as a result of it’s winds resistance.
      The reason why scientists even today do not know the origin of the Cosmic Rays, is the fact that they consider the Black Stars as Black Holes! in that order, a black hole is all vacuum!

        Armagh Observatory and Planetarium · May 31, 2019 at 14:45

        Hi Theodore. While Tachyons would certainly add even more interest to Physics as we know it, they have not been proven to exist. Enfeeblement, as you outline, does not have widespread support as a theory in the scientific community. I enjoy reading these theories too but until we can be more certain of their existence I would not put any weight in these claims. Thank you for your insights 🙂

    Troy · November 12, 2015 at 22:17

    Quick note. Higgs-Boson particle is not named the “God Particle” for any special reason, it was first referred to as “the godamn particle” because it was so hard to find. Since journals couldn’t print this, they just changed the name to “God Particle” during editing.

    So, speaking from a physicists point of view, the “God Particle” has nothing to do with religion.

Rodney · August 16, 2014 at 16:16

Here’s my thoughts:
I think that tachyons do exist, but you have to put a large amount of energy into it. And there might have to be a particle that transforms a ship into energy and shoves it into a tachyonic shell. The tachyon would then have enough energy to produce a quark-gluon string effect that pushes dark energy away from it in a bubble shape. When you arrive to another planet with an atmosphere, your ship exits the tachyonic shell and transforms back into material. ( in my ideas, everything is communication, but I thought I should put it in a way in which it implies forces, rather than simulated forces.)

    Romir Srivastava · July 13, 2015 at 16:40

    that would be a good idea

Terry Moseley · June 19, 2013 at 22:11

Hi Colin,

Thanks for a fascinating and timely (!) article. I agree with your general concusions. But two things puzzle me:

1. Is there any reason to assum that tachyons, if they exist, are charged particles? They could be like neutrinos. If they have no charge, there would be no Cerenkov radiation.

2. Quote “As a final piece of weirdness, tachyons would propagate backwards in time, being destroyed before flying around space until they were created. ” As we know, matter can neither be created nor destroyed, it can only change form. So as a tachyon is ‘destroyed’, it must change into energy. And as it is created, it must be created from energy, presumably as per e = mc2.

So could tachyons explain ‘dark matter’? (I’m not even going to dip my toe into surmising as to whether they could explain dark energy!)

And congrats on another excellent Astronotes overall.


    admin · June 20, 2013 at 13:53

    Hi Terry,

    I’ve re-emphasised that there is no evidence that tachyons ought to be charged. One thing I didn’t mention is I believe there was an assumption that the word tachyon described not a single particle but rather a whole class of FTL particles with various other properties (mass, charge, spin etc). You’re quite right that a neutral tachyon would not lose energy by the Cherenkov effect, so it seems charged tachyons do not exist.

    Your second point really made me think! How is an imaginary mass particle generated or destroyed? The answer I reckon lies in the relativistic version of the energy-mass equivalence equation ie E²c² − p² = m²c4, which implies that to conserve momentum tachyons would have to be created in pairs (one with postive momentum, one with negative momentum). If that’s correct, tachyons can only be destroyed in mutual annihilation events or decay into tachyon daughter particles. If that’s correct (and I’m only speculating here) it’s hard to see how tachyons would interact with ordinary matter (with real mass).

    I have no idea what a kind of gravitational effect a tachyon would have but I can’t see them contributing to dark matter. We’ve mapped dark matter and it appears relatively stationary (rather than zooming all over the place faster the speed of light) but I could be proved wrong tomorrow, that’s the joy of science!

      Ethanael · August 21, 2014 at 04:41

      As Charlie Sheen says, this article is “WG!IINNN”

      VoiceOfReason · May 24, 2017 at 20:41

      This is actually interesting. Tachyons (the field, not the particle) actually do exist. There is such a thing as an imaginary mass field in the standard model, as I’m sure you know. It exists in a state of maximum potential energy unlike every other particle’s field which exists in it’s minimum potential energy state. Any quantum excitation of this field causes what we interpret as tachyonic condensation, and it emits a higgs boson. The reinterpretation principle in Balanuiks original paper asserts that a tachyonic particles sent back in time can always be reinterpreted as them traveling forward in time, because observers cannot distinguish between their emission and absorption. The attempt to detect one of these from the future (and violate causality) would actually create the same particle (or perhaps a decay product) and send it forward in time (which is causal). This is interesting because as you stated, tachyons could only be destroyed by decaying into a daughter particle, or by mutual annihilation. Perhaps when we witness the emission of a Higgs boson from a tachyon field, what we’re also witnessing is the death of a superluminal tachyon. Again.. it’s all just speculation. Since there is no way to detect a tachyon particle without a violating causality, we may never know.

    Jimmy · October 29, 2013 at 20:54

    A tachyon can be transported through time but only for a few seconds and at the temperature of absolute zero. History as we know it would change.

      Takhys · August 5, 2016 at 23:35

      A Tachyon is not transported through time. The 4th dimension is part of the construct of a tachyon, not the other way around.

    Nathan MacInnes · February 27, 2014 at 07:14

    I have had an opinion on this for quite some time. I have also worked in the Aerospace world where secrets are kept close to the Chest. I am talking about some discoveries that they have made and still pretend to the world that they are undiscovered. I cannot disclose what I know as is the nature of working in these top secret places but I do know this.

    Man is a very tiny speck in the universe that is much bigger than him. Man wishes to think and has always stated that they know all there is to know at that period of time. Man Assumes too much… Man assumes that the speed of light is the fastest fixed speed, because at the time they could experience no smaller particles. For some reason scientists (many influential) will not question the questionable.

    I have seen that there are rules that govern killo physics that governs concepts like Gravity; that we still do not understand, Macro Physics; the world we live in, Micro Physics that has massive differences, and nano physics and below that has complete different set of rules, and these are kept super secret (as I have witnessed).

    Dark matter is just an excuse to make a filler for the things that science can’t understand, the same with black holes…. For example polyrystic material makes up for 3/4 of the universe… who can prove me right or wrong.

    Do Tachyons exist??? Probably. Can our bodies travel the same speed with them… Probably not… Why… Because our matter is not phased the same as the matter Tachyons are made of, it is like a ghost touching a human. Usually the only way we can interact with any particles like these, is by magnetism…. But hold on, they just recently discovered a new type of magnetism that can exist in liquids…. So the mystery goes on and on.

    All I can say, is man knows nothing. An incredible amount of archeology are OOParts, and the scientists lock them down and hide them (because they challenge their doctorates etc). This is the Carnegie foundations Legacy, and they control our education. My perception of history and science is very different from your… only because I have experienced the things they hide.

      Brian · September 24, 2014 at 06:44

      Nathan, You have sparked a drooling curiosity of said “undiscovered” discoveries. Please tell us more…

    Robert Hutchison · August 30, 2014 at 10:04

    If tachyons exist, could they be modified to drive a starship faster than light?

      admin · September 1, 2014 at 09:46

      Although as the article says this is a common idea in science fiction, I don’t know of any suggestion by a scientist that this might be possible.


        John Cramer has suggested that should tachyons be discovered they could be used as a rocket’s exhaust

      but only slower than light speeds would be attainable.

      Note that there is zero evidence for the existence of tachyons.

      Biggsy · September 22, 2014 at 22:59

      Simple answer no. Nothing with resting mass can travel the speed of light. Regardless of what’s actually coming out the back end of a rocket or vessel. The rocket or vessel would still have mass. The best current theories in relation to FTL travel are via wormholes or Alcubierre drive. Neither of which actually allow travel at FTL speeds, but rather take advantages in loopholes in relativity. Alcubierre drive relies on the knowledge that whilst nothing can travel FTL through space, space itself can travel at any speed. Utilising some form of exotic energy, the theory states it is possible to compress space in front of the ship & expand in behind. Giving the effect of FTL travel, without actually traveling at FTL speeds.

        Biggsy · September 22, 2014 at 23:14

        Just to qualify my point. The theory underpinning the Alcubierre drive seems mathematically sound. This doesn’t mean it’s in anyway practical or that we are in anyway close to creating such a device.

    Dr.Julius Eastravic · January 4, 2017 at 13:43

    Could Tachyons be absorbed into the human body and cause changes to the body

      Pedro · September 20, 2017 at 05:07

      It is in the body,if excited it annihilates subtle dense waves of low vibrating energy wich blocks the natural flow of tachyon in the body, in a hypothetical view or theoretical point of view tachyon is needed for the body and all functions to work properly if enough tachyon is flowing without any restrictions the physical body functions well, if absorbed in a very large quantity the brain can experience something like euphoria and the body can possibly increase its biological and kinetic potential.

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