**Date:** July 1, 2010

**Title:** Tachyons

**Podcaster:** Craig Robertson

**Link:** Craig’s website – www.myfavoriteauthor.net

**Description:** In this podcast I aim to explain the complicated history of the theoretical particle dubbed the tachyon. As an inhabitant of a faster than light reality, it would be a boon to science and interstellar travel. That the tachyon moves backward in time unlocks the long dreamed of hope of time travel. So, is this a theoretical construct or a real and useful particle? Listen in and decide for yourself!

**Bio:** Craig Robertson is a physician in the Sacramento, CA area, and science fiction author. In the 1970’s he studied astronomy and geophysics at UC Berkeley. In addition to his busy Internal Medicine practice, he has written several science fiction novels available on Podiobooks.com as podcasts, and as ebooks on Amazon and Barnes and Noble’s sites. His lifelong love of astronomy keeps him young at heart and continually challenges him to maintain an open mind and a sharp wit. He can be contacted at his website, www.myfavoriteauthor.net.

**Today’s sponsor:** This episode of “365 Days of Astronomy” is sponsored by Michael Wildish and dedicated to my daughters Shannon and Emily and a thank you to Dr. Carl Sagan and Dr. Philip Morrison for inspiring me in my youth.

**Transcript:**

Tachyons: The Tale of the Theoretical Theatrical Temptation

Hello, this is Craig Robertson and I’m pleased to be presenting another 365 Days of Astronomy podcast. I’m the author of the science fiction novels Anon Time, The Innerglow Effect, and very soon The Prisoner of NaNoWriMo, all available as free mp3’s on iTunes, and free ebooks on Smashwords.com. Not surprisingly, as a speculative fiction author, I am also a big fan of the genre. I read sci-fi, I watch sci-fi, I blog sci-fi and I talk, whenever possible, sci-fi. I willing bet you are an aficionado also. How often have we observed some advanced technology or alien culture putting the tachyon to work to do some wondrous thing? It affords its users faster than light (FTL) engines, time travel, and instant communication across all of space-time. So, where can we get some, so we too can journey to the stars and beyond? Well, I hope to provide you with a brief overview of this elusive yet compelling particle, highlight tachyon’s roles in science fiction, as well as debunk some of its touted used and application.

Special Relativity ( SR )was proposed in 1905 by Einstein, and deals with the physics of frames of reference, especially as they apply to light speed. He puts forth that there is no preferred reference frame, and demonstrates that no particle with real mass can travel at or faster than speed of light in a vacuum (‘c’, by convention). If one tries to accelerate say an electron to c, it requires ultimately infinite energy, the mass of the tiny electron increases to the infinite, and time in the electron’s frame stops compared to ours. One of the consequences of special relativity, called causality, is that no information signal or material object can travel FTL in a vacuum. It was generally assumed that SR meant that travel FTL was not allowed. Arnold Sommerfeld was the first to point out, and in 1967 Gerald Feinberg coined the term tachyon when showing that SR did not exclude FTL motion.

This is a classic case where the mathematics of physics need not be bound by the constraints of our everyday reality. In the equations of SR, mass is defined as the ratio of resting mass divided by the square root of one minus the ratio of a particles velocity (v) squared divided by c squared. As v approaches c, the denominator of the ratio approaches the square root of 1-1, or zero, and the mathematics break down. Feinberg simply observed that if v were greater than c, the denominator was not zero, but a multiple of the square root of -1. Bare with me here, the math is almost over. The square root of negative one does not exist, in our reality, as there are no two numbers which can be multiplied together to get the product -1. Mathematicians get around the inconvenience of reality but calling any number which is a multiple of the square root of -1 an imaginary number, as it can only exist in one’s imagination. So, back to Feinberg. He simply reported that a tachyon, moving FTL, would still solve the mass equation, and that the denominator would not be zero, but an imaginary number. Hence, the tachyon would have an imaginary resting mass. What does that mean, an imaginary resting mass, to you and me? Who knows! As I said earlier, this is a case where scientists can solve equations in a theoretical manner which have no clear physical meaning.

So, now we have a particle, the tachyon, which lives in its own private reality, where it has an imaginary mass. Theory predicts that is not the only astounding property it possesses. Relativity tells us that if the tachyon looses energy, it will speed up, as opposed to the slowing down we anticipate if a particle on our side of the light speed barrier would similarly lose energy. Consequently, if a tachyon lost all it’s energy, it would speed up to an infinite velocity. Counter intuitive, eh what? Also, a tachyon, at FTL speeds, will be moving backward in time. Neat you say, where’s my time travel machine? Well, it’s all nice on paper, but picture this. I invent a machine to generate a tachyon beam today. You, my close friend, have moved to a colony on a planet 4 light years from Earth. I shoot the beam at you, set at twice the speed of light. It takes two years to get there, right? Well, yes and no. Remember, at FTL speed, the particles are moving backwards in time. It actually hits your planet before I have invented the machine in the first place. Anyone have a headache yet?

String Theory, which differs greatly from Relativity and traditional quantum theory, does have a place for tachyons in its particle pantheon. Particles are said to represent different vibrational states of the same underlying string. So the differences between a proton, an electron, and a tachyon are only the vibrational states. The tachyon’s vibrational representation is unstable and degenerates, but it can be represented mathematically.

So, where are all the tachyons? Unfortunate reality check here: none have ever been observed. The lack of documentation of tachyons is not for want of trying. Several physicists has looked carefully for them, and have come up empty. Without going into the details, charged particles moving FTL in a given medium, say water, emit something called Cherenkov Radiation. It can be readily observed, for example, in the cooling water surrounding a nuclear reactor. So, tachyons would forever be emitting Cherenkov radiation, and in spite of careful attempts to observe their tell-tale traces, none have been found. Even neutral tachyons would scatter off normal matter in predictable ways and none have been documented.

Now that we have some feel for the physics of the tachyon, should we conclude that they do or do not exist? It is, I have concluded, hard to say. Remember that mathematical beauty and correctness does not in any way predict reality. Until some cleaver physicist catches one in a bottle, I will assume they do not exist. Even if we do someday trap or generate tachyons, their perverse and contradictory properties make using them more than an enormous challenge.

OK, but recalling that I’m a speculative fiction fanatic, who cares? Just because they can’t exist, why should that stop us from using them to extend fiction into the far off and future realms? It shouldn’t, that’s why. So, imaginary though tachyons are, where do they crop up in tall tales? Really all over the place. As they appear in speculative fiction, I applaud their use. So, here’s a partial list of 10 sightings:

1. Isaac Asimov’s novel Foundation’s Edge uses tachyons for FTL travel;

2. In the movie/graphic novel Watchmen, Dr Manhattan’s ability to see into the future is blocked by ‘a squall of tachyons’;

3. Star Trek loves tachyons. Romulans use them in their cloaking devices, tachyons can help detect cloaked ships, in Insurrection, ships fire tachyon pulses at one another, and in Deep Space 9 a tachyon stream propels a wooden sailing ship to warp speeds;

4. In the movie K-Pax, the hero’s race has harnessed incredible energies and travels at ‘tachyon speeds’;

5. Dr Who ran across the Argolins, who used tachyons as part of a cloning procedure;

6. The TV show Eureka had someone create a tachyon accelerator, which unraveled time;

7. In Babylon 5 tachyon fields alter normal space, so large objects can be moved though time;

8. In the recent movie Land of the Lost a tachyon amplifier created a time warp central to the plot (if there was one);

9. Computer games incorporate tachyons widely, including Sid Meier’s Alpha Centauri, Wing Commander, Battleships Forever, The Fringe, X-com and Anvil’s Freelancer;

10. In Fantastic Four: Rise of the Silver Surfer, tachyons are used to separate him from his board.

Gotta love those tachyons!

Unfortunately from my point of view, the concept of tachyons are misused in other settings. The internet is rife with products claiming to have harnessed the power of the tachyon from thing ranging from jewelry, to holistic healing, to vitalize drinking water, and to have been scientifically verify to harmonize subatomic structures. My personal favorite claims for tachyonic energy I found in a brief survey of the internet were:

1. It activates and intensities the structure of cells, reminding them of their perfect order;

2. It enhances therapies through harmonizing the chakras;

3. It recharged subtle electric fields in the body while harmonizing the chaotic impact of electrical AC current on life forms;

4. And finally, it can effect positively all the problems we have, mental, emotional, spiritual, or physical, as it has stored all the potential needed to create a perfect energy continuum in every individualized form of life.

Gotta love those tachyons!

So, in the final assessment, what are we to make of the deliciously enigmatic tachyon? Is it a purely mathematical construct, an elusive super particle packed full of incredible properties, or a cure for whatever ails you? Part of the tachyon’s allure is certainly its very name, it just sounds so high technology, so new age, so totally cool. I will, for now, have to be counted among the group thinking tachyons will always remain an imaginary solution to a set of difficult equations and are nothing more. However science fiction geek and an author that I am, the tachyon will always have a place in my heart, and in my stories. No concept opens such untold worlds of wonder and possibilities of imagination as tachyonic technologies. It offers such speculative hope for us isolated carbon-based life forms stuck for the foreseeable future here on planet Earth that it is hard not to be draw to it, like a moth to a flame.

I’d love any feedback you might want to offer, positive or constructively else wise. You can contact me though 365 DoA, or directly at my website, www.myfavoriteauthor.net. Until we meet next at some point in the tachyonic future, stay well and stay dreaming………….craig

**End of podcast:**

365 Days of Astronomy

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