Take the 2-minute tour ×
Science Fiction & Fantasy Stack Exchange is a question and answer site for science fiction and fantasy enthusiasts. It's 100% free, no registration required.

A phaser fires a nadion particle beam at its target. That sounds like inertial mass is involved so it doesn't reach light speed. Semi-Out-Of-Universe we see how fast a phaser beam is: I'd estimate something around 80 kph. You can see it moving with the naked eye. But that might be just a way to tell a story; to establish causality to the audience: "Look! First the beam is here, now it's here, now something's exploding." So the audience knows why the enemy ship explodes: It was a phaserbeam, going from here to there. So maybe we are just shown a "symbolic slomo" to let us know what's happening.

Are there any in-universe insights on how fast a phaser beam travels? E.g. can I escape (escape not evade) one on full impulse?

share|improve this question
My understanding is that a phaser beam travels at the speed of light. You could escape it, but you'd have to be traveling at warp speed. –  Chahk Apr 14 '14 at 19:56
Don't apply real Physics.. It can travel even faster than light.. –  SS-3.1415926535897932384626433 Apr 14 '14 at 22:06
@SachinShekhar - The canon(ish) quote is that they travel at lightspeed unless being fired from a ship travelling at warp. –  Richard Apr 14 '14 at 23:51
@Richard No, I am saying it "can" travel FTL in sci-fi. The question is good except that inertial mass involvement thing. –  SS-3.1415926535897932384626433 Apr 15 '14 at 5:42

3 Answers 3

up vote 12 down vote accepted

The "Voyager Technical Manual" (written by longtime Star Trek production staffers Michael Okuda and Rick Sternbach as an 'aide-memoire' for potential scriptwriters) specifically states that phaser beams travel at the speed of light.

enter image description here

This is backed up by another quote from the earlier "TNG Technical Manual" which clearly states that the beam travels at "c"

TNG Technical Manual

Given that full impulse is supposedly well short of the speed of light, the short answer to your question is "no, you cannot escape a phaser beam by travelling at sublight speeds".

Travelling at warp speed would be considerably more effective against a foe travelling below lightspeed since you would simply outrun the beam (unless the phaser is fired from a ship travelling at a similar warp factor).

Out-of-universe (e.g. from a TV production standpoint) phaser beams do often travel considerably slower.

As the video below shows, beam speed is wildly inconsistent. At the slowest they seem do seem to be moving about a couple of feet per frame. At the fastest, the beam is instantaneous from one shot to the next

share|improve this answer
That is exactly the answer I was looking for. But if you don't mind I'd like to wait for a possible second opinion before marking it as the right one. To me there is so much consitency standing or falling with this... –  Einer Apr 14 '14 at 20:33
They also travel significantly faster than the speed of light. There are several encounters between Voyager and Kazon ships traveling at warp when phaser fire is exchanged. Or is that a consequence of the warp field? –  Dacio Apr 14 '14 at 22:49
@Dacio - From the same source; img835.imageshack.us/img835/19/3u6h.png - Phasers can be used at warp –  Richard Apr 14 '14 at 23:50
Doesn't change the fact that, from my sub-light observation frame, those phasers were traveling above light speed. –  Dacio Apr 15 '14 at 0:05
@dacio - Apparently if you've got the right technology you can strap a torch onto a speeding train and have it go faster than lightspeed. –  Richard Apr 15 '14 at 0:09

The ST:TNG Technical Manual's description of phaser operation clearly states that the beam will "travel at c to the target".

Disclaimer: I do not have the book in my possession. Quoting from the Google books version.

share|improve this answer

Since characters in all of the Star Trek series are shown ducking from and dodging phaser beams, it would seem that their speed is somewhat less than the speed of light and often slower than the speed of a bullet from a projectile weapon. If,as the Voyager Technical Manual states phaser are indeed light speed or even relativistic speed weapons missing with them or dodging their beams would be impossible.

Simply put when someone aims and fires a phaser, there is no way for it not to strike its intended target unless the weapon was deliberately aimed away from them. The weapon has no recoil and it would be as if you shined a flashlight at someone (e.g. you can’t miss them)

share|improve this answer
That has been my thinking too, but think about it: When you see someone pointing a flashlight at you and you see that he is about to activate it, you can always jump behind a rock. If you detect a phaser lock you can still do evasive maneuvers. –  Einer Apr 15 '14 at 5:15
@einer - Ship-to-ship evasive maneuvers are intended to present as small a target as possible and to prevent a prolonged exposure to incoming fire. –  Richard Apr 15 '14 at 5:35

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.