Physics of a phaser blast

This is about the Star Trek universe, natch…

I’m really not sold on the entire “disintegration” thing when a phaser (or disruptor,
or as happened in one ep. a lightning bolt) set to maximum setting will really be
able to disintegrate (vaporize) the target, be it a Klingon, Gumato (err Mugato), or
cute shapeshifting chick impersonating Kirk.

My feeling is that the phaser will just blast a beam-sized hole in the target more or
less instantaneously, leaving the rest of the body intact. For disintegration to occur
the intense heat from the phaser blast would somehow have to very quickly
propogate through the target body without much loss of said heat, down to the
toes and up to the head; I just don’t see that happening. Maybe a disruptor works
on a different principle, so you might have an out there (like that model which
works agonizingly slowly).

In one ep. Riker fell in love with a female spy, and confronted her at a conference
meeting where she was attempting to assassinate an enemy leader. He eventually
vaporized her, but I was struck by the fact that Picard was right behind her ,
and made no attempt to get out of the line of fire! Riker could have easily hit him

Why do you think Riker wore a beard?

I don’t have any answer for you, but I will add another question that always had me going ?? when someone was vaporized by a phaser.

Assuming that by some magic, your phaser did in fact affect the entrie target at once, you are raising the temperature of the victim to a level that ensures disintegration in a second or less. What about the radiated heat from this? I always thought this would just fry anything in the immediate area. (In a sort of token acknowledgement to this, the old TV series “The Invaders” did at least have nearby objects catch fire when someone was disintegrated by one of the Invader’s ray guns)

Later Star Treks seem to have less of a “vaporization” than some sort of disruption, but I’m not a complete Star Trek geek, so I dunno.

Perhaps it doesn’t heat up the target, but uses some other mechanism to cause the molecular bond to lose strength.

What I want to know is, where does all that matter go? If you disintegrate an average-sided person, you should end up with several thousand cubic feet of steam and/or plasma. Unless it turns into solid ash, but we never see that.

This reminded me of one of the most disturbing lines in newspaper comics:

Dick Tracy, in his sci-fi days, used a weapon like that and then a blank panel appears with the dialog:

*Soldier [coming in]: * “Where is the enemy?!?”

Tracy: “You are breathing him…”

From the old Star Trek Technical Manual I read years ago, phasers use something called nadions. When they distintegrate something, most of the target’s particles “transits the continuum” and vanishes. It’s referred to as the “rapid nadion effect”.

I think it’s supposed to be starting some kind of chain reaction/cascade effect, so that destruction of matter propagates out from the point of impact.

Couple of problems with this that are not adequately dealt with on screen:
-Why doesn’t the effect propagate out of the bottom of the victim’s shoes and start disintigrating the ground (if not the whole planet, there should at least be a crater)
-When a victim is hit in the midsection, the disintegration propagates outwards, leaving a void; the upper body/limbs should at least begin to fall as they continue to disappear, but they don’t they just remain suspended in place until they are gone.

Pfffffaahahahahaha. I love Trek pseudoscience babble.

Even before Star Trek you had this problem. It bothered me even when I was a kid that, even if you were “grazed” or “wingesd” by a tray gun, you completely disintegrated. The real answer is that, as Nicholls’ Encyclopedia of Science Fiction first pointed out, the whole point of such ray guns is to “leave a minimum of bloody pieces to sweep up”. They’re not supposed to be realistic – they’re a fantastic, kiddie equivalent of perpetually-loaded six guns. better, in fact, since no bodies are left around.

In real science fiction weapons don’t work that way.

I had a long and detailed discussion with a friend about this very topic not so long ago. Here are the salient points we came up with (backed up with examples from episodes, natch.)

-Phaser beams do not travel at the speed of light. They are therefore composed of particles with rest mass. See “Wink of an Eye,” TOS, when the hyperaccelerated alien Scalosian Queen Deela easily sidesteps Kirk’s phaser blast.

-There is some sort of phase transition in the phaser beam at a certain energy and/or intensity level. The effect of this is that at low energies/intensities, such as a stun setting, the phaser beam particles (we’ll call them nadions, for consistency) operate (as the Star Trek Encyclopedia says) on the strong nuclear force in the atoms of the target. This causes the atoms to break apart, and the subsequent chemical reactions cause the remainder of the damage. However, at high energies/intensities, the nadion beam perhaps becomes a more coherent entity, maybe something vaguely like a Bose-Einstein condensate. This allows it to act on a molecular level.

-The evidence for this conclusion is threefold: first, the myriad times we see someone stunned. Second, what we see from a ship’s phasers in action. They induce explosions. That’s a molecular-level phenomenon. The final piece of the puzzle is from the TNG episode “Contagion,” wherein Worf destroys a tricorder containing the Iconian computer program that is plaguing the Enterprise. When he does this, there is a burn mark on the floor. This is consistent with the fact that Worf was told to completely vaporize the tricorder: he upped the energy level and the phaser beam acted chemically on the entire object and even the floor.

Also known as technobabble or Treknobabble. I once had a Star Trek book - it may even have been that Technical Manual - that had a funny set of tables for creating technobabble. Just pick a random word from 2 or 3 and you’re set : “Quantum . . . resonance . . . scan !”

This being the case, we have another problem; how much energy (or if not energy, dissociated ions or something) would be released by such a phenomenon? How would a phaser be safe to use as a handheld weapon on naked-eye targets?

They began addressing that in DS 9, where they were treated more like assault rifles.

It’s VAPORIZED. As in becomes vapor. Not ASHIFIED (like the beam weapons from War of the Worlds).

Anyhow, maybe it’s a variation of the teleport technology. Only instead of transmitting your molecules it just scatters them randomly.

I have read articles by writers for popular SciFi shows/movies where they mention that most of the effects used are constructed strictly for visual effect. There is no thought or science behind it. There is a “stun” setting so you can shoot someone/thing and they live to talk later. There is a “vaporize” setting so you can kill multiple people and still get a PG rating. Visually it is much more impressive to have someone dematerialize than to have them burst open b/c of internal heating, or have a beam of light burn a hole through them and they slowly die of internal bleeding.

Always funny to me when debates brake out on the “science” of SciFi, especially when you get to the level of TV and popular film.

No one ever complains about the fact that a big ole spaceship makes a huge noise when it explodes. Where is the science in that.

If you want to get into the “science” of SciFi, check out Larry Niven books. His doodads have pretty reasonable explanations behind them.


Yeah, this is a valid point. My friend and I went back and forth for a while on whether or not this actually causes fission. I don’t remember offhand what we concluded; I’ll have to ask him again.

Perhaps the “disintegration” scenes are supposed to be slow-motion…