Science Question

[Warhawk]

I was thinking last night about this and not sure what the answer is.

What happens to a ship laser that fires and misses the target?

I was thinking of the B5 Shaodows for example their large laser would it go on "forever"? If so what if you are two systems way a few years later would that same laser beam hit your ship(wrong place, wrong time)? :?

I can understand torpedoes set to blow up after 20 mins(or something) so they would not keep going. And ballistic rounds would be pulled into planets and suns by gravity. But lasers are just light and expect for black holes will keep going till they hit something.

I know the odds of hitting a ship in a diff system are 1 in (insert really big number here) but in a battle there could be 20 ships shooting dozens of times each so it could happen. It would suck to have your ship blown up by a laser beam that was shot before you where even born :lol:

So what is the reason for it not happening in any movie or TV show?

Thanks

 

[Lokai]

not a real science buff, but as i understand it you are correct. for all practical purposes theres nothing in space other then stellar bodies that are going to interrupt that beam, but i doubt any science show/movie has considered it worth pointing out....it just wouldn't add anything to their show/movie. Then again who is to say that those beams are COMPLETELY straight...that is to say perhaps each lil particle(probly not the right word) is moving along at just oh so small a different path in relation to the other particles and so after....a LONG distance they actually start off on a differnt path....but i can't say how they're focused

don't ya hate when completely random, probably pointless things pop into the ol brainpan? merry christmas.

 

[Da Boss]

doesn't the beam graduallay disperse as it travels?

 

[CheesyRobMan]

I don't know the equations, but basically no laser-type beam is completely 100% coherent and focussed, so it will diverge (go in different directions) and disperse (lose energy) as it travels, the only question is how much and how quickly.

Mind you there are very few sci-fi shows that even try to be true to the laws of physics I can only think of one off the top of my head (Firefly) that actually made space silent even when things went kaboom, and they dropped that for the movie Serenity. Most of the other obvious ones (fiery explosions, a blatant disregard for inertia, laser beams that travel in big thick glowing pulses slow enough for the eye to follow etc etc) crop up in the huge majority of sci-fi.

 

[Warhawk]

I did not think about the laser disperse.

 

[wkehrman]

How else would a beam weapon have a range? From somewhere on the Internet, someone figured that the Heavy Laser Cannon on an Omega has an effective range of about 7000 km. This was based on the battle between the Alexander and the Roanoke (?) at B5 in the series.

 

[harikaridog]

"The beam remains collimated over a distance which varies with the square of the beam diameter, and eventually diverges at an angle which varies inversely with the beam diameter."

In other words a laser beam disperses/diverges over distance. To the point where the concentration of the energy will not be strong enough to do any damage......however it could still be strong enough to blind sensors and individuals.
The dispersion can be reduced through the use of lenses and other optics. So basically your Omega laser would travel immense distances but all the time the beam would become wider and weaker.

 

[Taran]

Of course, that's not including the feccets of gravity on the lasers. A typical planetary gravity well may not have much effect, but it will speed up the dispersion.

Also, Space is not truly empty. Dust, meteorites, ice, radiation interfering light waves... They will all break up and absorb the beam.

 

[Banichi]

So by the time the shadow's slicer beam gets to your system, (200 years after it was shot) it might only be strong enough to give you a tan. I could just picture it, "Fred! What the heck happened to you? You go out for five minutes, and come back with a bronze tan! And it's night time!"

 

[nekomata fuyu]

You know how some of the religious types seem to like the idea of a pillar of light shining down from the heavens upon The Chosen One(TM)? Now you know the truth! :lol:

 

[greenboy]

You know how some of the religious types seem to like the idea of a pillar of light shining down from the heavens upon The Chosen One(TM)? Now you know the truth! :lol:

More vorlon interference

 

[Da Boss]

just what I was thinking

 

[David Anla Shok']

Sorry, all I have to contribute is "flashing lights means science!"

 

[Taran]

Flashing lights...
Lasers that flash-tan us after missing their targets...


..."She blinded me with science!"

 

[harikaridog]

...as Clarke s third law says...."Any sufficiently advanced technology is indistinguishable from magic"

 

[Banichi]

I don't think you would get too many volunters to see just how far away from a shadow ship you have to be before it just gives you a tan. As opposed to turning you into steam.

 

[greenboy]

Gives the centauri something to do with all those narn

 

[No. 1 Bear]

Just imagine all the consequences of firing hundreds of beams at another planet from a diferent system. We'd all look cooler

8)