Nasa / Space

The physics behind the Death Star superlaser


Reason #4786 why I love math geeks: This article on Death Star Firepower (thanks, digg).

Death star superlaserA guy with enough grasp of calculus and physics to convince me (which, really, isn't saying much) works out how much energy had to be in the beam that blew up Alderaan. Long story short, something in the range of 10^32 joules is necessary to blow apart a planet.

Bear in mind that a joule is one watt-second, so considering that the beam struck Alderaan for about one second in Episode IV, that means the Death Star superlaser had a an output of 10^32 watts. Now, also bear in mind that the National Ignition Facility--which is using the world's largest laser array to try and create a microsoecond of fusion--informs us that the entire United States has an electrical generating capacity of about 5 x 10^11 watts. Back-of-the-napkin math: It would take 10^21 United States-worth of generators--as in a billion trillion Americas--to generate the same amount of energy that the Death Star superlaser released in one second.

This leads us to only one logical conclusion: Emperor Palpatine for U.S. Energy Secretary! If anybody can figure a way to wean us off Middle Eastern oil, it's Darth Sidious.

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Jay Garmon has a vast and terrifying knowledge of all things obscure, obtuse, and irrelevant. One day, he hopes to write science fiction, but for now he'll settle for something stranger -- amusing and abusing IT pros. Read his full profile. You can a...

9 comments
techrepublic4js
techrepublic4js

The analysis is flawed - here is the truth! Nobody ever said it was "laser" beam. In fact, thinking it was a "laser" only shows how backwards and shortsighted this little blue planet of yours really is. I was an app. programmer on the guidance system for the directional mirrors controlling the beams. And I can tell you right now: "Laser" had nothing to do with it. It was in fact a Planetary Core Destabilizer Beam (PCDB) - the pride of the Imperial Engineering Center at the time. Instruments carefully measure the inner resonance frequency of the planetary core, and the beam is then aligned to a special frequency designed to start a constructive resonance cascade in the planet core. The result is a rapid expansion of the core (not actually an explosion - this is trigged later when the molten core interacts with the colder outer layers) which destroys the planet. The beam requires much less energy (in fact only about 1?? x "United States-worth of generators") than your calculation shows. In addition, it was actually fired for a period of approx. 5,2 seconds. The reason for your assumption of only 1 second is because the scene was cut short by the movie production company... in a very unscientific way I might add! All the best, and thanks for all the fish. - Jesper/SplatMan

ozi Eagle
ozi Eagle

Hi, The death ray doesn't need the energy of a billion billion US's, just the same as a handful of neutrons don't need the energy to blast a city off the face of the earth. The death ray just needs to provide a (relatively) small amout of enery to break the binding force of a few quarks, which releases a (relatively) large amount of energy. This released energy then breaks the binding energy of a lot more quarks which releases a hell of a lot more energy .... and so on, ie a chain reaction. Hence the energy required to destroy a planet is supplied by the planet itself, excepting the initial push provided by the death ray. Herb

Mikiel
Mikiel

TheRealPauper "...it's only a matter of time before they're forced to realize that even those do not actually exist ... that there is not a speck of real stuff anywhere in the universe. All that exist is laws ? JUST beautiful laws. From those laws, we merely PRECIEVE that matter and energy exist." What a beautiful vision. I guess we should have realized we were headed that way when we discovered how much space and how little "stuff" comprises a given atom. You're probably right that both matter and energy are merely artificial (albiet convenient) heuristic concepts that derive from the basic laws. Sounds like the wave view of mass-energy. Is there really anything anywhere?

deepsand
deepsand

sustained for how long? Left to their own devices, would the quark-gluon plasma not simply recondense into hadrons?

deepsand
deepsand

we & all Earthly matter would literally meld into a single mass under the force of gravity.

ozi Eagle
ozi Eagle

I had ron's, but they gave me indigestion. Now the plasma energy levels habve drastically decreased recently, check out plasma TVs and displays. Now the quark-gluon thing - the gluons would melt under the energy released by the quarks being changed in colour and hence wouldn't be able to hold anything together eg hot melt glue. Ergo the beam from the death star just sets up an initial condition that is self sustaining, ie a chain reaction, as I previously mentioned. The death star doesn't need to chuck squillions of USAs at a planet, only enough to cause the planet to have a peptic ulcer and self destruct. Herb

deepsand
deepsand

to co-operate. It's common knowledge that the behavior of "strange" quarks is unpredictably bizzare. And, the "charmed" ones, having charmed lives, generally see no need for conforming to the expected norms, and thus do so only when it serves to amuse them.

ozi Eagle
ozi Eagle

Hi Deepsand, You are on the way to comprehension. The superlaser sets up a zone of plasma in which the quarks are stripped naked and change colour to an embarrassed red. (NOTE: This can only be surmissed, because, in quantum physics, the act of observation affects the outcome.) The gluon force is "softened", and as you say becomes stronger as the quarks are moved apart. Now a stronger force represents greater energy, so when the gluon force finally totally melts and lets go, there is a tremendous amount of energy released, which spreads to areas outside the original zone and initiates the chain reaction. At this point my physics is starting to come a bit unstuck, so maybe I need to look up some gluons to help. Cheers Herb

deepsand
deepsand

The further the quarks are separated, the [b]stronger[/b] the gluons' force.

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