As the late, great Han Solo once said, “Hokey religions and ancient weapons are no match for a good blaster at your side, kid.” A bit disrespectful, in retrospect, but a good point nonetheless. Just take the new series Star Wars: Andor, which is based around the struggle of ordinary people – those who are born without space magic – who must stand up to the Empire with nothing but firearms that, according to Wookieepedia, are fire bolts of ‘particle-based energy’. But what does that mean? Patrick Johnson, author of The Physics Of Star Wars, has a few ideas.
“A lot of people assume that blasters fire lasers, but the blaster beams travel at a speed where we can watch them move,” he says. “Lasers, meanwhile, move at the speed of light, which is so fast that we wouldn’t be able to see anything move. If blasters were lasers, it would be nearly instantaneous from pulling the trigger to arriving at a target. People would seem to suddenly fall down for no reason.”
Johnson also points out that lasers would not resemble ‘bolts’, but would travel in one continuous stream. “And if it didn’t kill you, it’s likely that a high-powered laser could radiate you enough to give you cancer in 15 years’ time.”
A more plausible answer, suggests Johnson, is that blaster bolts are made out of plasma, the electrically charged matter that makes up lightning, the Sun and – in his opinion – lightsabers. Beyond the fact that plasma would travel at a speed that could be observed, Johnson also highlights the fact that in Star Wars, blaster ammunition is said to derive from gas (more specifically, the fictional tibanna gas), much like real-life plasma.
“The temperature at which materials turn into a plasma is fairly consistent, so we could estimate that tibanna gas becomes a plasma at 360,000°F [200,000°C],” he says. “That would vaporise whatever it touches”.
As for whether this plasma could be launched from a blaster in the form of a bolt, Johnson cites the Large Hadron Collider (LHC) as an example of how it could work. “At the LHC, they send beams of plasma around in circles very fast, in a magnetic containment field,” he says. “But if you turned off that field, the beam would shoot off in a straight line.” Reduced down to a handheld blaster, he adds, it would be like, “taking a can of soup, opening the lid and throwing it outwards really fast.”
Plasma’s susceptibility to magnetic fields also feeds into two quirks of the Star Wars universe. The first is how lightsabers are used to swat away blaster bolts. “If a lightsaber beam is being contained in a magnetic field, then a different plasma entering that field could in principle lead to a deflection away. It’s more likely to just absorb it, though,” says Johnson.
The second quirk is the terrible aim of Stormtroopers, who can’t hit a bantha in a barrel! But there could be a scientific reason for this, suggests Johnson.
“Plasma is a soup of charged particles,” he says. “And so it is going to experience forces from electric and magnetic fields. If we were on a planet with a large magnetic field, or if there were a lot of stray fields in a structure like a Death Star, it could lead to a bolt’s path being altered along the way.”
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This would mean that everyone’s aim is affected, but we’re going with the simple theory that magnetic fields hate fascists!
Verdict: Blasters, if they shoot out plasma, behave according to the laws of physics, so these weapons aren’t beyond the realm of possibility.
About our expert, Patrick Johnson
Patrick Johnson is an associate teaching professor in the department of physics at Georgetown University. He is the author of The Physics Of Star Wars.
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