The Death Star is the spherical, Moon-size, space station and lethal weapon, which appears in the “Star Wars” cosmos. Crewed with 1.7 million military personnel and 400,000 droids, it’s capable of blowing up planets to smithereens.
In episode IV, “A New Hope” (1977), it fires a fluorescent green beam at princess Leia’s home planet, Alderaan, a world about the size of Earth. Within the blink of an eye, it explodes into a cloud of dust, and disappears.
To effect destruction of that magnitude, the Death Star would have to subdue the very force that holds it together—that is, its gravitational force. It’d have to send its way a jaw-dropping 2.24 × 1032 joules of energy. Even the Sun’s total daily energy output, which is 3.8 × 1026 watts, falls short of that. But channeling a whole week’s worth of its heat and light in a single direction would do the trick.
Assuming that the Death Star fires a laser that packs 2.24 × 1032 joules of energy, per the law of action and reaction (“for every action, there is an equal and opposite reaction”), it should’ve hurtled away in the opposite direction when it activated its guns. But it doesn’t recoil.
Therefore, it must have brought about the annihilation in another way, reasons Siegel.
If Alderaan is made of matter, then it’s most likely that the Death Star lobbed pure antimatter at it. In which case, it’d need to supply only half that energy—because the target itself, would provide the other half.
It’d take 1.24 trillion tonnes of antimatter to create the minimum energy needed to rip the planet apart. That may sound like a colossal number, but it’s a mere 0.00000002 percent of the planet’s mass. (Likewise, a single star, made of antimatter, of average size, such as Vega, would be able to undo an entire Milky Way-size galaxy.)
That antimatter could be delivered in the form of a torpedo of metallic antihydrogen, the antimatter equivalent of ordinary hydrogen.
As “matter and antimatter are like the good and evil twins of nature,” writes Dennis Overbye in the NYT, “they’re endowed with equal and opposite characteristics like charge and spin.” So, if they meet, “they obliterate each other, releasing a flash of energy upon contact.”
h/t: STARTS WITH A BANG