字幕表 動画を再生する 英語字幕をプリント That's no moon. It's a space station. The enormous, planet-killing kind, designed for only one thing — to bring order to the galaxy. It's Star Wars' Imperial superweapon, the Death Star. I've got a bad feeling about this. But it took the Empire 19 years to build their first Death Star, so we'd better get started. It's unclear exactly how big the DS-1 Orbital Battle Station was. Estimates vary between 120 km (75 miles) and 160 km (99.5 miles) in diameter. That's substantially smaller than our Moon. But compared to some of the smallest moons in the Solar System, it's enormous. And we'd only need one thing to build it. Big projects cost big money. In this case, we're talking $852 quadrillion. Eight hundred and fifty-two with 15 zeros. And that's only the cost of construction. Once the Death Star is ready, keeping it up and running wouldn't be any cheaper. Weapon or not, this space station would require 1.7 million staff to run the station's retail shops and troop cafeterias. Add 25,984 stormtroopers and 342,953 Imperial Navy soldiers, and you'll get 2,068,937 people living aboard the Death Star. If each person on the Death Star created 1.13 kg (2.5 lb) of waste every day, it would cost $564,925 daily not to turn the Death Star into a landfill. That doesn't include people who fell into a trash compactor and weren't able to blast their way out. "Come in 3PO!" The daily electricity bill would add up to $52 billion. $274,000 to feed the crew, with another $20,400 to supply tea or coffee. $233,000 for one cycle of laundry. You wouldn't expect your troopers to run around with dirty underwear, right? The total for keeping the Death Star operational would amount to $7.8 octillion — That's more money than we currently have here on Earth. And it doesn't include the cost of a single blast of superlaser. That would be an additional $8 octillion. Still feel like firing lasers into planets? Okay, then let's talk about how you could build the Death Star. You already know it would come with the price tag of $852 quadrillion, but... First, you'd need a hypermatter reactor core. Let's not go into the specifics of how such reactor would work, and we'll just assume you already have one. You'd build four reactor shafts, all joined along the equator, and a large column running from top to bottom. This column would help to distribute power and also act as a station stabilizer. This mega project would require a lot of steel. By some calculations, the Earth has enough iron in its core to provide for two million Death Stars. But you wouldn't want to sacrifice our planet for an army of deadly weapons, would you? Even if you took only the amount of iron needed for one Death Star, it would take over 830,000 years to produce enough steel so you could begin construction. And it would take millions of rocket launches to get the steel where it needed to go. By the time the Death Star was finished, this might make the atmosphere so polluted that we'd be forced to move away from Earth to another planet. We can't get too far from our planet, but... you definitely don't want that thing in Earth's low orbit. There's too much of a chance of it falling down to Earth. You could start building outside of the Earth's atmosphere. Just make sure to not accidentally blast our planet with the superlaser. Speaking of the blast... In reality, light doesn't behave that way. Instead, it would keep moving in whatever direction it was fired. "Sorry about the mess." By the way, destroying an Earth-sized planet would require a lot of power. You'd need to spend a week collecting all of the Sun's energy before you could fire up the Death Star. And don't stand anywhere close to the beam at the moment of the blast. So much energy right next to you, even when not aimed directly at you, would cause you to evaporate in a matter of seconds. Then there's the recoil. The third law of motion teaches us that every action has an equal and opposite reaction. That means if you packed a big enough punch to destroy a planet using the Sun's energy, it would send the Death Star in the opposite direction at a speed of 77 km (48 miles) per second. That's unless you had an antimatter device aboard the Death Star. Antimatter is matter, but with its electrical charge reversed. When antimatter meets matter, the two destroy one another. That's why you'd only need 0.00000002% of a targeted planet's mass in antimatter to turn that planet into space debris. In this case, the recoil would be almost unnoticeable. But you'd better not aim the Death Star at any planets in the Solar System. There is a better application for this weapon. It could be used to vaporize any asteroids that could be a risk for our planet. Although a giant death orb might be a little overqualified for the task. At least when an interstellar asteroid is hurtling in our direction, we'd be ready to knock it out before it destroys us. "I've got a bad feeling about..." "Quiet". Building the Death Star would be a very long and very expensive process. Do. Or do not. There is no try. But maybe spare the Earth for now, and save the deadliest weapon in the galaxy for some angry aliens that might come to visit us one day. But that's a story for another WHAT IF.