In Portal, using the portal gun to get to the moon is the obvious space travel usage, but I think people are overlooking how it’d let you trivially break the rocket equation.
Hell, you could build a >1g torchship using nothing but the ocean.
In Portal, using the portal gun to get to the moon is the obvious space travel usage, but I think people are overlooking how it’d let you trivially break the rocket equation.
Hell, you could build a >1g torchship using nothing but the ocean.
BTW, as a variant on the kzinti lesson, the portals are extremely dangerous as a weapon, because of how good they are as a weapon.
Ignoring the obvious ways to fight with them like opening a portal on the enemy’s hull, shoving out a nuke and then closing the portal…
You could also just have a rock that you’re letting accelerate to arbitrary speeds in a vacuum. That’s free unbounded kinetic energy, the only limitation being the “charge” time.
@foone@digipres.club there are no unarmed spaceships
@foone@digipres.club I recall Peter F. Hamilton doing just that in one of his books. The nuke part at least. Not sure about the space rock yeeting.
@foone@digipres.club I love this, just for the “Variant of the Kzinti lesson” reference.
@foone@digipres.club k’chee u’riit maraai, indeed.
This isn’t a ship-destroying weapon, this is a civilization-ender if not planet-killer.
You’ve got a projectile moving at a significant fraction of the speed of light. This is a relativistic weapon: it’s going to hit harder than if it was a nuke.
You can also make it bigger by not using a roughly round rock and instead using a long rod of the densest material you can get your hand on.
But mass you pay for, speed you don’t.
Like, the worked example from Atomic Rockets has 7 kilograms of cat litter moving at 90% of lightspeed hitting a stationary target with 195 megatons of kinetic energy.
https://www.projectrho.com/public_html/rocket/spacegunexotic.php
@foone@digipres.club That passage out of The Killing Star when the Relativistic projectiles hit Earth…
But yeah this is the ultimate doomsday weapon. You can accelerate indefinitely for free, you just have to wait.
(and if you can put your portals in orbit of a more massive object, you get faster acceleration than 1g)
So you don’t need more than a portal gun, a tungsten rod, and some time to blow the atmosphere off a planet.
@foone@digipres.club how do you make sure it’s aligned right? It’s no good if it drifts to the side and hits the edge of the portal, maybe already at a dangerous speed, at your weapon site rather than your target
Sir Isaac Newton may be the deadliest son of a bitch in space, but the deadliest son of a bitch in the Half Life universe is Cave Johnson.
The Nihilanth could teleport an entire army to earth, the combine can conquer a planet in hours, the g-man has control over time and space, but Cave Johnson’s invention could put a hole in a planet
@foone@digipres.club boring “explanation” that the energy which can cross a portal is limited by the power of the portal generator - so you can only accelerate to c if your generator can output that much juice - it’s not free just super efficient
Alternate ending to Half Life Alyx where it turns out the scary thing the Combine has locked up in the vault is Chell.
There’s also the gravity interaction: an infinitely falling object that never reaches the bigger body is also accelerating the bigger body.
Your forever falling object is shoving the earth upward, very slowly. That could matter in the long enough term… But it seems kinda meaningless compared to the other ways you could use a portal.
Still, might be handy if you need to adjust the orbit of a planet and are willing to wait.
@foone@digipres.club So with something 4 times bigger than the Tsar Bomba we could get a bag of cat litter to 90% the speed of light?
@foone@digipres.club honestly, a baseball at a significant fraction of c is sufficient - you don’t need a tungsten crowbar
@foone@digipres.club yup. Doc Smith level planet busters are near trivial with portals