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.
Anyway the lazy, boring way to use a portal and pretend you aren’t violating a bunch of physical laws is to just use it for fuel transport.
You have a bunch of fuel on the ground, a tiny tank on your rocket, and you keep topping off the rocket’s tank by piping in the fuel.
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 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 k’chee u’riit maraai, indeed.
@foone@digipres.club I love this, just for the “Variant of the Kzinti lesson” reference.
@foone@digipres.club there are no unarmed spaceships
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.
@foone@digipres.club yup. Doc Smith level planet busters are near trivial with portals
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
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
Alternate ending to Half Life Alyx where it turns out the scary thing the Combine has locked up in the vault is Chell.
@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
@foone@digipres.club
I think this is predicated on the assumption that a portal acts as if it’s anchored the same way a bell is to a rocket engine.
I don’t think it is. Does anything in the games show a portal imparting thrust onto the wall/object it’s mounted on? I don’t think so. I think portals can’t be used for thrust.
It’s also pretty clear to me that transfer through a portal is instantaneous, not limited to lightspeed. You can hang out/change direction halfway through a portal as much as you want.
@foone@digipres.club That passage out of The Killing Star when the Relativistic projectiles hit Earth…
@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 The Pierson’s Puppeteers did this to fuel probes in Ringworld. The only difference was their technology required a physical teleportation device to be placed at the destination instead of just opening a portal anywhere, & transmission was limited to the speed of light.