281–290 of 500 posts
I don't care so much about the physics side, it's just so bloody pretty. Is there anything like this that will play infinitely, with similar sliders to tweak the visuals? It'll look so good on an OLED.
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You are right. One addendum: many humans would be bothered by one-way trips, but humanity is large, and in absolute numbers there are still plenty of volunteers for one-way trips to the planets and stars.
When talking about how efficient a given reaction mass engine, such as a rocket, can be the unit is specific impulse in seconds. That unit represents how long a given engine carrying a given propellant can maintain 1g acceleration. For context, the most powerful chemical rockets peak around 450s-530s. A nuclear rocket of the sort we can build today would be more than twice that value, and super-efficient ion thruster…
Like what?
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Sure, there are plenty of practical problems that would make the trip impossible. The fuel mass alone that would have to be shot out the back to make that trip would be something on the order of 800 million times the mass of the payload (you). So a 100kg person sitting in a 100kg spaceship would require something like 160 billion kg of fuel, assuming zero energy loss in burning the fuel. Relativistic rocket calculato…
Imagine a generation ship, consuming the energy of an entire star for the trip.
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Unless you could somehow make an Alcubierre warp drive. Of course…even if that was possible, it’s conjectured that the colonists already at your destination won’t appreciate you boiling the atmosphere when you hit them with blue shifted radiation. https://www.universetoday.com/93882/warp-drives-may-come-wit...
> it’s conjectured that the colonists already at your destination won’t appreciate you boiling the atmosphere when you hit them with blue shifted radiation. There's a general principle known as Jon's Law (not sure where the name comes from) that any powerful space drive is by definition a weapon of mass destruction. You see this in The Expanse when incredibly powerful fusion torchship rockets (a major part of the Exp…
Also known as "Project Thor", it was devised by Jerry Pournelle before he became a science fiction author. More on various iterations of the concept can be found in Wikipedia:
I had no idea you could achieve relevant amounts of time dilation so "easily" with relatively small (1m/s) of constant thrust - such that interstellar travel becomes somewhat viable provided you can continuously accelerate for the entire trip. Googling it, it would take approximately three years of observed time for a traveller to get to alpha centauri at 1g. Could any somewhat-plausible technologies (fusion etc) get…
After an observed 12 years of constant 1g acceleration, you will be 113,000 lightyears from your point of departure, which is enough distance to cross from earth to the opposite side of our galaxy.
Of course, you are now traveling at 99.999999996% of the speed of light. If you actually wanted to stop at the other side of the galaxy to take a look around, you would need to turn around at the halfway point to decelerate, which roughly doubles the travel time.
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For practical values, nuclear pulse propulsion would only get you up to a few percent of the speed of light. The best nuclear thermal, gas core, would give you 7000 seconds[0]. A "dusty plasma" rocket (suspend the nuclear fuel in dust form in a magnetic field) might get 100,000 seconds, or just over a day of accelerating at 1g. [0] for the benefit of non-space nerds: the unit of measure is "lb-force seconds per lb-ma…
g-seconds then? That seems like a very handy unit
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Every proton would have the energy of a baseball. It's bananas. Granted, space is really empty, but it's not that empty, somewhere around a hundred atoms per cubic meter. Your ship might look like a very, very long shooting star. Probably dialing the speed down a touch would be worth it for whatever your shielding material is, but who knows? We're talking miracle engines here. I think in the "Valkyrie" ship-on-a-stri…
> Every proton would have the energy of a baseball I wonder if you could capture that energy and use it to generate thrust. Most of the energy is coming from your thrust so it'd be a lossy process however if you're able to capture all of the energy then there won't be anything left to damage the ship.
But then there's e=mc^2, so if the stuff you're running into is the fuel source for your fusion engine (could be a fission engine, but unlikely you'll run into heavy atoms like Uranium or Plutonium) then you have an unlimited source of energy...
So maybe sort of? Running into things slows you down, but then you capture that mass and release the energy out of it to go faster... because of the nature of e=mc^2 you'll usually get more energy out of something if you convert its mass than what you lose by running into that mass.
I had no idea you could achieve relevant amounts of time dilation so "easily" with relatively small (1m/s) of constant thrust - such that interstellar travel becomes somewhat viable provided you can continuously accelerate for the entire trip. Googling it, it would take approximately three years of observed time for a traveller to get to alpha centauri at 1g. Could any somewhat-plausible technologies (fusion etc) get…
Things get more insane the further you go. After an observed 12 years of constant 1g acceleration, you will be 113,000 lightyears from your point of departure, which is enough distance to cross from earth to the opposite side of our galaxy. Of course, you are now traveling at 99.999999996% of the speed of light. If you actually wanted to stop at the other side of the galaxy to take a look around, you would need to tu…
Apparently, it takes just over two lines of "9"s on a 1920px display for this to happen. The speed wraps back around to zero, and the world time becomes NaN as an added bonus for (nearly) breaking the laws of physics.