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…
> Could any somewhat-plausible technologies (fusion etc) get us to that point?
Nuclear thermal or nuclear pulse propulsion. No fusion needed.
> Now you are staring into the big bang in all its glory Don’t they mean the CMB?
Blue shift, it’s no longer radio waves if you’re traveling fast enough.
Of course it’s not microwaves anymore, but it’s still the CMB, that is, decoupling/recombination, not the big bang. Unless you count the CMB as the big bang.
Yikes. At around 90%c, it's starting to look like a sunny day. Any physicists care to weigh in on the accuracy of this? I can search for the energy density of starlight in interstellar space... but how fast does one need to go to hit that "sunny day" point?
I'd think the small amount of atoms per cubic meter in interstellar space would make your day very sunny long before you got up to 90%C and the photons out there started to matter.
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…
It isn't possible without a magic reactionless drive; it might even require a zero-energy drive since the kinetic energy is huge and needs to come from somewhere.
The rocket equation kills you. A reasonable fusion rocket would require an enormous (like an entire planet worth) to continuously accelerate to relativistic speeds. Antimatter drives are the only option and still require large amounts of reaction mass since have to absorb the energy to throw it out the back, or use a laser.
Great visualization of the unintuitive nature of special relativity. It's kind of mind blowing to realize that if we could accelerate our spaceship at a mere 1G continuously, we could visit the center of the Milky Way in under 20 years (spaceship time), totally do-able in a human lifespan. Of course 27900 years would have passed on Earth, so you wouldn't be able to tell anyone about your vacation.
I suppose you would also have to worry about surviving the trip - every atom in the interstellar medium would damage your ship, likely penetrating the entire way through, and electromagnetic repulsion would only work with charged particles.
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-string concept, they had some sort of magnetic thingummy that generated more power as more stuff smacked into it, then as they decelerated they let out this sort of gas mist to go ahead of the ship and smack into things.
Great visualization of the unintuitive nature of special relativity. It's kind of mind blowing to realize that if we could accelerate our spaceship at a mere 1G continuously, we could visit the center of the Milky Way in under 20 years (spaceship time), totally do-able in a human lifespan. Of course 27900 years would have passed on Earth, so you wouldn't be able to tell anyone about your vacation.
I suppose you would also have to worry about surviving the trip - every atom in the interstellar medium would damage your ship, likely penetrating the entire way through, and electromagnetic repulsion would only work with charged particles.
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 calculators are fun!
Great visualization of the unintuitive nature of special relativity. It's kind of mind blowing to realize that if we could accelerate our spaceship at a mere 1G continuously, we could visit the center of the Milky Way in under 20 years (spaceship time), totally do-able in a human lifespan. Of course 27900 years would have passed on Earth, so you wouldn't be able to tell anyone about your vacation.
I suppose you would also have to worry about surviving the trip - every atom in the interstellar medium would damage your ship, likely penetrating the entire way through, and electromagnetic repulsion would only work with charged particles.
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.
This is something I've wanted to try in VR one day. Does anyone know if there is an app/game available for one of the popular headsets? Is there a technical limit to how realistic the effect could be?
> Is there a technical limit to how realistic the effect could be?
You won’t feel the acceleration ;) nor the light intensity of the higher velocities (luckily).