It's quite probably not, though. It may well be that interstellar travel is, for all practical purposes, impossible, and that all cultures remain stuck as single-planet cultures.
Interplanetary travel is pretty clearly possible, so I assume you mean single solar system cultures.
It doesn't seem likely to me that that is the case. The energy/time requirements to go the closest neighbouring star aren't really that high in the grand scheme of things. Accelerating one ton to c/10 takes 125 terrawatt hours, less than 0.1% of our current annual energy usage. We could then reach the nearest star/expolanet in ~40 years (taking a similar amount of energy to decelerate).
Obviously we aren't putting that much energy into a rocket tomorrow, but give it a few hundred years of technology development and it seems pretty reasonable.
As an exercise, work out how much energy it would take to transport a capsule with three people in it to the moon orbit, send a 2 person capsule to the surface and bring them back. Just raw theoretical energy. Then work out how much actual energy the Apollo program took to build an entire Saturn V rocket and all associated infrastructure. Bear in mind most of the time you’re not just accelerating th capsules, you’re also accelerating the rest of the rocket at various stages. The rocket equation is a harsh mistress. I think you’ll find you are many orders of magnitude off.
There are various ways to cheat the rocket equation that weren't possible during Apollo because of our level of technology, and to some extent the constraints of a mission where a substantial portion of the energy is consumed getting to LEO. I don't want to suggest I know how to build an interplanetary spaceship accelerator, but here are some common basic ideas
- Accelerate the ship be pointing lasers (or something that accelerates matter) at it from the launch point. Now one doesn't need to carry fuel and the rocket equation no longer applies.
- Use some form of ion engine where we accelerate particles to very high speed relative to chemical rockets. This makes the rocket equation very tame since so little of the mass (relatively speaking) is in propellant.
- Combine the above ion engine with some form of "ramjet" that takes hydrogen we collide with and turns it into fuel. This makes the rocket equation irrelevant since we don't carry our fuel (to the extent that we can get our fuel via the ramjet anyways).
Also as laumars says the 0.1% of annual energy usage was just a point of comparison because terwatts is such a foreign unit to most of us (including me) that it doesn't mean anything by itself.
The annual energy point is a point of comparison. Obviously we don't have the means of delivering the enegery required yet, and when we do I like to assume many of the issues you raised would also be possible to work around. Such as not requiring as much weight (samples plus autonomous ship and AI means we might not even need to send humans out there in the first shipment).
>Accelerating one ton to c/10 takes 125 terrawatt hours, less than 0.1% of our current annual energy usage. We could then reach the nearest star/expolanet in ~40 years (taking a similar amount of energy to decelerate).
The first rule of rocketry: For every ton you fire up add 10 tons to what you fire up.
There is a reason space is hard and that is that every ton you launch will require fuel to get into orbit. And now you have to accelerate the fuel for the majority of the way too so you need more fuel. But that also needs fuel ... etc.
Shooting up 0.1% of our annual energy usage will require an exponential amount of energy to get up.
The biggest rocket I ever build in KSP weighed in at 500'000 tons. With a 1 ton payload it only achieves about 250km/s acceleration. That's less than c/1000.
The Saturn V weighs 3'000 tons and has significantly less thrust (though NASA engines outperform KSP engines).
It's simply not realistic to achieve unless you manage to fire up the mentioned 0.1% of our current annual energy production PER ton of weight.
Firstly, technologically advanced species have the ability to modify their own bodies. We already do this with great success and we're barely a few generations into the era of washing our goddamned hands before doing surgery. Additionally you have to consider the difference between individuals, species, and civilizations. Can intelligent robots carry on a civilization? There doesn't seem to be any good reason why they couldn't. And once you are there, then it doesn't matter whether or not it takes 10 years, 100 years, 10,000 years, or even a million years to travel from one star to another. Intelligent, conscious beings who carry our civilization into the stars could indeed do so successfully. Even if they take many thousands of years to hop from star to star and even if they take thousands of years to build up a civilization (on a planet or in orbit of the star using resources from the stellar system) that is then in a position to send out more voyages across the stars. Even then the result will be a massive, sprawling network of our civilization spread across countless stellar systems within a time frame that's a blink of an eye in cosmological terms.
If it took 10 million years for a voyaging vessel to land, settle, grow, and send out only 2 voyaging vessels (and then stop voyaging) then they would colonize a million worlds in 100 million years. In only 400 million years they would have colonized the entire Milky Way.
190 million, but your point remains. Exponential growth is surprising even when you understand it.
The fact we don't see the galaxy teeming with life is either
1) intelligent life inevitably evolves rapidly into something unrecognisable
2) we are unique, and not just in our galaxy. Once you hit galactic scale civilisation, neighbouring galaxies don't take long
3) we are part of that expansion
Yes, many things are seemingly impossible to us at this time. They might not be to future us at another time. Future us might laugh at our impossibles like we look at the impossibles of humanity just 300 years ago.
There are things which are provably impossible. No amount of future cleverness will change that. It is, for example, impossible to find three nonzero positive integers A, B and C for which the cube of A plus the cube of B equals the cube of C.
They are keeping up with the 5th% which sorta makes since with regard to radiation and if you'll forgive the guess, higher than average blood flow that kept them from passing out.
It looks like we have 4 left:
Buzz Aldrin, age 88: https://en.wikipedia.org/wiki/Category:People_who_have_walke...
David Scott, age 85: https://en.wikipedia.org/wiki/David_Scott
Harrison Schmitt, age 82: https://en.wikipedia.org/wiki/Harrison_Schmitt
Charles Duke, age 82: https://en.wikipedia.org/wiki/Charles_Duke
It will be a sad day for me when there's nobody left who has walked on our nearest neighbor. It feels like a turning away from possibility.