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Deviousness `anmari has been spreading her infectious positivity throughout our community for over 6 years. Throughout this time Ana has been at the core of all things devious, passionately developing an eclectic gallery, helping organise devmeets, participating in chat events and also recently completed dedicating her time as a Community Volunteer. We are absolutely delighted to bestow the Deviousness Award for May 2013 to `anmari, congratulations! Read More
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Sta.sh
One thing I was surprised to learn about STL interstellar travel is the large amount of energy required to attain high sub-light velocities. Let's say a slowboat weighed 107kg (the mass of the Sark-1 solar sail interstellar ark design) and travelled at 10,000 km/s (almost 590 times the speed of Voyager 1, fast enough to reach Alpha C in about 130yrs.). The starship's kinetic energy would be 5x1020 joules, equal to the total world annual energy consumption in 2010. KE=1/2(107kg.)(1x107m/s)2=5x1020J
This is the minimum amount of energy required to accelerate this ship to that velocity. A rocket engine would take far more, because much energy would go into accelerating the exhaust stream, and even assuming a magic space drive that converted stored energy directly into kinetic energy, there would still be inefficiencies. Leading experts say that obtaining the energy for a starship may be the primary challenge, even once we have the technology to build one. However, we already generate huge amounts of energy through fossil fuels- mere chemical energy!!- just imagine how much more energy a spacefaring society that possesses widespread space solar power and fusion reactors will have access too. Still, even a colony ship requires great amounts of energy, and to go faster- so we could get data return from a mission in the lifetime of those who sent it, for instance- will take much more since KE goes up to the square of the speed, and mass increases at relativistic speeds. Even with small payloads, energy is the limiting factor of STL space flight.
Also, remember the 1st. rule of space combat. A pebble weighing one gram (1x10-3) will hit our slowboat with KE=.5(1x10-3)(1x107m/s), which equals 5x1010joules, which is supposedly equal to the yield of a Massive Ordnance Air Bomb (MOAB), the second most powerful non-nuclear weapon ever designed. And it is only one pebble. Our starship will need a thick shield to dissipate the smaller impacts from dust grains, and maybe lasers could be used to disintegrate potentially deadly impacts with interstellar "mines" like a stray pebble.
Rendering them little more than a target in a war they never really had anything to do with.
I wonder if anyone's written a story along those lines yet?