"Science begets knowledge, opinion ignorance.
I stand by my post #23.
V=a x t, ; 1 g =9.8 m/s^2I'm still running into the question of what passengers on such a ship would be capable of doing during the voyage. I'm thinking that the answer is to harness acceleration to a point where humans can function somewhat, but then I'm adding (years?) of travel time...
the barrage of laser light to drive a few grams??
"Mass is the bane of accelerating objects to great speeds. To significantly increase the velocity of a heavy object takes a tremendous amount of energy. So, if the goal is to reach a distant star in a reasonable amount of time, say within a generation, a spacecraft must be extremely tiny and, therefore, robotic. Plus, it still requires an insanely energetic boost to get up to speed."
" . . . propelling a lightsail-equipped nanocraft, or Starchip, would require hundreds of individual lasers ,spanning roughly 200 acres (1 square kilometer). The array would also need access to enough energy to fire a coherent 100 gigawatt laser beam for several minutes during each . . . launch.
That's roughly the amount of power generated by all the nuclear power plants in the U.S. in a given year."
I think the breakthrough starshot project is good and instead of sending laser guided tiny instruments towards proxima or other system, they should be directed towards our black hole sagittarius A, black hole exploration must be the first priority, since there is very much to learn and know about black holes. We already have plentiful of information about stars and planets abd their moons.Acelleration rate is not going to be the problem. One can reach very near light speed (3e8 m/s) in just 3e7 seconds at one G force (10 m/s^2). This is but one year.
The problem is where are you going to get the energy?
Ignoring relativistic effects (which make it worse), a single kilogram at .9 c requires an energy input of 1/2mv^2 joules to get there.
1/2 * 1 kg * (2.7e8 m/s)^2 = 4e16 joules.
A kilogram of matter converted to energy equals 9e16 joules. You would need to convert half the mass of your spaceship to energy in order to power the rest of it.
This is completely out of the question:
- using chemical energy (rocket fuel) convertes about one millionth of a percent of the mass into energy.
- Using fission energy (uranium) converts about .3% of the mass into energy.
- Using fusion of hydrogen into helium gives about .7% conversion.
- Fusing helium into heavier elements all the way up to iron gives you about 1% conversion into energy.
- Using antimatter annilhiation will convert only 25% of its mass into usable energy as 75% of that reaction is emitted as unusable neutrinos that fly off in every which direction and cannot be intercepted except by a thickness of lead light years thick.
Any scheme to acellerated a spaceship must rely upon external application of energy to it. Such a thing as a laser on Earth pushing against it only works to acellerate on the outward journey and decellerate on the return. You still have to stop at the destination and turn around.
The only scientifically plausible option you have is to blast your spaceship with a laser beam to push it away from Earth, loop around a black hole at the destination and then use the laser beam to brake it back at home. Or just make it a one way trip.
Energy needs again become a problem. You need about ten Newtons of force to accelerate a one kilogram mass at one G. Each Newton of force requires 5e15 watts of laser beam reflected off your target. The entire energy output of the World is about 1e13 watts. So for a 100 ton spaceship you need ten times 5e15 times 100,000 watts which is 5e21 watts which is 500 million times the current human energy output. This may take some work.
2. I've read that a trip to Neptune at .9 would take just over 4 hours to reach Neptune. But how long would it take factoring in Acceleration and Deceleration
(A + D)? I would have the same question for Ross128B, which is just over 11 light years from earth.
3. Assuming the trip to Neptune was planned to reach her at her closest point to earth, would it matter much if the return trip were delayed? Let's say that the vessel planned a 3 day loiter and the time was increased a day?
Our brains use processes that won't work at the speed of light, without lots of borg brain teach. We have electrical synapses. They won't work well at .9c. The thoughts will be slowed down and entire brain regions affected.