Newtonian ships or not?.

[capnq]

There are theoretical FTL particles called tachyons, but they've never been experimentally observed.

[geoschmo]

While I personally cannot concieve of any realistic theory of propulsion that will allow us to achieve FTL travel, (heck I personally can't concieve of the theory of relativity and quontum mechanics, and those have been demonstrated in experiments. ) I hope that as a species we don't give up dreaming about it trying to discover ways to do it.

It would be as if we became so convinced that the earth was flat that we don't bother to send sailing ships beyond the horizon.

[Lord Chane]

Originally posted by Atrocities:

When we start exploring space, and I believe we will never do this, but the ships used will be a standard design for many decades.

Why not?

[Baron Munchausen]

In order to 'maneuver like a plane' there would have to be an atmosphere for wings to work on. Or alternatively, you need to be moving at a signifigant fraction of the speed of light in order to get similar effects from the 'vacuum' of space (which is of course not an 'absolute' vacuum even between the galaxies). The maneuvering spaces would be seriously huge at those speeds, of course. Your turn radius would be larger than the solar system.

Did you know that they have estimated ships moving at around 70 percent of the speed of light between stars will heat up to several thousand degrees like an SR-71 due to the friction of interstellar gases? So even if they develop a means to accelerate near the speed of light they will have to develop a means of dealing with the heat buildup to actually travel that fast. In space all you've got for eliminating heat is radiation.

Now as for the 'Newtonian' movement question I think that what you are asking is will we ever have reactionless drives or will we always have to throw something out behind our ships to make them move... It's tricky to predict technology. If they ever figure out how gravity works they very well might find a way to manipulate it, and then we've got reactionless drives.

[narf poit chez BOOM]

your post stired up a thought...what if the heat generated by interstellar dust was used to pre-heat the reaction mass?

[Randallw]

Originally posted by Baron Munchausen:
In order to 'maneuver like a plane' there would have to be an atmosphere for wings to work on. Or alternatively, you need to be moving at a signifigant fraction of the speed of light in order to get similar effects from the 'vacuum' of space

Ha, I knew saying plane, someone would think of spaceships with wings . Let me use examples to show what I mean. Hard Science ship, a ship that accelerates at a fraction of c and needs to do stuff like turn halfway through the journet to decelerate. Pulp ships, the good old Star Wars or Star trek ship. Disregarding their faster than light speed, when they move at sublight speed they can turn whenever they want and stop suddenly without regard to inertia.

[Baron Munchausen]

Originally posted by narf poit chez BOOM:
your post stired up a thought...what if the heat generated by interstellar dust was used to pre-heat the reaction mass?

A fascinating thought. But any 'reaction' drive suitable for interstellar travel is going to need to have a very high impulse (thrust per weight units of fuel) ratio. This means something with very high energy like a fusion reactor with an opening pointing out the back. It sounds good in theory to run your coolant around the spaceship skin and then route it to some sort of 'converter' to preheat the fuel -- but how are you going to convert plain old radiant heat carried by a 'coolant' medium into the extremely intense sort of energy needed for fusion reactions? A pelet of fuel (probably hydrogen in a little glass 'bubble') has to be heated to thousands of degrees in a tiny fraction of a second -- probably by lasers. If this extreme conVersion can be done at all it looks likely to be very involved and complex. And once you figure out all the tricks necessary to do this, are you gonna have any space left in your ship for cargo between all those heat-exchanger coils and electrical generators and what not? So though it sounds good on its face I wonder if it can be done in practice.

This sort of reminds me of the idea of putting generators on the wheels of an electric car. Yeah, it should work (and some electric cars do recover a small amount of energy this way) but the inherent inefficiencies put some pretty steep limits on its effectiveness.

Maybe there are simpler ways to do it? Do thermocouples actually 'use up' energy and reduce their heat levels by generating electricity? A ship with a skin made of thermocouples is an interesting concept. Peltiers reduce temperature by moving the heat around but you still have to dispose of it somewhere, somehow and the Peltier effect USES energy and creates more heat.

It's a very difficult problem.

[ March 27, 2004, 04:02: Message edited by: Baron Munchausen ]