accelerate in space without propulsion?

Question

i have an idea to accelerate in space without rocket propulsion, but i feel selly to say it, if it allready exest and well known . so the question is there any other way to accelerate in space without rocket propulsion

i thank all for the response, and i guess now i can say that my idea is new. it dpends on the reaction of rotating 2 weights from the sides to the rear...then resesting them (thus using thier inertia) when the want to to continue rotating from the rear to the opposite sides...and so on

Answer 1

Solar sails are one way. Photons from the Sun transfers momentum to the spacecraft. This requires a huge area to mass ratio to have much effect.

Gravity is a second way. Planetary probes have used the gravity of the planets they pass by to slingshot them out to further planets for a couple decades at least.

Additional details: You did read the first couple lines of your Question is my Command's response didn't you (the part before he ventured off into into fantasy). Propulsion is based on Newton's second law.

I'm not positive I understood your additional details correctly, but it seemed like you had a device that would accelerate forwards until the weights reached the back of the spacecraft, then accelerate backwards when the weights were reset back to the front. You would oscillate back and forth going nowhere.

Answer 2

the question of propulsion hinges on the application of newton's second law: for every action, there is an opposite reaction. pushing hot gases & stuff out (aka propulsion) makes the pusher go forward. Similarly, pulling things in pulls the puller forward.
What we want to achieve here, (yes, WE, even i can't wait to make science fiction a reality) is some method to cheat the forces governing this law. Given how we have inherently cheated rules, authorities, diseases, physical limitations, etc to carve up a place in this world, I believe even this breakthrough should be somewhere around the corner.
Here's my idea to achieve acceleration without propulsion (mostly lifted from sci-fi stories i've read & seen):
Warp space-time lines: relativity tells us about objects having world-lines which they would follow without exerting any extra forces. Einstein interpreted gravity as not a force, but the bending of these lines around a massive object. Here's an analogy: consider a log of wood floating in a river. when the river changes direction, so will the log, but by no effort of its own, it's just travelling in what IT thinks is a straight line. the river is the one bending. (this is not an exact analogy..)
Similarly, the moon will THINK that it's going straight, but dear old earth has warped its world line into a circular orbit. So now the moon is going in circles, changing its directional velocities periodically, thru no effort of its own. Even light can bend similarly.. what do you think diffraction is all about?
Now, what if we were able to warp these lines in space, and were able to control it? Could we 'trick' a rocket into thinking that it's falling towards a massive object somewhere in the direction we want to go? if we could create such a 'virtual' gravity, we wouldn't need any propulsion.. the rocket would accelerate on its own.

Of course, this sort of approach goes dead-on against several traditional theories of today, which hold true for most objects. But again, the last century also proved that there are always some exceptions to the rules: black holes, worm holes, heisenberg's uncertainty principle, even the electrons that make us are proved to have wavelengths as well as mass.
So if we can see so many rules giving in in certain conditions, why can't the propulsion principle give in? Do tell me when you find a way to do this, i'd really like to "boldly go, where no one has gone before..."
---"Sci-Fi Rules, by breaking rules"

Answer 3

Despite what others say, ion and nuclear propulsion still uses propellant. However the electrodynamic tether drive is the only other drive outside of solar sails and M2P2 drives that can propel a spacecraft without propellant. It uses a tether kilometres long that has an electric current running through it, where it interacts with a planet's magnetic field and launches the ship into space.

Answer 4

Gravitational forces associated with the field of planets, stars, moons or any other significant body of mass.

I have a mental image of a vessel trying to swim through space however there is no friction in space so dont see that working to well.

Also weight is a force you mean attach two masses no offence intended but it is a fundamental misconception.

Acceleration requires a force of some kind to act upon the vessel. I think the point you are concerned with is reaching speeds which make neighbouring stars accesible. The rate of decceleration is something which I believe will be more challenging.

Answer 5

Yes there is a way. You should use gravity, i.e. you get close enough to a planet (or to the Sun) for example, to be attracted by that celestial body you accelerate in a first stage, then you (hopefully) get out of the gravity zone with accelerated speed.
References in SF : "Rama" and many other books by Arthur C. Clarke.
It is highly recommended to use a computer to calculate your trajectory.
You can also use the characteristics of "hyperspace" like in "Dune" but be careful, you need a medium for that.

Have a nice trip, and ... come back!

Answer 6

To accelerate, an object must be moved by force . A stretched rubber band could move an object in weightless space!

Answer 7

Well as long as their is a net force acting on the object you will have accelaration. Newton's second law states that the net force is equivalent to mass times accelaration. Therefore, an object with any net force (i.e. not zero) will have SOME accelaration.

Answer 8

ionization. a small amount of gas is released in a shroud behind the craft, and a ground based lazer fires at a reflective cone in the center of the shroud, ionizing the gas, thus propelling the craft.

Answer 9

no, propulsion is what cause movement......if you don't have propulsion you can't go anywhere.......and if you're still and let everything move around you then you're not the item moving

Answer 10

There are THEORIES on this subject and that's about it. Solar is one of them. Here's a link: http://en.wikipedia.org/wiki/Space_propulsion