Cloaks, momentum, propulsion, and transporters

[Alyeska]

This is a catch all thread to discuss the possible ways that cloaked ships may attempt to travel in real space while attempting to mask or outright remove traditional propulsion emissions to hide the cloaked ships from sensors.

Physics dictates that for a ship to move itself forward it must propel something in the opposite direction. Any attempt at bringing these drive emissions back into the ship invariably counters any momentum the engines put out in the first place.

In a debate over AIM with IP I've put forward the possible theory that transporters can be used to remove these drive emissions all together because they lack the physical link other methods use. Part of the purpose of this particular discussion is IP says this is a violation of CoM and he is going to educate me on this. The other purpose of this discussion is so that I my evaluate the information he gives me and potentialy point out how this doesn't apply to transporters. If IP succedes, then I will attempt to come up with another means of propulsion in real space that masks drive emissions.

[Illuminatus Primus]

Simple: transporters do not work because they have never been shown to violate CoM. The momentum of the oft-transported objects is negligible compared to the mass of the starship. The transporter mechanism itself probably absorbs the momentum. The last ditch conclusion is that transporters violate CoM. We do not start off by asserting that technology violates physical principles.

Anyway, because of this, transporting the exhaust back into the ship will cause the ship to absorb the momentum and the momentum of the exhaust will be equivalent and opposite to the momentum of the starship. The next momentum will be zero and the starship will not go anywhere.

[Alyeska]

So what you are saying is that when we have seen transporters work with moving objects it merely absorbs and stops the momentum through sheer size.

How does this work when you take into consideration that the transporter converts the target into pure energy? Mass is lost, momentum disapears.

[omegaLancer]

The only solution to your problem is to assume that the Romulian have mastered Reactionless space drives.

NASA had a group of researchers looking into such theorical drives. The Breakthrough Propulsion Physics Consortium have written a number of papers and haved conducted a series of lectures on the matter.

Check out the following link : http://www.grc.nasa.gov/WWW/bpp/TM-107289.htm

It discusses the various types of drives that maybe possible. In either case no Reaction mass is throw out the back of the space craft.
also checkout their main link.

http://www.grc.nasa.gov/WWW/bpp/

Now most of their work is unproven, but there is slight evident that Momentum can be siphon from the vaccum of space. The effect was first predicted by Hermann Minkowski's and works on electromagnetic fields in materials, combined with quantum mechanics, leads to a prediction that an object can move by pulling momentum out of empty space.

the effect is very slight almost undetectable like the Casmir effect.

for more on this check out the following article : http://focus.aps.org/story/v13/st3

[drachefly]

How does this work when you take into consideration that the transporter converts the target into pure energy? Mass is lost, momentum disapears.

Even 'pure energy' (whatever the fuck that is, a gauge boson, i.e. force carrier, I guess) has mass and momentum.

[Alyeska]

I have got to hear more of this. I've heard for years how energy has no mass or momentum and that light is extremely odd with its partial mass but no apparent momentum to it.

[SirNitram]

I have got to hear more of this. I've heard for years how energy has no mass or momentum and that light is extremely odd with its partial mass but no apparent momentum to it.

'No apparent momentum'? What the fnord do you think U/c is, then? The formula for pot brownies?

[Alyeska]

I don't even know what u/c means.

Remember, I never took physics.

[SirNitram]

I don't even know what u/c means.

Remember, I never took physics.

p=U/c

Means.

The momentum(p) is equal to the energy of the beam(U), divided by the speed of light(c).

This means that you need a 300,000 Joule laser to have one newton of momentum. This is why there's no 'apparent' momentum. It takes alot of energy to produce any.

[Alyeska]

And converting mass to energy would create a lot of energy, so converting engine emissions into energy still creates mass and attempting to transport it all still negates momentum, hence CoM still applies and your ship isn't going anywhere.

That about sum things up?

[SirNitram]

And converting mass to energy would create a lot of energy, so converting engine emissions into energy still creates mass and attempting to transport it all still negates momentum, hence CoM still applies and your ship isn't going anywhere.

That about sum things up?

Quite. However, keep in mind that if the Transporter evenly spreads the momentum over the entire Starship, it's going to seem to vanish because of all the extra mass.

[Alyeska]

Well if I want to look at a ship that can move itself without leaving drive emissions, I am going to have to look at subspace and the likes now. Potentialy low level warp movement. Of course such a ship would leave a visible trail in subspace to be spotted.

[SirNitram]

Well if I want to look at a ship that can move itself without leaving drive emissions, I am going to have to look at subspace and the likes now. Potentialy low level warp movement. Of course such a ship would leave a visible trail in subspace to be spotted.

I'm just wondering when it was established crap could be dumped in subspace. It's probably obvious, but I've never seen any signs of such.

[Prozac the Robert]

Light has momemtum, as can be shown in experiment, but it has no mass. To see the momentum, they can make a flywheel type thing on a very low friction pivot and very small mas. As the light hits it, it will start to spin.

The thing you describe is called a crookes radiometer. The effect of light on the 'paddles' doesn't impart enough momentum to do anything. The spinning effect comes from thermal effects.

http://en.wikipedia.org/wiki/Crookes_radiometer

[omegaLancer]

Well if I want to look at a ship that can move itself without leaving drive emissions, I am going to have to look at subspace and the likes now. Potentialy low level warp movement. Of course such a ship would leave a visible trail in subspace to be spotted.

Wow You ignore my post totally. the links I was providing actually had some solution to your problem.

In one case the use of a material with negative mass would basically solve your problem.

Diametric Drive


This first type of hypothetical field propulsion, as illustrated in Fig. 4, considers the possibility of creating a local gradient by the juxtaposition of diametrically opposed field sources across the vehicle. This is directly analogous to the "negative mass" propulsion suggested by Bondi 12, Winterberg 13 and Forward. 14 The diametric drive can also be considered analogous to creating a pressure source and sink in a space medium as suggested previously with the Induction Sail.

Negative mass propulsion is not a new concept. It has already been shown that is theoretically possible to create a continuously propulsive effect by the juxtaposition of negative and positive mass 12 and that such a scheme does not violate conservation of momentum or energy. 14 A crucial assumption to the success of this concept is that negative mass has negative inertia.




Such a system one give you a ship with an undetectable drive system

[Alyeska]

Wow You ignore my post totally. the links I was providing actually had some solution to your problem.

Calm down, geeze. I was talking with Nitram and IP about a specific topic, why the hell would I respond to you when your post wasn't even on that specific topic?

[omegaLancer]

Wow You ignore my post totally. the links I was providing actually had some solution to your problem.

Calm down, geeze. I was talking with Nitram and IP about a specific topic, why the hell would I respond to you when your post wasn't even on that specific topic?

This is a catch all thread to discuss the possible ways that cloaked ships may attempt to travel in real space while attempting to mask or outright remove traditional propulsion emissions to hide the cloaked ships from sensors.

Physics dictates that for a ship to move itself forward it must propel something in the opposite direction. Any attempt at bringing these drive emissions back into the ship invariably counters any momentum the engines put out in the first place.

Let see the topic was? Method to propel a ship without Propulsion emission Geez maybe if you look at the link, it may have given a clue
Sorry for trying to help...Trekkie

[Bob the Gunslinger]

In the TNG episode where people are abducted (Schisms I think is the name) the people are moved into a strange hive of subspace and cease to exist in the normal universe. I don't know if there is canon specifically saying Fed tech can do it, but all the warp field things are pretty strong.

The travellor and Wesley sent Dr Crusher into a warp bubble that was not a part of our universe in one episode, too.

[Deathstalker]

This thread involves physics, which means I probably should have stayed out of it, but I was wondering if the sniper rifle with the transporter can be entered into the conversation. The transporting effect obviously did not effect the bullet's momentum, which doesn't make sense to me. When the bullet gets to the transporter part, it would seem that the bullet would stop and when re-materlized, the bullet would simply drop to the ground because it's momentum was stopped by the transporter effect. I am probably missing something though.

[Batman]

This thread involves physics, which means I probably should have stayed out of it, but I was wondering if the sniper rifle with the transporter can be entered into the conversation. The transporting effect obviously did not effect the bullet's momentum, which doesn't make sense to me. When the bullet gets to the transporter part, it would seem that the bullet would stop and when re-materlized, the bullet would simply drop to the ground because it's momentum was stopped by the transporter effect. I am probably missing something though.

Apart from the fact that it doesn't happen that way, you mean?
You're presupposing that transported material loses it's momentum, which it obviously doesn't (otherwise the bloody rifle wouldn't work). The seeming loss of momentum in other transporter instances is easily explained by SirNitrams idea of the momentum being dispersed across the transporting ship's mass.

[Deathstalker]

I'm not sure what I mean Batman! I guess it is that if transporters are used to eliminate propulsion exhaust back into the ship, the exhaust is still going to be moving.

[Darth Wong]

Well if I want to look at a ship that can move itself without leaving drive emissions, I am going to have to look at subspace and the likes now. Potentialy low level warp movement. Of course such a ship would leave a visible trail in subspace to be spotted.

Wow You ignore my post totally. the links I was providing actually had some solution to your problem.

Not within the context of technologies known to exist in the Trek universe and be accessible by the Federation.

In one case the use of a material with negative mass would basically solve your problem...

Oh great, so if they create a planet-sized positive mass in front of them and a planet-sized negative mass behind them, they can accelerate at 1G (assuming the negative-inertia assumption is valid), which is less acceleration than a modern race car. Could you think of an even less efficient propulsion system, please? And what makes you think it would be hard to detect these gigantic positive and negative masses appearing in front of and behind the ship, for fuck's sake? The idea is to hide a cloaked ship, remember? This fucking system would be detectable at tens of thousands of kilometres by a device as simple as a lead weight on a string.

[Alyeska]

In order to safely transport people the transporter would have to negate any momentum they have to prevent them from hurting themselves after being transported. This safety feature wouldn't be necessary and the transporter sniper rifle wouldn't have to absorb and remove the bullets momentum.

[Illuminatus Primus]

So what you are saying is that when we have seen transporters work with moving objects it merely absorbs and stops the momentum through sheer size.

How does this work when you take into consideration that the transporter converts the target into pure energy? Mass is lost, momentum disapears.

Energy has momentum, buddy. You really need to take some science before you make these claims.

The rest mass and the kinetic energy will go into the conversion.

[Quadlok]

Isn't the whole problem with cloaks that they always leave some sort of propulsion trail? I always figured they just had some sort of baffle in the engines to diffuse the exhaust and make it less apparent. Or, alternatively, used a low level warp field to destroy the exhaust wake, like scraping a branch along the snow behind you to cover your tracks.

Also, on the subject of reactionless drives, the game Escape Velocity:Nova has a vessel that sucks in the very fabric of space and spits it out the back. I mention that less because I think it has anything to do with anything but more because I think its cool.

And quite picking on Alyeska. Physics is hard, and he's doing better with it than most of the people I've seen.