Spaceship propulsion: Real vs The Movies

[Nobber22]

I have been watching several programs about space/stars/our solar system on Discovery Channel lately - they seem to be doing a "space theme" - and something struck a chord with me:

As we all know, space is a big bugger and travelling to other places in the Universe takes a very long time (eg. Jupiter) with current technology. However in movies, ships scoot all over the Universe in seconds. Most films are set in the future eg. Battle Star Galactica or "another time & place" ie. Star Wars and so I feel we tend to take the speed craft travel at, for granted.

Now there are many different ways that film-makers choose to power/propel their ships through the Universe, but do we as viewers actually notice how many kinds they use and perhaps how many contradictions there are?

For example: some crew members sleep (Aliens) while the ship cruises (normally?), while in Star Trek they use Warp Drive to zip ahead at light speed and get there almost instantly, while the crew look out the window at the converging lights..... Same with Star Wars.

Some use both: Fifth Element (crew flies at light speed while passengers sleep), while others like Andromeda use worm holes which seem to take an hour or two......

Some films (Lost in Space) try to show/explain the engine's function/working while others (Star Trek's Scotty) just "Canna' give ya more pooowar Capt'n!) from the warp drives?????.

Even more strange, are those ships whose travel across vast distances is never explained, yet they seem to get there in a day, but then handle like pigs at low speed (Starship Troopers).

Flying Saucers in many shows spin round quickly, while in Independance Day, the saucer-shaped ships just glide in left to right.......

Armageddon tries to use almost-current technology with a space-shuttle launch and sling-shooting around the moon to build up speed - which is what NASA probes to Jupiter, etc do - but then the ship just flies off the asteroid later like a Cessna! George Lucas shows us some of current thinking about what may be realistic at the end of ATOC, when Count Duku's ship spreads out a silver sail and travels by sun's rays pushing it along.

So what exactly is the technology that drives these ships - what is the thrust we see usually as white light out the back of these ships that suddenly propels them forward? Ion drives? Nuclear Fusion? Dark Matter? Hollywood bullcrap?

I can't recall anyone actually calling any of these exhausts into question in any films. I realise that writers can make up anything they choose because nothing like it has actually been invented yet, but are we giving movie-makers too "easy a ride" by not ridiculing some of these travelling modes?

 

[Ed Selley]

You missed "Bending Space" ala Event Horizon.
I suspect that the level of thought that goes into these things is limited at best. If a film or series is popular, some fan will try and "fill in the gaps" as it were at a later date. Some series (Star Trek being a notable example) also flesh out some of the "principles" inherrent to their machinary. Warp/Transwarp etc.
Just my 2p.

 

[Nobber22]

Originally posted by Tons of fun
You missed "Bending Space" ala Event Horizon.

Must have blanked that from my memory on purpose!

 

[t-force]

Dune talks about "folding space", which involves, as far as I can understand, using a fourth (or higher) space dimension to get from one place to another instantaneously.

This IS theoritically possible: one just has to work out how access these higher dimensions, and harness the massive energy involved for the process.

For proof of the theory, look at it in 2-3 dimensions: imagine a man on one side of a giant CD; he wants to get to the other side. He lives in a 2 dimensional world, so the only way he can see to get across is a straight line across. However, someone in a 3-d world can just pick up the CD and fold it in half, so the distance the man needs to travel is zero.

Lesson over, normal service can now be resumed!!

 

[Sinzer]

In a Universe of inifinite possibilities surely anything is possible?

I do believe that Dune/Event Horizon is the most likely answer. The ship doesn't actually move through normal propulsion but is simply transported from one point to another through folding.

 

[Nobber22]

Originally posted by Sinzer
The ship doesn't actually move through normal propulsion but is simply transported from one point to another through folding.

By what? Pixie dust? How do you fold space? With giant hands?

 

[Miyazaki]

re: the folding space bit.

There are several theories about the nature of the universe, all probably wrong.

One of those that allows the folding of space is to do with the "unifyed theory of the universe" otherwise known as quantum gravity, as it includes all four forces, the two atomic forces, electromagnetism and gravity.

Basically suggests that the universe isn't "flat" and that is it actually quite like an ocean with peaks and troughs.

Traditionally speaking any spaceship would weather this ocean by travelling over these peaks and troughs, taking a lot longer to reach a distant point.

A space "aeroplane" or "submarine" could travel through rather than over, "tunneling" through space.

Its all obviously just conjecture as there is no way we could ever know anything for certain concerning these things until we are actually out there having a look.

 

[eviljohn2]

A few points to consider, I'll be back with more when I'm less busy!

Originally posted by Nobber22

For example: some crew members sleep (Aliens) while the ship cruises (normally?), while in Star Trek they use Warp Drive to zip ahead at light speed and get there almost instantly, while the crew look out the window at the converging lights..... Same with Star Wars. [/B

These ships must be travelling much faster than light speed to travel some of the distances they mention. Star Trek solves this by remaining within a single quadrant of our own galaxy which would still take days/hours to cross at light speed. Light travels at ~300,000,000metres per second in a total vacuum. Sound in air travels at ~300metres per second to give you an idea of scales.

Originally posted by Nobber22

George Lucas shows us some of current thinking about what may be realistic at the end of ATOC, when Count Duku's ship spreads out a silver sail and travels by sun's rays pushing it along.

I would imagine the silver sail simply to be a way of gathering energy (without needing enormous batteries or warp cores etc) with the propulsion being different.

Originally posted by Nobber22

Hollywood bullcrap [/B

There it is in one!! Current technology and knowledge can't even begin to comprehend the advances we still need to make to travel in this manner.

Sorry to spoil anyones hopes of holidays in other suns!!

 

[t-force]

Originally posted by Nobber22
By what? Pixie dust? How do you fold space? With giant hands?

Well, according to Dune, they use the Spice gas - so I suppose that's fairly close to pixie dust!!

 

[Sinzer]

Yeah I wish I had what those pixies were eating!

I suppose it is like wormhole theory, where a wormhole opens and ends somewhere else, you do not travel that distance in a normal sense.

I think I remember watching Stephen Hawkings and his explanation that the Universe is a like a big balloon, however some parts of it are expanding and some are contracting.

Seen as I don't understand half of what this crazy dude goes on about, I would assume that like a big balloon you could contract two points and therefore shorten the distance between them (like squeezing the balloon together).

I think that is what some of the current theory goes on about.

 

[Nobber22]

Originally posted by eviljohn2
I would imagine the silver sail simply to be a way of gathering energy (without needing enormous batteries or warp cores etc) with the propulsion being different.

No, it really is in some NASA-type engineer's thoughts. Last night on Discovery they suggested that a huge sail could be used to catch light particles and propel a craft along as an ordinary sailship does with the wind - only problem: the sail would need to 1/4 the size of Texas!

Remember the "solar winds and mylar sails" idea which was rejected in Armageddon (too much coffee!) for sailing the asteroid off-course?

Actually if you have Sky, look out for a show called (I think) Exodus Earth on Discovery Science channel - all about escaping Earth as it "dies". Full of genetic engineering, space travel, Human Arks, etc.

 

[eviljohn2]

Originally posted by Nobber22
No, it really is in some NASA-type engineer's thoughts. Last night on Discovery they suggested that a huge sail could be used to catch light particles and propel a craft along as an ordinary sailship does with the wind - only problem: the sail would need to 1/4 the size of Texas!

Actually if you have Sky, look out for a show called (I think) Exodus Earth on Discovery Science channel - all about escaping Earth as it "dies". Full of genetic engineering, space travel, Human Arks, etc.

Seen it As a physicist I've seen most of the engineering/space/military documentaries on sky!

I made my comment based on the size of Duku's sail, as (to me) it's comparable to a solar array which are similarly sized on current satellites.

 

[Ed Selley]

I suspect that the dramatic flow of a film might suffer if the cast were forced to open up a mylar sail the size of Texas and wait a couple of decades to go anywhere- the attack on the death star would certainly plodded anyway.

 

[Nobber22]

Exactly! We let Hollywood get away with it, 'cos we are in a hurry to see more stuff blown up!

 

[eviljohn2]

I don't think the attack on the Death Star is a fair example as that was all localised and so didn't exactly involve traversing enormous distances across space and/or time!

I think that flying saucers should spin so they can induce some form of gravity on board. It worked on Babylon 5

 

[Miyazaki]

What the hell is babylon 5?

Sounds like a bloody Iraqi boyband

 

[t-force]

Originally posted by Games Guru
What the hell is babylon 5?

Sounds like a bloody Iraqi boyband

WHAT!!!????!!!!

You've never heard of Bab 5?

Babylon 5 was an absolutely fantastic Sci-Fi series back in the 90s. It lasted for 5 seasons, with some massive story arcs encompassing the entire lifetime of the show.

I'd suggest you head over to www.babylon5.com to find out more.

With regard to the gravity thing: yes they used that on Bab 5, but the gravity would have been far stronger towards the rim of the station, and practically non-existant at the hub.

 

[Garrett]

Originally posted by t-force
WHAT!!!????!!!!

You've never heard of Bab 5?

Babylon 5 was an absolutely fantastic Sci-Fi series back in the 90s. It lasted for 5 seasons, with some massive story arcs encompassing the entire lifetime of the show.

I'd suggest you head over to www.babylon5.com to find out more.

That was one of the best ever sci-fi programs. Each week was more or less a story in it self but each one part of the bigger one.

 

[Klippie]

Hi all,

How about the Holly Hop Drive, from Red Dwarf....

Klippie.

 

[Sammy Jankis]

Getting from a to b in space by bending the fabric of space is based on the idea of a gravity amplifier. It is a theory based in quantum physics whereby gravity is a wave form just like sound or light. And just like sound or light the wave form can artificially amplified. You would focus the gravity beam on the part of space you wished to be, pull it to you, step across and switch off your amplifier. Easy.

Sammy

 

[eviljohn2]

Originally posted by Sammy Jankis
Getting from a to b in space by bending the fabric of space is based on the idea of a gravity amplifier. It is a theory based in quantum physics whereby gravity is a wave form just like sound or light. And just like sound or light the wave form can artificially amplified. You would focus the gravity beam on the part of space you wished to be, pull it to you, step across and switch off your amplifier. Easy.

Sammy

I've heard of that, but although I've a good knowledge of fundamental quantum mechanics I find the idea of a "gravity wave" difficult to justify. We would then need "force waves" and subsequently everything we know about physics would be wrong!

 

[Shady]

...isn't it just a big white / blue / red light that you see at the back of the spaceship...

...I understand that the colour of the exhaust depends on the type of fuel being used - white = 4 star, red = 2 star, blue = diesel.

Obviously the green one is unleaded, but you don't see many of those.

 

[eviljohn2]

Where does LPG fit in then? renewable sources like solar power

 

[Ed Selley]

Originally posted by Shady
Obviously the green one is unleaded, but you don't see many of those.

Making the Borg the most eco concious of the alien groups bent on the elimination/subjegation of mankind.

 

[Miyazaki]

So called gravity waves are a joke!

Anyone with a basic understanding of physics know that (relatively) gravity is an extremely weak force!