Good Sci-Fi?

[white-wolf]

Muizer, there are good sci-fi movies out there. Blade Runner is one of them, probably the best.

Edit: another one is the the first film of Riddick.

[Denny Crane!]

The forever war is one of the closest things I've come across that takes into account all the factors relative to space battles, at least to my puny physics mind it does.

[Condottiere 40K]

The Forever War was one of the most fascinating books I read, but my teenage brain couldn't quite cope with the concepts of finger lasers, clones and transsexualism.

[GreyFox]

assuming the actual habitable space needs to be deep in the ship and as little crew as possible anyhow I wonder if you can't mask that to a degree though I don't know if sufficiently. being able to come out of the sun or have other huge heat sources behind you might help at least to give some edge.

This article give a great overview on detecting ships and the impracticability of masking ships' heat signatures.

http://www.projectrho.com/rocket/spacewardetect.php

Besides, how would you get your ship (radiating at a bare minimum 285 kelvin - assuming you have all your much hotter reactors and engines turned off) between the sun and the enemy without being noticed against the 3 kelvin backdrop of space? Even if you managed that feat, a widely dispersed sensor net would make it near impossible.

With currently existing technology the space shuttle's main drive is detectable with passive sensors from beyond the orbit of Pluto. Its manoeuvering thrusters are detectable from the asteroid belt.

[TheDarkKnight]

Well if anyone is interested, I watched the pilot of Eureka last night...I thoroughly enjoyed it.

[Mangalore]

This article give a great overview on detecting ships and the impracticability of masking ships' heat signatures.

http://www.projectrho.com/rocket/spacewardetect.php

Besides, how would you get your ship (radiating at a bare minimum 285 kelvin - assuming you have all your much hotter reactors and engines turned off) between the sun and the enemy without being noticed against the 3 kelvin backdrop of space? Even if you managed that feat, a widely dispersed sensor net would make it near impossible.

With currently existing technology the space shuttle's main drive is detectable with passive sensors from beyond the orbit of Pluto. Its manoeuvering thrusters are detectable from the asteroid belt.

I do not really buy that number since we do not actually detect much in our immediate neighborhood, let alone something around Pluto with current visual imagery. I don't say it is impossible but since we don't see tons of stuff in our solar system it is still pretty easy to postulate there is a certain desirable state in which it would be hard for one ship to see another.

Overall the argument is rather selective and absolutistic. So what if a good sensor network can detect a ship? That what even B-2 bombers have to expect when trying to pass through the Russian radar networks! There are plenty of scenarios where there won't be widely dispersed sensor networks.

And directed heat radiation is not perfect... but guess what a B-2 bomber has: Directed heat radiation so one half of the hemisphere (the ground) doesn't see its jet exhausts. It might be much harder to do in space but I don't quite see how that is not useful.

Assuming scientifically feasable scenarios there wouldn't be much room to actually disperse a big sensor network in itself since that would have to follow the very same rules of space travel and suddenly you would need some real effort to actually cover an area of space.

Overall science fiction would have to break some fundamental rules anyhow though because that's the reason why do not do any of the stuff right now.

[GreyFox]

I do not really buy that number since we do not actually detect much in our immediate neighborhood, let alone something around Pluto with current visual imagery. I don't say it is impossible but since we don't see tons of stuff in our solar system it is still pretty easy to postulate there is a certain desirable state in which it would be hard for one ship to see another.

We don't see tons of stuff in the solar system because they are not actively generating heat. A 285 kelvin ship is infinitely more detectable than a cold rock at the ambient temperature of 3 kelvin. And the main engines of the shuttle are far hotter than 285 kelvin.

Overall the argument is rather selective and absolutistic. So what if a good sensor network can detect a ship? That what even B-2 bombers have to expect when trying to pass through the Russian radar networks! There are plenty of scenarios where there won't be widely dispersed sensor networks.

You're right, it could be possible to use designs that could fool radar, which is useful for (relatively) short range stuff. I was on about heat, which is far easier to detect in space and nigh-on impossible to conceal.

And directed heat radiation is not perfect... but guess what a B-2 bomber has: Directed heat radiation so one half of the hemisphere (the ground) doesn't see its jet exhausts. It might be much harder to do in space but I don't quite see how that is not useful.

Sure radiating heat in one direction only could be useful, but only from hiding from 1 direction only. But that ability becomes useless if you're trying to come upon something that has 2 passive sensors that are spread out.

Then you would also have to know where these passive sensors are so as to point your heat radiators away from them.

Then you also have to be able to figure out a way to slow down without being detected. Remember, if you are accelerating at 1 kps^2 in one direction for an hour, it will take an hour decelerating at 1kps^2 to slow down to the original velocity. Ships with the main engine on one side (the back) would do that by flipping end-for-end.

You also need to figure out a way to hide the temperature of the outer hull of the ship. Simple conduction of heat from the living spaces/reactors will raise the temperature of the hull above ambient space temperature.

Assuming scientifically feasable scenarios there wouldn't be much room to actually disperse a big sensor network in itself since that would have to follow the very same rules of space travel and suddenly you would need some real effort to actually cover an area of space.

I'm not sure I follow you. In this hypothetical world we have warships that are capable of at the very least interplanetary (intra-solar) travel, with all the costs that it entails, yet it is difficult to simply throw up a few dozen satellites into stable orbits around the solar system?

Overall science fiction would have to break some fundamental rules anyhow though because that's the reason why do not do any of the stuff right now.

I agree, the trick is to keep it to an acceptable level so it doesn't get stupid.

[white-wolf]

Sure radiating heat in one direction only could be useful, but only from hiding from 1 direction only. But that ability becomes useless if you're trying to come upon something that has 2 passive sensors that are spread out.

That is meaningless in the space considering how big it is. Tell me how many leagues must be 2 passive sensors apart from each other to sense any direction of hemisphere?

[GreyFox]

That is meaningless in the space considering how big it is. Tell me how many leagues must be 2 passive sensors apart from each other to sense any direction of hemisphere?

I'm not a mathematician nor a physicist. The website I've linked to is as far as I can tell as legit as they get, and the mathematics seems sound, with contributors from actual honest-to-god physicists and 'rocket' scientists.

But like you said, space is vast. All you need to do is put the satellite sensors as far apart as you want, and then figure out how long it does to take a full-sky search (4 hours or so with current tech) and then figure out how quickly you can identify a really bright spot.

Look at the website I linked to. Its quite informative.

[white-wolf]

I'm not a mathematician nor a physicist. The website I've linked to is as far as I can tell as legit as they get, and the mathematics seems sound, with contributors from actual honest-to-god physicists and 'rocket' scientists.

But like you said, space is vast. All you need to do is put the satellite sensors as far apart as you want, and then figure out how long it does to take a full-sky search (4 hours or so with current tech) and then figure out how quickly you can identify a really bright spot.

Look at the website I linked to. Its quite informative.

Let me re-phrase my question; suppose you are at Earth, an object coming from north of Sun's orbit. Its over-heat is directed to north. How can you detect it?

[GreyFox]

Let me re-phrase my question; suppose you are at Earth, an object coming from north of Sun's orbit. Its over-heat is directed to north. How can you detect it?

Ok, I'll take a stab at it, but again, I'm not a mathematician or a physicist.

Assuming you are radiating heat away from the observer, and the observer is not moving, and there is only one observer (or that all observers are in one location), then I suppose it wouldn't be detected. At least not until it got close enough that the observer is able to detect the hull temperature.

And that's exactly the reason why satellites would be used, so that you can detect the heat. For instance, placing satellites in orbit of the sun to ease detection from this 'stealth' ship.

[Mangalore]

...
I'm not sure I follow you. In this hypothetical world we have warships that are capable of at the very least interplanetary (intra-solar) travel, with all the costs that it entails, yet it is difficult to simply throw up a few dozen satellites into stable orbits around the solar system?
...

If the ships need some kind of rocket fuel: How do you place your sensor grid and how would sensor drones look like? They wouldn't be able to be deployed quickly, they would massive amounts of fuel themselves, would be very easy to spot and you would need lots of them. What do sensor plaforms do to report their findings and how is that supposed to elude the enemy?

And it all only works when you are static. If you are moving, too, you have no real chance to deploy a sensor grid ahead of you because your ship will have more thrust and certainly a longer burn time so you would overtake any of the drones trying to get ahead of you in a matter of time. And it gets worse if you change course because your drones won't be able to follow since they would lack the reserves to keep up many maneuvers. How much time would you need to bring all those platforms into position and how do you prevent the enemy from seeing that? We are sublight speeds which means they are within the same solar system.

It makes incredibly brash assumptions about tactics. For one: Once you have finally deployed the sensor network which is scattered all over the place, what do you think the enemy will start blowing up because it is nice strategic asset to neutralize? So where do you think lots of your defenses have to go? Why would the enemy need tactical surprise anymore anyhow if he can dismantle your attempts this way.

[GreyFox]

If the ships need some kind of rocket fuel: How do you place your sensor grid and how would sensor drones look like? They wouldn't be able to be deployed quickly, they would massive amounts of fuel themselves, would be very easy to spot and you would need lots of them. What do sensor plaforms do to report their findings and how is that supposed to elude the enemy?

And it all only works when you are static. If you are moving, too, you have no real chance to deploy a sensor grid ahead of you because your ship will have more thrust and certainly a longer burn time so you would overtake any of the drones trying to get ahead of you in a matter of time. And it gets worse if you change course because your drones won't be able to follow since they would lack the reserves to keep up many maneuvers. How much time would you need to bring all those platforms into position and how do you prevent the enemy from seeing that? We are sublight speeds which means they are within the same solar system.

It makes incredibly brash assumptions about tactics. For one: Once you have finally deployed the sensor network which is scattered all over the place, what do you think the enemy will start blowing up because it is nice strategic asset to neutralize? So where do you think lots of your defenses have to go? Why would the enemy need tactical surprise anymore anyhow if he can dismantle your attempts this way.

The satellites would work if you intend to watch what is entering and leaving a solar system and where they are. Since all you have to do is place them in stationary orbits, they wouldn't need engines themselves, and so wouldn't be as visible as manoeuvering ships. Solar power could be used to power the satellites (which means no truly hot power source), and normal electronic emissions control (such as burst transmissions, directional signals etc) would take care of the rest. From the website I linked to before:

The maximum range a ship running silent with engines shut down [in this case a satellite] can be detected with current technology is:
Rd = 13.4 * sqrt(A) * T2
where:

• Rd = detection range (km)
• A = spacecraft projected area (m2 ) [This is the surface area of the craft facing the observer]
• T = surface temperature (Kelvin, room temperature is about 285-290 K)

Since the satellite is unmanned, I believe its surface temperature should be well below 290 kelvin, though somebody will probably have to check that.

For a fleet of ships all you would need would be the WW1 naval equivalent of destroyers and light cruisers, which were the eyes of the main battle fleet. Disperse them and the trick of merely radiating head away from where you hope the enemy is rendered null or merely just a temporary olution that will allow you to get slightly closer before detection. In my opinion, and that of arguments on the website, the difference would be negligible.

All your problems in your second paragraph are very good arguments, and are the exact reason why space fighters are unfeasible. They lack the fuel capacity and the delta-v necessary for their tasks.

As for your final paragraph - if he's going to come and destroy your satellites, he's going to have engines on and be manoeuvering. You are going to see him coming and be able to intercept him long before he is able to detect your satellites.

And even if he does manage to kill a few observer satellites, their very nature mean that they are relatively cheap (compared to crewed ships) and easy to replace.

[Mangalore]

We are assuming "realistic" speeds and somehow the enemy is not within our solar system so we can walk around deploying sensor grids as we please? You are assuming full control over the battlefield here. Yeah, okay, then the enemy would be screwed. But any enemy on any battlefield would be usually screwed then.

For the destroyers etc.., so they are somehow behind the enemy? Why would the enemy allow some measely ships to get behind him? They are easy pickings so his destroyer escort would be after them.

If you have e.g. Earth vs Mars or some other scenario the whole "hope where the enemy is" is actually quite easy: We are over here, they are over there and masking as good as possible that your ships are moving somewhere even if it is only temporary and doesn't mean they can completely sneak up to someone is already a good idea.

It's the absolutes they are talking about which doesn't really make sense to me. There's always an aspect of stealth. You just don't do it to accomplish some bravado sneak attack.

[GreyFox]

For the destroyers etc.., so they are somehow behind the enemy? Why would the enemy allow some measely ships to get behind him? They are easy pickings so his destroyer escort would be after them.

Why would the destroyers need to be behind the enemy? All they would need to be is in spread out in such a way that you can see the heat radiating away from the ships. You won't be able to radiate heat in one direction only, it will be in a cone shape, assuming you manage to design the radiators in such a way that they don't radiate into each other.

If you have e.g. Earth vs Mars or some other scenario the whole "hope where the enemy is" is actually quite easy: We are over here, they are over there and masking as good as possible that your ships are moving somewhere even if it is only temporary and doesn't mean they can completely sneak up to someone is already a good idea.

If they are at Mars then they are going to have to use main engines to, say, lift off or move someplace. There is no way you can hide that. The only way you won't detect a heat signature from engines is if they have some sort of magical reactionless drive, in which case you have planet-crackers as the limit is 0.999999999.......c.

I don't see what your problem with launching satellites into space is. We do it all the time today. All you have to do is spam a few into space and hey-presto you have a fairly thorough sensor grid. There is no need for space superiority. If you have ship, they can place them into orbits themselves.

If you are assuming inter-solar (low fractional c) speeds then it is going to take weeks or months to go from planet to planet. You fire off a few satellites, and if they see something heading your way you can rush warships to attempt an intercept.

Anyways, this is quite an interesting debate.

[TheDarkKnight]

Alrighty...so...Back on topic.


What are some other good Sci-Fi shows? I'm set for winter break but I'm curious what else is out there.

[Juvenal]

Alrighty...so...Back on topic.


What are some other good Sci-Fi shows? I'm set for winter break but I'm curious what else is out there.

There is SPACE 1999.

Now it may not suit your refined modern tastes, and it doesn't follow traditional US storylines (good-looking leading man triumphs alone against adversity and gets the girl). It also has some anachronisms that may grate on modern eyes (such as the moon-base computer, which communicates either by voice or through what looks suspiciously like a cash-till receipt printer).

But despite all this I have to say I really enjoyed it. It has this

Spoiler Alert, click show to read: 

and these

Spoiler Alert, click show to read: 

and I think the writing is pretty good. However I didn't like Season 2, so I recommend you stick to Season 1.

Oh... and I also liked UFO featuring the late Ed Bishop and the luscious Gabrielle Drake and features my favourite flying saucer.

[TheDarkKnight]

I have heard of Space 1999...I don't think I would like it very much.

[Magicman2051]

No, no you wouldn't. It hasn't aged well at all.

[TheDarkKnight]

No, no you wouldn't. It hasn't aged well at all.

I can tell. It looked bad.