Announcement

Collapse
No announcement yet.

physics of space battles

Collapse
This topic is closed.
X
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    physics of space battles

    Hi,
    A while ago I remember reading a webpage that specifically talked about real space physics when it came to space battles, like for example 'there is no 'up' in space, how then does a ship meet another right side up?' and 'you can't dodge lasers, let alone see them'
    Unfortunately I cannot remember what the site was. Could someone please post a link, as I'm interested in creating some 'more' realistic cgi.
    thanks
    Tetrion

    #2
    Originally posted by tetrion View Post
    Hi,
    A while ago I remember reading a webpage that specifically talked about real space physics when it came to space battles, like for example 'there is no 'up' in space, how then does a ship meet another right side up?' and 'you can't dodge lasers, let alone see them'
    Unfortunately I cannot remember what the site was. Could someone please post a link, as I'm interested in creating some 'more' realistic cgi.
    thanks
    Tetrion
    Watch Andromeda for "realistic" space battles. As for the dodging thing, lasers aren't what you want to use in a real space battle. They are unguided once fired and only an idiot would come closer than at least 30 light seconds to their enemy, allowing plenty of time to dodge the unguided laser.

    What you want are guided missiles traveling at around .9 c, almost as fast and a lot harder to dodge. Lasers are relegated to a point defense role.

    Don't know what site you mean but those are just a few general points.

    Comment


      #3
      This thread deals with it in a secondary manner but it hits the high points.

      http://forum.gateworld.net/showthread.php?t=42313

      Comment


        #4
        This is a good site for information on "accurate" space battle physics. It is a fairly detailed anaylsis of just about any form of weaponry you can think of. I have no idea how truly accurate it is (as I am not a physicist) but it at least comes across as being relatively well founded.

        http://www.projectrho.com/rocket/roc...html#lasermiss
        "May God stand between you and harm in all the empty places where you must walk." - Susan Ivanova

        "The universe is run by the complex interweaving of three elements. Energy, matter, and enlightened self-interest. " - Citizen G'Kar

        "I will see you again, in the place where no shadows fall." - Delenn

        Comment


          #5
          This site might be the one you're thinking of: Insultingly Stupid Movie Physics. Most of the page discusses common film industry idiocies. Scroll down to the bottom for specific movies.

          And my pick for decent space scenes: I noticed in watching some Babylon 5 Starfury flight scenes that often they fly at different orientations. (Hey, any show that requires "matching rotation" for two ships to join up had *better* think of that.) I can't name specific episodes, but I can list a couple of videos with such scenes if anyone wants examples.

          Also, for some decent use of Newtonian physics, these videos on YouTube have some good bits:

          The Physics of Starship Battles- Laws of Motion and Momentum, especially from 3:10 onwards.

          Whitestar Music Video

          As for 'you can't dodge lasers, let alone see them', there is the problem of letting the audience know what is happening. The only alternatives to glowy beams are missiles, whether self-propelled or propelled by the launcher. But if you don't have a good sense of what draws the audience's eye, the audience may end up so busy trying to figure out exactly what's going on they won't have time to invest emotionally in the scene. Mind you, it's not necessary for the audience to be able to easily make out every detail. Seeing a chunk of rock launched at a planet, then seeing a streak of light or a break in the clouds traced on that planet can be just as effective as having an insert of the rock whizzing by the "camera". So can the look of horror on the face of a witness (Babylon 5 again).

          As for dodging, yes it looks really stupid to dodge a "beam" that has already been fired. But you the director can play with that timing by having the target evade before the beam is fired, or you could have the beam sweep an arc (as with the Shadow ship weapons used in Babylon 5), so there is some audience interest generated in seeing a moving ship avoid those sweeping beams.

          A lot of making space maneuvers work is building the audience's assumptions beforehand. In watching Babylon 5 we become conditioned to the notion that there is a lot of computer control. We also know which ships have artificial gravity and which ones don't. So when a Whitestar seems to bump while doing evasive action, we assume that's a natural consquence of the computerized firing of multiple thrusters and we know no one aboard felt anything. But if a Starfury lurches sharply we think "Oh no, the poor pilot!"
          Last edited by Wordsmit2; 04 August 2007, 01:33 AM.
          Wordsmit2

          The story of my life. I finally find a city like this, intact, deserted for ten thousand years, probably contains hundreds of patents that I can exploit--and I'm going to die. I can appreciate dramatic irony as much as the next person, but this is pushing it a bit. --Max Eilerson, Crusade "War Zone"

          Mess with me, you mess with my whole family. --Max Eilerson, Crusade "Ruling From the Tomb"

          Comment


            #6
            Originally posted by Emperor Tippy View Post
            As for the dodging thing, lasers aren't what you want to use in a real space battle. They are unguided once fired and only an idiot would come closer than at least 30 light seconds to their enemy, allowing plenty of time to dodge the unguided laser.

            What you want are guided missiles traveling at around .9 c, almost as fast and a lot harder to dodge. Lasers are relegated to a point defense role.
            For one, at 30 light-seconds, any active non-FTL sensor array would take at least one minute to acquire a target, plus another thirty seconds MINIMUM to hit the target with said relatavistic kill missiles, assuming that the system can process the sensor return, arm a missile, and fire with no delay.

            Not only that, but the amount of energy that the sensor will be putting out in order to actually work at that range will pretty much paint a gigantic 'I AM HERE' bullseye right on top of you. As soon as the target ship's passive sensors detect your active sensor pulse, they are probably going to arm thier own missiles and fire them at you. Assuming that they are ALSO relatavistic kill missiles, they will probably impact around the same time that your computer processes the return.
            Best case scenario, You fire at them, and thier missiles hit you shortly afterwards.
            Worst case scenario, They have a cloak or some other equivelant stealth system, get the drop on you, and reduce your ship into so much scrap metal.
            Either way, you are at a disadvantage.

            My point is that there is alot more to space combat than putting distance between you and them. Andromeda Is slightly less unrealistic than most other soft-sci fi, but it still has a fair few implausable technologies of its own (The GFG is #1)

            As for lasers, you cant actually 'dodge' a laser, as any non-FTL sensor will be unable to detect the beam before it hits. What you probably mean is that the unguided laser beam will be unable to adapt to sudden target acceleration. However, this assumes that the target is aware of you in the first place, and has commenced evasive maneuvers. Otherwise, they are travelling in a straight line, which is absurdly easy to hit.

            Comment


              #7
              Originally posted by Arania View Post
              For one, at 30 light-seconds, any active non-FTL sensor array would take at least one minute to acquire a target, plus another thirty seconds MINIMUM to hit the target with said relatavistic kill missiles, assuming that the system can process the sensor return, arm a missile, and fire with no delay.
              Yes, you use sensor drones with FTL communication abilities. Or FTL capable sensors.

              As for the delays, thats why you use missiles and not lasers. A missile can be guided a laser can't.

              Not only that, but the amount of energy that the sensor will be putting out in order to actually work at that range will pretty much paint a gigantic 'I AM HERE' bullseye right on top of you. As soon as the target ship's passive sensors detect your active sensor pulse, they are probably going to arm thier own missiles and fire them at you. Assuming that they are ALSO relatavistic kill missiles, they will probably impact around the same time that your computer processes the return.
              See above. And Passive sensors are a better idea anyways.

              Best case scenario, You fire at them, and thier missiles hit you shortly afterwards.
              Worst case scenario, They have a cloak or some other equivelant stealth system, get the drop on you, and reduce your ship into so much scrap metal.
              Either way, you are at a disadvantage.
              Um, only if they are actually a **** with halfway decent tactics. Start naming Sci-Fi movies and shows where combat takes place at these kinds of ranges. It's a short list. No ship shown in Stagate can fight at those ranges, same for Starwars and Star Trek.

              My point is that there is alot more to space combat than putting distance between you and them. Andromeda Is slightly less unrealistic than most other soft-sci fi, but it still has a fair few implausable technologies of its own (The GFG is #1)
              Every technology used in pretty much all futuristic Sci-FI is highly implausible.

              As for lasers, you cant actually 'dodge' a laser, as any non-FTL sensor will be unable to detect the beam before it hits. What you probably mean is that the unguided laser beam will be unable to adapt to sudden target acceleration. However, this assumes that the target is aware of you in the first place, and has commenced evasive maneuvers. Otherwise, they are travelling in a straight line, which is absurdly easy to hit.
              Um, if you are in combat and staying still you deserve to get hit with a laser beam. The Reason laser beams are worthless in any half way decent space battle is that the odds of one actually hitting a target ship even 10 lightseconds away are astronomically small.

              Comment


                #8
                Originally posted by Emperor Tippy View Post
                Um, if you are in combat and staying still you deserve to get hit with a laser beam. The Reason laser beams are worthless in any half way decent space battle is that the odds of one actually hitting a target ship even 10 lightseconds away are astronomically small.
                If you're talking about a ship as big as the Andromeda (4 km across IIRC), then even if it has inertial dampeners (which don't exist) that are 99% effective it is still going to have a huge amount of inertia. You don't just instantly change course with that much inertia unless you want to tear your ship to pieces. Especially a "collapsible" ship like Andromeda, which was specifically made weak.

                At 10 light seconds all you'd have to do would be to point your laser at their centre of mass. They would never be able to move fast enough to dodge it, especially if they are already moving toward you at 10psl (to use Andromeda terminology). The faster you are moving, the harder it is to change course. Remember, they only have 10 seconds, and those are bigs ships. Just hope they don't have a mirror with them.

                Comment


                  #9
                  A **** traveling at 10% of lightspeed would move more than 3 kilometers in 10 seconds, meaning that even if you aimed at the center of a 4 KM long ship you wouldn't hit it.

                  With inertial dampeners (which almost all space based sci-fi uses) the problem exacerbated. And with Andromeda style ones it is non existent (they are apparently 100% effective)

                  As for Mirrors, we have magnets

                  Comment


                    #10
                    Originally posted by Emperor Tippy View Post
                    Watch Andromeda for "realistic" space battles. As for the dodging thing, lasers aren't what you want to use in a real space battle. They are unguided once fired and only an idiot would come closer than at least 30 light seconds to their enemy, allowing plenty of time to dodge the unguided laser.

                    What you want are guided missiles traveling at around .9 c, almost as fast and a lot harder to dodge. Lasers are relegated to a point defense role.

                    Don't know what site you mean but those are just a few general points.

                    That's 8 993 773.74 km, or 23 times the distance betweem the Earth and it's moon..

                    Comment


                      #11
                      Originally posted by Dutch_Razor View Post
                      That's 8 993 773.74 km, or 23 times the distance betweem the Earth and it's moon..
                      Yes it is, and when you are using laser weapons and missiles traveling at relativistic speeds it is a minimum distance for a fight.

                      And if you are fighting with weapons that move at slower speeds the odds of you being able to be effective in a battle, even if your enemies are confined to the same weapons, are astronomically low.

                      Comment


                        #12
                        Originally posted by Emperor Tippy View Post
                        Yes it is, and when you are using laser weapons and missiles traveling at relativistic speeds it is a minimum distance for a fight.

                        And if you are fighting with weapons that move at slower speeds the odds of you being able to be effective in a battle, even if your enemies are confined to the same weapons, are astronomically low.
                        Have you even WATCHED Stargate...?
                        Click the banner or episode links to visit the virtual continuations of Stargate!
                        Previous Episode: 11x03 "Shore Leave" | Previous Episode: 6x04 "Nightfall" | Now Airing: 3x06 "Eldest"

                        Comment


                          #13
                          Originally posted by s09119 View Post
                          Have you even WATCHED Stargate...?
                          Yes. And just like Star Wars and Star Trek it sucks at presenting an even half way accurate picture of what space warfare would be like.

                          The OP wanted to talk about the physics of space battle in general, not necessarily in the Stargate Universe.

                          And the comment about you being effective in battle is in reference to the fact that your enemy never has to meet you on the field of battle. In space warfare stellar bodies are the only real important things. Sometimes a space station can make the list but thats a rarity. Now space is big, real big. The attacker always has the advantage because you can never cover all of the liens of attack. You are also fighting in 4 dimensions, not 2. Flanking and surrounding an enemy isn't possible unless you have enough ships to make it a non issue. Any weapon you use will be dodged at any range greater than a few light seconds under the best circumstances (unless it is a guided missile capable of traveling as fast or faster than its target).

                          I could go on for hours about all the differences between space battle and land based battle but I'll just give 1 more explanation. Look at how the US navy and Air Force fight wars any more. In an Air to Air dog fight the US planes launch their first salvo of missiles at ranges exceeding 50 miles (and in some cases up to a hundred+ miles). They generally consider a fight at 5-10 miles to be close in knife fight range. 10 miles being 1 minutes flight time at Mach 1. And most missiles are traveling Mach 5+. The navy fights at ranges exceeding a hundred miles regularly.

                          Comment


                            #14
                            Originally posted by Emperor Tippy View Post
                            A **** traveling at 10% of lightspeed would move more than 3 kilometers in 10 seconds, meaning that even if you aimed at the center of a 4 KM long ship you wouldn't hit it.

                            With inertial dampeners (which almost all space based sci-fi uses) the problem exacerbated. And with Andromeda style ones it is non existent (they are apparently 100% effective)

                            As for Mirrors, we have magnets
                            I'm guessing that you misspelled "ship" with the **** up there heh. Woo for the auto-censor!

                            You lead the target. And they aren't 100% effective, else they wouldn't be getting jostled around every time there is a nearby explosion (the ship would simply compensate with artificial gravity and inertia dampners *perfectly*. The reason they get jostled is because of inertia. Their ship moves, but they don't). Assuming you someone see a laser the instant it is fired, and that you can avoid it by an emergency thrust, what is to stop them from firing 2 lasers in slightly different directions? If you avoid the first, the second hits you. If you stay where you are, the second one misses, but the first one hits you. Bad either way.

                            That's the tactic they use with missiles on Andromeda. If you fire one missile, the Point Defences take it out. If you fire 10, one might get through.

                            Comment


                              #15
                              Originally posted by gopher65 View Post
                              I'm guessing that you misspelled "ship" with the **** up there heh. Woo for the auto-censor!
                              Yep. Although flinging **** at .1 c would most likely be fairly deadly.

                              You lead the target. And they aren't 100% effective, else they wouldn't be getting jostled around every time there is a nearby explosion (the ship would simply compensate with artificial gravity and inertia dampners *perfectly*. The reason they get jostled is because of inertia. Their ship moves, but they don't). Assuming you someone see a laser the instant it is fired, and that you can avoid it by an emergency thrust, what is to stop them from firing 2 lasers in slightly different directions? If you avoid the first, the second hits you. If you stay where you are, the second one misses, but the first one hits you. Bad either way.
                              The problem with leading the target is the vast area you have to cover. Space battles are fought in 4 dimensions and in distances measured in light seconds or even light minutes. With ships capable of sublight speeds measured in percentages of c. Even from 10 Light seconds out you are talking about an area millions of square kilometers in diameter. And the ship (which is 4 KM long) can be at any location inside that box.

                              That's the tactic they use with missiles on Andromeda. If you fire one missile, the Point Defences take it out. If you fire 10, one might get through.
                              Yeah,and those missiles were traveling at 95 psl are were guided. It was also salvos of more like 50 to a hundred missiles and hope 1 gets through.

                              Comment

                              Working...
                              X