Notes on technology

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Picard578
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Notes on technology

Post by Picard578 » Tue Aug 21, 2018 5:15 pm

OK, I had been writing a work on science in science fiction. Among others, I analyzed Star Wars and Star Trek. In the process, I found some things that might be of use. These are just quick and dirty notes, feel free to check and elaborate on them.

1) Slave I and Kenobi's fighter are distanced some 10 - 20 meters during chase scenes. I tried to calculate number of shots fired during close-tail chase and probability of hit. Overall, I calculated (from apparent rate of fire and length of chase, so there could have been more or less) 250 shots fired, for only one (maybe two) hits. This is probability of hit of 0,4%. For comparison, fighter aircraft had weapons zeroed in at 100 - 300 meters (10 - 15 times greater distance), and achieved some 2% hit probability per projectile (5 times higher than Slave I).

2) We see Republic Assault Ships (Acclamator in non-canon) landing on sand. Now, in distance we can see "AT-TE" walker near a landing leg of one. From that I calculated some 750 m2 for total ground area of three legs. Taking minimum mass of 4.070.000 t from G2k's volumetrics page, ground pressure works out to 542,7 kg/cm2. Now, dense sand (and the area seems sandy) can withstand 6,12 kg/m2. This makes landing configuration impossible without some form of mass lightening. As in, "90 million times more pressure than allowed" unlikely. Now, mass lightening might be the answer... but at this point, it comes to the question of "why the heck did they even bother with landing gear".

3) S-foils might be there to help cool the starfighters.

4) AT-AT should have, based on eyeball estimates, ~24 m2 foot area, for 72 m2. Comparing size of walker to M113 I got 870 t for armoured box and maybe 1.088 t for total walker weight. Ground pressure is thus 1,51 kg/cm2 or 21,48 psi or 148 kPa - around the same as a horse.

5) Bespin seems to be an ice giant, as it clearly has breathable atmosphere (gas giants do not). However, temperature would be -200 degrees Celsius. So sorry, Luke, you are a frozen popsicle. As is everyone else.

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Re: Notes on technology

Post by Picard578 » Tue Aug 21, 2018 7:40 pm

On Star Trek combat ranges: if my memory serves me right, sufficiently powerful subspace field can jam sensors. We also know that ships emit low-level subspace field all the time (as a function of their propulsion). Consequently, starship's engines can act as, basically, jammers. This would serve to explain a lot of Star Trek's low combat ranges.

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Re: Notes on technology

Post by Khas » Wed Aug 22, 2018 12:29 am

Picard578 wrote:
Tue Aug 21, 2018 5:15 pm
5) Bespin seems to be an ice giant, as it clearly has breathable atmosphere (gas giants do not). However, temperature would be -200 degrees Celsius. So sorry, Luke, you are a frozen popsicle. As is everyone else.
https://en.wikipedia.org/wiki/Hot_Neptune

You were saying?

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Re: Notes on technology

Post by Iscander » Wed Aug 22, 2018 12:54 am

Picard578 wrote:
Tue Aug 21, 2018 5:15 pm
2) We see Republic Assault Ships (Acclamator in non-canon) landing on sand. Now, in distance we can see "AT-TE" walker near a landing leg of one. From that I calculated some 750 m2 for total ground area of three legs. Taking minimum mass of 4.070.000 t from G2k's volumetrics page, ground pressure works out to 542,7 kg/cm2. Now, dense sand (and the area seems sandy) can withstand 6,12 kg/m2. This makes landing configuration impossible without some form of mass lightening. As in, "90 million times more pressure than allowed" unlikely. Now, mass lightening might be the answer... but at this point, it comes to the question of "why the heck did they even bother with landing gear".
It may be as simple as the need to stabilize the ship as they land troops more than support the weight of the ship.

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Re: Notes on technology

Post by Iscander » Wed Aug 22, 2018 2:44 am

Also, good thought to look at ground material. It opens up another interesting aspect to landing a star ship aside from the usual X-million ton star ship lands on spindly legs, obviously made of MegeMetal™.

It means either the Assault ship is incredibly light or actively supporting its own weight.

Ground pressure is a boring and important part of super sized vehicles.

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Re: Notes on technology

Post by Picard578 » Thu Aug 23, 2018 12:18 pm

Iscander wrote:
Wed Aug 22, 2018 12:54 am
Picard578 wrote:
Tue Aug 21, 2018 5:15 pm
2) We see Republic Assault Ships (Acclamator in non-canon) landing on sand. Now, in distance we can see "AT-TE" walker near a landing leg of one. From that I calculated some 750 m2 for total ground area of three legs. Taking minimum mass of 4.070.000 t from G2k's volumetrics page, ground pressure works out to 542,7 kg/cm2. Now, dense sand (and the area seems sandy) can withstand 6,12 kg/m2. This makes landing configuration impossible without some form of mass lightening. As in, "90 million times more pressure than allowed" unlikely. Now, mass lightening might be the answer... but at this point, it comes to the question of "why the heck did they even bother with landing gear".
It may be as simple as the need to stabilize the ship as they land troops more than support the weight of the ship.
Iscander wrote:
Wed Aug 22, 2018 2:44 am
Also, good thought to look at ground material. It opens up another interesting aspect to landing a star ship aside from the usual X-million ton star ship lands on spindly legs, obviously made of MegeMetal™.

It means either the Assault ship is incredibly light or actively supporting its own weight.

Ground pressure is a boring and important part of super sized vehicles.
Good idea. And yeah, ground pressure is important. We see Voyager land in few episodes as well... notably, on one episode they undergo warp coil maintenance, meaning that the ship is unlikely to be supporting its own weight. I'm not sure whether we ever get a good look at landing gear that would allow calculating ground pressure, though.
Khas wrote:
Wed Aug 22, 2018 12:29 am
Picard578 wrote:
Tue Aug 21, 2018 5:15 pm
5) Bespin seems to be an ice giant, as it clearly has breathable atmosphere (gas giants do not). However, temperature would be -200 degrees Celsius. So sorry, Luke, you are a frozen popsicle. As is everyone else.
https://en.wikipedia.org/wiki/Hot_Neptune

You were saying?
Thanks. So that's one off the list.

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Re: Notes on technology

Post by Iscander » Fri Aug 24, 2018 11:02 am

For Voyager, I believe the episodes where they are landed are "The 37's", "Demon", & "Nightingale".

With "The 37's" & "Demon", having a landing sequence that shows the legs extending.

Also the pressure should be in N not kg, per area.

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Re: Notes on technology

Post by Picard578 » Sat Aug 25, 2018 7:52 am

Iscander wrote:
Fri Aug 24, 2018 11:02 am
For Voyager, I believe the episodes where they are landed are "The 37's", "Demon", & "Nightingale".

With "The 37's" & "Demon", having a landing sequence that shows the legs extending.

Also the pressure should be in N not kg, per area.
Pressure is measured in various ways, you have psi (pounds per square inch), kg per square whatever, tons per square whatever... Newtons may be more correct for physicists, but other units are easier to understand.

Anyway, thanks.

EDIT: Landing pad width seems to be about a quarter of deflector dish width, but since there are four "toes" I will figure at 60% the area. Voyager is 116 m wide, of which a third or so is a deflector dish. Overall landing pad area would thus be 224 m2, but since these are quick-and-dirty eyeball calculations, there is *significant* room for error. At any rate, 700.000 tons would lead to 3.125 t/m2, or 312,5 kg/cm2. This leads to 30.465,78 kPa, whereas bearing capacity of clays would be up to 600 kPa. Factor of difference is thus 51... suffice to say, even though it is not as bad as the assault ship example above, it is still waay too much, even if factoring in for possible calculation mistakes.

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Re: Notes on technology

Post by 2046 » Mon Sep 03, 2018 9:23 pm

Awesome… not sure I ever tried to calculate the Republic transport's ground pressure before . . . just the X-Wing and AT-AT, as I recall.

When it comes to space vessels (a la Voyager and her absurd little landing pads), we can assume a little antigrav or forcefield cheating unless the ship is actively stated to be powered down completely.

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Re: Notes on technology

Post by Darth Spock » Mon Oct 22, 2018 12:37 am

Picard578 wrote:
Tue Aug 21, 2018 5:15 pm
OK, I had been writing a work on science in science fiction. Among others, I analyzed Star Wars and Star Trek. In the process, I found some things that might be of use. These are just quick and dirty notes, feel free to check and elaborate on them.

1) Slave I and Kenobi's fighter are distanced some 10 - 20 meters during chase scenes. I tried to calculate number of shots fired during close-tail chase and probability of hit. Overall, I calculated (from apparent rate of fire and length of chase, so there could have been more or less) 250 shots fired, for only one (maybe two) hits. This is probability of hit of 0,4%. For comparison, fighter aircraft had weapons zeroed in at 100 - 300 meters (10 - 15 times greater distance), and achieved some 2% hit probability per projectile (5 times higher than Slave I).

2) We see Republic Assault Ships (Acclamator in non-canon) landing on sand. Now, in distance we can see "AT-TE" walker near a landing leg of one. From that I calculated some 750 m2 for total ground area of three legs. Taking minimum mass of 4.070.000 t from G2k's volumetrics page, ground pressure works out to 542,7 kg/cm2. Now, dense sand (and the area seems sandy) can withstand 6,12 kg/m2. This makes landing configuration impossible without some form of mass lightening. As in, "90 million times more pressure than allowed" unlikely. Now, mass lightening might be the answer... but at this point, it comes to the question of "why the heck did they even bother with landing gear".

3) S-foils might be there to help cool the starfighters.

4) AT-AT should have, based on eyeball estimates, ~24 m2 foot area, for 72 m2. Comparing size of walker to M113 I got 870 t for armoured box and maybe 1.088 t for total walker weight. Ground pressure is thus 1,51 kg/cm2 or 21,48 psi or 148 kPa - around the same as a horse.

5) Bespin seems to be an ice giant, as it clearly has breathable atmosphere (gas giants do not). However, temperature would be -200 degrees Celsius. So sorry, Luke, you are a frozen popsicle. As is everyone else.


On Star Trek combat ranges: if my memory serves me right, sufficiently powerful subspace field can jam sensors. We also know that ships emit low-level subspace field all the time (as a function of their propulsion). Consequently, starship's engines can act as, basically, jammers. This would serve to explain a lot of Star Trek's low combat ranges.
1) "250 shots fired, for only one (maybe two) hits." Counting blast marks after things calm down says 5 hits here. Ultimately I gave up trying to extract useful information from that scene, the ships twist and turn too fast, the camera keeps moving and the asteroid clutter adds to the mess. Even so, there appeared to me to be quite a few shots that burst near the ship. Considering how many shots do clearly pass by, the flak explanation seems less likely here. That leaves either a lot of gravel soaking up some of that fire or perhaps a few more hits before the shields were defeated. It always struck me as odd that Fett would go to all that trouble chasing Kenobi down with his guns only to switch to a seeker missile after finally doing some damage.

2) Good point, although I was under the impression that in SW we're more likely looking at anti-gravity or repulsion tech rather than mass lightening, if that matters.

3) Cooling fins on space vessels make sense, but given SW ships consistent tendency toward tight, aerodynamically inspired maneuverability, I'd been wondering if that should be taken as more than just Hollywood shenanigans and if some of those protrusions actually employ some esoteric tech to emulate aerodynamic drag to gain "traction." Dameron needing an extra jumbo booster to close on the dreadnaught in TLJ, but only needing to open his S-foils to slam on the breaks pretty well cinches it for me.
The recent addition of some pilots flipping their ship on its axis to shoot an enemy behind them caused some doubt, but the trick seems rare and only used by highly skilled pilots (just Vader and Hera Sendula IIRC). Typically, a pilot wouldn't want to give up that kind of control to attempt some sort of Rockford Turn, considering the realistic alternatives of spacecraft maneuverability. As projectrho.com puts it: "Your spacecraft will NOT move like an airplane, it will act more like a heavily loaded 18-wheeler truck moving at high speed on a huge sheet of black ice."

4) Neat. But can a six-legged horse scale a rock face with cleats, THAT is the question!

5) Khas addressed this one, but some of the details about Bespin could be useful someday, if we ever get more specific information about tibanna gas to compare it to, narrowing down some of its properties.

Bonus) Regarding ST combat ranges, jamming sounds likely but I doubt if the natural interference from the warp engines would be all that effective in that roll, considering that many times it is specifically what they use to target other vessels. The projection of a fake Federation warp signature on a power generator to induce friendly fire during the First Battle of Chin'toka being a noteworthy example.

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Re: Notes on technology

Post by Picard578 » Mon Oct 22, 2018 4:25 am

Darth Spock wrote:
Mon Oct 22, 2018 12:37 am
1) "250 shots fired, for only one (maybe two) hits." Counting blast marks after things calm down says 5 hits here. Ultimately I gave up trying to extract useful information from that scene, the ships twist and turn too fast, the camera keeps moving and the asteroid clutter adds to the mess. Even so, there appeared to me to be quite a few shots that burst near the ship. Considering how many shots do clearly pass by, the flak explanation seems less likely here. That leaves either a lot of gravel soaking up some of that fire or perhaps a few more hits before the shields were defeated. It always struck me as odd that Fett would go to all that trouble chasing Kenobi down with his guns only to switch to a seeker missile after finally doing some damage.

2) Good point, although I was under the impression that in SW we're more likely looking at anti-gravity or repulsion tech rather than mass lightening, if that matters.

3) Cooling fins on space vessels make sense, but given SW ships consistent tendency toward tight, aerodynamically inspired maneuverability, I'd been wondering if that should be taken as more than just Hollywood shenanigans and if some of those protrusions actually employ some esoteric tech to emulate aerodynamic drag to gain "traction." Dameron needing an extra jumbo booster to close on the dreadnaught in TLJ, but only needing to open his S-foils to slam on the breaks pretty well cinches it for me.
The recent addition of some pilots flipping their ship on its axis to shoot an enemy behind them caused some doubt, but the trick seems rare and only used by highly skilled pilots (just Vader and Hera Sendula IIRC). Typically, a pilot wouldn't want to give up that kind of control to attempt some sort of Rockford Turn, considering the realistic alternatives of spacecraft maneuverability. As projectrho.com puts it: "Your spacecraft will NOT move like an airplane, it will act more like a heavily loaded 18-wheeler truck moving at high speed on a huge sheet of black ice."

4) Neat. But can a six-legged horse scale a rock face with cleats, THAT is the question!

5) Khas addressed this one, but some of the details about Bespin could be useful someday, if we ever get more specific information about tibanna gas to compare it to, narrowing down some of its properties.

Bonus) Regarding ST combat ranges, jamming sounds likely but I doubt if the natural interference from the warp engines would be all that effective in that roll, considering that many times it is specifically what they use to target other vessels. The projection of a fake Federation warp signature on a power generator to induce friendly fire during the First Battle of Chin'toka being a noteworthy example.
1) So that woud make it 5 / 250 = 0,02. In other words, exactly 2%, or the rate of hits for World War II fighters. I know that for OT Lucas reviewed some World War II gun camera footage, could this reflect that fact?

3) Yeah, that is why I like new Galactica and Babylon 5.

Bonus) It might be possible that a large number of warp signatures in small area confuses sensors somehow, and IIRC shields have jamming effect themselves. If true, then it would explain both dense starship formations we see in Deep Space Nine, and the low combat ranges present in those battles.

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Re: Notes on technology

Post by Darth Spock » Tue Oct 23, 2018 5:19 am

Picard578 wrote:
Mon Oct 22, 2018 4:25 am
1) So that woud make it 5 / 250 = 0,02. In other words, exactly 2%, or the rate of hits for World War II fighters. I know that for OT Lucas reviewed some World War II gun camera footage, could this reflect that fact?
Possibly. Although in searching for more information on that statistic, I found indications that the 2% average in WWII is one of those broad statistics that benefit from context. Namely that most kills apparently were scored by a minority of skilled combatants who actually did fairly well, while everyone else racked up the misses and dragged the average down. In which case Jango kinda sucks. Then again, he was chasing a Jedi though a dense asteroid field, and may have even scored a few more hits on the shields, so maybe he deserves some slack.

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