Observed Death Star surface gravity?

[Alan Bolte]

Has anyone looked for instances in ROTJ and ANH where things fall toward the DS? It's been a while since I've seen either, and I was just sort of thinking about it now. I mean, if the DS2 was a solid sphere of something heavy, like lead, you'd be certain to see accelerations of a few m/s/s. Not that it is, of course, but it's not like we have a mass estimate that I know of.

[Shinova]

The most obvious one is the Executor, but that's probably cause of the problem in the bridge more than anything else.

[Spanky The Dolphin]

There are no instances that I know of.

[Alan Bolte]

The most obvious one is the Executor, but that's probably cause of the problem in the bridge more than anything else.

Um, yeah, that's what I'd call powered flight there.

[Spanky The Dolphin]

The most obvious one is the Executor, but that's probably cause of the problem in the bridge more than anything else.

In the case of Executor, that was due to the engines misfiring, not from gravity.

Therefore, there are no examples that I know of.

[Montcalm]

The most obvious one is the Executor, but that's probably cause of the problem in the bridge more than anything else.

In the case of Executor, that was due to the engines misfiring, not from gravity.

Therefore, there are no examples that I know of.

For big ships i`m not sure,but in ANH the X-wing a Y-wing crashed on the DS when they were shot down.

[Alan Bolte]

I was thinking more if we saw sparks fly or something. That sort of trajectory would be easier to be certain is due to gravity.

[YT300000]

There are no instances that I know of.

[Jaded Masses]

Wouldn't be easier to use the size, and use a reasonable density (I think using that of an automobile is standard), and assume its made of iron (also as far as I know a standard), then figure a lower limit for the gravity. Then get an upper limit by figuring the most it could weigh in till certain effects would be unmistakable...

[Spanky The Dolphin]

There are no instances that I know of.

http://www.stardestroyer.net/Empire/Tec ... olaser.jpg

And that's proof of what, exactly?

[nightmare]

There are no instances that I know of.

http://www.stardestroyer.net/Empire/Tec ... olaser.jpg

And that's proof of what, exactly?

You see the green stuff falling down?

[ShinjiGohan]

see the green stuff going up as well?

[Darth Wong]

see the green stuff going up as well?

Don't be an idiot; stuff can briefly go up even at sea level on Earth. But there is an asymmetrical pattern of expansion, and it just so happens to be biased downwards.

[Howedar]

Amusingly, you say that it is gravity on your Turbolaser page.

Some of the visible portion of a turbolaser bolt can be affected by gravity, as demonstrated by the green discharge falling toward the Death Star in the picture above. This indicates that the characteristics of the luminous green material vary depending on its proximity to the bolt; if it's in the bolt, then it is unaffected by gravity, but if it is too far from the bolt, then it behaves like normal gas.

[Darth Wong]

Amusingly, you say that it is gravity on your Turbolaser page.

Why is that amusing? Was there something about my previous post which might suggest that I've changed my mind since then?

[Howedar]

It's amusing because I'm a retard with poor reading comprehension.

[Alan Bolte]

Wouldn't be easier to use the size, and use a reasonable density (I think using that of an automobile is standard), and assume its made of iron (also as far as I know a standard), then figure a lower limit for the gravity. Then get an upper limit by figuring the most it could weigh in till certain effects would be unmistakable...

The calcs are easy to do. As I said, the gravitational field near the surface of the DS2 is almost certainly in the relm of 1-5 m/s/s unless either the DS is substantally hollow or the reactor fuel and armor is amazingly dense. The DS1 probably has a much lesser gravity, more like 0.1-1 m/s/s. The intention here is to test that idea against evidence. If we could aquire a few frames before and after the pic Lord Wong posted, perhaps we could use that for a DS1 estimate. I, unfortunately, have no video capture capability, nor sufficient income to make aquiring any feasible. Even so, if no one else takes the initiative I shall endevour to watch the videos myself and make a few estimates.

[YT300000]

It's amusing because I'm a retard with poor reading comprehension.

I'm sigging that.

[Phantasee]

Has anyone looked for instances in ROTJ and ANH where things fall toward the DS? It's been a while since I've seen either, and I was just sort of thinking about it now. I mean, if the DS2 was a solid sphere of something heavy, like lead, you'd be certain to see accelerations of a few m/s/s. Not that it is, of course, but it's not like we have a mass estimate that I know of.

What are the odds...I was just thinking of putting a thread up (would've been my first one) with a similar if not the same question: Would the DS1 or DS2 have a sufficient size or gravitational field (say, equivalent of a small moon) to pull something out of hyperspace? I'm sure the designers made sure there were some of those things that interdictor cruisers have to do the same thing, but would it even need it?

[Wild Karrde]

Has anyone looked for instances in ROTJ and ANH where things fall toward the DS? It's been a while since I've seen either, and I was just sort of thinking about it now. I mean, if the DS2 was a solid sphere of something heavy, like lead, you'd be certain to see accelerations of a few m/s/s. Not that it is, of course, but it's not like we have a mass estimate that I know of.

What are the odds...I was just thinking of putting a thread up (would've been my first one) with a similar if not the same question: Would the DS1 or DS2 have a sufficient size or gravitational field (say, equivalent of a small moon) to pull something out of hyperspace? I'm sure the designers made sure there were some of those things that interdictor cruisers have to do the same thing, but would it even need it?

I don't remember where I recall this from but the DS 1 supposedly had some first-run interdictor generators onboard.

Even if it did though the DSs would still have their own moderate gravity presence due to their super-dense armor and hypermatter fuel.

[airBiscuit]

The fallacy I see with there being any significant gravitational attraction for either the first or second deathstar is twofold:

1) The diameter of the either Death Star is considerably smaller than our own moon. This means that volumetrically they are significantly less. Our moon has gravitational pull that is a small fraction of a G, so if other considerations are equal, the Death Stars would be that much less gravitationally attractive, probably on a cubic order.

2) Volume aside, what is more significant is mass. What is also significant is density, which determines how much mass you will find in the given volume. I can tell you right now that neither Death Star has anywhere near the density of the moon or similar bodies. They are effectively hollow stations. They have crew spaces, decks, docking bays, and one hell of a huge reactor core space (as depicted in ROTJ,) as well as an enormous weapon system, which is probably constructed along the lines of a particle accelerator. Planetary and moon bodies, though not homogeneous in their strata densities, are generally solid or liquid throughout, with extreme pressures and temperatures, and many times with a solid core, of iron or other dense material. This of course leaves out gas giants, which are massive simply because of their incredible volumetric dimensions.

[Phantasee]

*snip*

I see...well, I suppose that makes sense. Thanks from refraining from using complex calculations, and just explaining it. They don't teach physics to us yet at the Gr. 10 level, although that will change soon enough (like next term, when we finish off Chemistry).

[Alan Bolte]

Alright, principally in response to airBiscuit here: If we're talking a density for the DS that's a tenth that of solid iron - and you can't tell me that isn't a lower limit - then:
DS1: .04 m/s/s
DS2: .1 m/s/s

That still might account for the drift in gas shown by DW's screen, but we need confirmation. Measurements. I'm up to my eyeballs in work, and have no equipment, which is the only reason for my postcount to date. I do not pretend to be a serious technical analyst.

Even so, the results above are quite low - though I never said we were necessarily discussing gravity of more than that of the moon, even for the DS2.

Now, if I recall correctly, previous calculations have shown that the necessary reactor fuel for the superlaser alone would give the DS1 an energy density greater than uranium. Add in the use of ultradense composites in both structural components and the armor belt, and you have yourself one massive warship. That is why, honestly, I think we're looking at:
DS1: 1-2 m/s/s
DS2: 3-4 m/s/s
If not more.

I think this may be enough for the TIEs we see flying over the DS2 in the beginning of ROTJ to actually be orbitting. I'm not sure, need to get velocities for them and try it out.

For those of you trying this at home:

a=6.67E-11*4/3*pi*D*r

a - acceleration due to gravity in m/s/s
D - density in kg/m^3
r - radius of sphere in m

Yes, I failed to note units for G. Suck me.

[airBiscuit]

Alright, principally in response to airBiscuit here: If we're talking a density for the DS that's a tenth that of solid iron - and you can't tell me that isn't a lower limit - then:
DS1: .04 m/s/s
DS2: .1 m/s/s

I would question whether that *is* a low enough limit. You're talking about a complete spherical solid, and I think even a 10th of the density might not be enough. My impression is that this is nothing at all like a moon in construction. It's a very large ship, with lots of air gaps. It's going to be mostly girders and vents and decks, and a large reactor space in the center. To make the station really dense would immensely increase the cost and time to construct such a station, and would make it quite literally immobile due to the enormous inertial properties.

That still might account for the drift in gas shown by DW's screen, but we need confirmation. Measurements. I'm up to my eyeballs in work, and have no equipment, which is the only reason for my postcount to date. I do not pretend to be a serious technical analyst.

I missed out on the gas drift part, but if it were gravity that were causing this, it could be an artifact of the decks and gun emplacements having artificial gravity. Let's face it, all of the ships in Star Wars, probably even the fighters, have artificial gravity generators. There is probably a weak residual grav field along the surface of the Death Star as a result, and would result in pyrotechnics showing ballistic drift, and so on....

Now, if I recall correctly, previous calculations have shown that the necessary reactor fuel for the superlaser alone would give the DS1 an energy density greater than uranium.

An interesting speculation, but I wonder if those assertions are based on 21st Century knowledge and are not allowing for new possibilities for energy generation and conversion in the Star Wars universe.

Add in the use of ultradense composites in both structural components and the armor belt, and you have yourself one massive warship. That is why, honestly, I think we're looking at:
DS1: 1-2 m/s/s
DS2: 3-4 m/s/s
If not more.

You don't have to have density to have strong structural resistance or firepower resistance, at least not in the sci-fi realm. Composites, honeycomb construction, new geometries, new metal alloys, stabilization fields, all of these can be attributed to the DS's toughness. Also, it has so much material surface area that it would take a month of Mondays to hope to cripple it with capital ship firepower.

[Elheru Aran]

Let's face it, all of the ships in Star Wars, probably even the fighters, have artificial gravity generators.

This is correct-- fighters do have artifical gravity. Refer to the X-Wing series-- most of them have scenes showing a pilot or two telling the astromech to "dial back the gravity point five" or some such. They use the variable settings as a method of inertial compensation-- Wedge says something in the first one about Porkins dying at Yavin 4 because he always had his gravity all the way off; he couldn't feel that his fighter wasn't moving upwards, away from the Death Star.

I don't see that having artifical gravity on the surface of the Death Star, even in localized regions, would be a problem-- IIRC, when the Millennium Falcon is being brought into the hangar bay, there are two spaceproofed stormtroopers outside the hangar bay, watching the ship come in. They aren't floating; they're standing on a deck in the equatorial trench. Of course, this could be explained by magnetic boots...

Also, IIRC, the TL turrets firing in the trench never had anything near them to compare with-- so maybe they've got an command post in the lower half? This would be of help if manual aiming was necessary (say if the autotargeting was on the fritz, or if anti-turret fire knocked out the links between the computers and the turret); and having the gravity on in there would be ideal, as to prevent any errors in aiming. And in battle-- as this was-- it would probably be standing regulations to have at least one person ready to manually aim at all times. The DS was big enough that any combat with small forces on or above the surface could reasonably be expected to be fairly localized. Sectors of the DS would likely have been placed on alert and the turrets would've been manned.

That's my two cents, anyway...