Pitch Black Astronomy

[jokergirl]

First of all, did anyone actually see this movie? (it's from 2000, according to IMDB) Well, I rented it recently, and...
I'll just get into the most striking questions here, as I certainly don't want to see this movie a second time to examine it any deeper. [img]/phpBB/images/smiles/icon_wink.gif[/img]

1) The protagonist's spaceship is hit by what seems to be debris off a comet's tail. While I won't question now a)why they were travelling at such a low speed so close to a solar system at that time and b)why the hull plating, though it could seemingly survive a re-entry at some wierd angle, did not stop them (yes, i know even grains of dust can leave huge craters at those velocities), the protagonists call it a "stray meteor" later. I spare you the meteor bit, but "stray"?

2)The ship is crashing on a conveniently near planet (why it is crashing in the first place is not questioned here, though it is a major plothole). Although it has about the same aerodynamics as a brick, they eventually manage to slow it down by jettisoning half of their ship and using airbrakes. Hmm. Anybody else got a problem with this? (I still don't know how they even managed through the atmosphere with holes in their hull and at what looked like almost a right angle...)

3)They discover they are on a planet which is apparently in a trinary solar system, with two reddish twin suns orbiting a bright blue sun (or the like). They claim that because of this, it's never night on the planet (You see this all very graphically on a toy planetarium in an abandoned mining colony, so I'm not assuming anything here). Actually, that would mean the planet is not orbiting any of these suns at all, but would have to stay in between the suns at all times. Hmm.

4)While we could still assume this as true, there is the matter of another planet - a Saturn-like ringed giant, which is so close to the other planet that you could assume the smaller to be a moon of the bigger one. This planet is the reason that every 22 years, when the blue sun has set, the two reddish suns go into eclipse behind it. And, as the two planets are "moving as one", this eclipse is said to last quite long.
Now, we see the red suns setting and the blue sun coming up before, so the day cycle can't really be so long that one spot on the planet can be in shade for that long (or I'm just too lazy to think up other scenarios where this is possible). Also, for such a wierd system, 22 years seem quite long a time for this to happen...

But let's stop this. Only one more point that I really found ugly:

5)When the red suns go into eclipse, you see the big planet rise on the horizon. Not only it looks huge, it's also darker than the rest of the sky, and the rings are clearly visible as the suns are shaded by them.
Hm... I never saw a dark moon rising in the sky... and though I have seen a total eclipse, I never saw the whole disk of the moon unless it was completely in front of the sun. I could assume you can see the planet as it is being lit by the other sun, but it is clearly much darker than the rest of the sky, and this is just Bad.

I guess I should stop this now... if anybody has anything to add, I left quite a bit of other questions that popped up during the movie. Those were just the ones that hurt the most.

[img]/phpBB/images/smiles/icon_wink.gif[/img]

[Donnie B.]

On 2002-12-15 15:17, jokergirl wrote:
First of all, did anyone actually see this movie? (it's from 2000, according to IMDB)

No, haven't seen it, but...

3)They discover they are on a planet which is apparently in a trinary solar system, with two reddish twin suns orbiting a bright blue sun (or the like). They claim that because of this, it's never night on the planet (You see this all very graphically on a toy planetarium in an abandoned mining colony, so I'm not assuming anything here). Actually, that would mean the planet is not orbiting any of these suns at all, but would have to stay in between the suns at all times. Hmm.

No, this is possible. There are two ways a planet could exist in a multiple-star system. The planet could orbit one of the stars, or it could orbit far outside the orbits of all the stars.

In the former case, we'd have a system a bit like our own, except that Jupiter and Saturn would have to be much larger, so as to be capable of fusion. You can see that it would be "day" on "Earth" any time either of these outer suns is in the night sky.

Of course, in a case like this, there would be various kinds of "day" - regular day, with the Sun up but the other stars down, a sort of dim day when the Sun is down but one of the other stars is up, and various combinations thereof.

Now, it's probably not correct to say that in such a system there would never be night. Certainly at times, the two smaller stars would be close to the primary one (in the sky, as seen from the planet) so that they would rise and set more or less together. And after all three stars set, you'd have night. No giant planet eclipse necessary.

This may answer some of the other questions you raised, too...

[jokergirl]

Well, in the movie the planets are shown clearly between the three stars, so the latter explanation falls flat. I know about the 3 possible orbits, but none of them would have no night at all.
But you're right, the orbit around one of those suns (or the binary system) could be very wide, so it would almost be an "endless" day, at least in human proportions...
But it's clearly the planet that does the eclipse. Bad?

[img]/phpBB/images/smiles/icon_wink.gif[/img]

(edit: added the last paragraph.)
_________________
There are two things that are infinite: The Universe and Stupidity, although I'm not so sure about the Universe. -A. Einstein

Trying to weigh up plot device and BA...

<font size=-1>[ This Message was edited by: jokergirl on 2002-12-15 16:02 ]</font>

[Donnie B.]

Well... let's just say it was more fun for the FX/graphics people that way...

Hey, if you want perfect accuracy, go watch a documentary. No wait... that won't work either... oh darn...

[Smaug]

I know of a way to have this 4 body system work. Ok, say that the blue star is the main star, and all the other bodies orbit this star. Ok now think of the two smaller stars in an equallateral triangle shape with the big star. The two smaller stars still orbit, but there are always in this triangle shape. Now you put the planet right in the middle, where it would be gravitationally balanced between all three stars. I believe then that this body would most likely be tidally locked? I think that is the correct term; in other words it would not really rotate, or rather it would rotate once for every one orbit, much like the Moon. This idea, as I have just now realized, would not be cooperative with the movie though. Well, anyways, you still wouldn't have perfect, constant day effect. On the areas of the planet that are perpendicular to the mid-points between the main star and either of the two smaller stars you would have an endless dusk, or dawn effect I think. And the areas on the planet perpendicular to the midpoint between the two smaller stars this effect would be even dimmer.

[Donnie B.]

Unfortunately, Smaug, the configuration you describe is not possible. If the three bodies (planet and two red stars) were in different orbits, they would not stay in the same position relative to one another. If they were all in the same orbit, it wouldn't be a stable configuration. That's basic "celestial mechanics" - Kepler's laws.

Of course, you could argue that perhaps the stars and planet are all being actively maintained in this configuration by some agent (maybe an intelligent, technological race). But... why?

[Iain Lambert]

As regards your first point, their computer system is off course, which is why they didn't notice anything until they crashed through what looked to be the dust from the rings of the other planet. Its a little hokey, as is the 17-year darkness thing, but it does look great at least.

Overall, I'd say that the film 'felt' a lot less bad than average, and the monsters are great.

[Resu]

i seen it. the actors and actresses are just plain ugly... not much of a movie I'd say. yeah, like you can put some polishing stuff into your eyes and then waaa-laaa, you can see stuff in pitch black ...

[Jetmech0417]

For an example of a planet that orbits (I think 3) seperate stars (orbits them ALL in a VERY weird orbit), check out the Alastor trilogy by (I can't remember his name right now, but if and when I find the book again, I'll let you know). It gives a really interesting scenario in the 3rd book about the planet that orbits multiple stars.




BTW, THIS IS MY 101st POST!! HOORAY FOR ME!!

[David Hall]

Congrats Jetmech! Seems to take forever, to go up don't it? [img]/phpBB/images/smiles/icon_smile.gif[/img]

Coincidentally, Pitch Black is being shown on one of my cable channels this month. I may have to try to catch it if I can get the free time. They're showing Battlefield Earth tomorrow, and since it's free I think I'll rot my brain a bit and see just how bad it really is. [img]/phpBB/images/smiles/icon_biggrin.gif[/img]

They showed Leslie Nielson's 2001: A Space Travesty last week, and, except for the opening sequence, it's definitely one to pass on. (I did like the "white dwarf", and the "moon" rising. Juvenile, but humorous.)

One nice thing about Japanese TV showing English movies is that they don't censor the language, none of the beeps or blanked out words you'd get on US tv. In fact, they don't censor anything except for really graphic sexual scenes.

[informant]

David Hall wrote:

One nice thing about Japanese TV showing English movies is that they don't censor the language, none of the beeps or blanked out words you'd get on US tv. In fact, they don't censor anything except for really graphic sexual scenes.

Ah, but do they translate it? [img]/phpBB/images/smiles/icon_wink.gif[/img]

Jetmech0417 wrote:

For an example of a planet that orbits (I think 3) seperate stars (orbits them ALL in a VERY weird orbit), check out the Alastor trilogy by (I can't remember his name right now, but if and when I find the book again, I'll let you know). It gives a really interesting scenario in the 3rd book about the planet that orbits multiple stars.

I don’t suppose you’re thinking of Marune: Alastor 933. If you are, it’s four suns, and I think it’s the first novel of the trilogy.
I have a vague impression that only one of the four suns was Marune’s “true” sun. in other words, Marune only orbited one of the satrs – but I’m not certain. The interesting part was that because of the shape of the orbits of the planet and its suns, it was only nighttime once a month. Don't know if this is bad astronomy too...

[David Hall]

On 2002-12-18 10:37, informant wrote:

Ah, but do they translate it? [img]/phpBB/images/smiles/icon_wink.gif[/img]

Well...I guess it all depends on how it's translated. Usually these movies are shown with Japanese subtitles, and Japanese subtitling is terrible. I can read some of it, and most of the time what's written is only a bare-bones version of what's actually being said. "You dirty rotten filthy slime" might be translated simply as "You are a bad man", for example. They tend to gloss over a lot of the really bad stuff that way.

When they're dubbed (and in that case the English is usually broadcast over a second audio channel), they tend to do a bit better. They are translated into what would pass for the most natural expressions available in Japanese. Exclamations especially will be a Japanese equivalent.

But in truth, there's just not really that much that's that offensive in Japanese. There are only a few Japanese words that would definitely get beeped when spoken, and those mostly refer rudely to certain parts of the anatomy. The Japanese version of the S-word is not very offensive, and there isn't really a swear-word equivalent to the F-word in English.

D'oh! I've done and got myself going off on a Japanese language tangent again. I gotta stop this. [img]/phpBB/images/smiles/icon_biggrin.gif[/img]

[Krel]

Totally off topic, but a great place for Japanese translations of english is http://www.engrish.com .

David.

[RickNZ]

I happened to enjoy Vin deisels pitch black [img]/phpBB/images/smiles/icon_biggrin.gif[/img]

I enjoyed the experience but admittingly i didnt study the film for authenticity.

I figured that it stayed in constant daylight was due to the time of orbit = time to do a 360deg rotation?

[johnwitts]

With regards to the triple eclipse shown in this movie, looking at the DVD, two of the stars seem to orbit each other quite a way out from the third, primary star. Sort of like Pluto and Charon in our solar system, only further out and further apart. The planet these folks are on seems to be orbiting between two much larger planets, whose orbits are also inclined. Looking at the model the pilot uses, the eclipse occurs when all these line up, so that our heroes planet is between the two larger ones. This does not explain however why there would not be darkness on the planet when the two outer stars were on the same side of the sky as the central star. Then it would be dark every day for at least half of the planets rotation. Unless there's some tidal locking involved...

[AKONI]

You know,.. I don't even know what I'm talking about here, but when I saw the other planet come up I thought, "Isn't that a bit big? Shouldn't its gravity alone pull the planet in?" And,.. "No,.. that ship would have been destroyed on entry."

Other than that I LOVED the blue hue film stock they used in the opening of the movie. I thought it gave the shots a nice artist feel. The weird part is that about the time the hue goes away and the movie turns from a sci-fi flick into a horror movie with monsters.



<font size=-1>[ This Message was edited by: AKONI on 2003-01-08 22:17 ]</font>

<font size=-1>[ This Message was edited by: AKONI on 2003-01-08 22:18 ]</font>

[whitegold]

I sent this to phil as well... but thought you people might be interested. Here are my major flaws with Pitch Black. Bear in mind I am 1) NOT an astronomer 2) not a physicist 3) not a scientist and 4) not very smart! [img]/phpBB/images/smiles/icon_smile.gif[/img]

Here are some GIANT bad science points:

1)coincidence: they happen to crashland on a random planet with breathable (though thin) air and sub-surface water? The day before a cosmic event?

2)iffy setup: the actual layout of the planetary system are ridiculous. Three suns. One binary pairing and one on it's own. Three planets. All of which orbit, on the same plane, around... nothing at all. There is NOTHING at the center. The suns orbit too. In fact, the binary is at the very outside! As I understand it, the point of an orbit is that there has to be something to orbit AROUND! The planets are also FAR too close together. Were they that close they would have all squished together long ago, surely. Still, makes for some nice scenery.

3)frequency: on this place they land one day (though the terms is meaningless here) before it happens there is a perfect alignment of all planets and suns. Not only that. But this happens EVERY 22 YEARS!
4)evolution: I would question the probability of the evolution (or successful survival if non-indigenous) of a creature that can't survive any light on a planet with a single day of darkness every 22 years.[other posters mention that it stayed dark for 17 years, etc. I'm not sure where they got that. I don't recall her knowing. In fact, I thought she said she didn't know. Could be hours, could be years. Still, years or not, the issue stands.]

That's my four cents. (I'm Australian. The exchange rate is appalling.)

[g99]

Good post!! Welcome to the board WhiteGold!!

[Geo3gh]

This is more Bad Biology (or maybe it's Bad Ecology), but what were those Giger inspired creatures eating all that time?

These things are apparently ravenous eaters, like locusts. You can see the skeletons of the large creatures that used to live on this planet; there's the implication that these photophobic beasts cleared them all out. Heck, it looks like they stripped the planet bare.

Watching how they are portrayed--a couple of hours into the eclipse they resort to cannibalism--I'm having a hard time buying the notion that they can survive for 22 years without a food source. Even if you suppose some sort of hibernation, give me a break!

[logicboy]

On 2003-02-07 12:32, Geo3gh wrote:
This is more Bad Biology (or maybe it's Bad Ecology), but what were those Giger inspired creatures eating all that time?

These things are apparently ravenous eaters, like locusts. You can see the skeletons of the large creatures that used to live on this planet; there's the implication that these photophobic beasts cleared them all out. Heck, it looks like they stripped the planet bare.

Watching how they are portrayed--a couple of hours into the eclipse they resort to cannibalism--I'm having a hard time buying the notion that they can survive for 22 years without a food source. Even if you suppose some sort of hibernation, give me a break!

Very Big Plot Hole

My opinion the biggest in this movie

Here on Earth every species "except for humans" develop a natural balance with nature

These "Giger inspired creatures" they
knew nothing about agriculture and didn't seem like the cattle herding type so I am assuming they relied on wild animals for their food source.

Has there even been a case where a species eats all of the food supply and goes extinct?

[tuttle]

On 2003-02-07 14:16, logicboy wrote:

On 2003-02-07 12:32, Geo3gh wrote:
This is more Bad Biology (or maybe it's Bad Ecology), but what were those Giger inspired creatures eating all that time?

These things are apparently ravenous eaters, like locusts. You can see the skeletons of the large creatures that used to live on this planet; there's the implication that these photophobic beasts cleared them all out. Heck, it looks like they stripped the planet bare.

Watching how they are portrayed--a couple of hours into the eclipse they resort to cannibalism--I'm having a hard time buying the notion that they can survive for 22 years without a food source. Even if you suppose some sort of hibernation, give me a break!

Very Big Plot Hole

My opinion the biggest in this movie

Here on Earth every species "except for humans" develop a natural balance with nature

These "Giger inspired creatures" they
knew nothing about agriculture and didn't seem like the cattle herding type so I am assuming they relied on wild animals for their food source.

Has there even been a case where a species eats all of the food supply and goes extinct?

T's never impiled in the movie that the creatures only eat every 22 years, only that they come to the surface during the night.
I would assume that the creatures would be feeding on whatever other creatures they could find underground during the long night. When darkness falls upon the planet they can hunt above ground as well.

[Colt]

On 2003-02-07 12:32, Geo3gh wrote:
This is more Bad Biology (or maybe it's Bad Ecology), but what were those Giger inspired creatures eating all that time?

These things are apparently ravenous eaters, like locusts. You can see the skeletons of the large creatures that used to live on this planet; there's the implication that these photophobic beasts cleared them all out. Heck, it looks like they stripped the planet bare.

Watching how they are portrayed--a couple of hours into the eclipse they resort to cannibalism--I'm having a hard time buying the notion that they can survive for 22 years without a food source. Even if you suppose some sort of hibernation, give me a break!

Maybe they were some sort of bilogical weapon (sort of like the Aliens were supposed to be) that would be dropped onto a planet and they would strip it clean and then die off for the arriving forces. On the planet in question though it was an abnormality that they had no regular night. They just dropped a pod of these things anyway. On a normal planet that type of carnage would happen every night. -Colt

[Tiron]

Sorry to drag an ancient and dead post from the grave, but ever since I saw Pitch Black a couple weeks ago I've been searching feverently for some sort of answer to how that bloody system could work.

From the images they use, and especially from the orrery in the movie...it looks like the trinary is set up like this:

Three stars, a yellow and a orange/red type(seem to be about the same size) in a binary pair, close together, and a Blue. The stars seem to, very oddly, orbit on the very *outside* of the system, from all appearances the three stars are on the *exact* same orbit, with the blue star always *perfectly* opposed to the pair.

There are three planets in the system, at three different sizes. All sizes are relative as I have no CLUE how how big they actually are.

There is a large, double-ringed planet on the next orbit in from the stars. It is several times the size of the other two planets.

The next orbit is is the planet they crash on, smallest in the system.

Further in than that is a planet about mid-size between the other two, on a VERY wierd, VERY high-angle(relative to the ecliptic) orbit.

The planets all orbit around what appears, from the orbits, to be the center of gravity of the three stars. There does not appear to be ANYTHING in the center of the system. The blue and binary pair very definetly are shown on the same orbit around that centerpoint and always perfectly opposed on opposite sides of the system(meaning the blue, gravity wise, has to match the binary pair perfectly!).

The planets, however, orbit at varying speeds. All orbits appear to be perfectly flat and circular(except the very innermost planet).

The very weird orbits result in either the blue or the binary pair lighting the planet at all times. In fact there's a scene early on where the blue rises right before the binaries set, and all three are visible(the binaries about to set, the blue having just risen), implying that the planet wasn't exactly between them.

This constant light isn't a given though. Every 22 years there's a *triple* eclipse. The orrery shows all three planets lined up on the same side of the system(side the binaries are on), perfectly in line. The Large, ringed planet blocks the binaries, and the mid-sized inner planet blocks the more distant blue(there is a very, very neat looking scene with the massive ringed planet rising up and blocking the binaries).

The whole thing just totally blows my mind because I can't figure out how the bloody thing could work other than sheer 'plot effect'. The orbits have too many instances of 'perfect' and I'm baffled at how the planets could be on the inside of the stars, especially with apparently nothing in the middle.

There is one other thing, though. From the things they show it becomes readily apparent that the large, ringed planet's orbit is EXTREMELY close to the small planet's. You never see the inner planet so how far it is, who knows. It appears on the orrery to be very close and have a very tight orbit around the centerpoint. The one distance in the system you don't get any hints on is the stars. On the orrery they show pretty close in but who says the orrery was built to scale? If they were that close to the planet they'd have to be *really* small otherwise they'd show up gigantic in the sky and the planet would be EXTREMELY bright. Only way that works at all is if they're farther out than they look on the orrery. But for the whole eclipse thing to work the planets have to be REALLY close together in the center of the system. But if the orrery isn't built to perfect scale who says the orbits it shows are exactly right?

it hurts my brain

[Avatar28]

Haven't seen the movie, so I can't comment. But perhaps there's some sort of neutron star or black hole in the middle of the system that everything is orbiting? I don't know, but I really don't see how the planets could orbit the barycenter themselves just because of the mass difference between them and the stars.

[Tiron]

Yeah, that's the same problem I had. And actually that's the only solution I could think of too, that something supermassive was in the center of the system...

problem with that is that the planets seem to be in orbits VERY close to the center, especially the innermost. The orbit shown for it on the orrery is very, very close to being dead center in the system, but not quite. You'd think that if there was something massive enough to get the stars to orbit it the planets would get sucked in...

as I said... HURTS ME BRAIN.

Edit: Managed to find a wallpaper image of the large, ringed planet rising and blocking the binaries. The way it's done in the movie, the rings block the stars out first, and then they flash out again for just a second before the actual planet blocks them.

I've uploaded it onto me 'image dump' geocities account, but if too many people look at it too fast I'll run outta bandwidth and none of the rest of ya will be able to see it for an hour. It's not very big, but if it whines try back in about an hour and it should work, you guys are gonna be the only ones looking at anything on there guarenteed.

http://www.geocities.com/graptorian/Pitch_Black_001.jpg

here's the link to where I found out it, it's a direct link to the image, but be warned that the page it was on had some *very* not-work-safe ads on it. :-?

http://e-heap.net/files/film/Pitch_B..._Black_002.jpg

This is the OUTERMOST planet in the system as seen from the 2nd planet in. The 1st planet is never shown except on the orrery. All three planets are supposed to be aligned very close on the same side of the system(as shown by the orrery).

[Amadeus]

I liked it....

I mean lets be real for a moment. Any movie set it space will suffer from this problem because

a) Movie writers are not normaly astro physics experts.

b) They could spend 30 mins explaining to the audience how a trinary star system could work with a 22 year eclipse. But most people would be bored.

c) It's fiction thats mainly about fear and violence and moral choices that puts the audiance into an unknow situation. It's not a documentry.

This is a good movie.

You may have prime cut rump steak at home but sometimes don't you just want a cheap hamburger? Or kebab if you're a fellow brit!

[johnwitts]

Mmmmmm. Kebabs.

Wait a minute. I have Kebabs at home and Rump steak when I'm out. 8-[

[nomuse]

Of course there are two easy ways to have endless day over one hemisphere (in a single-star system); tidal lock, and an axial tilt of around 90 degrees.

Then there's the possibilities if a planet is at the lagrange node of a binary. You get light from two sources 90' apart, but that would only halve the remaining night.

Hrm.

If you can't get a planet in the right relation to the suns, put suns around the planet. Or rather, high-albedo moons. THAT's easy to set up.

In the opposite direction, I was working on a short tale set on a world orbiting a gas giant. The inclination of that orbit was such that the nodes crossed only every hundred years or so (I forget what I worked it out as...maybe every other orbit or something). Trouble is, even with the biggest gas giant I could come up with, I couldn't get an eclipse that lasted longer than twenty hours or so. I was doing this all on paper, of course, so it took a while to change paramenters and run it again!

[Tirdun]

My complaint about PB was not the astronomy, although I squinted awfully hard at that little toy system to figure out how you'd get a planet with no darkness anywhere, it was the biology.

There appear to be exactly 3 species on this planet, and of those, the humans aren't exactly native. There aren't any plants, the other native species are only shown as giant skeletons. What, exactly, do the darkness-loving critters eat? I mean, when there are no marooned humans stopping by or starting sand-farming colonies during the dozen or so hours that the species is actually awake. And why would a species evolve to be active during, what: .00016% of the time? GAh, it makes n sense.

The critters seem to eat each other, which is a losing proposition no matter how it works, so the only answer I could reach was that this planet wasn't always locked into whatever magical orbit it now occupies. This means the critters are slowly going extinct by cannibalizing themselves into oblivion. This stretches credibility in all sorts of ways, so I gave up. Would it be so hard to develop an actual ecology for this place?

[johnwitts]

Maybe there's loads of stuff living underground? Maybe the flying monster things only come out at night to breed or fly or something like that? Then again, there's not much use for flight underground. Maybe they're like those bugs from wherever, that only come out every 17(?) years? Maybe it's something we can't think of?