The Physics

[pinkgothic]

Not sure about you guys, but when I watched Sunshine, I was left with a few questions that weren't answered in the movie itself, as well as a whole bunch of plausibility questions. I made the mistake of wanting to discuss some of these on IMDB - but, alas, it didn't seem like a good place to bring the questions up.

My first question relates to the premise of the movie. I'm not entirely sure if I like this omission or not - part of me is disappointed that it was never further elaborated in the movie, part of me is glad they didn't sthingyfeed me with everything. Suffice to say, it's frustrating. Specifically, I wanted to know precisely what had caused the sun to die - and what 'dying' in this case meant.

The answer that immediately comes to mind is that the sun is, at time of the movie, leaving the main sequence and slowly transforming into a Red Giant. Unfortunately, I know nothing of the timespans that would be involved in such a transition. We're talking about cosmic scales, so a few years at the very least seems plausible, but fact is, I don't know. Can anyone else fill me in on the timespan it would a main sequence star between showing first signs of fuel exhaustion and first actual expansion into a red giant?

On Wikipedia, on the Red Giant talk page, someone posted:

Once this Red Giant phase starts, how much time does it take to complete? I read years ago, that it bloats to Red Giant in a matter of hours. Now that astro-science is more developed is that still the theory?

Now, that's even more than I've heard.

At any rate, even if it's about to enter its Red Giant phase, that's only supposed to happen in about five billion years from now. Is the movie implying we were so grossly wrong about that estimate - or has something faciliated the transition? At this point, promptly, the Xeelee Sequence comes to mind, as already mentioned in another thread.

Second question:

This one has pretty much been 'beaten to death' on IMDB, but the manner the discussions were held there don't instill faith in the results. Specifically, if one were drifting through space without a spacesuit, would one freeze as quickly, quicker or far slower than depicted?

I'm aware that a vacuum makes for a splendid isolator - and that this is used in flasks to keep their contents warm or cold, regardless of outside temperature. However, those flasks are built like so:



Specifically, there's a solid object between the contents and the vacuum. The human body is, of course, mostly solid, so there should be very little difference, but the difference that comes to mind instantly is that we're constantly losing humity via our skin - quite a lot, even. That would be like, say, the contents of the flask leaking into its vacuum.

So I suppose my question is if that would make a huge difference or not. With the humidity would go a lot of the warmth that wouldn't be returned to the body by a surrounding atmosphere / source of warmth.

More musings will follow in another post, if I can sort my thoughts enough to remember all my questions properly.

[pinkgothic]

To lighten the mood, a few commonly misunderstood parts of the movie that are pretty easy to explain (feel free to add your own, these are just those that immediately come to mind, and I like compiling lists ).

- Mercury's speed past the sun - This scene, by the way, is quite possibly my absolute favourite in the movie, and so I'm very happy that it's available on YouTube. There are a few things that come to mind here to explain it. The first and most obvious: perspective, and orthogonal approach:


The small dot denotes the Icarus, the large dot is Mercury. This is, of course, very schematic, and nowhere near to scale.

Anyway, the point it that sun is bound to look smaller in relation to Mercury's orbit than it is. So in the scene, Mercury isn't moving across the full length of the sun, but a fraction of it - it just stops being "in the way" of the Icarus viewing the sun a lot sooner, largely because they are so close both to Mercury and the sun itself.

(The second aspect would be if they're heading towards the sun at an angle, rather than orthogonally - in "passing" Mercury, it would seem like the planet is flitting by faster than it actually is, providing their angle has them pass Mercury in the opposite direction that Mercury is moving in.)

- The last scene with Capa - Well, obvious, but still, it seems some people on IMDB didn't get it, which caused me to utter many spiteful giggles. Obviously, Capa isn't touching the sun, either the one created or the one they were flying into. Or rather, he is - for the absolute smallest fraction of a second! Of course he's incinerated almost instantly. It's a moment, though, where time, for him, seems to stand still.

- The spacesuit being "gold" - I can't spell the actual substance to save my life, but there's a nice Behind The Scenes video on YouTube that deals with this.

- The radiation levels (not just the heat and visible light) - Well, what's this with YouTube having so many cool videos lying around for the discovering, anyway? Not that I'm going to complain. But, yet again, there's a video about this. In a nutshell, whilst the physical "heat shield" would indeed not help very much in regards to solar radiation, it's electromagnetics that can keep it out. I suppose this is another case of it being unfortunate that something isn't elaborated in the movie.

And, not something that needs explaining in that I see it crop up on IMDB (or other film discussion boards) a lot, but:

- The Icarus' second shield - I don't know how many people bothered to notice this in the cinema (I presume of those reading this thread, all! But I mean in general ), but the Icarus has a second, smaller shield for the return home. Whereas the travel-to-sun shield is both larger so it can continue its travel past being disconnected from, it's also bent outwards like, say, a lens. What excited me massively was that the second, smaller shield was bent in the opposite direction... my immediate association? Solar winds! Beyond shielding the crew, it could offer a wonderous amount of extra push, which would mean the amount of fuel they would've needed to return home would have been considerably reduces. Agreed? Or do I have my physics borked?

Since I'm realising that I don't have the rest of my questions lying around at the moment, this'll be my last post in this thread - for now. If I can come up with anything else, you guys will, of course, be the first to be consulted.

[sunshinedna]

PinkGothic-

All of the videos are on SunshineDNA so you don't have to search YouTube for them. Unless it's fun.

This video explains the early death of the Sun. The reason an explanation wasn't in the film is probably because it's just too Michael Bay (a president or as was considered at one point, Pinbacker, giving a speech explaining the mission... meh.) The point of the film isn't the dying Sun...

Harvey freezing. Yep. Bad mistake. But... by the time the science advisor was brought on board that scene was well underway (it's effects- and CG-heavy so was one of the first things started)... Brian talks about it on the DVD commentary. The reason for the mistake is that very few people understand the difference between temperature and heat... I'm still trying to get this confirmed, but: the Sun's corona is millions of degrees, yet because it's a near vacuum, if you were able to stand in the corona (which you couldn't cos there's other stuff that would destroy you), you'd freeze (not as quickly as Harvey).

Space is weird.

Brian also worked out that with a gold shield you'd be able to get within about 100,000km of the Sun's surface which is about where the 'top' of the coronal loops are. After that the gold would 'disappear' and underneath it would have to be something like carbon-carbon... but basically gold is what is actually used as a shield. The reason why it's 'gold' like the Sun is that it's just really, really good at reflecting sunlight.

Mercury:
Also...It's traveling at about 200,000km per hour (actually it would move its diameter in distance in just over 1 second). The Icarus II is fairly close to it. It *would* move fairly quickly.

Capa's final scene:
Danny is on record saying it lasts a billionth of a second. Actually, when the Sun breaks through there is a shot from above which shows Capa being consumed entirely by flames - in real time - it then goes *back* and shows the whole scene as he experiences it. If people can't deal with 'art' then they should just wait for Die Hard 4 I think that scene is one of the most beautiful in cinema... Brian went to the film with one of his colleagues (another physicist - one of the youngest professors in the UK, super-genius...) who actually *cried* during that shot he thought it was so moving...

The dorks on IMDB have no brains. End of.

The interesting thing about watching films with scientists is that there are certain things they are incapable of suspending disbelief for - ghosts, the supernatural - and other things they are perfectly capable of accepting - the billionth of a second, everything goes in slow motion when you're dying shot. Of course, they understand the relativity of TIME more than most!

"Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That's relativity."
-- Albert Einstein

[pinkgothic]

sunshinedna said:

All of the videos are on SunshineDNA so you don't have to search YouTube for them. Unless it's fun.

It is, actually, because it makes some things so easy to find again (I'm horrible at remembering where things are, and am wholly in favour of the search engine for real life... "Where did I put my socks?!"). But, nonetheless, thank you for the head's up.

sunshinedna said:

This video explains the early death of the Sun. The reason an explanation wasn't in the film is probably because it's just too Michael Bay (a president or as was considered at one point, Pinbacker, giving a speech explaining the mission... meh.) The point of the film isn't the dying Sun...

I know it's not the point of the movie, hence why I've my mixed feelings about it not being mentioned - rather than being downright disappointed.

Thank you for the movie link! I'll take a look once I've installed QuickTime and then report back.

sunshinedna said:

I'm still trying to get this confirmed, but: the Sun's corona is millions of degrees, yet because it's a near vacuum, if you were able to stand in the corona (which you couldn't cos there's other stuff that would destroy you), you'd freeze (not as quickly as Harvey).

That's pretty backwards. Cool! Thanks.

sunshinedna said:

Space is weird.

Truer words were never spoken.

sunshinedna said:

If people can't deal with 'art' then they should just wait for Die Hard 4

*laughs fondly*

sunshinedna said:

The dorks on IMDB have no brains. End of.

Hence why I ask my questions here. I'm glad I'm not alone with my perception.

Thank you for your elaborate post with the details and additions.

I'm home sick today and my brain has ceased higher functions, so I don't yet remember my other questions. What's frustrating is that the thought pops up every once in a while, and then I'm nowhere near pen and paper, and I forget. Again. But I can at least confirm I do, in fact, still have some. *grumbles something ridiculous about 'old age'*

[pinkgothic]

Hee! I guess the science advisor didn't check over the subtitles to the clip, though. Anyway, that's really a very interesting clip, thank you very much for the direct link to the relevant video - now I'm researching Q-Balls, instead of being productive. Argh!

[sunshinedna]

pinkgothic said:

Hee! I guess the science advisor didn't check over the subtitles to the clip, though. Anyway, that's really a very interesting clip, thank you very much for the direct link to the relevant video - now I'm researching Q-Balls, instead of being productive. Argh!

Ha! Nope he didn't check the subtitles... and the person who did them is no dummy. I guess it goes back to 'space is weird'.

[Arya]

agreed...space is weird, weirder yet is the universe. well, we don't have to worry about our sun dying any time soon, in roughly 5 billion years it is estimated that the sun could die...that is assuming humanity is around until then to see it (we could blow ourselves to bits by then). What many astronomers predict will happen is that our very own sun will begin to expand and practically consume nearly all of the 9 planets (well 8 since now Pluto is not "considered" to be a planet but w/e) in our solar system. So we won't have to worry about freezing to death, like in the movie, more like being roasted to death. In the movie, the sun is dying much faster than predicted, and i wouldn't be surprise if (in the movie) the government had a top secret project involving our sun because when u think about it, the sun, all stars, are natural sources of massive amounts of energy. although the movie does not reveal any information on this, i bet the government had something to do with the sun's rapid deterioration.
they should make a movie about Andromeda colliding with our very own Milky Way...predicted to occur in a couple of hundred million years....
Imagine looking through your window and seeing Andromeda's brilliant star clusters and colourful cosmic gasses...now that would be something worth saving mankind for.

[ferrari333sp]

I watched a documentary yesterday about parallel universes, aired on the BBC. Talk about a serious mind-f***. Some of these things that physicists are theorizing, like string theory, are crazy nuts complicated.

[kagerou]

Yay, I love this thread. I always loved those random unproven (or is that unproveable?) physics theories...

When Corazon says that it's -273 degrees Fahrenheit (sp?), isn't that the closest mankind's come to emulating absolute zero? Which, had the vacuum thing not been a problem, would have explained Harvey freezing so quickly. I think?

[bunkergate7]

From NASA's website:

How Long Can a Human Live Unprotected in Space?

If you *don't* try to hold your breath, exposure to space for half a minute of so is unlikely to produce permanent injury. Holding your breath is likely to damage your lungs, something scuba divers have to watch out for when ascending, and you'll have eardrum trouble if your Eustachian tubes are badly plugged up, but theory predicts -- and animal experiments confirm -- that otherwise, exposure to vacuum causes no immediate injury. You do not explode. Your blood does not boil. You do not freeze. You do not instantly lose consciousness.

Various minor problems (sunburn, possibly "the bends", certainly some [mild, reversible, painless] swelling of skin and underlying tissue) start after 10 seconds or so. At some point you lose consciousness from lack of oxygen. Injuries accumulate. After perhaps one or two minutes you're dying. The limits are not really known.

imagine.gsfc.nasa.gov/docs/ask_astro/answers/970603.html

[starbrat]

From yesterday:
Check out this article in Slate, which specifically addresses the plausability of Mace's survival during that specific scene we're talking about...basically, another argument that certain 'Sunshine' sequences are more scientifically sound than not!!
www.slate.com/id/2171522/nav/tap3/

[brittany]

starbrat said:

From yesterday:
Check out this article in Slate, which specifically addresses the plausability of Mace's survival during that specific scene we're talking about...basically, another argument that certain 'Sunshine' sequences are more scientifically sound than not!!
www.slate.com/id/2171522/nav/tap3/

Very nice! Thanks for the link (and have a LY on me

[bunkergate7]

starbrat said:

From yesterday:
Check out this article in Slate, which specifically addresses the plausability of Mace's survival during that specific scene we're talking about...basically, another argument that certain 'Sunshine' sequences are more scientifically sound than not!!
www.slate.com/id/2171522/nav/tap3/

The article was informative.

The rest of this post is TOTALLY OFF THE TOPIC OF "PHYSICS"...

Slate's review of Sunshine (on another page) was a bit stilted. They even used it as an opportunity to make fun of Alien, which, as far as I'm concerned, is blasphemy.

Here is an excerpt: "But there's a development in the last half-hour that's so corny (not to mention outright confusing—for more head-scratching details, listen to the Spoiler Special on Sunshine) that you wouldn't be surprised to see Sigourney Weaver run by in her underwear, pursued by a gooey space beast."

Read the entire posting at: www.slate.com/id/2170731

[IIC]

Thanks for posting all that pinkgothic! I love physics and I enjoyed reading your posts. I'm a total geek. LY for you!

[colin]

Yea pink you rock. There is something unbelievably cool about a chick that is into stuff like this. Why can't you be in Canada? lol, and I don't know what an LY is, but I'm sure you deserve one from me as well!