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Superman Returns and Zero-G

And it is even more interesting than that, because the equivalence principle (that there is no experiment that one can perform that can distinguish a linear acceleration from immersion in a gravity field) is a cornerstone of the General Theory of Relativity, the theory that leads to the definition of the field equations of gravity.
 
Just a quick note, the moon is not out the earth's gravity to begin with so nothing in a low orbit out of the earth’s gravity either. In orbit things are in free-fall and appear weightless but are still under gravity's influence and their path of travel is curved.

Paul

:) :) :)
 
Schneibster said:
That's what comes to mind off the top of my head. To critique it any better, I'd have to see it- and I am singularly uninterested in watching a movie that the producers, writers, and directors didn't think enough of to hire someone who knows enough physics to steer such things correctly- or else to listen to them after they had hired them. It's difficult enough for me to suspend disbelief enough to watch Superman in the first place- to have someone blatantly screw up something as easy to get right as this situation is would have me out of my seat and up at the box office demanding a refund.
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Pah. Now I suppose you're going to tell me that a 200lb man can't fly around the earth so fast that it starts spinning backwards and thus reverses the flow of time. :rolleyes:
 
Roboramma said:
The plane is attached to a space shuttle that has accidentally caried them along for the ride.
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I haven't seen the film and don't want to spoil it for anyone else, but for some reason I can't resist asking how on Earth you "accidently" attatch a loaded passenger plane to a space shuttle.
 
trip.i said:
I say the plane should have continued onward and out into orbit since that's where the shuttle's trajectory was taking it and it had already reached zero gravity. Who's right?
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You are right, IF the shuttle continued on into orbit without making a further burn. If it made a further burn, you are both wrong.
 
Cuddles said:
I haven't seen the film and don't want to spoil it for anyone else, but for some reason I can't resist asking how on Earth you "accidently" attatch a loaded passenger plane to a space shuttle.
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It's a plot device, but the accident isn't the attachment, it's the failure to detach. Someone thought that having a passenger jet lift the shuttle would save energy. Personally I doubt that any passenger jet in existence could generate the forward thrust necessary to lift the shuttle and itself at the same time. The fluid dynamics of that union are horrendous and would give me a headache.
 
127068main_sca-discovery.jpg

http://www.nasa.gov/returntoflight/crew/ferryflight.html

Now this is without fuel on the shutte.

Paul

:) :) :)
 
Okay, so do we now discuss whether a 777 could structurally withstand being balanced on its nose, and then slowly lowered - still by its nose - to an upright position? :)
 
You just don't understand superpowers, geeeee, the wings did get riped off didn't they.

Paul

:) :) :)
 
Zygar said:
It's a plot device, but the accident isn't the attachment, it's the failure to detach. Someone thought that having a passenger jet lift the shuttle would save energy. Personally I doubt that any passenger jet in existence could generate the forward thrust necessary to lift the shuttle and itself at the same time. The fluid dynamics of that union are horrendous and would give me a headache.
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It only has to generate the forward thrust necessary to overcome the drag of itself and the shuttle. The wings generate the lift.

A 747, for example, has around a 17 to 1 Lift to Drag (L/D) ratio. So to maintain level flight, the thrust only needs to be around 1/17 of the aircraft weight. With more thrust than that, it can climb.

Using a jet to get a spacecraft above most of the atmosphere has some theoretical advantages (you don't have to carry oxidizer, for example).
 
I think we're forgetting something here, guys...

It FRAKKIN' SUPERMAN.

This is a movie who about a guy who can fly. Whose skin deflects bullets. Whose gaze can weld steel.

Why are we arguing about whether a fictional space shuttle in a fictional universe whose laws of physics are almost infinitely malleabe depending on the requirements of the action can actually do x?

Okay, yeah, I'm guilty of that kinda thing, too. :) But let's get some perspective!

Incidentally, Superman RULZ.
 
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TjW said:
It only has to generate the forward thrust necessary to overcome the drag of itself and the shuttle. The wings generate the lift.

A 747, for example, has around a 17 to 1 Lift to Drag (L/D) ratio. So to maintain level flight, the thrust only needs to be around 1/17 of the aircraft weight. With more thrust than that, it can climb.

Using a jet to get a spacecraft above most of the atmosphere has some theoretical advantages (you don't have to carry oxidizer, for example).
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It's not quite that simple. The issue is that when you attach two crafts together, you have to treat them as one craft. The combination of a 747 and the shuttle do not make an efficient aircraft. Perhaps I could go back and review the scene, but IIRC the shuttle and airplane in the movie are approximately the same size and the airplane is fully loaded with passengers and amenities. The actual NASA SCA is a gutted 777 which is about twice the size of a shuttle and has almost no extra weight, and it barely manages to tote an unfueled shuttle.

My point isn't that this is a bad way to lift the shuttle. Quite the contrary. My point is that the specific situation seen in the movie is patently absurd and the plane and shuttle would not fly.
 
I have to agree it's not real clear to me why you would have passengers along in the booster stage.
 
TjW said:
I have to agree it's not real clear to me why you would have passengers along in the booster stage.
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It was a PR stunt by a private spaceflight company like Virgin Galactic (in fact, if you pay attention you'll see Richard Branson and his son as pilots). There was a press conference in the carrier aircraft that Lois was attending. There weren't many people -- in fact, being the feisty dame she is, Lois commented on this, causing the company rep to bristle.

Dang it, ya'll are suckin' me in.
 
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