Superman Returns Phyics *SPOILER*

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SUMMARY

The forum discussion analyzes the physics behind Superman lifting Lex Luthor's landmass into space in "Superman Returns." The estimated volume of the island is approximately 1.7e12 cubic meters, with a mass of 4.3e15 kg, requiring around 2.6e23 joules of energy to achieve escape velocity. This energy expenditure is equivalent to the detonation of approximately 4.4 billion Hiroshima bombs. The conversation also touches on the implications of Superman's energy source and the structural integrity of the island, suggesting that it may be made of Kryptonian material, which is stronger than earthly materials.

PREREQUISITES
  • Understanding of basic physics concepts, including energy and mass calculations.
  • Familiarity with escape velocity and its implications in physics.
  • Knowledge of material science, particularly the properties of Quartz and Kryptonian crystals.
  • Basic comprehension of cinematic physics and its portrayal in superhero films.
NEXT STEPS
  • Research the physics of escape velocity and its calculations.
  • Explore material science related to the properties of Quartz and Kryptonian materials.
  • Study the concept of energy equivalence in explosive events, such as comparing joules to Hiroshima bomb energy.
  • Investigate the portrayal of physics in superhero films and its impact on audience perception.
USEFUL FOR

Physics enthusiasts, film analysts, and anyone interested in the scientific accuracy of superhero narratives will benefit from this discussion.

Quaoar
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OK, I'm giving away the ending, so don't say I didn't warn you...At the end, Superman lifts Luthor's new landmass into space. I did some rough hand calculations to figure out how much energy Superman had to use to lift the island into space. Judging from the scale presented in the movie, I'm estimating the island was roughly 5 miles in radius, 5 miles thick. This yields a volume of pi * 5^3 ~ 400 cubic miles = 1.7e12 cubic meters. Given that the island appears to be made of a material similar to Quartz, with a density of 2600 kg/m^3, this gives us a total mass of 4.3e15 kg. Escape velocity at the Earth's surface is 11,000 m/s.

Assuming that Superman accelerated the object to not much more than escape velocity, that gives us 1/2 * 4.3e15 kg * (11000 m/s)^2 = 2.6e23 joules. Hiroshima was 6e13 joules. So this act is equivalent to exploding about 4.4 BILLION Hiroshima bombs!

Anyhow, just thought I should share... :)

Edit: Whoops, forgot to square the velocity.
 
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I guess that's why he's called superman :)
 
On some tv channel, I think national geographic or something, they will have a special on the crappy physics in that movie and how some of the people he "saves" would be far more hurt by him catching them the way he does than them falling to the ground and stuff like that. I can't wait to watch it...
 
Supermans energy source is the sun of krypton not awesomeness I believe. This is true in the old Reeve films however in the New adventures and Smallville it is in fact our own sun that is the source of his power.

Anyhoo...
 
moose said:
*EDIT* did you forget to square your velocity? if so, the answer is 2.6e23 joules and 2 892 890.15 kilograms of awesomeness used

Oops. Fixed.
 
Kurdt said:
Supermans energy source is the sun of krypton not awesomeness I believe. This is true in the old Reeve films however in the New adventures and Smallville it is in fact our own sun that is the source of his power.

Anyhoo...

This is still true in the movie, though the amount of energy he expends would take a LOT of sunbathing to collect...
 
Yes i was thinking that.
 
If he gave it Earth escape velocity, unless he's planning on visiting this landmass in 1/2 of its solar orbit to give it a perihelion boost, he just inserted a a huge asteroid into an Earth-crossing orbit. It would definitely make the list of PHAs (potentially hazardous objects).

As long as he's immortal, and as long as he doesn't plan on abandoning Earth again (that is the theme of the movie, right? He returns after an absense) we'll be ok.

BTW. Wouldn't he be more likely to punch a hole through the island, rather than lift it? I can't lift a pillow with the tip of a pin.

I can't wait to see the movie.
 
  • #10
tony873004 said:
Wouldn't he be more likely to punch a hole through the island, rather than lift it? I can't lift a pillow with the tip of a pin.

Well, the island kinda crumbles a bit as he lifts it, but not as much as you'd imagine. It's not an Earthly material though, so it might be extra strong.
 
  • #11
Guillochon said:
...It's not an Earthly material though, so it might be extra strong.
Sorry, I forgot to take that into account :-p
 
  • #12
tony873004 said:
Sorry, I forgot to take that into account :-p
Isn't a large enough portion Earth-made, so that it wouldn't have the necessary integrity?
 
  • #13
The raw material must come from Earth, but it's a Kryptonian crystal, so it's structure would be extra-strong, nigh indestructible. But he wouldn't have to accelerate it to escape velocity from the surface, as he lifts it up into orbit first. Same amount of total energy expended on his part, but he would be able to spread out it's expenditure a bit.

*Another Spoiler*: My problem with the movie came at the end when Kitty dropped the crystals onto the island. They'd quite likely fall into the ocean, no? Maybe not necessarily. But if they did, that would just make the problem a lot worse.
 
  • #14
BoTemp said:
The raw material must come from Earth, but it's a Kryptonian crystal, so it's structure would be extra-strong, nigh indestructible. But he wouldn't have to accelerate it to escape velocity from the surface, as he lifts it up into orbit first. Same amount of total energy expended on his part, but he would be able to spread out it's expenditure a bit.

He appears to only lift the island a couple hundred miles above the Earth's surface before letting go (He starts reentry shortly afterwards). The escape velocity difference between being on Earth's surface and a couple hundred miles away from Earth's surface is neglible, so we can treat it as if he expended all the energy at the surface.

BoTemp said:
*Another Spoiler*: My problem with the movie came at the end when Kitty dropped the crystals onto the island. They'd quite likely fall into the ocean, no? Maybe not necessarily. But if they did, that would just make the problem a lot worse.

Well, the crystals are on the island Superman gets rid of. Some chunks fall off, but I guess we are to assume that the crystals are able to hang on for the ride...
 
  • #15
I hate to necropost, but this is the most appropriate thread for the question that's been bugging me.

Luthor said something to the effect that crystals mimic the properties of their environment. I don't see anything at Wikipedia that supports this. Perhaps license taken by the writers?