Film of 2007 directed to Danny Boyle, the seventh in his director career. In this film eight astronauts travel to the Sun in the “Icaro II” spaceship. The before mission call “Icaro” failed and they are the last hope to the humanity. The mission is launch a nuclear weapon to the Sun for reactivated it and to save our cold planet.
Again a nuclear explosion (in this time as big as Manhattan island) to resolve the problem. This is a repeat solution used in many films: The Core, Armaggedon, ID4, etc.
After this brief film resume, we going to introduce in the Science to understand and to refuse of this film.
The Sun is made up for Hydrogen (H), in the nucleus two atoms of H fusion in an atom of Helium (He) producing a high amount of energy. The real process of fusion is a range of reactions more complex. This fusion is produced because the high pression and temperature in the nucleus, about 15 million ºC. The rate of H consume in the Sun is 4 million Tm for second and in 5000 millions of years the H will run out.
Now, we going to know how the film use this information.
The film is set in a future not concreted, but this same set is not for an expected world in 5000 million of years.
How in the film do not say the year, we will restrict that the Sun is turn off in a next future for an unknown cause.
Then, we come a new question…
How is turn off the Sun?
When all the H is consumed in the nucleus, these can not be replace with H of superior layer because the high pressure and the formed He acts as a barrier.
Accordant the emission energy down, the star become to contract, the temperature increase and the H around the inert nucleus start to fusion. When this happens, the energy liberation push the superior layers increasing the diameter hundred of million of kilometers. This expansion will cold the external layers transforming the star in a red giant. In this growing up process, the sun will gobble Mercury, Venus and Earth; for this, there will not a planet for launch a spaceship to save us.
In the film
Our star, the Sun, will never turn off as a low batteries lantern; It is a more complex process. Also, the transform of the Sun in a red giant will swallow Mercury, Venus and the Earth; for this there will be no planet to send a mission. Avoiding this so annoying of a scorched planet, we accept this act in the film.
The actor Cillian Murphy is the Physic who have to launch the bomb, in a conversation Cillian says “We have to collect all fissile material in the Earth to make the bomb”, but the spaceship is “Icaro II”, Did they know that the first mission will failed and for this they save fissile material for future missions?
Well, go to explain the mission. The bomb have to lunch through the south pole of the sun. Assuming that the bomb arrives (look the high pressure and temperature there), what will happen with a nuclear explosion inside the sun?. Well, we do not know; but I think that will not reactivate the sun.
The fission process consist to bomb a fissile material with neutrons, when the material breaks liberate a high amount of energy. The products of the fission are two heavy nucleus and more neutrons that continue with the same process of fission; this producing a chain reaction. To resume, we produce energy, heavy nucleus and neutrons.In the fission, the liberate energy is more lower than the fusion process. We can see that the consume of hydrogen in the sun is enormous, so that the radiated energy is very high comparing it with any nuclear weapon.
It will impossible reactivate the sun with a nuclear weapon, however large it may be.
The light of the sun
At the final of the film, the principal actor says to somebody in the earth: “If the mission end successful, you will know after eight minutes. This is the time that the light arrive to the earth from the sun”. It is totally real, but from the surface of the sun. As we have seen, the photons are produced in the nucleus, not in surface, and they need to travel 700000 kilometers for arrive to the surface. To make this travel, the photons need hundreds of millions of years because the continuous shocks with the particles (hydrogen, helium) prevent.
Well, here a short example to how this film use the Science, but wrongly.