This is a very interesting documentary. What if Earth was about to be destroyed? Not an Armageddon-type disaster, not just an asteroid or comet that could damage the ecosystem, but Earth itself (and the Solar System) getting utterly thrashed?
There's a serious effort to paint a realistic picture of an escape plan, and the pace is quite enjoyable. The film succeeds in conveying to the viewer the need to take care of many separate matters. This is not just about building a big ship and getting out of here. There are many issues to be resolved: propulsion, selection of destination, selection of passengers, ecosystem, impact of the construction on the world's economy, etc.
It should be pointed out however that, in order to create some drama and allow 75 years for the construction of the spaceship, some important sacrifices were made in terms of scientific accuracy. I was a bit surprised that, with so many astronomers consulted and testifying on camera, none had noticed that the premise was somewhat flawed:
The neutron star is in (almost) direct collision course with Earth, due to encounter it 75 years in. Surprisingly, the orbits of the planets don't get altered until the neutron star passes by and they're just pulverized by the star's gravity (Saturn's destruction is shown). Unless we're talking about a tiny fragment of a neutron star (and it's explicitly mention this errand is about 2 solar masses), its gravity would totally disrupt the entire Solar System without any need to get anywhere close to Earth. Planets would be swung out of their orbits way before any encounter. Actually, if it takes 75 years for the neutron star to reach Earth, and the first sign of it is a huge asteroid shower due to its gravity perturbation, one could assume that it has already reached a point near the Solar System (perhaps near the Oort Cloud) by then.
With this scenario, there would be no 75 year warning, no time for a ship to be built, hardly time for a prayer. The first sign of a neutron star coming close to us would be in fact a noticeable change in Earth's orbit (with the obvious climatic consequences). Not as spectacular on screen as a meteor shower, but far more scary and effective. Our planet would turn into a gigantic oven or a colossal freezer (or both, alternatively) that would kill all life on Earth before the first meteorites arrive, simply because gravity propagates at the speed of light, much faster than any asteroid shown in the film.
Physical inconsistencies continue with the depiction of the slow death of planet Earth, which is however somehow capable of sustaining life (despite some catastrophic events) until just a few years before the deadline.
Another aspect that was poorly explored was: when would the decision been made to build the ship? After all, if the neutron star isn't schedule to arrive until 75 years from now, this generation might just choose to ignore a danger that would not arise during their lifetimes. Would 2 generations sacrifice their economy and comfort to save the unlucky last one? It may sound selfish, but that's unfortunately the way many humans think.
And what about social unrest? It's just barely mentioned during the documentary, but it would be the biggest threat to the project. It's easy to envision a scientist dedicating his life to the project in the first decades, but what about those in the last 10-15 years? Would they just keep working as usual, despite the fact that their family would die soon? What would they think about working in a project to save 250,000 lives, and not having a chance of their families to go as well? And what about the millions of assistants, general workers, security guards, all in that complex? Even outside the project, all human activity in the last few years would need to be dedicated to the starship. Would you work tirelessly in a project to save a few from certain death, and then go home and look at your child knowing that he will not be part of those few?
From this long review, it's clear that the premise of the documentary is a great catalyst for a long discussion involving scientific, social and philosophical questions.
There's a serious effort to paint a realistic picture of an escape plan, and the pace is quite enjoyable. The film succeeds in conveying to the viewer the need to take care of many separate matters. This is not just about building a big ship and getting out of here. There are many issues to be resolved: propulsion, selection of destination, selection of passengers, ecosystem, impact of the construction on the world's economy, etc.
It should be pointed out however that, in order to create some drama and allow 75 years for the construction of the spaceship, some important sacrifices were made in terms of scientific accuracy. I was a bit surprised that, with so many astronomers consulted and testifying on camera, none had noticed that the premise was somewhat flawed:
The neutron star is in (almost) direct collision course with Earth, due to encounter it 75 years in. Surprisingly, the orbits of the planets don't get altered until the neutron star passes by and they're just pulverized by the star's gravity (Saturn's destruction is shown). Unless we're talking about a tiny fragment of a neutron star (and it's explicitly mention this errand is about 2 solar masses), its gravity would totally disrupt the entire Solar System without any need to get anywhere close to Earth. Planets would be swung out of their orbits way before any encounter. Actually, if it takes 75 years for the neutron star to reach Earth, and the first sign of it is a huge asteroid shower due to its gravity perturbation, one could assume that it has already reached a point near the Solar System (perhaps near the Oort Cloud) by then.
With this scenario, there would be no 75 year warning, no time for a ship to be built, hardly time for a prayer. The first sign of a neutron star coming close to us would be in fact a noticeable change in Earth's orbit (with the obvious climatic consequences). Not as spectacular on screen as a meteor shower, but far more scary and effective. Our planet would turn into a gigantic oven or a colossal freezer (or both, alternatively) that would kill all life on Earth before the first meteorites arrive, simply because gravity propagates at the speed of light, much faster than any asteroid shown in the film.
Physical inconsistencies continue with the depiction of the slow death of planet Earth, which is however somehow capable of sustaining life (despite some catastrophic events) until just a few years before the deadline.
Another aspect that was poorly explored was: when would the decision been made to build the ship? After all, if the neutron star isn't schedule to arrive until 75 years from now, this generation might just choose to ignore a danger that would not arise during their lifetimes. Would 2 generations sacrifice their economy and comfort to save the unlucky last one? It may sound selfish, but that's unfortunately the way many humans think.
And what about social unrest? It's just barely mentioned during the documentary, but it would be the biggest threat to the project. It's easy to envision a scientist dedicating his life to the project in the first decades, but what about those in the last 10-15 years? Would they just keep working as usual, despite the fact that their family would die soon? What would they think about working in a project to save 250,000 lives, and not having a chance of their families to go as well? And what about the millions of assistants, general workers, security guards, all in that complex? Even outside the project, all human activity in the last few years would need to be dedicated to the starship. Would you work tirelessly in a project to save a few from certain death, and then go home and look at your child knowing that he will not be part of those few?
From this long review, it's clear that the premise of the documentary is a great catalyst for a long discussion involving scientific, social and philosophical questions.