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I thought I'd comment on Stephen Hawking's interview with the BBC from earlier in the month, summarised in this BBC news article:
Hawking castigates Donald Trump for supposedly putting Earth on a path where the atmosphere turns into something like conditions on Venus as a result of pulling the USA out of the Paris climate agreement:
""We are close to the tipping point where global warming becomes irreversible. Trump's action could push the Earth over the brink, to become like Venus, with a temperature of two hundred and fifty degrees, and raining sulphuric acid," he told BBC News.
"Climate change is one of the great dangers we face, and it's one we can prevent if we act now. By denying the evidence for climate change, and pulling out of the Paris Climate Agreement, Donald Trump will cause avoidable environmental damage to our beautiful planet, endangering the natural world, for us and our children.""
The Czech physicist blogger Luboš Motl does a pretty good debunking job on this particular assertion in a blog post called "Venus and Hawking's scientific illiteracy":
Lubos Motl debunking
In another part of the news article, Hawking suggests that the Earth is doomed, and the best hope for the survival of the human race might be to set up independent colonies in space:
"When asked whether he felt we would ever solve our environmental problems and resolve human conflicts, Prof Hawking was pessimistic, saying that he thought our days on Earth were numbered.
"I fear evolution has inbuilt greed and aggression to the human genome. There is no sign of conflict lessening, and the development of militarised technology and weapons of mass destruction could make that disastrous. The best hope for the survival of the human race might be independent colonies in space.""
Hawking has been making this point a few times in interviews over the past year or so. A pretty good debunking of this idea is given in this Forbes article called "Sorry Nerds, But Colonizing Other Planets Is Not A Good Plan":
colonising planets debunking
In another part of the news article, Hawking claims Brexit will be bad for British science:
"And on Brexit, he feared UK research would be irreparably damaged.
"Science is a cooperative effort, so the impact will be wholly bad, and will leave British science isolated and inward looking"."
It depends what you think "British science" is. To me "British science" sounds like an activity that is mostly carried out by native Brits. To Hawking "British science" is probably international science, carried out by people with a world citizen mentality, and without any specific British flavour, that happens to be hosted in the UK. I suspect that if you asked UK taxpayers what they expected to get out of their money being spent on funding scientific research, it would be a) some sort of economic return, b) if nothing else, some sort of kudos or 'soft power' for the UK. In the case of Hawking's field of scientific research, an economic return is unlikely - for example Hawking identifies his greatest achievement as the not particularly useful discovery that 'black holes are not entirely black'. At first sight, it looks like the UK is getting a significant soft power benefit from Hawking as he is the probably the world's most famous scientist (as far as the mainstream media is concerned), and he is British. But is Hawking recognised as being British in the rest of the world? In the USA, I believe a lot of people think he's American because his speech synthesiser has an American accent, and that might apply in other countries as well. Hawking could use a speech synthesiser which has a British accent (they are available), but he prefers to keep the original one with the American accent - it probably helps with his book sales in the USA. So British science may not actually gain any benefit from Hawking's fame, if people around the world don't realise that he's British.
Stephen Hawking's enthusiasm for the idea of mankind colonising other planets looks like it is being heavily indulged by the BBC in the form of a new two part TV documentary that is to be broadcast this year:
"Expedition New Earth
Professor Stephen Hawking thinks the human species will have to populate a new planet within 100 years if it is to survive. With climate change, overdue asteroid strikes, epidemics and population growth, our own planet is increasingly precarious.
In this landmark series, Expedition New Earth, he enlists engineering expert Prof Danielle George and his own former student, Christophe Galfard, to find out if and how humans can reach for the stars and move to different planets.
Taking in the latest advances in astronomy, biology and rocket technology, they travel the world in search of answers. From the Atacama desert to the wilds of the North Pole, from plasma rockets to human hibernation, they discover a whole world of cutting edge research. The journey shows that Prof Hawking’s ambition isn’t as fantastical as it sounds – that science fact is closer to science fiction than we ever thought.
Expedition New Earth a 2x60' for BBC Two is a Brook Lapping production, in partnership with The Open University. The Series Producer is Lucy Haken and the Executive Producer is Greg Sanderson. The BBC Commissioning Editor, Science, is Diene Petterle."
This may explain something that the Forbes article (that I linked to in my previous post) was puzzling about. Previously Hawking has been talking about a timescale of a thousand years for mankind to colonise another planet, but this year the timescale has mysteriously dropped to only a hundred years. The 100 year period looks a lot more urgent, and might be a much more suitable timescale for the purposes of making a TV documentary.
I don't think this documentary has been broadcast by the BBC so far this year, as Im pretty sure I would have noticed it.
The first step in achieving this objective of establishing "independent space colonies" would be to set up a moon base, a development which was assumed to be almost certain to happen back in the days of the Apollo moon landings. A moon base is not likely to be very independent, but it would be an essential starting point for the general idea of setting up space colonies. But since the 1970s NASA has been reduced to, as one of Donald Trump's advisers put it, "a logistics agency concentrating on space station resupply and politically correct environmental monitoring", and US Democrat politicians in particular seem to prefer to keep it in its current state.
If Hawking wants the independent space colonies idea ever to materialise he would in my opinion have to encourage his large army of nerd followers in the USA to vote for Republican presidents, as they tend to be much more favourably disposed to the idea of setting up a moon base than the Democrats.
I vaguely remember George W Bush talking about establishing a moon base a decade ago, but my guess would be that it must have been subsequently killed off by Obama. A quick bit of Googling confirms my suspicion after finding this news article from 2010:
Obama cuts moon base
Obama cut off the money for Bush's moon base project and just spent more money on the International Space Station.
The documentary featuring Stephen Hawking that I referred to in my previous post was broadcast on BBC2 earlier this week. I'm not sure what has happened to the idea of it being broadcast in two parts, it seems to have been just one documentary film that lasted 90 minutes. Hawking was only on screen for a total of about two minutes out of the 90 minutes. I suspect that the documentary will be uploaded to YouTube within the next few weeks.
For people who didn't see the documentary, this article gives some idea of its content:
article on documentary
I was expecting the documentary to include a sizeable chunk of doomsayer material putting forward the case for why we had to find a replacement for Earth in the next hundred years, but thankfully that sort of material was absent.
Hawking seems to think the most suitable planet for a new Earth would be a recently discovered planet called Proxima B which orbits the closest star to our Sun, Proxima Centauri, a red dwarf star that is 4.2 light years away. Virtually everybody else would pick Mars in our own solar system as being the best available candidate. It is not currently known whether Proxima B is habitable, but Wikipedia suspects that it isn't habitable:
"Proxima Centauri b orbits the star at a distance of roughly 0.05 AU (7,500,000 km; 4,600,000 mi) with an orbital period of approximately 11.2 Earth days, and has an estimated mass of at least 1.3 times that of the Earth. Its habitability has not been established, though it is unlikely to be habitable since the planet is subject to stellar wind pressures of more than 2,000 times those experienced by Earth from the solar wind."
One thing that I expected in this documentary, given that a left wing, CND supporting scientist like Hawking was lending his name to the documentary, is that it would only promote politically correct forms of rocket technology, and it did. It only talked about plasma rockets, and talked up some light propulsion technology where tiny spacecraft (the size of a SIM card) are propelled by an array of laser beams to about one fifth the speed of light in order to do a reconnaissance mission of the Proxima B planet. Back in "The Space Age" (the 1960s and 1970s), it was regarded as a 'no-brainer' that the next generation of rockets would be nuclear powered, but the powerful Green lobby that emerged in the 1970s effectively killed that development off. Nuclear powered rockets were talked about as recently as ten years ago in connection with Bush's ill-fated moonbase project (the moonbase project was subsequently killed off by Obama) as mentioned in this Register article from 2007: