Starmus Festival Final Session

The final session of Starmus 2014 involved talks from Alexi Leonov and Stephen Hawking.

Alexi Leonov, a soviet cosmonaut and the first man to walk in space, spoke about the soviet space program and why, eventually, they did not land men on the Moon.

However he started by paying tribute to Neil Armstrong and expressing his surprise that he had never been awarded a Nobel Prize for his unique achievement of being the first man on the Moon. Armstrong can never now receive a Nobel Prize bcause they are not awarded posthumously but it is Leonov’s view that the achievement can still be marked by awarding he Nobel Prize  to the two remaining Apollo 11 astronauts, Buzz Aldrin and Michael Collins.

He then turned his attention to the soviet space program.  Starting with the decree issued by the central committee of the communist party in 1962 that the Soviet Union should aim to send a man to the Moon and return him safely by 1968. At this stage it was not even known if people could survive and work in the vacuum of space. To resolve this problem the Voshkod program was initiated which saw Yuri Gagarin’s first flight in space and then Leonov’s own first spacewalk. Despite the problems he had getting back into the spacecraft he reported that working in space was perfectly feasible and so the program moved into its next stage.

The Voshkod capsule was further developed to become the Soyuz capsule which, ironically, is now the only manned space vehicle in service and is used to get astronauts of all nations to and from the International Space Station.

They had less initial success with their rocket system however. The Proton rocket was a monster. It had 30 engines each developing 150 tons of thrust. It was so powerful that it repeatedly destroyed the first stage of the rocket and so was unable to achieve orbit. By comparison the Saturn rocket developed by the Americans used a much lower pressure system and worked well. In the longer term the problems with Proton were resolved and they went on to sell 20 of them to the USA ( I assume he is talking about the R180 engines but the translation was not clear on this point).

The program the Soviet Union had developed envisaged sending only a single astronaut on each flight to the Moon rather than the three who went on each of the Apollo missions. The most difficult part of the mission would be choosing the actual landing site. Whilst the Apollo astronauts had 30 seconds to make their choice the Soviet astronaut would have precisely 2.53 seconds to make their choice which, after tests he had conducted himself, he believed to be adequate. Given he was likely to be the first person to have to do this you can only admire his confidence.

However, it would appear, that the problems with  the Proton rocket together with the death of their chief rocket scientist, Korolev, led to the end of the attempt at a manned landing and led to unmanned missions, soil sample return missions and the two Lunakhod rover missions.

The first soil return samples showed a 1% water content in the samples. Later they discovered 600 million tons of water at the bottom of a crater on the north of the Moon. Much more data was secured from the Lunakhod missions.

The final point he made was a comparison of costs. The Soviet Union spent $2 billion  on Lunar missions whilst the Apollo missions cost $20 billion. I get the distinct impression he was not dissatisfied with the return they got.

The final Starmus talk was given by Stephen Hawking on the subject of the quantum nature of Black Holes.

He started by outlining the process for creation of a black hole through the collapse of a massive star pointing out that a Star of 10 times the mass of the Sun would collapse to a black hole with a Swartzchild radius of only 30 kms.

He also pointed out that, the early Universe black holes may well have formed from the collapse of the hot interstellar medium with these black holes being tiny with radius of about the size of a proton.

On the basis of classical physics nothing can escape a Black Hole because the escape velocity at the event horizon is the speed of light. However quantum mechanics, in particular the Uncertainty Principle, says that things are not that simple and this led in due course to the discovery that some radiation can escape in the form of Hawking radiation. He offered two explanations of how this happens.

The first depends on the creation of matter/anti matter pairs which normally form and self destruct very quickly. However it may be that one of the pair gets caught by the gravity of the event horizon whilst the other does not so one of the pair escapes. The second explanation is based on viewing one of the particles as travelling back in time until it meets the other particle.

The discovery of Hawking radiation was important because it allowed for Black Holes to achieve thermal equilibrium at a temperature other than absolute zero and therefore not breach the first law of thermodynamics.

As a result of this all black holes will, in the absence of new material, evaporate over immense periods of time. However Hawking radiation is random in nature and this means that the information which initially fell into the black hole appears to be lost. This breaches the principle of determinism which in turn means that not only can we have no chance of knowing the future but the past becomes random as well. The solution to this problem is found by applying Richard Feynman’s sum over all histories approach to quantum mechanics. Put another way. If you burn an encyclopaedia but keep all the smoke and ashes you have not lost any of the encyclopaedia’s information it is just very very difficult to reconstruct the information.

So all in all Black Holes are not as black as you may have thought. And on that slightly mind bending note Starmus ended.

 

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