Day 3719: Stars

Tuesday:


My mum died and the universe ended.


We are made of stardust.

In the Doctor Who episode "The Big Bang" there is a Richard Dawkins who believes in stars even when there are none in the sky.

But our Professor Richard Dawkins, in his book "The Ancestor's Tale", says:

"It's hardly surprising that we see stars when we look up into the sky at night, because stars are a necessary prerequisite for organisms that see."

He means that the elements necessary for life – carbon, nitrogen, oxygen – are only created through nuclear fusion, and thus only in stars.

So the evidence of our own existence requires that there must be stars, even if we do not see them.

So the Richard Dawkins in the story is not a blind believer but a rationalist who has inferred the stars' existence from the very fact that we are here at all.


Listening to the 500th "In Our Time", Melvyn Bragg and his guests, philosophers all, discussed free will and spent the better part of forty minutes trying to find different excuses for why determinism doesn't rob us of choice.

Determinism is the belief that given any one arrangement of physical space, the laws of physics determine that there is only one possible thing that can happen next. If that's true, then even the atoms that make up our brains, the patterns of electrons that describe our thoughts among the neurons and axons, are just one "arrangement" and physics determines what will happen next: what we think, what we do is determined by simple physical laws and any experience of choice is an illusion generated by the chemistry, our "will" no more than along for the ride.

Obviously, this presents a huge problem for morality: if we truly have no choices then how can it be fair to judge anyone by their actions? Yes, yes we would have no more choice about whether to punish or not and the punishment itself would be inevitable – but suppose you believe in a god outside of the laws of space and time: how could it be moral for such a god to set up a deterministic universe and then judge people to heaven or hell based on actions they cannot control?

But that can't be right, can it?

I believe in free will. And I believe that even if I'm wrong, I have no choice but to believe in free will. But I see the universe as intersecting matrices: space and time; matter and energy; observation and awareness. In Quantum Mechanics, in the Copenhagen interpretation, all possible outcomes of quantum event occur simultaneously in multiple "superposition states", all stacked up – super-positioned – on top of each other and our observation collapses this into a single state that we see, without necessarily disturbing the others.

If our awareness, our continuous observation of our own existence, our long reiteration of "I think therefore I think I am", if that means anything then it means we can and do choose the quantum superposition states that we observe.

We can, with our actions and choices, change the universe, even it is only the universe that we ourselves are aware of, passing like ghosts along one path through the myriad observable superposition states.




In another Doctor Who episode, "Utopia" by Russell Davies, the TARDIS carries the Doctor, and Martha – and Captain Jack clinging to the outside – to a hundred trillion years into the future, to the End of the Universe.

That's almost right. We live in the Stelliferous Era: the Age of Stars. And in a hundred trillion years the Stelliferous Era will come to an end as the last stars go out.

In his "Wonders of the Universe", Professor Brian Cox took us there too. He presented us with the Heat Death of the Universe as an inevitable consequence of Entropy, the scientific measure of disorder, and the Second Law of Thermodynamics: "In a closed system, entropy increases". Or as it has been satirised: "Things Can Only Get Worse".

That's bleak, very bleak, and not a little controversial – it is by no means a certain thing that the Universe will end that way.

In a nice simple universe, the Big Bang scatters matter in all directions and gravity tries to pull it all back together. If there is enough mass in the universe, then eventually gravity stops all the bits from flying apart and pulls them back into a Big Crunch, a reverse Big Bang that ends the Universe as it began in a fiery cremation of all matter, energy and time; if there isn't enough mass then things just expand into the cold and black forever.

Astonishingly, the amount of matter in the universe – the stuff we can see and the so-called dark matter that we have to guess must be there from the way the rest of space moves – is right on the borderline between being just enough to stop the acceleration and not quite enough to stop it going forever.

But whatever happens, that expansion should gradually slow down and slow down under the pull of gravity.

Except that's not what we observe. The expansion of the universe actually appears to be accelerating.

So we DON'T live in a simple universe; and until we have any idea what the "Dark Energy" powering the acceleration is, all bets are off.

The law of entropy, that Second Law of Thermodynamics, means – says Professor Cox – that nothing is forever.

But that's not right, is it.

Not even nothing is forever.

Quantum Mechanics tells us that particles can just happen, appearing out of nowhere in matter/anti-matter pairs. In our busy universe of stars and matter they almost always collide and vanish again. Almost always. But who knows what the rules are for a cold, empty universe, trillions upon trillions of years after the last stars. Our universe began in a single point of time and energy bursting into existence: everything from nothing. Perhaps that is how the next universe will begin.

Not even nothing is forever; there is always, always something new.

I believe in hope and I believe in choice and I believe in life.


Mum is with the stars now.
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