June 20, 2011

The Evolving Universe

Dr Roger Hanson

Report by: Chris Sutcliffe & Mike Dryland

Dr Roger Hanson

This lecture was presented by Dr Roger Hanson who lives in New Zealand. Roger gained a 1st class honours degree in chemistry from Manchester University, and a PhD from Trinity Cambridge. He subsequently became a chemical engineer for Big Oil, designing industrial chemical plants. Roger asserts that there is a strong connection between chemical engineering and astrophysics, hence his extensive knowledge and propensity to muse about the Universe.

He began with the Hubble Deep Field, an image of hundreds of galaxies, and made the point that the Voyager spacecraft which travels at 18 km per second would take a thousand million years to cross just one of the galaxies. The Universe is a big place.

He reminded us that our special Universe has 19 separate fundamental physical constants – parameters of physics that we cannot derive from our theories or from other constants. The precise value of these constants determines key processes in the Universe like how quickly stars form and die. If any of the constants were different by even a tiny amount, the Universe would be a dramatically different place which almost certainly could not support life as we know it. The probability that the values of these constants have arisen by chance is 1 in 10229 (10 to the power of 229, or 1 followed by 230 zeros — please don’t ask how this one was worked-out!) The Universe seems to have been fine-tuned specially for us.

One way of rationalising this cosmic coincidence is by the ‘anthropic principle’ which can by summarised as “we’re here because we’re here ..”. If the Universe was unable to support life as we know it, we wouldn’t be around to wonder why. Taken in conjunction with the ‘multiverse’ hypothesis, we can surmise that all possible universes exist somewhen-where (in 11 dimensions), and here we are in the one that uniquely suits us!

Roger’s ‘what if’ speculation about all this (and Roger is careful to say it is speculation) is that our Universe is one result of an evolutionary process in which generations of new universes are spawned by Black Holes. This is where his insights from chemical engineering come in. Here’s roughly how his thinking goes (but if this isn’t clear it’s because our brains hurt, not his fault. Read Roger’s book!) —

One: to make anything, the following are needed —

Raw materials
Energy
Machinery
A set of instructions
The right conditions

These will give the desired product (eventually).

Two: The facts of life –

Life is a process in the same way. Life depends on proteins. The body has 10,000 proteins made of atoms and molecules all held together by the electromagnetic force — the subject of chemistry. Proteins are very fragile. The body is running a massive repair and maintenance programme as we lose 8 proteins a second. These are replaced. The function of life is to extract food to make energy to replace proteins.

There are two key instruction sets in the body —

How carbon atoms line up and bond
How DNA controls the formation and coupling of amino acids.

Three: Evolution —

Evolution comes about in organisms, through an instruction set slightly modified (mutated), forming the basis of variation and competition. Evolution depends upon being better at extracting food than the competition. One’s instruction set is different from one’s parents.

Right conditions – if the ambient temperature increased by 20 – 30%, the human race would not survive.

Four: The time/complexity paradox —

The longer the set of instructions, the quicker the answer. (To an ex-computer programmer, this statement has some resonance, but a stiff drink would help make it clearer). Evolution is the master-stroke — it took 2,800 million years to come up with a very long set of instructions for a human body, each of which is then constructed in only 9 months. (By contrast, the NHS will only need 100 million years to come up with a national IT system – Some mistake here, surely. Ed)

The living organism is in a league of its own in terms of its evolution and complexity.

To put things in perspective, the Wright Brothers flew 200 metres in 1903, and in 1969, the Boeing 747 took to the skies – one of the most complex achievements of the 20th century. The set of instructions for the Wright flyer was an A4 folder of 20 pages. The 747 is horrendously complex and required Boeing to develop CATIA and use oodles of computer power (must be a moral here somewhere…!)

Five: The Universe —

Again, the following are needed — Raw materials, Energy, Machinery, Set of instructions, the right conditions

These will give the product.

The raw materials came about at the time of the Big Bang but it is impossible to measure the precise location of the particles because of the speed (Heisenberg), and the minimum size which can be measured is 10 to the power of minus 35 metres (Planck). (Short lesson here – quantum mechanics in 5 minutes. If you think you know quantum physics, you haven’t understood it. I think Neils Bohr said that and he should have known).

Instruction set — the instructions for the universe deal with how particles interacted at the time of the Big Bang, and led to a set of equations with fundamental constants. Clear?

What of the machinery? Roger speculates that Black Holes are the factories creating new generations of universes. Remember Black Holes? The velocity needed for a body to overcome the gravitational pull of another larger body and not fall back to the surface, is the escape velocity. The escape velocity at the Earth’s surface is 11.2 km per second. A neutron star has a lot of mass in a small volume and its escape velocity is 150,000 km per second. The escape velocity for a Black Hole is greater than the speed of light – nothing can escape (just like the Spanish Inquisition).

Roger imagines that there could be a history of universes before ‘our’ Big Bang. Black Holes have off-spring — new universes. New generations of universe will be barren unless they contain Black Holes. Our universe is selected for Black Holes – hence the fine-tuning of constants. The multiverse is becoming increasingly complex over time and the process of evolution itself delivers increasing complexity and promotes Black Holes.

Just where are the off-spring universes we hear you shout? Somewhere-when! Luckily we need not be worried by the facts of what is happening inside Black Holes – nobody knows. Phew!

Confused? You should be!

The presentation was rounded off with a lively question and answer session (no kidding!), following which Roger signed copies of his book “The Cosmic Engine”. Roger’s talk was highly stimulating and strong views were expressed afterwards on both sides. How can each Black Hole receive enough mass/energy to spawn a new universe? What of the ‘missing energy’? Shouts of ‘cosmic snake oil!’ Well… it’s at least as plausible as the ‘standard model’ – the Big Bang and inflation. Such larks Pip lad! A worthy end to an excellent Flamsteed season.