Walking the Planck

Max Planck, a German physicist who died in 1947, is regarded as one of the fathers of Quantum Theory – the branch of physics which deals with the tiniest packets of matter that have a kind of dual personality, behaving like both a wave and a particle. Its an intriguing world where nothing is certain and some things are impossible to measure.

Bearing his name is the concept of the 'Planck length'. This minute distance is the length at which we enter the quantum world and therefore is the smallest measure of length that actually means anything. Below this distance space, time, gravity and all of conventional physics dissolve away.

Following on from this is the 'Planck time'. This is the length of time it would take a photon of light to travel the 'Planck length' – and its 10 to the power of -43 seconds! In a similar way to the Planck Length any time less than this is effectively meaningless, for the reasons given above.

The Planck time has deep philosophical implications. It means that the Universe effectively 'began' at this age, this is actually when time began. It also means that we cannot be sure of anything that happened 'before'*. Therefore, any world view that depends on determining what might have occurred prior to the Plank Time is on very shaky ground.


* NB Even the word 'before' is inappropriate here. Its like asking whats south of the South Pole!

A 10 dimensional universe

Superstring theory calculates that the universe has ten dimensions. Very early on there was an amicable split. Four dimensions expanded and went on to produce the observable universe's space and time (3+1 dimensions). The other six shrivelled up so as to be invisible, although they still exist. As Dean Overman remarks in 'A case against accident and self-organization':

For the purpose of the formation of life, this split was fortunate, because carbon-based life could not exist in any other than three spatial dimensions. Gravity would not allow for stable planetary systems unless it functioned in three spatial dimensions because it follows an inverse square law which requires the force of gravity to decrease as distance increases. In four spatial dimensions, the force of gravity would fall to a fraction of one-eighth its power (rather than one quarter) for every doubling of distance, and in five spatial dimensions, the force would fall to one-sixteenth its strength for every doubling of distance. Moreover, in more than three spatial dimensions, the force of electromagnetism would not function in a manner which would allow for life, because electrons would either spiral away from or into the nuclei.

Lego DNA

The problems with trying to piece together a plausible mechanism for the origin of life multiply up. Its not just about thinking up possible scenarios where the various complicated molecules could be manufactured and thrown together. Scientists also have envisage a scheme that explains the origin of the whole system of genetic information with its unique language, replicating systems, translation devices.

This video provides a great animated version of what some of that entails. Looks like Lego DNA to me!

An Anthropic Biological Principle?

For a while now I've been wondering if there is a biological parallel to the Anthropic Principle in physics (i.e. that the universe has a number of physical properties that are fine tuned to a level that allows life to exist).

An example of this could be the properties of a chemical like DNA polymerase.

For evolution to occur organisms need to be able to replicate themselves exceptionally well, but not perfectly. If they are not good enough at this process then there is no hope of any useful genetic information being passed down from generation to generation. On the other hand if they are too good at it then there is no room for error – errors that have the potential to bring about innovation and thereby evolution.

One of the biggest players in this process is DNA polymerase. This clever piece of kit is responsible for the putting together of new DNA strands and even has the ability to proof-read the code as it goes along. This, together with other factors, means that the copying process is over 99.9% accurate - just right.

It would be interesting to know how bad this copying process could get and still be viable for life, but certainly there can't be much margin for error.

The meaning of 'bara'

I've come across this interesting paper on the meaning of the Hebrew word 'bara', which is often translated as 'created' in the Genesis 1 creation account.

The word is used selectively:

v1 In the beginning, God created the heavens and the earth.

v21 So God created the great sea creatures and every living creature that moves, with which the waters swarm, according to their kinds, and every winged bird according to its kind.

v27 So God created man in his own image, in the image of God he created him; male and female he created them.

Its interesting to ponder on why these aspects were selected for bara creation. Traditional lexical entries for the word have defined it as meaning 'to create or form' but this paper suggests that it is better rendered as 'to separate'. Van Wolde describes it as being:

... a temporal process in which God moves the objects along a path, at the beginning of which they are not distin- guished and proximate, and at the end of which they are spatially distant and kept separate

This difference is a significant one. I don't think it would be in keeping with the context of this chapter to force the meaning of the words to fit the physical creation processes (this approach nearly always ends up going wrong somewhere along the line), but rather to think about what spiritual messages this is giving us....

P.S A number of scholars and commentators disagree with this thesis. See here, for example.

Bad Religion

Last week there were a number of reports in the press of a debate between Tony Blair and Chris Hitchins on whether religion is a force for good in the world or not. Most accounts agree that Hitchins won the debate, indeed he has previously written at great length on the evils of religion (e.g. 'God is not good').

For those of us with a positive experience of religion it is not hard to see how distorted Hitchens' views are. He is more one sided than the Second Test in Adelaide, rarely giving any acknowledgement to the other side of the story (though ironically his younger brother, Peter, is a convert to christianity from atheism).

But, with a tip of the hat and a nod of the head to Heaven in ordinarie, I saw this quote from Charles Dickens' character 'the Ghost of Christmas Present'. It neatly describes the difference between good and bad religion, a difference which often parallels that between good and bad science.

‘There are some upon this earth of yours,’ returned the Spirit, ‘who lay claim to know us, and who do their deeds of passion, pride, ill-will, hatred, envy, bigotry, and selfishness in our name, who are as strange to us and all our kith and kin, as if they had never lived. Remember that, and charge their doings on themselves, not us.’

Life out of death

Perhaps Agatha Christie would have been intrigued by this piece of new research.

The chemistry of life revolves around six key chemicals. Carbon, oxygen, hydrogen, nitrogen, phosphorus and sulphur make up the major ingredients of many of our body's building materials.

However, from the bottom of a lake in California comes a bacteria that uses arsenic as a substitute for phosphorus. Arsenic has a similar size and charge to phosphorus which makes the switch possible and this in turn presents interesting discussion points. If phosphorus can be substituted then what else? Could there be an entirely different system of life out there based on different elements?

Whilst this is a genuinely novel discovery it is unlikely that it can be extended so far. For a start even this finding has its limits:

It is thought that downstream metabolic processes are generally not compatible with As-incorporating molecules because of differences in the reactivities of P- and As-compounds. These downstream biochemical pathways may require the more chemically stable P-based metabolites

This microbe probably represents the outer fringes of what makes up the biosphere, rather than the doorway into another world of possibilities.