Why is the universe finely tuned for life?

If any the fundamental unitless constants of the Universe were only slightly different in any direction, no life of any kind would form; the entire universe would be a uniform structureless mass. What can account for this fine-tuning of our universe, if not the hand of a creator God?

See here for a detailed exposition of this argument.

I don’t buy it, but I’d like a snappier comeback!

Posted: November 4th 2007

bitbutter www

Because we’re living animals, we’re tempted to think the capacity of a universe to give rise to life (as we know it) is somehow special in an absolute sense, and in need of explanation. That’s an unwarranted assumption. Here’s a similar question that you might find useful.

Posted: April 1st 2010

See all questions answered by bitbutter

flagellant www

I recently watched a programme about the Dover trial and I’ve had enough of Intelligent Design, née Creationism; it is totally vacuous. Instead of your link, I’ve referred to more reputable sources for what I hope will be a snappy answer. First, some background information about the nature of the argument

In the middle ages, lives were governed by the behaviour of an unpredictable and vicious god. He would punish humanity with disease, earthquakes, volcanoes, and storms. The poor people knew no better. This is an example of the 'God-of-the-Gaps’ argument – 'God’ explained everything that couldn’t be explained otherwise at the time. Now, we know much better.

This is the Creationist method: look for something where science hasn’t a generally accepted answer – a 'gap’ – then say 'God did/explains it’. However, with the advance of science, there are fewer and fewer gaps into which this ludicrous nonsense can insinuate itself. The relationship between the cosmological constants is one gap of sorts but there are refutations of 'Goddidit’, now. Here’s the shortest:

The Universe (including the Earth) and its constants are not fine-tuned for life and humanity; instead, life and humanity, through evolution, are fine-tuned to the Universe (especially the Earth) as it is.
That’s why the current search for extra-terrestrial intelligence is looking for planets near other stars with similar characteristics to our own. We look for life where it might have arisen because the conditions suit it.

An analogy demonstrates error inherent in the argument. It is like saying that the sun radiates light, which falls on the Earth, so that we can see where we’re going. That’s codswallop: the human eye evolved to be sensitive to light from the sun.

There are additional answers involving theoretical physics but they’re not so snappy!

When there are problems, the proper scientific position is to say 'We don’t know but we’re working on it’. Accepting 'God’ as an explanation with no evidence – and there never is – is intellectually lazy.

Posted: December 5th 2007

See all questions answered by flagellant

SmartLX www

Many things could account for this supposed fine-tuning (I don’t like the phrase, as it pre-supposes a tuner). Some of them are exotic, but none more exotic or unlikely than a prior perfect intelligent being.

  • A multiverse: there are many universes, either concurrent or sequential, each with different values of those constants. We came to be in this universe because it’s one of those in which we are possible.
  • Other points of equilibrium: adjusting the constants by tiny amounts could be the wrong approach. If their current amounts form an unstable equilibrium, of course a small tweak them will screw things up. Maybe instead you’d need to drastically alter five of them, all at once.

(Given that the constants might have any value at all, some even negative, we have an infinite six-dimensional sample space with which to experiment. I doubt we could rule out the whole thing except for our own universe’s co-ordinates.)

  • Inevitability: It may not be possible for the constants to have any other value. It’s possible that the constants are dependent on each other or a common value, and different results are as impossible as 2+2 = 7, or pi = 6.

Though the following is not an explanation, I would also add that if a creator fine-tuned the universe for life, it would have made the whole thing a lot more hospitable. Giving us only Earth out of the whole universe is like buying a man a Big Mac and then breaking him off a piece of lettuce too small to see.

I don’t see “why is the universe ideal for humans” as being any more convincing than “why is there a universe at all”. The god explanation demands an even more outlandish explanation for the god, which nobody will provide.

Posted: December 3rd 2007

See all questions answered by SmartLX


Richard Dawkins discusses several variants of the multiverse theory which is presented as an alternative explanation to positing God as the reason for the fine tuning of the universe. In The God Delusion (pp 145-147), he writes: ... that there are many universes, coexisting like bubbles of foam, ... (p. 145).

The anthropic principle (our universe exists because it is the one that makes it possible for us to exist, else we would not be here) serves as the reliable framework in which one can then focus on the improbability of the God solution: ... any God capable of designing a universe, carefully and foresightfully tuned to lead to our evolution, must be a supremely complex and improbable entity who needs an even bigger explanation than the one he is supposed to provide… (p.147).

Dawkins goes on to say: The multiverse may seem extravagant in sheer number of universes. But if each one of those universes is simple in its fundamental laws, we are still not postulating anything highly improbable. The very opposite has to be said of any kind of intelligence.

EDIT: For a snappier response to why do six finely tuned constants (or knobs) exist, try this quote from Richard Dawkins (p.144, The God Delusion): Far from God being needed to twiddle six knobs, there are no knobs to twiddle.”

Posted: November 4th 2007

See all questions answered by logicel


Is your atheism a problem in your religious family or school?
Talk about it at the atheist nexus forum