Bad Astronomy

I object!

I was recently involved in a discussion of post-modernism and relativism that started when a commenter on my blog tried to support how astrology can be true and then continued when I posted on Twitter about it. I wrote:

The human condition is relative from human to human and culture to culture. But there are scientific truths outside and independent of us.

I thought my meaning was clear. What might be moral in one culture may not be in another, and in many cases that’s OK. Cultures are different. But in the objective reality of the Universe, such relativism may fall apart. Physical laws have an objective reality; we may interpret them, but they continue to do what they do whether our interpretation is correct or not.

This led to a discussion of the meaning of things, and that I think is the important issue.

A follower on Twitter said:

Gravity may well exist. But if we can’t describe it, it’s hardly objective. And we can’t possible know it’s [sic] meaning.

I think this is completely wrong. It’s objective whether we can describe it or not. Gravity exists. Since the Earth has been orbiting the Sun for 4.55 billion years – a good 4.549 billion years before humans were around – we can be pretty sure gravity is objective.

But it’s the last word he used that got me really scratching my head. “Meaning?” Of gravity? Why should gravity have a meaning? It’s a law of nature, not a piece of art.

You can look for meaning in the Mona Lisa, or a sonnet, or in a child’s smile. You can argue over the meaning with someone else, and you can both disagree and yet both be right. When something is created with artistic intent – or just simply created by the human with or without that intent – it’s open to interpretation.

But the Universe itself as a physical object isn’t like that. You can look for meaning if you’d like, but the Universe is a semi-random collection of energy and matter, and based on all the evidence I have seen was not created with intent. A nebula is beautiful in form and color, but is simply a collection of particles, photons, fields, and motions. It has no meaning outside of your personal interpretation of it. But whether you think it has emotions and is alive or not, it will still do what it does: make stars. Nebulae have been doing this for billions of years before us, and will continue to do so long after we are gone.

You might even ascribe purpose to a nebula: its job is to create stars. But that’s what’s called the Pathetic Fallacy: ascribing human characteristics to inanimate objects. The nebula doesn’t want to do anything. It just does things according to the laws of physics.

You might want to use the same reductionist reasoning on humans too, and say we are nothing more than machines and have no free will, no choice but to obey whatever laws of physics command us. And I cannot discount that, but I suspect we are richer than that. The laws of physics are not binary; they don’t say to us “Behave this way or that.” There are huge, perhaps even uncountable numbers of choices that lie before us. It’s not just a matter of cranking all our atomic states and field equations through a black box and determining what we must perforce do; there are probabilities involved, so that our actions may be predictable in a sense but are not fundamentally determined in advance.

That is the difference between us and a nebula. We can choose. And that’s why a post-modernist relativism can work when describing Mozart, but will fail when applied to a black hole. The event horizon of a black hole cares not what we think of it.

Incidentally, saying that the Universe is meaningless doesn’t imply there’s no reason to live. What I am saying is that there is no direction to the Universe, no intent, no internal morals or purpose or meaning. But we still exist. People look for meaning in everything, even when it isn’t there, and it can lead them astray. Don’t ask what a halo around the Sun means, using it as a sign or an omen or a symbol. Look at it, enjoy it, gasp at its beauty and the wonder that such a thing exists. Know that the Universe obeys a set of laws, and that those laws are knowable without meaning.

And finally, don’t ask what I think the meaning or purpose of life is. I think it has neither, but that makes it no less magnificent or joyous to me. I know what I want my life to be like, and I have enough real questions to keep me busy for a thousand lifetimes. I don’t feel the need to look for ones that aren’t there.