It’s one of humanity’s biggest questions, and there’s no simple answer, but let’s give it a try anyway: what is the meaning of life? We asked a philosopher and a physicist to shed some light on the darkness.
“Defining the meaning of life in philosophy is difficult,” says Emily Thomas, deputy director of philosophy at Durham University. “You could be asking for the purpose of life – for example, God created us to worship him, or procreate. Or the value of life – for example, life is valuable because it makes us happy, or brings beauty, or moral good.”
“For what it’s worth, I don’t think life has a purpose, but I do think it has value.” The meaning of life also brings up the question of whether or not life exists elsewhere in the Universe. “I’d be astonished if it didn't,” Thomas says. “It seems very unlikely that we are the only happy accident.”
Thanks to modern censuses of planets in our galactic neighbourhood, like Nasa's Kepler mission, we know that planets are common and that small, Earth-sized planets are not the exception, but the rule.
Most scientists agree today that life in the Milky Way, and other galaxies, is common. However, most of that life is in the simplest possible form, microbes. Other galaxies, like Andromeda, are so huge that, statistically, life in them is almost certain. Thinking about it in this way, life on Earth can seem pretty irrelevant.
"Contemplating the sheer scale of the Universe and the tininess of our world, it is easy to dismiss humanity as insignificant in the ‘Big Picture’. We seem like just a tiny brush stroke or a random pixel in that picture," says Jaymie Matthews, professor of astronomy and astrophysics at the University of British Colombia. But Matthews explains why this is not the case.
“When I was a student starting out in astronomy, the recipe of the Universe was simple,” she says. “Everything was made of the particles that make us, and our planet, and our Sun, and all the suns and gas and dust in interstellar space. We were part of the main ingredient of the dish.”
Now, however, the discovery of dark matter and dark energy has thrown this completely off. Today, the recipe of the Universe is about 75 per cent dark energy, 21 per cent dark matter, and four per cent normal matter – the stuff we are made of. On top of this, the actual elements that make Earth and life on Earth represent only a tiny fraction of a per cent of the composition of the Universe.
“We've gone from being the main ingredient in the recipe – the cheese in the fondue – to a pinch of spice,” Matthews says. “That's not a loss of stature in the cosmic kitchen, but a promotion.” Think about this the next time you wonder whether life has any meaning.
Matthews says: “Every time you look up at the stars, and wonder what they are and how they got there, you give the Universe meaning, and add to your own meaning.”