Last Thursday, I negotiated my bicycle through the customary crush of Trafalgar Square to the RSA, for a talk by R Beau Lotto in association with the Barbican Radical Nature series. Beau heads up Lotto Lab, whose aim is to explain and explore how and why we see what we do (do check out their website) - mainly through looking at how we see colour, which is one of the simplest things we do.

All images by R Beau Lotto, courtesy of Lotto Labs

Here's a quick science bit, which he gets in at the beginning of the talk to a packed full lecture theatre - light and colour are not the same. Light can be represented on a linear scale. It has just wavelength and intensity. Colour has three bits to it. So it's much more complicated to describe : hue (red-green-blue-or-yellowness), brightness, and saturation (greyness).

The whole talk is full of questions I asked as a six-year-old, and I'm left with a kind of wide-eyed amazement at how clearly everything is explained and presented - I'll pick out one of the most satisfying.. Why is the sky blue? This is one to try at home. Get the biggest glass bowl or see-through container you can find, and fill it with water. Shine a desk lamp through it - the lamp's now the sun and the water space. If we had no atmosphere, the sky would be black with a bright sun - as it is from the moon. Now add a little milk at a time to the water, stirring as you go. As it spreads through the water, the milk will scatter the light like the atmosphere does, and at the right level, will scatter blue. Add a bit more, and you'll make a sunset - the longer-wave red light scatters when it goes through more atmosphere, as sunlight does when it's low in the sky. Add more again, and it'll go grey : you made a cloud, where all the light scatters equally.

The colour of space changes. We never quite see the surface of anything in the world - we see the result of the light shining, the character of the surface, and the space in between. So colours really are brighter in St Ives than Old Street. So the patterns of light that fall onto the eye are strictly meaningless.

We learn to see. We find relationships between things we look at - the context of anything we look at is essential to how we see it. This is what the 'illusions' spread through this article show so bogglingly. And context is what links the present to the past - we associate patterns with what we did last time, and learn from it. Beau asked at one point for a volunteer from the audience. I was desperately far back, in the middle of a row - smooth escape from that one. But the demonstration itself was quietly mind-blowing. A target was projected on the screen, and Rob the lucky volunteer was asked to hit it (this as a control - the exciting bit comes next). Next, he put on a pair of glasses which shifted the world 30 degrees to his right. Throwing again, he missed by miles. After a few goes, though, Rob's whole body movement changed and he hit the target every time. Then he took the glasses off again, and immediately missed the other way - his mind had learnt for that moment to see the world utterly differently.

We don't see the world as it is - in fact it doesn't make much sense to talk about the world 'as it really is' - only what's useful. Colour, for example, is great for not being eaten by orange tigers in a green jungle. We constantly figure out what is 'normal' - and what should stick out from this normal. So... there are no absolutes - only perceptions of a world relative to a changing normal. No one is outside of this relativity. We are all defined by our ecology. We all learn to live in the world that's presented to us - and that in a very relative way.

Beau has four 'C's that he leaves as teasing thoughts - Compassion, Creativity, Choice and Community. And this is where, if you've been reading along wondering quite why I thought this was a good idea for an 'Earth' article, I started thinking about the way we tell stories about the environment, the way we tell stories about what happens in the world around us. Getting your head around different mindsets could be wonderfully informed by these ideas - things like understanding how to persuade business profit-heads that sustainability is the only way to long-term profit, or grassroots activists that FTSE 500 companies have been organising and managing disparate groups of employees for years - there's surely something to learn there.

Knowing that everything we do - down to something so simple as seeing colour - is essentially informed by what we did before, and the kinds of context we've ever been exposed to - this can only add possibility to whatever buzzes round our brains : more compassionate, as we see where others might have come from; more creative, questioning these reflexes; more conscious in our choices, if we think a little past the instinctive; and more communal, in a broad sense, as we're each a unique part of a whole, all sharing in individual perceptions and histories.

That was what I took from it, anyway. Do get in touch, or leave a comment, if you saw any other cool patterns here - I'd be intrigued to hear.