I gave a talk about the future of science on Friday night at Bryanston School in Dorset (quite a place, I have to say). I had a warm-up act, Milly - I forgot the surname, sorry - who gave a short talk about the future of space travel. She took two questions afterwards, and they were good ones. First, should we travel to other worlds, are we likely to mess them up? And second, is it all worth it anyway?

I'm fond (probably over-fond) of telling people that England's Astronomer Royal, Sir Martin Rees, once said finding life on other planets is the most important task in science. That's because, he believes, it will tell us an enormous amount about ourselves - whether we're somehow special or not, for a start - and about evolution. If life evolved elsewhere, it might have seeded life on Earth. Or we might answer Christian De Duve's question over whether life is a cosmic imperative; whether it is somehow a product of the laws of physics and will always happen given enough time and physical resources.

Is it worth the investment? I believe it is, as I've said publicly. But I can have an opinion without having to put up any money - unlike the US government at the moment. This is a crunch time for NASA. The current adminstration is having to decide whether to invest further in human space exploration, a "Kennedy vs Nixon moment", according to NASA's former head honcho Mike Griffin.

Me? I'd be Kennedy. You? 

  

I am running badly behind schedule with my posting, thanks to a heinous deadline load. So, here’s two for the price of one, and weird science Wednesday is on an indefinite break (I'm switching to Thursdays on George Lamb's show, cos we're taking it up a notch or two - more on that later).

Got a piece on the Mars conspiracy (is there one?) on the Times science blog. It gives a little insight into the mind of Gilbert Levin, the man who is convinced he discovered life on Mars in 1976.

And the cover story in New Scientist this week: the Seven Mysteries of Gravity. My favourite is the role of gravity in biology – turns out you don’t know what you’ve got till it’s gone.

Back to the grindstone... 

Very gratifying to have a piece doing so well on the Times website. It’s a little taster of each of the 13 Things, and was the “most-read” over the weekend (or so the people at Profile Books told me this morning).

The original piece on the New Scientist website (which has a slightly different set of Things) was extraordinarily popular, becoming the sixth most circulated article on the internet in 2005. People keep asking me what the draw is: why is it so appealing to examine what we don’t know?

My answer is, essentially, answers take the fun out of life: speculation is more interesting. I’m convinced that, while mysteries are appealing to everyone, solutions appeal only to some.

No doubt this is the root of those staples of the news agenda: conspiracy theories, UFO reports and weird spookiness. So maybe 13 Things reinforces that innate sense, which I’ve written about here, that there’s more to the world than we can perceive.
 

I have a story in this week’s New Scientist about robot mathematicians. The idea, really, is to see if we can work out what maths is, and how we do it, though it’s tempting to speculate about how a robot mathematician might create new mathematics. One of the aspects I didn’t get to go into is how intertwined are our bodies and our mathematical concepts. ET, for instance, might do maths differently from us.

When researching the feature, I talked at length with Rafael Nunez of the University of California, San Diego. Nunez, working with George Lakoff of the University of California, Berkeley, was first to put forward the idea that mathematics is “embodied” (their book is here).

The original forms of measuring and accounting all have to do with bodily forms, they pointed out: the foot, the yard (a stride length), hands for measuring horse size. Even concepts such as future and past are related to our bodies. Western cultures speak of “looking forward” to a future that is “ahead” of us, for example, while the past is “behind us”.

That research took place in the early 1990s. Now, thanks to further discoveries, they are more convinced than ever that mathematics is nothing more than a useful way of making sense of the world – and that it is certainly not innate.

For a start, plenty of cultures have no mathematical concepts to speak of, Nunez says. Then there is the Andean culture that he has been studying. They have time the other way round from us. Because they can’t see the future, they think of it as lying behind them. Our maths is all to do with our bodies. “Our mathematics comes out of things like our bipedalism, and having a visual field on only one side of the body,” Nunez told me. “But the fact that this culture is so different to ours shows it is not hard-wired or genetically determined.”

Our bodies make maths possible, but it has only ever been a tool, invented only if it can help with something else humans are trying to do – like snowboarding or windsurfing, Nunez says. The mathematical concept of transfinite numbers are an example. They were invented in Germany at the end of the 19th century as an extension of natural numbers. How, Nunez asks, is that any different from the invention of snowboarding, invented in the 20th century as a new form of winter thrill?

What’s really interesting is that, just as snowboarding would be different if we had differently-shaped bodies, so would maths. The fact that we have ten fingers is probably what leads us to prefer the decimal system, for instance. That has interesting implications for the popular notion that we would recognise alien communications by their mathematical form. Martin Rees put this idea forward most recently, also in New Scientist.

The thing is, if your maths depends on the kind of body you have, aliens with different bodies would have different maths. So we wouldn’t necessarily even notice that signal from space. Does that mean that SETI should go back to the drawing board? Even better, does it mean that a signal based on physical constants – like the Wow! Signal – is the most likely to be seen?

 

There’s a great paper just come online. It’s by Keri Langridge, who I met a few times when I was writing a piece for New Scientist about cuttlefish. These are extraordinary creatures. My New Scientist piece, published last year, is here. Here’s a little teaser:

When they come across cuttlefish,some divers offer a greeting, the two-fingered“peace” sign. in what is surely one of the few cross-species salutations in the natural world, the cuttlefish reciprocates by lifting two of its arms. this message of peace is actually quite the opposite – a startle response to what thecuttlefish perceives as a threat. sticking two fingers up at divers or predators is a secondary level of defence which cuttlefish use on therare occasions that their camouflage fails.

The big point of Keri’s paper (abstract only, in press at Animal Behaviour) is to do with this kind of response. Cuttlefish don’t just flee when a predator comes along. If it’s only a minor threat they send out a “big eye” signal to ward them off. In other words, they distinguish between different kinds of predator. It’s an enormously rare thing, and shows how big (relatively speaking) their brains are. No wonder they've been compared to an alien intelligence.

Of course, the whole camouflage routine is just stunning. Roger Hanlon, the cephalopod king has some amazing video here.

You gotta just love these amazing creatures. And they taste good too - here are some recipes!

Here's a couple of pictures of the craft that will find strong evidence for life on Mars. I hope.

One of the things I have never understood is the view that there probably isn’t life on Mars. Surely, in the age of extremophile bacteria, it would be odd if there weren’t something there beneath the arid surface?

A couple of new results strengthen my conviction. First up a paper in Science that reports the discovery of organisms that live independently of the sun. Instead, they get their energy from natural radioactivity in the basalt rocks where they live. The organisms live 3 to 4 km down a South African gold mine, in water trapped in a crack.

The radioactive uranium in the rocks breaks up water molecules to produce hydrogen gas. The microbes use this to turn sulphate molecules, also in the rock, into hydrogen sulphide – basically a mimic of photosynthesis, but powered by radioactivity not sunlight. Read more about it here. It’s enough to make you think that life is a cosmic imperative, as Christian de Duve once suggested. Wherever there is chemistry and the release of nuclear energy (which is everywhere), something conspires to create that process we call life. Maybe it’s just the laws of physics at work.

All of which makes it even more exciting that NASA are now thinking of searching for biologically-generated methane again, more than 30 years after Gilbert Levin did it for the Viking mission. In 13 Things I’ve written about his results: positive, but, essentially, shouted down by the (false) negative of another experiment. When the Mars Science Laboratory launches next year (that's the aeroshell in the picture), it might finally vindicate his claims.

There is new evidence that methane is being given off in “hotspots” on Mars. Methane is often (not always) a result of biological processes, such as microbial processing of nutrients. This is what Levin claimed to see in 1976.

A Nature News story says methane clouds spanning hundreds of kilometres form over these hotspots. It seems to be created at an astonishingly fast rate, indicating the possible presence of methane-generating bacteria.

One of the hotspots was on the longlist of landing sites for the MSL lander, but didn’t make the shortlist. That decision is now being revisited. Since MSL can detect the ratio of carbon isotopes in methane, that might give good indication of a biological origin for the gas. Terrestrial biology produces more carbon-12 than any other isotope: if the Martian methane is rich in carbon-12, it’s a strong suggestion that Gil Levin was right all along.