I'm conducting an experiment in there come with me so Joe what is the experiment we're doing today right okay so the experiment is over here I have sugary water and over here what you're pouring is a low calorie alternative and what we're going to do is we're going to see if people can tell the difference all right roll up roll up ladies and gentlemen see if you can taste the difference [Music] well I think the results are fairly conclusive J the kids thought that was sugar and that was sweetener allit a couple they could tell
that they were both sweet but they could also tell the difference between the two drinks but the thing that's intriguing is why does one of those give you energy and the other not give you energy what has that got to do with vines Springs medicine horns shells you know and in fact the very foundation of life on the planet it's all comes down to something called chirality chirality yeah which comes from the Greek for um hand so Joe what is chirality we say that something is chyal if its Mirror Image looks different to the original
thing let me give you an example we've got one behind us actually of aon's hands which very big yeah they a lot like our hands okay so our hands are chyal if you look at them my right hand looks a lot like a mirror image of my left hand yes but whatever I do I can't make my right hand look look just like my left hand oh I see my thumb stick out not even if I do that I get it they're different they're not the same yeah so I say that my hands are kyal
and kyal object we also split into being either left-handed or right-handed just like our own hands oh now Alan I'm guessing it's no coincidence that you're standing here with this Exquisite shell and now it is that kyal yes absolutely this is a right-handed structure and actually quite amazingly most SE in the worlds are right-handed with a ratio of about 9 to1 question is why do we see this happening this is exactly the kind of question that motivate my work but then you're a mathematician so how does that bear on any meaning on this question of
left and that and right and de a question of symmetry which is really at the heart of mathematics but most importantly we can use mathematical formula what we call modeling to understand the different level where carity arise for instance if I look at these I see the same structure at different level the same carity we can use mathematical formula as a microscope to study our carali pass from one level to the next level all the way down to the cell and inside the cell wow so does this really only take place within biology no carity
is observed everywhere in in nature yeah so we see this in physics from the very large the very smaller scales and also in chemistry the way molecules interact with each other the cality is extremely important right oh so these are chemicals then are they they're model of a molecule and they're the same molecule in terms of the the atoms that make it up right but you'll see these are actually mirror images of each other and they behave differently is that how the experiment with the sugar and the sweetener worked exactly the ability of our body
to absorb molecules depends on the shape of the receptor site bit like a key fitting into a lock the sugar is the right-handed form of the molecule and that actually does get absorbed into our body but the left-handed form the sweetener doesn't get absorbed right so that's why only one piles on the pound exactly and actually right now we're going to go and see one of the most important chyal forms in nature remember that in nature life seems to prefer one chiral form to the other yes and if you look at biological molecule you see
that they almost exclusively have one handedness so for example amino acids that make up all the proteins in our body they go left and DNA is right-handed right but do we know why this happens this is a mystery but one that could hold the key to understanding the origin of life there are actually two theories first we know from physics that there is a tiny difference in the elementary force that bind particles together that can distinguish between left and right and maybe very early on in the evolution of life this tiny difference acted to select
one type of handedness over another another theory looks at the very large and maybe at some point the early biological soup received polar rise light coming from a neutron star or a supernova that could have again chosen between one handedness over another but nobody really knows and this is why it's so really fascinating so it might just be left and right to you and me but chirality could be the key to life the universe and everything and who knows Somewhere Out There nature may have made the opposite choice and there's a mirror image of all
of us what can maths tell us about why shells form why do different chyal forms of the same chemical have different effects on the human body and is there a mirror image of us out there somewhere for the latest research to answer all these questions and more visit Oxford spark.net sland [Music]
