January 2009

Chemistry World Podcast - January 2009

00:12 -- Introduction

01:58 -- Chemists take control of robo-moths   

04:27 -- Did meteorite strikes seed life on earth?

07:18 -- Fraser Stoddart discusses the impact of Richard Feynman's famous 'Plenty of room at the bottom' talk, fifty years on    
 
13:54 -- Trace metal molybdenum could be limiting tropical forests' carbon capture  

16:28 -- Could the world's toughest ceramic deliver smash-free dinner plates?

20:06 -- The chemical conundrum - whisky's magic dilution

(Promo)

Brought to you by the Royal Society of Chemistry, this is the Chemistry World Podcast.

(End Promo)

(00:12 -- Introduction)

Interviewer - Chris Smith
Hello! Welcome to January's edition of Chemistry World with Richard Van Noorden and Matt Wilkinson.  I'm Chris Smith.  Coming up, part Moth, part Machine, it seems Cyborgs are now a reality.

Interviewee - Richard Van Noorden
And the general idea of this kind of research is to make a moth, which will act as a remote robot, a cyborg, a mixture of living and non-living things that will go off and search out explosives or land on land mines or perhaps ultimately beam back camera images to the viewer who is controlling it.

Interviewer - Chris Smith
More on that story from Richard shortly.  And also on the way, a new theory on how the building blocks of life could have arrived on the early earth.

Interviewee - Matt Wilkinson
They've been studying what might happen when meteorites land in the sea and they've actually found that they can actually produce small amounts of amino acids such as glycine.

Interviewer - Chris Smith
So life could really have come from outer space, although only indirectly.  And as science becomes increasingly more multidisciplinary, we will be hearing from chemist Fraser Stoddart; hope it wasn't always like that.

Interviewee - Fraser Stoddart
When I started out as a scientist here in the UK and I don't think it would have been different anywhere else.  I was branded as an organic chemist.  I had eight colleagues.  If I was seen to be speaking to anybody else other than these eight colleagues, I was called into the professor's office and had to account for myself.  In other words, it was heresy to speak to a non-organic chemist or a physical chemist or a theoretical chemist.

Interviewer - Chris Smith
Persecution for speaking to the wrong species of chemists, thankfully times have changed.  That's all coming up in this month's edition of Chemistry World.

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(01:58 -- Chemists take control of robo-moths)  

Interviewer - Chris Smith
Ask a devoted Trekee whom they feared most amongst the alien races encountered by the crew of the Starship Enterprise over the years and a common answer would be the Borg.  These were a race of part men, part machines.  But now scientists are doing almost the same thing with moths.  So tell us more about this Richard.

Interviewee - Richard Van Noorden
Well this is actually quite incredible.  This is a team who are working with the U.S. Defense Agency DARPA.  They are actually based at Cornell University in Ithaca led by David Erickson and they are making moths, which they inject a paralyzing chemical into to stop the moth flying and the general idea of this kind of research is to make a moth, which will act as a remote robot, a cyborg - a mixture of living and nonliving things that will go off and search out explosives or land on land mines or perhaps ultimately beam back camera images to the viewer who is controlling it.

Interviewer - Chris Smith
Okay, talk us through how do they control it and how do they actually stop it where they want it to go?

Interviewee - Richard Van Noorden
So if you have a bit of back on it, you need to know that DARPA have previously publicized some research where they've used electrodes to make the muscles of the moth beat at different rates so they can turn it and they can speed up it's wing flight or slow it down a bit and it's involved in planting some electrodes into the moth.  What they have done here is they implant a microfluidic chip into the thorax of the insect two days before it actually matures into a fully grown moth and if it survives this procedure, about a third of insects do, they've got a chemical on this chip, GABA, which is an inhibitory neurotransmitter which essentially just paralyzes your whole system and whenever they want the moth to stop, they turn ON the chip.  They've got an electric potential, they turn ON the chip, the chemical floods the moth's system within minutes, the insect is immobilized, but within perhaps two hours it can recover and fly again.  And you can control quite the length of the time that it's immobilized for.

Interviewer - Chris Smith
Sounds excruciating work though, why moths and how easy is this to do?

Interviewee - Richard Van Noorden
In fact there aren't the same laws about what you can do in insects as there are about what you can do on rats and monkeys and in fact I think in the U.S., I don't know if this is same in the UK, but you can basically do anything on insects and there are no restrictions at all.  They say as I said that about a third of insects do survive this procedure and I suppose that must be something that they got used to doing.

Interviewer - Chris Smith
Terrifying prospect.  Thank you Richard.

(04:27 -- Did meteorite strikes seed life on earth?)

Interviewer - Chris Smith
Now Matt this is very interesting, because this is not much moths, but where life in general possibly came from.  Tell us about this.

Interviewee - Matt Wilkinson
Yes, this is a new research published by a Japanese group from Tohoku University led by Takeshi Kakegawa and they've been studying what might happen when meteorites land in the sea and they've actually found that they can actually produce small amounts of amino acids such as glycine.

Interviewer - Chris Smith
So what they're saying is that it is not actually the meteorite bringing the things to earth.  It's not actually the meteorite kick-starting life, it's the meteorite kick-starting chemical processes themselves produce things that could be used by life.  

Interviewee - Matt Wilkinson
Exactly.  It's providing one of the building blocks and what it is, it is an unique mixture of graphite, iron, water, nitrogen and ammonia that's found in various meteorites and when they hit the earth with the incredible speed that they travel through, which is some 2 kilometres a second, they actually generate carboxylic acids, amines and small amounts of amino acids.

Interviewer - Chris Smith
Now obviously they can't be studying real meteorite impacts because they are sufficiently common at this kind of scale to do that.  So how have they modelled this, and have they done it physically or is it just a computer simulation.

Interviewee - Matt Wilkinson
They have been modelling this physically with very small copies of meteorites basically.  The idea is in itself, a new idea, it was actually first proposed by an American astronomer called, Carl Sagan, in the '70s, but he just mentioned the hypothesis in one scientific paper and since then nobody has actually tried to copy his idea.

Interviewer - Chris Smith
How does this sit with other hypothesis about where the building blocks of life came from because someone we featured on the Chemistry World podcast a little while back that was Jeff Bada from the University of California, San Diego, his suggestion was based around the work of Stanley Miller, which is that on the early earth you had hydrothermal vents, volcanoes essentially and they triggered lightening and the environment that they created led to the chemistry that produced the building blocks of life.  So how does this hypothesis sit with what Jeff Bada had to say?

Interviewee - Matt Wilkinson
Well, it's quite interesting because we actually spoke to Jeff Bada about this paper to see what his opinion was and while he thinks that it is actually very interesting chemistry that's being going on, he does believe that the amount of glycine produced is actually very small.  It's only going to be some 10-30gm/L of seawater, which is not really a meaningful concentration.  However, Kakegawa admits that while the concentration are quite small, he thinks, the shear thought of meteorite impact might be that much bigger than what they are currently finding with small meteorites that it could have played an important role in producing some of the chemicals that we needed to form life.

Interviewer - Chris Smith
Quite literally a meteorite discovery, of how life could have been kick-started by the impacts of rocks arriving from space, thanks Matt.  

(07:18 -- Fraser Stoddart discusses the impact of Richard Feynman's famous 'Plenty of room at the bottom' talk, fifty years on) 

Interviewer - Chris Smith
This year marks the 50th anniversary of the Caltech physicist, Richard Feynman's famous lecture, 'Plenty of Room at the Bottom'. Many people say that this marked the birth of the field of nanotechnology, the science then was very different beast to the multidisciplinary environment that we work in today, and to set the scene of what it was like here's Fraser Stoddart.

Interviewee - Fraser Stoddart
When I started out as a scientist here in the UK and I don't think it wouldn't have been different anywhere else, I was branded as an organic chemist.  I had eight colleagues.  If I was seen to be speaking to anybody else other than these eight colleagues, I was called into the professor's office and had to account for myself.  In other words, it was heresy to speak to an inorganic chemist or a physical chemist or a theoretical chemist.  I knew this was absolute nonsense because I've been brought up on a lowland Scottish farm, where when you are faced with a problem, it really was one you had solve, you know, you got your friends to come and help you if you need it and the problem got solved a lot of quicker, everybody enjoyed themselves in the bargain and it represented progress.

Interviewer - Chris Smith
So how do you think that mindset got entrenched with people saying, you shouldn't be talking to the people down the corridor who are the wrong species of chemist.  Why wasn't there more of the idea of people being the Scottish farmer, like you are describing?

Interviewee - Fraser Stoddart
Well, I think what happened after World War II was that a number of people were left on both sides of the pond with a lot of authority.  In other words, there was a group of people for about 10 years, who I would call the barons,  it all came down to them being fairly self-centred, being incredibly arrogant and they, you know, just used their power effectively to browbeat young people into submission.  They wanted the maximum amount of, I think, idolation from the young at the same time they wanted to keep us in our place and so this was reasonably successful until the dearth of that activity started to show through.  I think, in higher places governments began to ask well what is coming out of all this money that we are pouring into science and technology and so forth and it may have happened anyway, but there were much harder and more rigid criteria placed on the scientific community.  This group of barons just threw in the towel, most of them were reaching 65 anyway, but if they weren't, they weren't prepared to have their science or their ideas looked at beforehand and ground complications of the like and the baton was passed onto a new generation and I think on both sides of the Atlantic because that's the place where the science was concentrated, Europe and the US at that time, went through quite a change and so there were whole areas of science like physical, organic chemistry that just died in their shall we say traditional classical model overnight because these people had behaved so badly that they had effectively finished their subject.

Interviewer - Chris Smith
So what do you think Richard Feynman's influence was to change that?

Interviewee - Fraser Stoddart
He was before, this happened in a way or as it happened, he was back in 1959 making these points by people coming together, if one read between the lines at least, but they fell on the deaf ears of the leaders of the day by and large because they were so myopic; they were so concentrated on their own little patch and their own ideas for heaven sake you know, somebody there was sort of installing the virtues of chemists and physicists working together wasn't going to get much of a hearing and so nobody really knew what this man was about until after the event and by that I mean, until after the first steps were taken into reaching into the nano world and I guess that started in the late '80s, early '90s and of course people quite rightly, went back as they should do as scholars and fount that out, ah, here is somebody who was saying something a long, long time ago that never reached our ears.

Interviewer - Chris Smith
Why do you think people took him so seriously because it clearly didn't harm him to be so outspoken about any of these issues at the time when he was saying them.

Interviewee - Fraser Stoddart
Yeah, but you know, he was already somebody, who had received a lot of recognition and he was a maverick, so he was able as anybody is in that position to stand above the crowd.  There was nobody who was ruling over him.  He was able to be his own person and maybe a bit of a prophet ahead of his time.

Interviewer - Chris Smith
So do you think he was a prophet or do you think he was just lucky that in the same way, I'm not saying as a monkey or anything, but given enough monkeys and enough time, just any one of them is going to reproduce the works of Shakespeare, because he happened to get it right and be outspoken enough.  His message is the one we still hear today.

Interviewee - Fraser Stoddart
He got some of it right, but he got some of it very wrong.  You know, what he tried to put into the minds of chemists was, I think, na?ve in the extreme and you know, I've pointed that out, but you know, one could excuse him that, I mean, there is a question of the approaches that one uses his grand idea was fine, but there was a time when it should be possible for a group of people who call themselves chemists to line up with a group of people who call themselves physicists to line up with the group of people that call themselves biologists and so on and so forth and tackle problems that are you know, out with the remit of any of these single camps and I think to that extent he foresaw the wonders that were ultimately going to come about as you say starting about the end of the 1980s under the banner 'nano', which was really a great uniter.  It was one that a lot of people, you know probably of a different ilk from the ones I was describing to marshal the forces come together and say, 'right we are going to work together toward some bigger problems than our predecessors have been tackling.'

Interviewer - Chris Smith
So having fragmented into a raft of different disciplines many of those scientific subspecialties are now coming back together to solve new problems in new ways.  That was Fraser Stoddart.  He is a professor of chemistry at Northwestern University in the U.S.  

(13:54 -- Trace metal molybdenum could be limiting tropical forests' carbon capture)

Interviewer - Chris Smith
When plants wouldn't grow, farmers usually resort to a traditional fertilizer mix of N-Nitrates, P-phosphorus, and K-Potassium, NPK, but may be we should alter that mixture to include MoNPK, in other words add some molybdenum, Matt.

Interviewee - Matt Wilkinson
Yes, indeed.  There's a new research published by Lars Hedin from Princeton University in the U.S., who has shown that in some rain forests, specifically one in Panama, the limiting factor for growth is actually molybdenum, which is a really rare trace metal.

Interviewer - Chris Smith
That's interesting because traditionally people think of phosphorus as often the limiting factor in fertilizing ground, don't they?

Interviewee - Matt Wilkinson
This actually suggested that the phosphorus theory as somewhat a mistake, in that Hedin's results suggests that the results were skewed in the earlier experiments by trace quantities of molybdenum impurities found in the phosphorus fertilizer that was used during those experiments.

Interviewer - Chris Smith
Do we know what the plants actually do with the molybdenum and why is it so important?

Interviewee - Matt Wilkinson
Well, it's not actually there that the plants do anything with the molybdenum itself it's actually bacteria living in the ground that use the molybdenum to fix the nitrogen.

Interviewer - Chris Smith
All right, so in other words if you don't have the molybdenum there the bacteria can't fix nitrogen and that means no nitrates for the plants to grow.

Interviewee - Matt Wilkinson
Exactly, yeah, molybdenum is a key cofactor in the essential enzyme of these bacteria for nitrogen fixation, nitrogenase and together with iron it aids the transfer of electrons in the enzyme helping to split the triple bond in dinitrogen.

Interviewer - Chris Smith
So how did they discover this in the first place?

Interviewee - Matt Wilkinson
Basically, they were looking at what was limiting the growth and they did some interesting studies on looking at what was in the soil and found that molybdenum was actually deficient and then found that by adding molybdenum to the soil, they could get them to grow further.

Interviewer - Chris Smith
And what are the implications.  They are saying that in areas where there is poor soil don't just chuck on NPK fertilizers, chuck on some molybdenum too.

Interviewee - Matt Wilkinson
Exactly.  But they're also suggesting that rather than just needing to add molybdenum and may be phosphorus as well, the ecologist need to be looking far more for those trace elements that may be all there or in fact actually aren't there to see what's going on in each specific environment because obviously this rain forest that they found in Panama maybe deficient in molybdenum which is what's limiting its growth, but somewhere else there might be plentiful supplies of molybdenum and there might be something else that actually interferes with that delicate balance.

Interviewer - Chris Smith
So it's not just a case of dosing the soil with something to make everything grow, it could be much more complicated.  

(16:28 -- Could the world's toughest ceramic deliver smash-free dinner plates?)

Interviewer - Chris Smith
Not only we have complicated stuff, a wonderful story has just emerged about borrowing from effectively biology to make the toughest ceramic that science has ever seen.  

Interviewee - Richard Van Noorden
Yeah, this is fascinating.  A ceramic is normally something you think of as a plate and you drop it on the floor and it smashes because it's very brittle, but what these guys have done and it's Robert Ritchie and colleagues from the University of California, Berkeley.  They have copied the structure of mother of pearl, which is naturally a brittle layer of plates, a bit like a ceramic with a protein interspersed between them and that makes mother of pearl very tough.  So you try and crack it, but the protein takes the strain and really dissipates the energy of the crack.

Interviewer - Chris Smith
Oh I see, so when a crack tries to go through propagating through the material it hits one of these intercalated layers and that just basically stops the crack propagating any further.

Interviewee - Richard Van Noorden
Yeah, and the protein acts like a kind of cushion.  Now, mother of pearl has calcium carbonate plates and conchiolin cushion, which is the protein.  What they've done with this artificial material is they've taken aluminium oxide, a typical ceramic and they've got plates of this aluminium oxide and interspersed polymethylmethacrylate or effectively superglue of polymer in between them.  Now what's really clever is that of course people have noticed this before, always learning from nature, but before chemists have tried to make this kind of structure by layering up the brittle plate and the polymer in a thin film, you couldn't really get much on a bulk scale.  This is incredibly clever because they've made this structure on an enormous scale of centimetre blocks by freezing the aluminium oxide plates in ice, they have frozen water together with the aluminium oxide and by adding salt and sugar, they can change the thickness or the distance between the plates and then they take the water off again by lowering the pressure and increasing the temperature in any polymer in the gap and you get this macro-scale, mother of pearl structure with an incredible fracture toughness, which is twice as tough as that of the aluminium oxide and the polymethylmethacrylate alone.

Interviewer - Chris Smith
And is it possible to make this in a viable way and what could we use it for?

Interviewee - Richard Van Noorden
Well, it's absolutely possible to make it in a viable way.  All you need is salt, sugar, water that you freeze, there's polymer and aluminium oxide.  That's it.  It's a very simple method, that's also clever about it and what they're saying, it might be useful is they reckon they can mould it into shapes.  So anything, application from aerospace engineering where you want, this is something that doesn't fracture or add in the tennis rackets, something that's light, strong, doesn't fracture again, I'm sure they'll start exploring all the possibilities.  I'll just give you an idea of kind of how tough this is.  It's about 15 times as tough as concrete, which doesn't fracture that easily and it's almost as tough as typical aluminium metal, aluminium alloys, like an aluminium alloy bar, but it's made of ceramic plates, it's a composite and it's essentially the toughest ever ceramic made.

Interviewer - Chris Smith
Thanks Richard.  So who knows may be in the future, you will be able to drop the iron on the kitchen floor with impunity and not have to worry about breaking the tiles.  Well that's almost it for this month.  It is just time to find out the answer to the chemical conundrum.  Last time we asked you 'what is the only additive apart from water than can be legally added to whiskey.  So Matt, are you a whiskey man?

Interviewee - Matt Wilkinson
I'm a whiskey man, and would you believe it, the answer is actually caramel.  It's used to enrich that lovely amber colour of the whiskey and if added in enough quantities, the taste as well.  The winners were Jeremy Carr, George Easdown and Yadhunath Kanmani.

Interviewer - Chris Smith
So kudos to all of them.  Thanks Matt.

(20:06 -- The chemical conundrum - whisky's magic dilution)

Interviewer - Chris Smith
And Richard what do you want to ask people to come up with for next month.

Interviewee - Richard Van Noorden
Well, we're staying with whiskey Chris.  You will be pleased to know and this, I guess, a New Year whiskey question, bit more scientific this time.  There's a magic concentration, a magic dilution, if you will, of water in whiskey where you get this continuous phase of water and ethanol.  It makes the drink taste very smooth and we want to know what percentage dilution is that magic number, water in whiskey.  If you know the answer, send us an e-mail to chemistryworld at rsc dot org.  Don't forget to give us your address and your names, so that we can post your winnings to you.  This month we're giving you your usual goodie bag with all the pens and magazines and anything else we can find around the office, which is normally quite surprising.  Please send this to chemistryworld at rsc dot org 

Interviewer - Chris Smith
And next month we'll also provide you with details of Alcoholics Anonymous, just on the off chance that anyone who has got too carried away trying to find the answer to tonight's questions by experimentation.  Thank you Richard.  You can also use the e-mail address that Richard gave you there to send us your thoughts and feedback on this or one of our previous Chemistry World podcasts and please don't forget that we also produced a weekly podcast that's called Chemistry in its Element, where we take a look at the sinister side of the periodic table and you can tune in to Chemistry in its Elements on I-tunes or via our web site at chemistryworld dot org forward slash elements.  Chemistry World is brought to you this month by Richard Van Noorden and Matt Wilkinson and I'm Chris Smith from the thenakedscientists dot com.  Until next time.  Good Bye.

(Promo)

The Chemistry World podcast is brought to you by the Royal Society of Chemistry.  Look us up online at chemistryworld dot org.

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