On the Flip Side - Earth's Magnetic Field

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have you loud and clear. I. Signs and that is to say, physics medicine, nature, brain the universe. Hello this week naked attraction, no, nor where you're thinking, we're actually looking at the magnetic field this keeping our planet safe, including finding out how is generated and with some animals can actually see it plus news of techniques to read out the time of our body clocks the people making the case to reinstate Pluto as a planet and how red alert signals can spread three plants in just seconds after something starts to eat them. I'm Clark on Christmas and this is the naked scientists. The naked scientists podcast is powered by UK fast dot coach, UK. First up as anyone who's ever suffered from jet, like knows, we are indeed all slaves to the rhythm. In this case, also Kadim rhythms body clocks, and the reason we feel so Gosse when our internal clocks go of kilter is because every cell up bodies uses time to control what it does and win tissues grow and repair themselves. Sometimes the day metabolism changes dramatically between dawn dusk, the medicines and vaccines given one time of the day can be much more effective than the same drug administered just hours later, this means there is enormous potential to improve healthcare, but only if we can reliably till what time tissues think it is now rose me Brown from Northwestern University in the US has developed a way to do this by comparing the activities of a collection of different genes in blood cells. You have an internal clock in your body, the signal for it originates in your brain, but it orchestrates a wide variety of processes across. Your body, including when you feel sleepy regulates your digestion, it regulates your blood pressure to get you ready for the day. It regulates your body temperature to allow you to sleep comfortably at night. And all of these things are coordinated by clocks that exist in each and every cell of your body. So there's a master clock in your brain and it synchronizes all of these little tiny cellular clocks. Do we know Rosemary the clock work is inside all these cells that are running these clocks to keep time like that. Yes, this is really fascinating. It's a set of genes that have an activity that varies over the course of the day and they interact with each other and a little circuit that allows them to regulate each other. So one comes up that pushes another one down and this push and pull results in Eban flow of activity with a twenty four hour cycle what the brain center than sits the tone for the rest of the body. How your brain secrete. Hormones that your cells pickup in order to reset their clocks so that they're right in sync with what your brain is telling them. So in theory, then if I were to read one of the clock signals from the end of my little finger should be telling the same time fall as well as my brain. Exactly. So why does this matter? Why do we need clocks in my finger? If I have one in my brain tool, the recent, the seven portent as that you need all of the processes across your body to be orchestrated in sync so that you remain healthy given that it controls things ranging from not just sleep to digestion and blood pressure. You can imagine that it has an enormous impact on your health if it's misaligned in some way. In fact, research has shown that circadian misalignment when your clock is out of sync with your environment is tied to diseases ranging from depression to diabetes, heart disease Alzheimer's. So having a missile line. Wind cluck and really adversely impact. Your health is not a part of our clinical practice. So when we go and seek treatments, all they aligned with Al clock to make sure that we're doing the right thing at the right time in the body's clock cycle. Presently, they're not, and that's what we're trying to change. So we know that it's incredibly important. But right now it's very difficult to measure it. The current way that people have been measuring people's internal physiological clocks is by taking samples every hour across the day and night, and you can imagine that's not really something that most people would want to do. So we set out to develop an easy blood test so that we can monitor people's circadian health and use that to make treatment decisions. When blood test, what are you measuring? It takes two blood samples, say one in the morning one in the evening, they can actually be taken any time of day as long as they're separated by a few hours. And then we look for that tippety of. Of different genes in the blood. So there aren't just the core clock cheats that are responding to the twenty four hour rhythm. The clock actually controls a huge number of other genes that sort of move in sync with the clock. And those are the markers that were looking for in the blood. So you take some blood, what do you get blood cells of the blood and then look in those living lead cells to see the gene levels all yeah, exactly. So how many genes do you consider them in order to to get a readout this? We started out our research by looking at all of the genes that we could measure. That's about twenty thousand different genes. And we is pretty sophisticated computational algorithm to try to whittle that down to manageable amount. And what our algorithms told us was that there's a set of about forty one genes that change over the course of the day. And by looking at the levels of those forty-one genes, we can pinpoint the time in your body Royd. So you literally all say, well, we know that when it's. Seven o'clock by my buddy clock. This gene should be doing this and it's council should be doing this because you know what the relationships across that smoke cluster of genes. You've got a reasonably accurate way of predicting my body time. That's right. And it's accurate to within about an hour and a half, which is good enough to be able to then make treatment decisions based on it. What sort of difference will it make? Then drugs have a different affective nece depending on where they're taken. So this is well known for certain blood pressure drugs and for chemotherapies that they're differentially effective at different times of day. But the optimal time for me to take my blood pressure drug might be different from the optimal time for you to take your blood pressure drug. If we can measure the time in your body, we can tell you exactly when the optimal time is for you to take your medicines. That means we could use lower doses, reduce the risk of side effects and hopefully have more effective treatments. Sounds very exciting. That was. Rosary Brown, and that study has just come out in the Geno pan. Aus a, you pollute, oh sympathizer, who's been made very despondent by this miniature Mobile's demotion to a dwarf planet long ago. Well, if so, you're in very good company because a paper has just come out auguring that Pluto should in fact be reclassified as a planet again, heavens, I hear you explain why an indeed was dwarfed in the first place, Georgia meals, not a Murphy been doing a little bit of stall gazing to find out for us. So you back when you and I were kids, it was very easy to remember that the planet in solar system, my very easy method just speeds up naming planets, mercury, Venus, earth, Jupiter Sutton, Uranus Neptune, and Pluto, except you're very easy method. Got it. Wrong, doesn't six international astronomical union voted. Three classify Pluto was a door planet. Teich Justice for Pluto? Why did they feel need to debate this back in nineteen thirty? When Pluto was discovered? It was the only celestial buddy in that part of the sky that we knew about. But there are actually a lot of buddies out there in the fringes of our solar system. Yes, this is the client about this is the massive Donut on the outisde system which is full of icy and gase bookies. Exactly. That's the problem. Pluto is just one of many objects and having the same orbital zone. We've been finding things they're almost as big as Pluto when call coir was found into to said into three an heiress in two thousand five, which was actually bigger than Pluto. Two thousand five the year before the big debate exactly. Did we have shed loads of new plummets all of a sudden you'd need a very long pneumonic something to be done. So committee sat down and practice. Define what constitutes a planet. After a lot of debating they had about on the following definition. It is a celestial body which is in orbit around the sun check, be a sufficient mouse for itself gravity to overcome rigid body forces so that it assumes hydrocyanic equilibrium shape. Is it round check and see, has cleared the neighborhood around its orbit? That is to say is dominant enough into orbit that anything else around either been absorbed or booted out in space. And failed on the lost huddle. The about is a very busy neighborhood. Exactly. So under the definition, Pluto gets booted from the exclusive planetary club into the dwarf planet economy lounge, hang on all we show that the other planets fulfill that loss definition has a heck of a lot of junk flying around the rest of the system will soon have argued that onto the new definition earth and Jupiter failed to meet the definition, but they're in the minority get stay a planet. I don't know how feel about living on a non planet. And what about this new paper? That definitely team Pluto is a planet very much. So let's argued. The poodle should be reinstated since decision for different reasons. This time they've gone through the literature and looked for examples about third part of the definition actually being used on this is the one about being the most dominant in the orbit. The one they checked in papers in the past two hundred years, they really care about blue type and they found it's barely been uses darkly only once in the nineteenth century, they argue that it's an arbitrary. Definition isn't that the point of a definition? It's hardly the first store. The strongest challenge the ruling on it won't be the last, but the reportedly happy to debate the topic again. So we'll have to watch this space. I'm demoting you from human. So Pluto is still adult planet that lease Fennell. That type discussing just came out in the journal it curves, gosh, the going to keep going on, isn't it now? But cave on the school year has begun an as we head into Windsor as well as long nights and dreary weather. Another Saturday is that soon. We'll all be succumbing to this season Sutculer strains of colds and flu viruses. The moment we do much about them except treat the symptoms because we don't know the details of what's going on when a virus gets into one of ourselves. So finding viral achilles heels that we can hit with drugs to trip up. An infection is very tricky Melville Cambridge Santus Ziff has found a coming way to freeze infecting Vars in its tracks, and then pull out the pulse of the cell the virus is interacting with so we can discover how it makes zeal and possibly with to focus out drug developing activities. We are interested in viruses viruses. I'll those little creatures that going side of buddies and make us ill. And we are interested to know how those viruses manipulate l. says, practically, tell the cell, stop everything you've been doing so far and start making more viruses. Yeah, because viruses sort of the pirates of the microbial well, don't they? They have to hijack how cells and turn them into virus factories because they're so tiny. They don't have spice inside the virus pontifical for any of the machinery that you need to might new viruses. They need one of our cells to do that. Yes, exactly. They end off says and manipulate whatever the cell is doing, but we don't know essentially how, what have you therefore invented here? How does your technique shed light on that? So we've been developing technique that enabled us to freeze in time, DeVos infection and find out how viruses interact with the host on the molecular level. Is that a bit, like if I were to put a virus into a cell white little while, and then as you say, freeze time and then look. Inside the cell, an ask, won't bits of the virus all binding onto or interacting with controlling bits of the cell. So I can see what's having a chemical conversation with what? Yes, exactly. Once we find those interaction, assuming that part of the might be essential for the virus. Again, we can think then of finding ways to target to inhibit into few is those interruptions in effect device life cycle, how if you've done this, how do you do that freezing time if eight? So to do that, we need to glue detracting molecules together to fix those instructions and then extract information in small chemicals, naval us to link to glue those instructions to get an identified interacting partners. So how do you might the glue set? How do you say right now I want to freeze time a Mike that binding effect kin, the gluing Stotts whenever I treat infected cells, those small Kim. Mika's that can enter the cell and glue physically interacting more one to each other. So are you saying that if you can spot what these interactions, all? It might highlight to us much more quickly than we would otherwise Bill to discover them potential essential prices that the Vars relies on to grow in my Kasan well, and therefore you could engineer some way of the switching off that target putting something into the cell would stop that interaction and therefore it could vires. Yes, exactly. We interesting both in the biology. So new technique might teach us how viruses replicate inside the says and also understand what those instructions targetable, whether we can use them for development of new medications. Say, who knows? Maybe thanks to a massive. He had that when now a step closer to cure for the common code. The technique Hughes describing is published in the journal nature methods. From baffling British weather. Vertebrae coming off. You're looking at the cheetah from the inside out. Games, making my way to the clinic, what to eat in your garden. The naked scientists in short podcasts, bring you a top-up of short compelling science stories. Listen, download the free making scientists dot com slash short subscribed to naked specials wherever you got your. Now still to come here on the naked scientists is the magnetic field facing a flip in future. But I some might say that we humans have it very easy. If something starts tweet us, we can register out displeasure by the making false getaway all beating the guilty party, but plants down have this luxury. They're literally rooted to the spot so they need to resort other means to discourage things, meeting them one to turn to that disposal is to make themselves Tystad appealing, but they don't wanna waste lots of resources on tasting bad until they really need to. So how do they send a rapid? I'm being eaten message or around the plant this week. A paper in the journal science reveals the ANSA Georgia mills paid a visit to the investor Cambridge's Sainsbury lab to speak to Philip wig who wasn't involved directly in the study, but he does work on how plants since environment. Looks like sort of Bank Fulton. She said, this is a therapist officers, and it's just a small mustard plan. And this was the same time that was used in the study which is described in this paper, and you can say quite a modest looking, fantasy, small wide leaves, but for research has been an absolute boon. So this is really sort of lab mouse for plant search because it has a fully sequenced genome and is very well understood. But unfortunately, for us sequenced, Jeanine Monae Arab says also lives in an incredibly noisy Heim. So we went to find a quaint part of the greenhouse. Quiet area. Which was hotter than it sounds. This noise you too. Few voices that you don't think about when you. Sweet silence. We settle down chat amongst some other plump specimens who believe it or not may have felt our presence and they need to. You could imagine if you are delicious plant sitting outside trying to grow in the sunshine, if an army of caterpillars comes along, you really want to be able to respond very quickly and defend yourself as best as you can quite complex because obviously you can't move away. So plans have to be very resources on very perceptive when dealing with pest caterpillars the want to have them for lunch. So if you matching this plant here, you could imagine this leaf and if we just pull the leaf apart, and as I do that, what I'm doing, I'm pulling apart millions of cells, a millions of cells being crushed and broken open. Now it turns out, although we can't see it as we share this leave, the plant is actually responding inside within second. We can't see it, but we have known plants are able to do something like this for a long time. But unlike you inmate, they don't. Have the luxury of a central nervous system. So this group among many others, wondering how are they sending these messages? What the show is that the plant is using a small amino acid Colt glutamate. Now glutamate is also used in humans as neuro transmitter remarkably enough. So what happens when sell his damage has the cell releases glutamate into the open and that glutamate is incensed and picked up by channels. And when these channels become activated, they loose calcium and it's the calcium signal. This paper shows is a mobile signal that travels within seconds throughout the plant. And then what plan does is it activates the expression of genes that control of a sponsor to passage. So one way before plan to protect against the Caterpillar is to make yourself taste very bad. How did they find this out? How did they work out? This is what was going on inside the plants. The used a number of tools from molecular biology to identify the actual. Receptors. And so they had a hypothesis that calcium could be involved. Glutamate could be the signal and then they were able to find particular plants that lack the channels that respond to luta mate. What were then able to show was if you take away just these channels within the plant, the plant, no longer transmits. This signal that's kind of definitive proof that you need these channels in order to respond to habitually. I feel kind of bad now for, you know, pulling up daisies make daisy chains and they're sending out these LA help me. That's a good point. Actually, we know plans to fund very much to any kind of perturbation and they have these large scale changes whether or not the aware of this or whether they feel pain is probably unlikely. So I wouldn't feel too guilty about cutting the lawn. But it's interesting to be aware that when you do cut the lawn, you're causing these large-scale changes in how every single blade grasses responding to being caught and you get not lovely. Smell is that the death froze. That's one way of looking at it, but I try not to think about that. And as someone who works on this in this field, how important and how, how much of a change has this paper which say, I think it's a really, it's a great study little to the textbooks. I think there's a whole range of very fundamental questions that we still don't know about plans. This is quite remarkable in a way because we are so dependent on femme grown plants to sustain the entire human population. And so until relatively recently farming has been largely a sort of trial and error process. And just in the last few decades, we've started to understand the molecular basis by which plants grow and how they develop. What this means is that it enables us to potentially improve for heels and food security. There's no question that whoever is a major problem in many areas of culture, so if we can create smarter plants. That are more perceptive and more resilient to feeding insects, and that's going to be potentially huge advantage. Gosh, I'm never look the same way again, that was Philip wig from the saints lab at Cambridge University, and the study he was discussing with Georgia was by Simon Gilroy and his team at the university of Wisconsin medicine. Now, is you often victim of mosquitoes? Oh gosh, they love me so frustrated. Don't go new me, but you might benefit from this because his story about something you definitely not going to see on the cat walk at London fashion week, and that's because it is something highly practical for. These are socks that could save you from mosquito bites and also malaria. So my name is Togo's the Sibanda from the invasive Dettori. When you're out those mosquitoes bite you on the ankles and fit ninety three percent of the time they attracted by foot auto. What isn't that? Where we spray the insect repellent then so you can. Spray took pennant. It will quickly if operates in an hour to is no longer active than you have to respraying again. So we needed to come up with a way of having a long lasting formulation to basically what we developed is as list technology, we spin a fiber and fiber specially engineered to hold liquid insect repellent, and the fiber will slowly release that over a long period of time can last up to eight months or if you need five hundred textile can wash that textile for minimum two, five times and still effective. So you would put the formulation into this fiber using technology invented and what you then spin it into a paradox or an class or something the other person would wear. That's correct. Does it work? It works. We have tested. It actually publish the results in high impact Saint fictional and how effective is it and how did you do that testing? Okay. So the number of tests recommended by the World Health Organization, the one that we. Us is pretty aggressive one where we put our formulated sock on one foot and control. So she's untreated on the other foot. We put what fit in a cage with three hundred female hungry mosquitoes. So they have to make choices which ankle do they feed on. So if you see all of them going to the untreated sock, then you know that your sock is working. Sounds like a really painfully. Did you do it? I did it, but you know, you have people run these insects in the us arms to feed the mosquito. So what I did is really nothing to what other people do. The things that people do science, but tell me about the technology that we do this. How does this clever fiber and fiber spinning technique work? And how do you get the inset repellent in there in the first place? So what we make is what we call a by component fiber. One is in the core in that polymer can absorb high amount of oil. And we have put him on that forms a sheath around the Coppola. So the oil have to diffuse through that shift in that way. The sheet slows down the operation of the oil overly. If you need the extent five wash the textile, you only wash the outside of the fiber bulk of the liquid still stored inside the fiber. It was to migrate to the surface indus- house sort of blemished in essence, Chubu within a tube and the tube inside the tube loves oily, things achieve outside the hate. So anything you'll repellent which is only based in the middle, and it's facing a Barrett diffuse out very slowly. What is the chemical that you're using the repellents that just eat or something because that's the industry leading standard data, isn't it? The did is stunned repellent on the market right now, Scott bed reputation. Unfortunately, although it has not been proven to be bad scientific. So why using alternative. Dylan cold. I at five thirty five says good as did we also use a natural repellent based on the eucalyptus tree and other socks or whatever you design fashionable because of especially with youngsters, people are not going to wear something that looks like a fashion disaster. So can you add color at patterning make it like it's a normal piece of everyday wear so it doesn't look out of place. So when it comes to that easy, those we can make the fiber into any color. We just added pigment so we can make any sock design who actually combine the our yon with the liquid with coach wool to make it nice comfortable in can make a nice fissionable soccer, how will I know though when my socks are no longer working because it's brilliant while it is working of course, but that has to be a way of knowing when I'm no longer protected as low as I could be out there with full confidence and catch something the biscotti we do a lab testing to determine the length that these products. Can what, and we can sort of calculate the minimum length that should keep them for. So they'll be able to say, can wet for this long enough that this is committed to get a new product. Can you recharge them or do you have to throw them away? Because obviously, that's great from the sustainability point-of-view? No, you're right country charge them. And what we are doing right now is what developing the fiber based on by degradable put him. The is research is ongoing to us by degradable forma so that they can be disposable and they're also planning to do a bedbug repelling mattress. The sounds like it could come in very handy to that was crazy sa- Banda and he was talking to me the bio Africa conference in the company that he set up to develop those inset repenting fabrics could Africa applied chemical, and the product should be in the market. He tells me to this year and if you'd like to find out more all the transcripts and the papers for the stories you've just had can be found. On our website, the naked scientists dot com. The naked scientists podcast is produced in a sociation with Spitfire cost-effective voice, internet and the IP engineering services. UK businesses find out how Spitfire can impel your company at Spitfire dot coach UK. This is the naked scientists with Christmas and with is e Clark. And in this offer the program where tackling an attractive topic that explains why this happens, please don't adjust your set. No, the rival have not taken over that. The sound of the Northern Lights or Aurora Borealis which formed when charged particles from the sun slam into our atmosphere producing visible light and radio signals. The POSCO's are deflected into was DiPoto regions by the earth elicit field, but wise, our planet magnetic in the first place have we always had the same magnetic field and is it true? Some animals could detect it and use it to find their way around this week. We're going to try and find out to answer some of these questions is Kathy Walea she's from the university of Edinburgh, Kathy maps, the earth's magnetic field, but she's also got an asteroid named after not at true. Kathy, did you buy off the internet now? It's actually when I was president of the Royal astronomical society, which also covers cheer physics. I was awarded that at the end of my savage good, good night. It's called Cathy Raila, very uninteresting. I'm afraid. In the asteroid belt imaginative bunch. These astronomers. Kathy now, look, I've got a camper sitting here and when I go walking, I use this to find my way around. It's a small magnet, which senses the planet's magnetic field response to it and tells me when I'm going in the right direction. So why has the earth got the ability to make a magnetic field and how's it? So we all sit and walk out and and drive over the s crust, which is a brutal ladder. Seven to sixty kilometers. Thank depending on where you are thinner over the actions, and that's made of silica. This made of rocks and beneath that is also another worke latte, the mantle slightly different in that it's able to creep on Bravo, slow timescales. So that's the top half at their when he got about halfway down. That's really maitre change. So we go from silica dominated material to, I n dominating the tail and they Iran is where we are magnitude Bill from, and we get it specifically from the outer part of what we call the. Call the area towards the center divided into liquid out apart and a solid in apart part of those two bits, the liquid, outer part on the more solid in apart is responsible for making the magnetism. It's the outer part because that's under the process that we co convection basically chance around. And as that liquid moves than it's able to self generate a magnetic field McGinn this is going on thousands of kilometers beneath our feet. How to you as a as a group of geologists, know what you told me is true. Well, we measure the field on different time scales and by different mechanisms, and that enables us to see the changes in the field. And the changes tell us that we have to have some active dynamic process that's responsible for its generation is not a residual fail for many earth was formed for instance on, and it has to be originating from that mobile core given is losing hate all the time caffeine cooling off that includes the core, doesn't it? So if if the call. To go solid, what would happen to our field? Well, if the call was to freeze out altogether, then we would actually lose magnetic field and then we'd lose this protective shield that we've just been talking about that that Texas from Sala when particles and things like that. For instance, if you think about our neighbor, Mars Mars used to have a magnetic field, but it stopped being generated and and as a result Muslim, it's atmosphere. Thanks Kathy, and we'll come back to you in a moment. But first we really need to explain what a magnet actually is and how the magnet and a compass is a bit different from what the earth is doing itself. So I shot on some safety goggles and headed to see physicist and science demo king, Dave, and to find out. Took my smitten. We hear looking at like this in this amazing workshop, I'm well with all the experiments we today. And is a permanent magnet sort of looking in a really, really small scale. Some materials like wine is one of them have atoms with more like trans guy. One way round than the other on that creates nitric current, which makes little tiny electromagnet now on its own. This doesn't make something even magnetic. These little atoms will be randomly arranged and the nineties average out there. But with some of these materials like nickel and Kabul's for where quantum mechanical reasons these little tiny atomic magnets lineup for a great big areas, the mines with all the magnets lined up. So it will mentally fields add together so they can interact with things magically really strongly caso. It's like that all acting ones I've action. So overall they have of magnetic pole eventually. That's right. And then if you put in another magnet, those magnets will interact the stick over repel. Okay. So is it that something can stick to a magnet but to is. A magnet itself. So this goes back to the domains talked earlier which other small magnets inside a piece on her little metal, not here inside the magnetic domains and they will make themselves. But there arranged randomly. So all is not a magnet, but if you put it near Magnette, those two Maine's will twist round lineup. So it becomes a magnet aligned with regional magnet. So North Pole next half also sticks. And we can say that because if we take a second, it was the first one. Third, fourth, fifth, sixth. So what we've got here is lots and lots of tiny little metal nuts on their own, then not stuck to each other. Whereas you bring a magnet into the game and all of a sudden one six onto the magnetic, then you can stick another onto one, not and so on. You've got an even bigger Magnus essentially. ROY here on take away from a magnet, the domains just of randomize again, and it stops being magnetized role so I can take them off from the next to each other. There's a big difference between something being a magnet and something having magnetic properties take your fridge. For example, you can sick magnets on it. Therefore it has magnetic properties, but it's not a giant magnet itself. I mean, it would make taking cutlery out of a drawl rather problematic. And these ion knots are the same on their own. They stick to each other, but because they have magnetic properties as long as there's a magnet in the vicinity they'll stick an act like an extension of it, but could we take one of these knots and actually transform it into parmanent magnet itself? I who need stone with ROY material. You want something, which is really hard to twist demands round. One of the best materials that is neat. Him on boron which is not all three elements. So this is a lump of needed him on boron and it will stick to magnet very weakly because not many demands twisting rounds, so forms of very weak magnetic. Okay. So how would we turned that into magnet? So what you have to do is make easier to turn these demands round and the way that is heating up and bring out this giant blow torch goodness. So now this up to orange Holt, and I'm going to take a step. Okay, so orange isn't exactly a temperature. We will understand Dave heated. This lump of Neo denim, iron boron to temperatures of above eight hundred degrees celsius. And Yep, it started to glow a now put that down next to a very strong magnet and let it cool down slowly, but does cooling a lump of hot metal near a magnet. Then turn into a magnet itself because it's really hot. These manage mains can twist around very. Easily. And then as it cools down that comes hauled in heart of them, spin rounds. Hopefully we're kinda freeze in the magnetic field which is now of now move this name on boron away from the magnet and put it next to campus. And if I spend it round become Stearns around, we have just taken something unturned to into opponent magnet because they didn't want on this very permanent magnetic site like this for years and years near. So would this method work? What's the magnetic failed? You'll get a much much we can position effect. So it's really important in geology, because if you get a molten piece of rock, it's heating up to red hot. And if your little lumps of magnetic material in there, as it cools down though freezing this failed, which was there when it was created and that can tell you stuff about the failed over time. Because if you how the Rockies this, I feel it was like, so is. The giant permanent magnet. The short answer is no, and I can prove why company? What I've got here is not again next magnet. It sticks really quite effectively. Now what I'm gonna do hate this up and back to the blatant watch, our school is full of iron. We took this tiny iron votes and heated it again, eight hundred degrees celsius, so we can use heat to turn certain metals into magnets. It can also demagnetize them enough. I put it near the magnet. It doesn't stick to as it cools down. Eventually it does start to stake. Oh gosh. Yeah, so it's just too. So what's going on here? If you heat up fire magnet like hot enough, you give it enough energy that the individual atoms stop linking to each other. And I just thought to randomize open team completely random action. So it stops being even magnetic tool. This happens at a temperature over Curie temperature than as it cools down. They start lining up again and it starts coming magnetic material again. So this improve the copy permanent magnet because Curie points, maybe thousand, maybe slightly about degree celsius and the center the is much much hotter than that, so it can't possibly be opponent magnet divan. So Cathy coming back to you. So the oath is getting its magnetic Phil from this mobile Multan on core in the center, wants the shape of the magnetic field that call produces. Well. Interestingly, the shape is very much like a bar magnet as just pay inhering with two pulse and North Pole and south pole, and because the convection the liquid is moving around strongly influenced by the earth rotation that bar magnetic field lines with the north south Pultz approximately. So it does look very much like a bar magnet, but it's caused by a different mechanism. What benefits does the field impart to us as dwellers. Owner? Well, we've already had about shielding us from the vagaries of space weather, so it stops charged particles which the surfaced over most of the part. It gives us a way to navigator. She was saying the start this program impacts a signature to the geology which we found helpful in exploration for resources and. It really is protective shield, and that's perhaps the most important thing about it and in protecting your so-so gives us that lovely light show that we call the the Aurora. That's right. And so why is it so important to study it? I'm not gonna tell us when it does provide our window on the court. So a lot of the information that we have about the earth's core has come from knowing it's magnetic field and knowing how that field changes over time. We can also use it to investigate the geology. We can look for mineral resources. We can look for hydrocarbon resources choose to help when drilling for those resources. We can even see magnetic field in the oceans looking at the data collected by lower putting satellites. So because the oceans are salty water as they move around, they also generate a magnetic field in a rather similar way to today escort self, and we can see the tides even Kathy. Thank you very much for telling all about Kathy the from the. -versity of Edinburgh. Still to come candidacy the asthma Natick failed so they can navigate by it. Meanwhile, if you'd like to get in touch with us, tweets, make it scientists or you can Email Chris, the naked scientists don't come now as we just heard, if you take potentially magnetic material and you raise it to a high temperature and cool it in the presence of a magnetic field. It remains magnetized. And this also happens on earth when motor logs from the planet's interior solidify at the surface, because as they do so they capture a snapshot of the magnetic field in which they formed. And that's how we know that the us might enter code has flipped around in the past and been changing Richard Harrison studies at the university of Cambridge, Richard, welcome to the program actually read these tiny signatures in the rocks that you in all about trae. Well, first of all, you have to collect some samples. So a paleo magnetism who studies ancient magnetic signals will go out into the field with something like a modified chainsaw drill into the. Brooke extract oriented coal. We know exactly what orientational was taken out of the earth. Take that back to a laboratory. You then have to measure its magnetising. So we have extremely sensitive magnetometers usually colder squid magnetometers superconducting quantum interference device. So they're able to detect the really weak magnetized Asian of these things. And we put that into what's called a shielded room. So we want to measure the magnetized in the absence of the field. So we built the shielded rooms, wooden structures lined with metal little bit like a Faraday cage for magnetism shields out the field. So we can measure it in zero field environment and see what the magnetic memory of that rock is. Does that tell you though how strong the magnetic field is? Because that's the other important component isn't not just what direction is pointing him, but also how big it is. Yes. So we get to fundamental pieces of information from these Roques. We can tell the direction of the field that was present when the rook erupted and cooled at the surface. But we can also tell how intense magnetic field. Field was, and we can trace both of those things back through time by looking at Rokkasho of lots of different ages. You gave me a very nice suppleme- came in this little crystal and the very strong magnet. What was that too show? Okay. So this shows why rox are magnetic in the first place and their magnetic because they contain a small proportion of a mineral coal magnate black crystal, yes. What you have in your hand, there is a is a beautiful octa heathen of magnetized, which is an iron oxide. And what you'll find is that if you place it close to that little bomb Ignat, it should. During the. So this is basically a chunk of rock, and I'm going to bring it close to the magnet and and it just left off my hand and stuck to it. So basically your recording, tiny signatures written into minerals a bit like that woman, you do your experiments. That's right. So Magna tight makes it very nice, permanent magnet. If the, if the particles are small enough, this sort of Goldilocks zone for particle size. So that piece you have in your hand is sort of millimeters in size. That would be too big. It doesn't have a very good memory, but if we shrink those particles down to just a few hundred nanometers, they become excellent magnets with a really good memory of the magnetic field. What have you learned about geology the Aleutian of magnetic field and the vision of the surface of the she studying these signatures, paleomagnetic measurements who have been absolutely fundamental in our discovery of how the work. So the theory of plate tectonics really came about through studying the magnetic signals in the ocean floor and through studying the the MAG. Attic memory that you see there, it was able to prove that the ocean was was spreading and that continents would drifting across the why the flow wise that critical during the second World War people mapped out the ocean flow magnetically detail. They wanted to detect submarines since they needed to map out the magnetism of the floor and what they fan with magnetic stripes that go parallel to ridge of o'kane's all the way down the center of the ocean and these magnetic stripes assymetrical either side of the ridge and what they track over time is this brand flipping of the magnetic field where the north and the south poles switch around on this metrical either side of the ridge because the sea flow is being born there and moving away the if it's parallel to the ridge because the flow was born on each side of the ridge at the same time. So inherited the same field of that moment. Exactly. Said, the magnetism is recorded as that new ocean crust in the center of the ridge is is cooled and it recalls the present, I failed and then its pushed aside. To both sides, and then later on the field flipped, and then you get a different direction being recorded at the center of the ridge. So that patent of magnetized Asian was absolutely critical to sort of determining that continental drift was real, and that led eventually to the revolution of plate tectonics. Can we use the same trick Richard with some polls from not just the other planets. We have meteorites for malls result, but we have some of lunar rock. Can we look at magnetic fields in those? Absolutely. A lot of the work that we do in Cambridge is looking extraterrestrial materials so that could come from studying meteorites where we can look at the magnetic fields generated by asteroids early on in the solar system. We looked at magnetism during the Apollo missions on the moon, and that we able to bring rocks back from the moon does have a magnetic field doesn't have one now, but it did have about full billion years ago early on in its formation. Yes. So where's it going then was the moon no longer. Got one. Well, the moon has a very small core as in the case of Mars, the conditions have to be just right. To for that call to generate a magnetic field. So when you have a smaller body that's Kooning quickly, the dynamo tends to switch off some point, and you mentioned earlier about the field flipping and things people often quite curious about this. Has that happened to lots of times in the past? When's it do next? Should we be worried? We shouldn't be worried the earth's field has flipped many, many times in the past. It flips on average something three to five times per million years. The last reversal was seven hundred eighty thousand years ago. Life has persisted through all of those reversals. So that doesn't seem to be any majorly dangerous impacts of having the field flip. The main thing you'll notice is that mobile phone signals will get worse when there's a flip. Oh, my goodness. Mine's bad enough already. I can't consolidate an even worse mobile as much as throw the phone away. Anyway, thanks for that great news richer, this ratio that life will persist. Richard Harrison is in the university of Cambridge now about from being very useful for. Geologists who want to understand the planet's past as well as fending off the onslaught of solar wind and helping humans. He wants to navigate the old fashioned way with a compass. The earth's magnetic field is essential to many migratory species, but appear to be able to read the direction of the field and use it to guide them as they fly thousands of miles Francesca Faizy spoke to Oxford scientists, pizza hall who suspects that proteins called cryptocurrencies in the bird's eye enable them to see magnetic fields. Close your eyes and turn around five times. Now without opening your eyes head towards magnetic north. Okay. So you don't actually have to try this and please don't, especially if you're listening near a busy road, but if you were able to do it, chances, are you'd be a Robin or any other kinds of migratory bird. Scientists have worked out that birds that migrate can actually sense the direction of the nag Nettie field using some neat tests. Here's professor Peter Hore at the university of Oxford who specializes in this area. Experiments involve testing the birds during the mica treason. So these small migratory songbirds like Robbins and during the micro Treason's in the spring and autumn. If you put them in a funnel shaped cage, the direction in which they hope to try and get out of the cages is the direction in which they would fly if they were released. Now here comes the clever bit using coils and currents. You can change the magnetic fields that the birds are experiencing. And then see if it changes the way they try and hop out of the cage and incredibly it did. So how do I fed friends do this. The leading hypothesis at the moment is that are magnetically sensitive. Chemical reactions in the retinas of the birds is that these chemical reactions allows them to sense the direction of the field. A recent study has identified specific protein with a great name cryptic room for that, they think is the most likely candidate for a magneto receptor. Envy's migrate responses. This is because crypto chrome, four or cry for as they like to call. It only seems to be expressed during the migratory season when they needed to guide the long journeys and get this bird who don't migrate like chickens, don't express cry for at all. The protein is located in specific cells in the retina which are involved with vision. So does this mean that the birds can actually see the magnetic field? Peter has a classic scientists onto this maybe so no flights of fancy for us today than return. No, nearly enough about how's the signaling works? It is clear of the detection of Mike field involves the birds visual system, so the receptors unlikely to be in the receptor cells. We know that when the information from the retina reaches the brain. It's processed in visual part of the brain. I think it's too soon to say whether that's literally see the magnetic field or whether it's some visual impression which of course is difficult for us to imagine because humans don't seem to have a magnetic sense. Although we have tried to find it. One study sent out blindfolded students into the woods and asked them to find a way out game. Amazingly they did without any serious injuries. And the researchers suggested that this was due to us having a secret sense of magnetic north much like the migratory birds. But like many of these findings, it has never been replicated. So we can't genuinely claim to have the superpower. Some other animals though might high-profile study a few years ago in which the scientists analyzed Google images of of wild deer and domestic cattle and found that the animal's body axes. Axes tended to align with the psychic field. Gosh, that proved difficult to replicate, but it's a hint at least that maybe these land animals that do migrate large distances might have some use for the us magnetic field. Sounds like a very attractive filled to be to me. Believe me. I didn't write that. I know everyone writes in tells me my jokes, terrible. Honestly, I'm not responsible for that one. That was, and he was beginning with Frencesco Faizy still with us is Richard Harrison. It's important to emphasize Richards isn't it that it's not just birds that sensitive to the magnetic field. There are lots of animals and other organisms that emerge now is being sensitive to main schism. Yes, that's right. And one of the best known examples of of an organism that uses the magnetic field to navigate is in a type of bacteria that we call magneto tactic bacteria. And these are amazing little creatures that have lent to built to be. Build chains of magnetic nanoparticles inside their cell, which essentially turns that bacterium into the compass, and they swim along the earth's magnetic field lines so that they can find very efficiently, the correct level in the water column for them to to to live always going to say what would be the advantage to bacteria to be able to sense the magnetic field? Well, they live under very specific conditions. They need too much. Oxygen would be poisonous to them too little is is again, not not ideal. So they live at the reeboks boundary between the two. And if you swim around randomly trying to find that level, it can be a very inefficient way. But if you own yourself in the field and swimming and exactly straight line, then you get there very efficiently. I read a story in the journal Il life about three years ago, researchers published a very interesting paper on tiny microscopic worms, and they found that these worms would swim in a certain direction through. Jelly, they grow them in when they're in England. But if you send them to Australia to Adelaide, where do these experiments, the worms will swim in the opposite direction and studying the worms. It turns out that there is a set of nerve cells at the back of the worm which are very long in one direction, but very narrow in the other axis, and they think they behave a bit like an antenna which means they might be sensitive to the inclination of my Nettie feel because if you also do the experiment grow these worms in an applied magnetic field, you can change this behavior and if you Bosch those nerve cells that are in the worms, they lose the ability to detect magnetic fields. So it looks like they have evolved away independently to have their own sort of magnetic antenna inside the worm again to to find the right level for they, they need to feed yet us very interesting. And the the idea there is in the northern hemisphere inclination, the earth's magnetic field is pointing down towards the ground. But if you go into the southern hemisphere, the earth is pointing up into the magnetic field is pointing up into the sky. So if they're sensitive to that change in intention than that might affect the way that they swim. Tricky for me went to malls. Then as we're hearing from Kathy earlier, the malls is lost magnetic field. Things like that just wouldn't work. Would they? Well, now's did have a magnetic field early on in its history and that there are the infamous claims of evidence for these magneto tactic bacteria in the Allan hills AL h eight, four zero zero one meteorite where people have found the magnetized Nanno crystals which are remarkably similar to those that we find in Earth-based bacteria. But I should say not everyone believes that theory and Tokyo people believing there are people also working on whether humans have these Bility's and we just ignore them because we have more dominant skills like air is an GPS. So we tend to suppress these other potential latent magnetic sensitive skill. Yes. I know people who are working on that, and they're finding some interesting results unfortunately under lab to talk about it because it's a top secret research. But we can say that there is some evidence pointing towards the fact that large primates should should we. Say, might be able to sense the magnetic field. Richard. Thank you very much. That's Richard Harrison from the university of Cambridge. Thank you to our other guests this week. We're Kathy Lee hall and physicist and science demo king, Dave Hansel, and now to finish. It's time for question of the week, towns in valves, been looking at this off the planet inquiry from Chad. Is it possible to tariff on the moon? So humans could live there long-term. We asked our follows on the form what they thought user diver. John points out that the moon is relatively close to us and suggest living in underground spaces would be possible. We could even use solar panels on the moon surface to supply electricity. I spit to planetary geoscientists David robbery from the open university terra forming usually understood to mean modifying the atmosphere, and hence also temperature of a body to give it an environment where we live. So in terms of us going to live in the open on the moon? No, because the. Moons gravity is too weak to hang onto relatively molecules which is water vapor, oxygen and nitrogen in the long term, even supposing you found a way to liberate enough of those guys is out the moon surface to give a brief atmosphere. You'd have to continually replenish it away to space. So like all bad, I date restaurants on restaurants on the men would have no atmosphere. It's not just for moons week, gravity problem. The noon has no magnetic field to deflect. The solar wind service would always be roading the top of the atmosphere. The closest we might one day come to tear formed environment on the moon being signed a large, transparent and leak. Truth dome fill this with the right mix. Oxygen come dockside water vapor and nitrogen to more or less much fear, soundless fear, and you probably arrange average temperature inside the dome to be comfortable for humans. Despite the nights lasting for two weeks, you could pull. Only grow crops there too. After a lot of work on the soil to get it structure and been micro organisms, right? If we did decide to move to the moon, we certainly would need to plan it. The biggest obstacle to Hume's sitting on the moon or indeed anywhere in space is the cost of transporting whatever resources you need from the earth. Things would be so much easier and cheaper if you could get most of what we need at our destination, rather than taking it with us. We know as water in reform of ice inside the shattered. Craters never moons polls. There's plenty of oxygen that you could liberate us a large energy cost from lunar rocks. Carpenter, Nordstrom might not be so easy to come by though, so we might need to depend on the earth of course awhile. Thanks for being back down to earth. David. Next time we'll be sticking to this one from Thome in Austria. Why is blue sticky stick around? And we'll tell you next week. If you have an answer to that or a new question, you'd like us to look into. You can Email Chris at the naked scientists dot com. Find us on Facebook tweets at naked scientists or get on our foreign. That's an scientists dot com slash forum that we've got time for this week. Thank you to Francesco Faizy for production and do shorter. Join us. Next time we're looking at the science of flu. It is one hundred years since the worst flu pandemic in history, and we'll put the past the present and the future of one of our most deadly diseases. Under the microscope, the naked scientists comes to from Cambridge University and it supported by the EPS RC and rose Royce. I'm Chris Smith. Thank you at home, very much listening until next time. Goodbye.

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