She seems to have an invisible touch

Imagine the things you would do if you had Harry Potter’s invisibility cloak. Everyone has had this fantasy, but now it seems that this staple of science fiction from Star Trek to Dr Who may be close to science fact, although it requires a little imagination, and a little faith in some extraordinary mathematics.

Within the last few months, a number of theories for developing cloaking devices have been unveiled. Two recent reports in the magazine Science have described how experimental "metamaterials" can change the way light bends around an object, to create an illusion that we might call a mirage.

Metamaterials are composite materials that are designed to have interesting properties, such as the ability to bend light. They contain microscopic rods or metallic rings that can be tinkered with to interact with light in controllable ways, such as to manipulate how quickly light travels when near particular parts of the material. However, despite our espionage fantasies, any invisibility cloaks made out of the material in the near future would be extremely heavy and thick, and you would not be able to see out of them.

Physicist Ulf Leonhardt, of the University of St Andrews and an author of one of the reports in Science, wrote "Imagine a situation where a medium guides light around a hole in it. The light rays end up behind the object as if they had travelled in a straight line. Any object placed in the hole would be hidden from sight. The medium would create the ultimate optical illusion: invisibility." This is like what happens to water when it runs around the outside of a smooth rock in a river, and occurs in our case here because of refraction - a characteristic of light where it takes the quickest, but not necessarily the shortest, path. We can see refraction by simply dropping a pen in a glass of water and observing that it looks like its bent, when we know its not.
Sir John Pendry of Imperial College London, author of the second report, also predicted that with sufficient funding, the first of these devices could be around within 5 years.

These devices could also be used to hide objects from other electromagnetic waves and even sound. This has obvious Defence applications. David Schurig of Duke University in North Carolina and Pendry’s co-author stated that this Defence goal "would be to conceal an object from discovery by agents using probing or environmental radiation." This is a different method of stealth than modern methods used to hide planes from radars. Current stealth technology revolves around reducing a plane’s "Radar Cross Section". Radars work by sending out electromagnetic radiation, and then detecting when it reflects back off its target. To reduce the amount of radiation that is reflected back by the plane, we can design the plane’s shape such that reflections do not go back in the direction they came, we can make it out of a material that is non-metallic and so less reflective, and we can paint it with paint that absorbs the radiation. But these methods never make a plane entirely invisible to radar. With this new technology, the hope is that the radiation does not even hit the plane in the first place.

Along with the problem of not being able to see out from the inside of such a material, is the fact that the more types of radiation against which that we make the material work – for instance, if the material cloaks against visible light and microwave radar – the more expensive and difficult the material is to produce.

Another recent study comes from Professor Graeme Milton, of the University of Utah, and Dr Nicolae-Alexandru Nicorovici, of the University of Technology, Sydney. They studied materials with bizarre optical properties first postulated in 1968 by Victor Veselago, a Russian physicist, to show that light could cancel itself out in some scenarios and make an object look invisible. This work remained a strange mathematical fantasy until six years ago with the creation of superlenses that can make objects, when placed near them, invisible. When an object is bathed in light of one colour, the light becomes trapped near the lens and "almost exactly cancels the light incident on each molecule in the object, so it has essentially no response to the incident light. Numerically we see that the molecule is effectively invisible."

This is a mathematical solution. The real test for any of these invisibility solutions will be when someone finally makes one and experiments with it. Until then, the best example of invisibility is that of Professor Susumu Tachi of Tokyo University, who made a suit with a video camera out the back, who's images were projected on the front of the suit, so it seems as though you were looking "through" the wearer. This didn’t quite work perfectly however, as you need to be looking from the right angle for it to be effective. So until our mathematical fantasies come true, we can only fantasise about a future where the Invisible Man is a possibility.

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What the Hack?

Computer hackers come in all shapes and sizes. Some are just curious to see what they can do and don’t cause any harm, others look for flaws in software design and work out ways to exploit them. Some seek power, others seek thrills, some steal money and others steal secrets. We see them in movies all the time. But the term hacker can mean many things, and they’re not all negative.

At their best, hackers may be people who know various programming languages and interfaces so well that they can write software expertly and quickly. These hackers can be brilliant at their tasks, writing detailed programs with little guidance in very quick time.

At their most interesting however, hackers can exploit computer security systems and gain unauthorized access through their own skills, tactics and knowledge. I’m sure that many listeners have been victims of this type of hacker, having perhaps had a Trojan horse, which is a program designed to look like legitimate software, but actually does something malicious, downloaded onto their computer.

A notorious, or famous depending on your point of view, computer hacker is Jonathon James, who obtained access to the source code on the International Space Station that controlled critical life sustaining functions such as oxygen filtering. He also intercepted communications between U.S. Department of Defense officials at the Defense Threat Reduction Agency who were discussing nuclear strategy, and obtained usernames and passwords of Defense Department officials. And he did this all at the age of 15!

Gary McKinnon is another infamous hacker, who is accused of the "biggest military computer hack of all time". The unemployed computer systems administrator is accused of hacking into 97 US government computers, including networks owned by NASA, the US Army, US Navy, Department of Defense, the US Air Force, and The Pentagon. The costs of tracking and correcting the problems he allegedly caused are estimated to be around $US 700 000.

Another, rather ingenious, hacker is Noah Burn of South Carolina in the US. Burn exploited a software flaw in the game EverQuest II so that his character within the game, a barbarian called Methical, could sell lots of desirable goods, and therefore make lots of virtual money. Now this might sound like it’s not worth the effort – after all, all this extra money is just virtual money, and you can’t spend it in the real world. However, with online gaming becoming more and more prevalent, a real life market has been set up on auction sites such as e-bay, whereby you can buy virtual goods for real life money – that is, you can buy the goods and have your character possess them, without having to earn them within the game. In this way, Burn made roughly $US 100 000 in the real world due to a minor glitch in his virtual world.

Indeed, this real life market for online commodities has taken off to such an extent that some players have been collecting real life money for destroying the property of other characters, or even the characters themselves. One such online character is Istvaan Shoaatsu, who is a mercenary destroying other characters for a profit within the game Eve Online. And whilst Shoaatsu may profit in the real world from these activities, those whom he destroys lose their own virtual money, which has taken time to earn and has a real life worth. Indeed, violence from the online world has spilled over into reality. Qui Chengwei from Shanghai, having loaned his valuable sword to a friend Zhu Caoyuan within the game Legends of Mir, actually murdered Zhu in real life when he discovered that Zhu had sold his sword on to another buyer.

This highlights an area where our laws are just not ready, as we have never had to develop laws for such situations. Another area where this is the case is in the situation of bio-hackers, who are similar to computer hackers, but instead of tinkering with computers and software, they experiment with DNA and other aspects of genetics. It is thought that in the future, computers themselves will contain biological devices. But until then, the risk of bioterrorism and biohackers with evil intent is high. Imagine if you could isolate the DNA of dangerous viruses and create even more deadly bugs? Tom Knight of the Massachusettes Institute of Technology thinks we have absolutely no choice but to try and do this better and faster than the bad guys, and work out ways of lessening the possible damage caused.

See Tim Guest’s book Second Lives, which will be published in 2007, for more information about online/offline adventures.

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Scientific Dating Tips

Some of us are pretty unlucky in love. The old tricks of buying flowers, buying dinner and whispering sweet nothings just isn’t working. Perhaps its time to turn to science to win us the heart of that special person. But can science successfully play Cupid? Here are some tips from society’s most lucky in love, the scientists.

Make your Body talk
Forget the pick up lines. Body language is more important than the smoothest of opening lines. When you meet someone for the first time, 55% of the initial impression is based on your body language, 38% is based on the tone, speed and style of your voice and only 7% on what you actually say! So what sort of body language should we employ? Mirroring the other person’s movements and posture is a good start. Most people do not realise they are being mirrored, but will view you favourably. Adopting particularly masculine or feminine postures can also help, like putting your hands in your pockets to puff out your chest.

When I look into your eyes...
It may seem like a pretty simple act, but looking into someone’s eyes can have a powerful impact. Gazing into someone’s eyes lights up parts of the brain associated with feeling good. Psychologist Arthur Arun performed an interesting study where he asked people, who had previously never met, to stare into each other’s eyes for four minutes. Their feelings of attraction rocketed compared to staring at other parts of the body. Indeed, one of these couples ended up getting married!

Our pupils dilate when we are interested in at what we are looking, and it has been shown that people are attracted to large pupils – in the way that people find big-eyed puppies cute! Indeed, in medieval Italy, ladies put bella donna in their eyes to make them look bigger. This is not particularly wide spread these days, as bella donna is a poison!

Be afraid, be very afraid
There is a strong connection between anxiety, arousal and attraction, and it has been found that couples who meet when physiologically aroused, or who experience fear together on a first date, have an increased chance of having romantic feelings for each other. No one is quite sure why this happens – it could be that the adrenaline rush from the danger is misinterpreted as attraction – but it suggests that a bungee jump first date could be a good idea. Or at least, choose the suspense or horror film over the chick flick.

Be Funny
Love and laughter go together. If you can make your partner laugh, you have a stronger chance of them falling for you. If you have ever noticed that couples in love tend to find each other funny whilst the rest of us think that their jokes are pretty bad, it is because a compatible sense of humour seems to be one of the keys to love.

Can there be more than one “one and only”?
Do we each only have one “soul mate”? Is there really such a thing as finding your one and only beloved in a world of over 6 billion people? Evolutionary psychologists at Indiana and New Mexico Universities used computer simulations to examine this question of how to best choose your partner from a set of prospective lovers. They set up their experiment such that the person making the choice of partner examined a bunch of potential partners to determine how attractive they were, and how high he should set his sights. Once this decision is made, based on those prospective partners he has seen, he goes for the next person who he comes across that fits his criteria.

The researchers found that one should only examine 9% of all the possible partners out there, before making your choice. For example, if you were at a party of 100 people looking for love, you should only scrutinize the first 9 possible mates you come across before focusing your attention on that special someone. Examining less than this number means that you do not collect enough information to make a good choice. On the other hand, examining more means that it is more likely that you wont choose your best possible choice as they are more likely to be amongst those you examined and then ignored before choosing. Whilst this model is far too simplistic to be an accurate representation of the search for love, it tells us that we should not search forever, as it is likely that we may let our true love pass us by.

So let us know how these tips work for you, as it would seem that love does not follow a rulebook.

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Sniffing out a partner

What makes you fancy someone? What is it that you look for in a partner? This week on Mr Science, we will continue our exploration of the science of love, and take a look at how your genes, your nose and even the Internet can all play a role in for whom you fall.

There are some facts that are unavoidable – some people are simply just beautiful. Perhaps they have symmetrical faces – it has been shown that men prefer women who are close to symmetrical. Perhaps their bodies contain the golden ratio, as discussed in previous weeks in the Mathematics of looking Beautiful. In women, men seem to look for full lips and soft facial features. In men, women seem to prefer broad shoulders and the appearance of sexual potency. The desire for these features seems to be conscious and universal.

However, not everyone can end up with the Brad Pitts and Natalie Portmans of this world. It would seem that people fall for those who have similar attractiveness, intelligence and "status" to themselves – that is, those within their league. If everyone fell in love with a movie star, only very few people would end up breeding, and this is obviously bad for evolution.

On the more subconscious level, a set of genes known as the Major Histocompatibility Complex (MHC), seems to play a role in to whom we are attracted. We actually look for people who have a different MHC to ourselves. The MHC helps us fight off pathogens, so the offspring of two people with different MHCs has a broader immune system than the offspring of parents with similar MHCs. And it would seem that our noses sniff out this difference. A 1995 study by Claus Wedekind of the University of Bern discovered that women prefer the smell of sweaty shirts from men who have a distinctly different MHC to themselves. This is similar to the situation with rats, who smell the pheromones in each other’s urine to determine their resistance to disease.

An interest exception to this rule is for women on the contraceptive pill. These women prefer men with a similar MHC to themselves. Women’s preferences also change throughout their menstrual cycle, as during periods of high fertility they prefer men with strong masculine characteristics, whilst at other times, prefer more stable caring men.

Another recent, rather Freudian, finding is that we seem to prefer a partner who reminds us of our parents. Men seem to prefer women who are like their mother, and women want the man of their dreams to remind them of their dad. David Perrett of the University of Scotland performed a computerised study where he morphed pictures of participants’ faces into the faces of others, and discovered that his participants preferred the faces that contained fractions of their own face – even though they could not consciously determine their own faces on the screen. He suggested that this was because these faces remind us of the faces we constantly see during our early childhood – the faces of our parents. It has even been suggested that we prefer someone to smell like our parents. It would seem that we are seeking our partner to possess an immune system which is a blend of the tried and true immune systems of a parents, and that of one that is completely different to our own, to make sure our offspring has a wide range of genes for immunity. We seem to desire a balance between inbreeding and outbreeding.

Not all relationships however are born out of compatible genes and smells. Many modern relationships start in that very modern of media, the Internet. There is growing evidence that the Internet can be more conducive to open relationships than first meeting in reality. This phenomenon has been called the “hyperpersonal” effect by Joe Walther of Cornell University, and refers to the fact that when communicating by typed messages, we have more time to construct our responses and are often more intimate and honest. By not having to look at, or hear the person to whom we are talking, we can focus solely on what we are saying and not the way we look or sound. This allows us to build positive impressions of each other without the visual clues that might have normally put us off. This means we get to know each other from the inside out. Walther also uncovered that, despite its ease, people are less likely to lie online, possibly because there are no uncomfortable consequences.

Another researcher, Katelyn McKenna of Ben Gurion University, thinks that in some cases, an attraction built on the Internet that may not have started in real life, may be strong enough when the couple do finally meet offline. Indeed, McKenna thinks that sometimes starting the relationship in the safe environment of the Internet, where people are more honest and open about themselves, may be preferable. The danger is that, because there is no physical contact, participants in online romance may fill the gaps with what they would like to believe about the other person, and not what is actually the truth.

The road to true love seems to be a mix of the conscious and the unconscious, and may take unexpected turns. Until next week, try and find yourself an object of affection, and next time on Mr Science, will we take a look at how you can best scientifically woo your love.

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Love is a many splendored thing

Love has inspired painters, songwriters and artists for centuries. Singers have cried that love will tear us apart and that love will lead us back together, that love can be tainted, and that the look of love is something to be desired. Some cultures have more than 10 words for love. But now scientists are starting to get interested in this fundamental human emotion, and this week on Mr Science, we will start a series of shows looking into this crazy little thing called Love.

The scientific understanding of love is still in its early stages, however when it comes to those warm tingly feelings inside us, it seems that our biochemistry is to blame. Right from the moment we are born, chemicals in our brain effect how much we bond with those around us. The love of a mother for a child is perhaps the most fundamental of loves, and scientists are now starting to understand that this love is cemented by a hormone called oxytocin. Late in pregnancy, the number of oxytocin receptors in the brain increases because of heightened levels of oestrogen. During childbirth, the hypothalamus gland releases high levels of oxytocin that then bonds to the many receptors, thus making the mother effectively “addicted” to her child. This makes evolutionary sense, as a strong bond between mother and child is essential for the child to survive.

Oxytocin is also thought to be associated with long lasting intimate relationships between adults. Oxytocin is released during intimate physical contact between partners, and boosts trust between partners whilst also helping people overcome “social fear” when getting to know each other. A study of “investors” and “trustees” at the University of Zurich suggested that with just a sniff of oxytocin, those playing the role of investors would hand over all their money to phoney anonymous trustees without any guarantee of its return. Those in love would recognise the thought that your partner can do no wrong.

But whilst oxytocin cements close relationships, other chemicals get us to that stage. Lust is driven by testosterone and oestrogen. These hormones encourage us to get out there and meet people, and cause the initial attractions. After lust comes attraction, and this is the stage that most people regard as being love-struck. You are unable to think about anything else and you spend hours daydreaming about that special person. Sometimes you don’t even need to eat or sleep. A group of neuro-transmitters called monoamines are to blame here. You are the victim of dopamine, which is also activated by smoking, adrenaline, which makes you sweat and your heart race, and serotonin, which has been shown to be associated with mental disorders. It would seem that you would have to be mad to be in love. Indeed, studies in Italy have shown that some people recently in love suffer some symptoms of Obsessive Compulsive Disorder. Some even suffered depression!

Another interesting chemical in the brain associated with long-term commitment is called vasopressin. The amount of vasopressin in the brain seems to determine whether or not a couple will remain monogamous. Monogamy, or having only one partner, is not as common among mammals as one may think. Although having monogamous parents could help in child raring, less than 5% of mammals have only one partner. Nature provides a good example of how vasopressin can determine monogamy. The Prairie vole bonds very closely to its mate, whilst its relative, the meadow vole, is promiscuous. It seems that the difference between these species is the amount of vasopressin receptors in the brain. In the prairie vole, when the hormone is released during physical intimacy, there are many receptors with which it can bond, and the deep monogamous relationship is cemented. In the meadow vole, there are very few receptors, and so the feelings of love are not generated and the meadow vole moves on to its next partner.

So it would seem that we are at the mercy of our biochemistry, and that love may indeed give us a mental disorder. In the next few weeks on Mr Science, we’ll have a closer look at what we look for in our perfect partners, and also how to best scientifically woo your lover. We’ll also take a look at internet dating.

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