Is an invisibility cloak really possible?

This is a really cool guest blog by the awesome Jonny Brooks!

Have you had a moment so embarrassing that you just wanted the ground to swallow you up? Or you’ve ever wanted to sneak into a room where you know your boss or teacher is talking about you, just so you know what they really say about you? At times like these it would be so handy to have an invisibility cloak just like Harry Potter so no one would ever know you were there.

Well this is what scientists around the world are trying to do right now.

Figure 1: Harry Potter and his awesome invisibility cloak........... that you can't see
Figure 1: Harry Potter and his awesome invisibility cloak……….. that you can’t see

How does it work?

To be invisible you have to make sure that no one can see you. Obvious right? But that’s not the only thing (otherwise hiding behind the door would make you “invisible”). In addition to not being able to see you, the tricky part is also making sure that the person can see what’s behind you. This creates the illusion that people can see straight through the invisible object.

This can be done in several ways, although two of the most common methods are by transformation-optics cloaking and optical camouflage:

transformation-optics cloaking – This method makes use of materials known as metamaterials. These metamaterials are engineered so they exhibit properties that have not yet been found in nature. Built correctly, these materials allow us to bend light around an object making the object invisible and also making sure people can see what’s behind you.

Figure 2: Bending light around an object
Figure 2: Bending light around an object

optical camouflage – This is one of the simpler methods of making an object invisible. Take an object that you want to make invisible (like a human for example) and put a camera on the back of the object. This camera records the images behind the object. If that camera is connected to a video feed in front of the object, then you can project the images of the camera onto the object, creating the illusion that you can see right through it.

Are we close?

Good question. I guess the answer is “kind of”.  Transformation-optics cloaking was one of the first successful demonstration of the method in 2006, but it only worked with microwaves. This means that if our eyes were able to see microwaves, then we would have an invisibility cloak. Unfortunately this isn’t the case. Our eyes see visible light.

Not only that, but many of the methods used to make objects invisible scatter more light, at a different part of the light spectrum, than the object that they were trying to hide. For example, if you had a cloak that made an object invisible to red light, it may actually be scattering lots of blue light. Therefore it may be invisible to red light but if you shine blue light at it, then the object was probably more obvious than it was before.

Despite this, new methods of cloaking are being developed that use electricity to make an object appear invisible. These have the benefit that the device will not scatter light over a broad range of the light spectrum. However, much more research is needed before we have something that truly works for visible light.

So in short, it’ll be a very long while before we have a true Harry Potter style invisibility cloak, but we are making progress. For now, we’ll just have to keep dreaming.

Thanks for writing for Sparkly Science Jonny!

Give him a follow on twitter @Jonny_CBB and check out the work he does at the University of Oxford

xxx

Increase productivity – all you need is some company

So we know that having your boss or a co-worker standing in view of your computer screen makes you minimise YouTube and look busy – but some new research suggests that just the presence of others in the room can increase your productivity. This is based on the psychological term ‘Social Facilitation’ – which means an improvement on performance based on the presence of others. This is nothing new- but a new study in France managed to explain how this works.

To be more productive all we need is a friend in the room
To be more productive all we need is a friend in the room.. sort of

The experiment:

This study was done on monkeys (so could we apply it to humans – hmm?), the monkeys were trained to touch images, and their performance in this simple task significantly improved in the presence of other monkeys – demonstrating social facilitation.

Attention- not motivation:

The activity of the circuits in the brain controlling motivation did not change, but when other monkeys were present the circuits controlling attention were really active. This shows that company can make us more attentive – which causes an increase in productivity.

What does this research mean for us?

If company improves our attention and productivity, does this explain why so many of us prefer to study in a library than alone at home? (until the person next to you starts to eat really loud crisps – then the whole theory is moot) If further research is done maybe this could make workplaces steer clear of using private offices and have everybody work in one big office together – although I am sure some big, human studies would need to be done to convince some people to give up their swanky private office space.

Till next time,

Lucy

xxx

The science behind why hair turns grey

Some of us embrace the idea of becoming a ‘silver fox’, while others will do literally anything to hide the 50 shades of grey sneaking into our hair. However we feel about it, the reality is we will all go grey as we age, so I was wondering – why does this happen? And could we use science to prevent us from going grey?

For some people turning grey is not a problem at all....
For some people turning grey is not a problem at all….

To explain how our hair loses colour, we have to think of hair growing in cycles. There is a ‘growth phase’, where hair grows in length, and a ‘rest phase’ where hair stops growing and eventually falls out of the follicle. In this cycle the hair pigment is produced in the growth phase, and turns off in the rest phase, then production resumes again as we go back in to the growth phase. When the pigment production stays switched off after the rest phase and fails to turn back on in growth, we grow a grey hair (with no pigment).

With every hair cycle we have, some of the melanocytes (cells that produce pigment) in our hair become damaged.This isn’t a problem as we can replace the damaged/dead pigment producing cells with others from a little stash of them that we have, but when this store of melanocytes becomes depleted as we age and have used all of them up, we no longer have any cells to produce pigment – so our hair grows grey.

How would we stop hair going grey?

We would have to make the melanocytes live longer and be less susceptible to damage, or increase the amount of them we have in our stash. Sounds difficult but some scientists in France have identified a chemical that can protect the melanocytes from damage – so our hair can stay coloured for longer. If you’re already grey this won’t help you, but for those of us yet to turn grey there is hope!

Can we re-pigment hair?

Those of us who are bored of the chore that is hair dyeing, there may be a more permanent solution on the horizon to permanently turn grey hair back into pigmented hair! A study found particular antioxidants can reverse the greying of hair – although this was intended to help those with the genetic condition ‘vitilligo’, this could also work on those who no longer want the salt and pepper look.

So, ladies and gents, do not stress about turning grey (by the way, stress won’t make you turn grey, so even if you are stressed about it, doesn’t matter!), there is hope on the horizon that we can prevent and reverse all 50 shades of grey, white and silver (if you insist on calling it that).

Till next time,

Lucy

xxx

6 Scientific reasons why chocolate is good for you

In keeping with the spirit of Easter and the imminent chocolate binge I thought I would find some research that will make us all feel slightly less guilty when we overindulge in chocolate in the next few days. 

Master chocolatier- or pretty much a life saver?
Master chocolatier- or pretty much a life saver?

 1. Chocolate can boost memory – A study at Columbia University has found that chocolate improved scores in memory tests in a cohort aged 50-69, to the extent that they had the memory of someone 10 or 20 years younger. However, this only worked if you ate INSANE amounts of chocolate…. I think I could definitely manage that though. 

2. Dark chocolate is a source of antioxidants – Research has found that the antioxidant activity of dark chocolate is actually really high, with some studies finding it a better antioxidant than fruits such as blueberries, cranberry and pomegranate.

3. Chocolate can sort out your PMS – Chocolate (particularly dark chocolate) can allegedly increase the release of the hormone serotonin, which improves your mood at your ‘time of the month’. I’m not totally convinced on the evidence for this one, but I know I am definitely a nicer person after some chocolate, so maybe there is some truth here, even if it is just a psychological effect. While we are on the subject – dark chocolate has high levels of iron and magnesium, which can be lacking during menstruation, which helps to explain why women crave chocolate on their period and why it can make us feel better. 

4. Chocolate can sort out your cholesterol – Trials have found cocoa powder to reduce LDL cholesterol (the bad one) activity and overall levels of LDL, while increasing HDL levels (the good one). This is partly due to the antioxidant activity of cocoa. Reducing LDL and increasing HDL leads to a reduced risk of cardiovascular disease, therefore chocolate is super important for a healthy lifestyle.

5. Chocolate can lower blood pressure – Chocolate contains compounds called flavanols, which can act directly on the walls of your arteries to stimulate the production of nitric oxide.The nitric oxide relaxes the artery walls, so blood flow is stimulated and blood pressure is lower. Studies found this effect to be small but significant.

6. Chocolate can reduce stroke risk – A large study in Canada has found that chocolate eaters were 22% less likely to suffer from a stroke than non-chocolate eaters. Chocolate eaters who had suffered a stroke already also had a better outcome being 46% less likely to die from a stroke.

Of course chocolate is full of fat and sugar etc that we know is really bad for us, but I choose to ignore that evidence for the next few days and focus on research that says chocolate is basically essential to our health.

Happy Easter!

Till next time,

Lucy

xxx

No more banging on the end of the bottle- New bottles that nothing gets stuck to!

We have all been there – banging on the end of the ketchup bottle, or desperately squeezing a shampoo bottle until your hand begins to cramp up – just to get the last bits out of the bottle. Seeing remnants of products around the sides and at the bottom of bottles really frustrates me – but luckily some brainiacs at MIT have developed a new super slippery coating for these bottles so that we can get out every last drop!

This new coating allows every last drop to be used - dramatically cutting down wastage!
This new coating allows every last drop to be used – dramatically cutting down wastage!

How does it work?

This technology, patented as ‘LiquiGlide’, is described as a ‘permanently wet, liquid-impregnated surface’. This means that the product inside the bottle will always be directly on top of a layer of liquid, this makes it really slippery – allowing the product to slip out of the bottle with ease. The liquid coating is held to the bottle by a porous solid and the water can cling to the gaps in the solid, you can this this in the diagram below.

How LiquiGlide works - clever stuff!  Sourced from: http://liquiglide.com/tech
How LiquiGlide works – creating a liquid-liquid interface between the bottle and the product
Sourced from: http://liquiglide.com/tech

You can see LiquiGlide in action here:

Perhaps one day all bottles will be coated with this- and the days of saying ‘stop, you’re not getting any more out of that, just open a new one!’ will be over! (Yes, that’s a direct quote from my Dad).

Till next time,

Lucy

xxx

NFL and head injuries – does Chris Borland have a point?

Today I learned that Chris Borland of the San Fran 49ers is retiring from the NFL at just 24 years of age, as he is concerned of the long term effects of the head injuries and concussions that are associated with the sport. Is this an over-reaction, or is Chris right? And if he is right, do we need to re-evaluate American Football as a whole over these safety concerns? I looked into this to see if there is any research to back-up Chris’ decision.

Chris Borland playing for the 49ers
Chris Borland playing for the 49ers

It is a fact that concussions are common in American Football, but did you know that 90% of all concussions don’t involve a knock-out? Which means these head injuries are even more common than we think.

Short term effects of football related head injuries are easier to measure. This was investigated in a cohort of college football players and revealed that the more head injuries a player had – the more changes there were in diffusivity in the white matter in several parts of the brain – which was also linked to poorer learning and memory scores

There has been some research on the long term effects of these repeated concussions on the brain. A particular study measured changes to brain white matter upon helmet impact and if this change in white matter recovered. It was clear that there was no white matter recovery in time. This is a huge problem as white matter changes can build up upon further repeated head impacts. This would back up Chris’ decision as it shows that the sport has a long term detrimental effect on the brain, but the full extent of these long-term effects are yet to be fully researched – this is a big issue, not just in American football but in all other contact sports.

So is this research a game changer? (Pardon the pun..) Maybe to stop more young NFL athletes leaving the game so soon, and to protect those who continue to play we should change the game rules to make it safer? I get that this is a pretty wild idea given the scale and popularity of the sport, but we could perhaps make things safer by fully enforcing rules against rougher play. This idea was suggested by  the American Medical Society for Sports Medicine who said that ‘fair play’ and proper rule enforcement could prevent these head injuries to an extent. They also suggested that designing helmets specifically to reduce the incidence and severity of concussions could help prevent these injuries, as current helmets are designed more with the prevention of impact injuries such as lacerations and fractures in mind.

I’m not sure I could give up a salary that good based on the research that has currently been done. There is a lot of support for his decision, but I feel like there is still a gap in the understanding of the long term effects of this sport. Chris is reported to be taking part in further research in this field, which is great news, we could do with more research on real people to inform and protect more players in the future.

Till next time,

Lucy

xxx

Raspberry Ketones – Weight loss miracle or just another fad?

The internet is full of people claiming that raspberry ketones have helped them to lose weight. On Instagram alone #raspberryketones has been tagged nearly 27,000 times. All this fuss surely can’t be based on nothing? I looked into the real evidence to see if the claims behind raspberry ketones live up to the hype.

Holland and Barrett have joined in on the raspberry ketone bandwagon
Holland and Barrett have joined in on the raspberry ketone bandwagon

How they work:

Raspberry ketones are the main aromatic compound present in raspberries

The chemical structure of raspberry ketones.
The chemical structure of raspberry ketones.

They are thought to cause weight loss by lipid metabolism and lipolysis (essentially – burning fat). They are also thought to increase weight loss by elevating the levels of adiponectin- which is a hormone that increases fatty acid breakdown.

The evidence:

What makes me sceptical about the claims of raspberry ketones is that the evidence is very limited. There are no human clinical trials providing back up for the thousands of anecdotal claims on the internet, and part of me thinks that some of the success reports are from people promoting the sale of these somewhat pricey supplements.

However, there are some interesting animal model studies that have shown raspberry ketones to increase lipolysis and alter lipid metabolism. The rodents in the studies that were fed raspberry ketones stored less fat and lost weight. This shows promise for its use in humans for weight loss, but a controlled trial on humans needs to be done to see the full effects this would have on people, particularly to see if the supplements work better than actual raspberries and if they have an effect only if combined with a particular diet.

Safety?

Because there are no studies in humans, this means there isn’t much safety data. I can’t imagine them being dangerous because they are a natural substance, but like any supplement they can be addictive. I think everybody that decides to take raspberry ketones should do so with caution because nobody knows the correct dosage for safe long term use.

My verdict:

I think there really isn’t enough evidence for the claims that raspberry ketones make. Sure, eat some raspberries, that’s always a good shout, but there isn’t enough scientific backup for me to part with my cash for these supplements. As much as I would love to believe all the success stories on the internet, I think a lot of it is a big placebo effect and I’m afraid it could be just another fad!

What do you think? Let me know in the comments below!

Till next time,

Lucy

xxx