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Friday, 25 July 2014

The Quest for Invisibility

Since long before Harry Potter, scientists have been searching for a way which can allow things to pass us by unnoticed. The invisibility cloak which features in J.K. Rowling’s books may seem magical and otherworldly, but in fact devices which have the effect of making objects completely disappear are much more tangible than you’d think. While they may not look like a silky blanket, cloaking devices are very effective at manipulating signals and jamming detectors so as to obscure the truth about their location.

So there it is, we’ve done it. We have successfully created magic and are able to hide enormous ships or helicopters from being spotted by the enemy – haven’t we?

Well, not exactly. The perfect cloaking device is still just a theoretical concept. Camouflage paint is often applied to try and confuse the eye, “stealth” coatings are used to hide from radar, while cooling techniques are employed to reduce the amount of infrared emission coming from the object trying to stay hidden. However, while these techniques are effective at helping to disguise ships and aeroplanes, we can hardly call them invisible. It is hoped the answer lies in the development of metamaterials – materials which possess properties not found in nature.

Image demonstrating variety of wavelengths of the electromagnetic spectrum
The electromagnetic spectrum covers all wavelengths of radiation, from radar to visible light to x-rays and gamma-rays. Until last year we could only hide things from very specific parts of the electromagnetic spectrum, in some cases by making the object more visible in other parts of the spectrum. Image credit: NASA (public domain)
The development of such materials has huge implications for lens and invisibility devices. The idea of cloaking devices is to create a material which can take an incoming signal, say visible light, and then send it on its way without any interruption from the cloaked object. If you could create a material which can do this effectively enough, it will trick any detectors into thinking there is no object to be seen, since there is no radiation signal to be detected. In theory it’s possible, but there are many obstacles blocking the way.

Wednesday, 16 July 2014

How reliable is psychological science?

Things We Don't Know Anymore


TWDK Psychology doodle copyright Giles Meakin / Things We Don't Know CIC
Our psychology editor Malte Elson explores the “replication crisis”, and questions our level of confidence in established psychology. Image credit: Things We Don't Know / Giles Meakin (CC-BY)

The last few years haven’t been easy on psychological science. Don’t get me wrong – the field in itself is flourishing, boasting an ever-increasing number of publications, journals, conferences, faculty positions, and university graduates all over the world. It has gained more and more respect and acceptance, both in academia and society. The case of Harvard evolutionary biologist and primate researcher Marc Hauser’s fraudulent publications was already fading from our minds when in September 2011, the discovery of the scientific misconduct by the Dutch social psychologist Diederik Stapel shattered the grounds of psychological science. In at least 50 cases of scientific fraud that have been discovered by the Levelt Committee, Stapel had doctored, mangled, and completely fabricated datasets to successfully publish in the field’s top-ranked outlets - up to the most prestigious journals like Science. Among Stapel’s highly regarded publications were findings on how untidy environments encourage racist discrimination[1], or how to reduce racist biases in judges' legal decisions on minority defendants[2]. Nullifying the content of these publications constitutes a setback for social psychology, and - to a somewhat lesser extent – society overall.

Although they work in a highly competitive environment, we trust scientists to be committed to finding the truth. And when playing it smart, like Stapel, it is quite easy to abuse this trust for personal gain in the form of a prestigious academic career. Instead of looking for the truth, Stapel was on a quest for aesthetics, for beauty, as he was quoted saying by the New York Times. One might think that it’s not that much of an issue - Stapel got caught after all! Reaching for the stars he committed fraud, but got brought back down to reality when his deeds were unveiled, so the system works. But does it really?

Monday, 7 July 2014

Sheffield students make TWDK science videos

We issued our challenge through the university's Venture Matrix™ scheme.
Earlier this year, we set students from Sheffield Hallam University a challenge - to take one of our published science articles, and turn it into a video. Four groups of media students took up the gauntlet, and over the next few months the students created four very different videos.

The students had a total freedom of choice regarding which of our articles they chose, and the style they would use to make the video. Our only condition was that each group choose a different article.

Tuesday, 1 July 2014

Mapping spacetime around supermassive black holes

Black holes come in many sizes ranging from tens to millions, or even billions, of solar masses. Their incredible size means they exert immense gravitational power over other objects, and can even warp space-time to such a degree that they behave like lenses and actually bend light around them – a process known as gravitational lensing. In many cases a large black hole will acquire another incredibly dense friend, for example a small black hole or a neutron star, which will orbit the central black hole whilst slowly spiraling into it. These physical systems are known as Extreme Mass Ratio Inspirals (EMRI's), called as such because of the vast mass difference between the two objects.

distorted grid with Earth at the centre demonstrating deformation of spacetime.
Physicists often consider space and time as a single continuum, called spacetime, which consists of the 'usual' three dimensions (up/down, left/right and forwards/backwards) plus time as a 'fourth' dimension. Spacetime is bent by anything with mass - an effect we see as gravity. Image credit: Wikimedia commons
Einstein’s famous theory of general relativity states that any mass will bend spacetime. Black holes, because they are so incredibly dense, will stretch and curve space-time to a much greater degree than our planet ever could. However something relatively tiny, like the Earth, still has an effect. For EMRI's, you can think of this as being like a bowling ball placed on to a taut sheet - the bowling ball will sink causing the sheet to stretch. If you place a marble onto the same sheet, it will also sink a little bit into the sheet because it has its own weight, but the bowling ball makes a much larger dip than the marble.

But getting out sheets, marbles and bowling balls isn’t a very accurate way of modelling these systems – so how is it done? I spoke to Dr Sarp Akcay, a postdoctoral fellow at the University of Southampton and an expert at creating models simulating the orbits of EMRI's.

Wednesday, 18 June 2014

Chariklo, the Celestial midget

In March, the European Southern Observatory in Chile made an astonishing discovery that has surprised astronomers. It’s no secret that the great gas giant, Saturn, has an impressive set of rings surrounding it - and while less widely known, in fact all Jovian planets (Neptune, Uranus, Jupiter and Saturn) have ring systems around them. These planets are the largest in our solar system, and have a tremendous gravitational pull on rocks, dust and gas due to their great size which keeps their ring structures in place. However, nestled between Saturn and Uranus, they’ve discovered a comparatively minuscule object with a fraction of the gravitational strength which has its very own rings - something many astronomers believed to be impossible.

Artist’s impression close-up of the rings around Chariklo
Artist’s impression of the asteroid Chariklo, and its newly discovered rings.
Image credit: ESO/L. Cal├žada/M. Kornmesser/Nick Risinger (skysurvey.org)

Chariklo 10199 is what’s known as a Centaur, an object which originates at the very limits of our Solar System (a region called the Kuiper Belt) and carries characteristics of both asteroids and comets. This particular Centaur is merely 250km wide, that’s roughly the same width as Lake Victoria in Africa and barely 0.0004% of Saturn’s volume, making it a celestial midget. It’s this midget which has been discovered to carry its own ring system made up of space dust and particles – just like the Jovian planets.

Why is it that this space boulder has rings too? How did they get there? What can they tell us about our Solar System?

Thursday, 12 June 2014

Summer Physics Internship 2014

Hi, my name’s Grace and I’m joining the crew here at TWDK as this year’s SEPnet summer intern. I’m currently a Physics student at the University of Southampton. Physics has always been my favourite subject, with English coming a close second. I love to get into the nitty gritty of how things work, and I love the feeling of being completely blown away by the complexity of the universe. For me, it’s not enough to know that things work - I want to know how and why. When I’m not trying to bend my mind around Quantum interference equations I like to read, write, climb and watch mindless TV.

TWDK Physics intern Grace Mason-Jarrett
Our latest summer intern, Grace, in our London office.
Photo: TWDK

Wednesday, 4 June 2014

Introducing Fiona

As the new communications manager here at Things We Don’t Know, I would like to introduce myself. My name is Fiona Hutchings and I am also a mother, a geek, someone who binges on Netflix, a music writer (and obsessive music fan) and a book worm. The one thing I'm not, is a scientist.

Portrait photograph of TWDK communications manager Fiona Hutchings
Fiona Hutchings is our new communications manager
At TWDK our mission statement is pretty clear; 'explaining the mysteries of science, in simple language'. As communications manager part of my job is to share our work and make it as accessible as possible to everyone from a rocket scientist to the casual reader. I am an avid science fiction fan, from Firefly to Star Trek and of course Doctor Who, but I have always found science fact more than a little intimidating. It wasn't a case of not being interested - I am - but as fluent as I may be in the basic functions of a TARDIS, I found attempts to try and understand the factual grounding behind these shows really difficult. I want to understand more about the body, planet and universe I live in. Trying to investigate and find the answers to my questions was frustrating - there seemed to be so many words I could hardly pronounce, never mind understand, and I don't consider myself stupid (karaoke choices aside). Like many, I suspect, I gave up trying to understand, figured science didn't need me and was discovering stuff all the time just fine on it's own.

When TWDK was born, it reignited my enthusiasm to find out more about the world (and galaxy) I live in. Scientific news so often concentrates on what we do know but now I could find out about the hundreds of questions we still haven't answered. Better still, I could find out about them in a language I understood. Questions so often lead to yet more questions but asking why, how, what and when has being driving discoveries for hundreds of years. Luckily, the rest of the team here and our many excellent guest writers are incredibly knowledgeable and enthusiastic about the many different fields of science, finding answers and sharing them with the world. I am thrilled to be a part of that.

Why am I telling you all this? Well, firstly because my mother always told me it is polite to introduce yourself. But also because I wanted the chance to tell you a little bit about my background and my way of working. If you pop by and talk to us on Twitter, Facebook or Google+ there is a good chance it is me you will be talking to. Complex science queries are referred to our editorial team, all of whom have a science background. Sharing articles we and others have written is part of my job and I want to do that in a friendly and accessible way. I want you to feel comfortable asking questions because questions are what TWDK is all about. And if you want to write for us or have a topic you'd like us to cover, then I want to hear from you too.