Question of the Week

Oct 092016
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What is the most useful invention of humans? Sure, most people will answer this question with “The Wheel!” Indeed, today almost any machine runs with some kind of wheel. But do we know whom to thank for this gift? Let’s take a little journey back through time.

Rewind to our greatest invention.

Rewind to our greatest invention.

Of course there was a time before the wheel, around 5000 BC. People used slides and logs of timber to transport goods. During the Bronze Age (ca. 3500 BC), wheels of clay and of wood were being attached to carts. Records of those first wheels are found in different cultures of the same age. For a long time, it was believed that the Sumerians from Mesopotamia were the inventors of the wheel. But new findings prove that other cultures from Western and Eastern Europe of the same age built something similar. The main difference of those earliest constructions were in the suspension – some were rotating with the axis, some were rotating around it.

Over the ages, this technology spread all over the world. The wheels became lighter and more stable. The development of trade, technology and (even) warfare, is due to the wheel. The wheel has made it possible for us to wonder at all the modern engineering marvels.

Still it is unlikely to identify a group of people – not to mention a single person – as the inventors of the wheel. To imagine what fortune one would amass today from such an invention…

– Tatjana Daenzer

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Oct 032016
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The story of music and human cognition is intricate and intertwined from the beginning. Since close to fifty millennia, music has remained an integral part of being human.[1]

Music has always aroused feelings of rapture and desire, even though it is intangible. And now science has unlocked the mechanism. As the reward center in the brain gets primed with the anticipation of listening to familiar music, there is a flood of dopamine, the “happiness” neurotransmitter.[2] Things can get discordant too. If one listens to unpleasant music, there is a reduced production of serotonin, our mood-regulator.[3]

Music for peace of mind.

Music for peace of mind.

It is quite natural to ask, if the audience is experiencing euphoria, what is the artist feeling ? Well, scientists have looked into that aspect as well.

The brains of musicians light up like a celebration of fireworks when they play.[4] The left and right hemispheres enter in a harmonious exercise when an artist performs on their musical instrument.

But can music improve how we interact with life ? And the answer is a resounding “YES”.

Learning an instrument with structured and disciplined practice, has an array of benefits.[5] It can enable us to find more creative solutions to problems in social as well as academic settings. Playing music makes for a greater neural plasticity in the brain which can better help with retrieving and indexing information – in short, a better functioning memory.

Even though we know what neurotransmitters are responsible and the neural pathways they seem to take in the brain when we hear music, still there is so much more that we do not know. For instance, the auditory cortex is still quite unknown to us in its organization and functions. Only recently, there was a discovery of two separate populations of neurons, sensitive to how we process music and human speech, different from ambient sound in the environment.[6] Though, it is still a question of speculation – are we born with it or is it developed through experience.

Four hundred years have passed since William Congreve remarked, “Musick has Charms to sooth a savage Breast”. Music, has indeed, displayed the ability to heal. It has shown promise to improve the lives of those affected with schizophrenia.[7] As music also helps in better connecting our episodic memory, it can have a positive influence in individuals suffering from Alzheimer’s or PTSD.

So let’s tune in to some nectar for the brain and turn those frowns upside down.

– Soham Roy

[2] Salimpoor, VN et al. Nature Neuroscience, 14, 257–262 (2011).
[3] Evers, S et al. Eur Arch Psychiatry Clin Neurosci., 250, 144–7 (2000).
[5] Miendlarzewska, EA et al. Front Neurosci., 7, 1–18 (2013).
[6] Norman-Haignere, S et al. Neuron, 88, 1281–1296 (2015).
[7] Talwar, N et al. BJP, 189, 405–409 (2006).

Aug 162016
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You certainly know the game little kids play where they have a cube, a sphere and a pyramid, and they have to put them through holes of the corresponding shape. In the beginning, this might be difficult, but it becomes quite easy and dull after some time. Now, it is simple for most people, but how difficult is the same task for blind people? i.e., Can people who have been blind for their entire life and are familiar with different shapes by their tactile sense, recognize the same shapes when they gain the ability to “see”?

This question, referred to as the Molyneux Problem, was first asked by William Molyneux, an Irish philosopher and politician, in 1688.[1] Of course, answers that could verify this question were not easy to find in the 17th century due to the impossibility of highly complex surgeries at that time. Nevertheless, a lot of discussions arose about the co-operation between our senses. For instance: Is the eye able to understand the geometry of objects or is the visual recognition just possible by a learned collaboration with the tactile sense?[2] Or the other way around: How do blind people understand shape; how do they “look” for them?

Just recently, in 2011, five children, who were born blind, became able to see after surgery at the ages between 8 and 17. They were familiar with several shapes by examining them with their hands. Interestingly, they were not able to relate this tactile information with the visual input from these objects, but they learned to connect both senses quite fast.[3] However, discussions are still not at an end, to unequivocally explain the outcomes.

The Molyneux Problem once again shows that even simple questions can result in long-lasting discussions and unexpected outcomes. Never stop asking questions and dig through the JUnQ to find the hidden treasures!

— Andreas Neidlinger

[1] W. Molyneux: Letter to John Locke, 7 July 1688, in: The Correspondence of John Locke (9 vols.), E.S. de Beer (ed.), Oxford: Clarendon Press, 1978, vol. 3, no. 1064.
[2] S. Pasewalk: „Die fuenffingrige Hand“: Die Bedeutung der sinnlichen Wahrnehmung beim spaeten Rilke, De Gruyter; Auflage: 1., 2002, pp. 106.
[3] R. Held, Y. Ostrovsky, B. de Gelder, T. Gandhi, S. Ganesh, U. Mathur, P. Sinha, Nat. Neurosci. 2011, 14, 551–553.

Aug 072016
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Lying on the grass and looking into a sparkling star-filled summer sky. Can there possibly be anything more beautiful? But it also makes me think about how small we really are and are we truly alone in the universe. This question has bothered humans since the beginning of our existence.

In the observable universe, there are at least 100 billion galaxies containing 100-1000 billion stars each. Not to mention the gigantic number of existing planets surrounding those stars including trillions of habitable ones. Consequently, there must be plenty of opportunities for alien life to develop.

But is the contact with extraterrestrial life really that likely? It has to be mentioned, that a huge number of existing galaxies are completely out of reach because of the expansion of the universe. Only the ones being part of our local group come into consideration for a theoretical alien contact. Anyways, if life had developed only on 1% of all planets in habitable zones in the Milky Way, there would be millions of planets inhabited by aliens. Since life on earth emerged rather late compared to the age of the Milky Way, potential super-intelligent and technologically advanced aliens would have had much time to build powerful space ships and to make a trip to our blue planet. In fact, if those guys would have been able to build generation space ships, they could colonize the Milky Way in a few million years. And that is not a long time when we think that life on earth exists since 4 billion years and the fact that other planets might have had developed life long before earth did. So if only one of those theoretical alien races would have developed into a super-technological civilization, shouldn’t we know by now?

So where are all the aliens? Why did they not contact or – in a bad scenario – attack us so far? This lack of proof for aliens despite its apparently high probability is called the Fermi Paradox, named after the physicist Enrico Fermi.

There are different scenarios which can resolve the Fermi Paradox and some of them are quite amusing and imaginative. Here is a small selection:
1. In spite of the apparent high probability, we are alone in the universe. We might always have been and always will be. The condition for the emergence of life could be much harder and complicated than we assume.
2. There were intelligent aliens long before humans came into existence. They could have gone extinct before someone on earth ever thought about extraterrestrial life at all. Indeed, we do not know everything concerning different thresholds life has to overcome in order to survive. We might just be lucky that we do not yet have encountered one really tough barrier, like the dinosaurs obviously did. Or maybe at some point, every sophisticated culture will destroy itself by inventing a highly destructive super-weapon.
3. Our extraterrestrial friends want to observe us in order to do psychological studies or maybe we are just part of some “galactic zoo” for aliens. They also might just wait until we are a threat to them and then kill us. This has also been a topic in various science fiction books.
4. Life forms from outer space are already among us and we do not notice.
5. The aliens are simply not interested in having communication or imperialistic wars with anyone else and stay peacefully and happy on their home planet.
6. The universe is full of extraterrestrial signals but we are not advanced enough to detect them.

Maybe there will be a day in the future when we get a more definite answer to the Fermi Paradox. Let’s just hope it will be a salubrious one!

– Jennifer Heidrich

Read and watch more:
— M. H. Hart: Explanation for the Absence of Extraterrestrials on Earth. Quarterly Journal of the Royal Astronomical Society. 1975, 16, 128.
— A. Frank and W.T. Sullivan: A New Empirical Constraint on the Prevalence of Technological Species in the Universe. Astrobiology. 2016, 16, 359.
The Fermi Paradox — Where Are All The Aliens? (1/2)
Drake’s Equation – A Deep Dive | Answers With Joe

Jul 242016
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If you ever wander about the barren lands of southern Africa, like the scarcely vegetated Namib desert in Namibia, you will most certainly stumble across a fascinating malformation of the soil called fairy circles. They are circle shaped bare patches of dry ground with a diameter of several meters enclosed by taller grass at the edge, compared to the steppe landscape of the surroundings.

Fairy circles in the Namib Naukluft Park, Namibia. (© Heike D?nzer)

Fairy circles in the Namib Naukluft Park, Namibia. (© Heike Daenzer)

Their origin has long been a cause of intense discussions. The earliest interpretation of their appearance may come from the Himba people, who share the legend that the circles are the footprints left behind by their ancestor Mukuru. Other stories tell of aliens, dragons or fairies.[1] On the other hand though, science suggests toxic gases or residues from already dead plants, radioactive elements or insects to be the origin of the features.[2] Lots of investigation have been made in the last decades to prove each theory but no one could come to a substantial and indisputable conclusion. Since no toxic or radioactive substances were found in the soil of the fairy circles, they must arise from something else.[2]

Supported by satellite images, Dr W. Tschinkel, from the Florida State University, was able to offer proof that the circles are not permanent. They grow and develop and after a lifespan of 41 years on average, they “die”.[3]

Cramer et al. used an empirical model considering various biological, chemical and weather factors to predict the appearance of fairy circles. They conclude that circle formation must be the result of plant organization and competition for nutrients since the plants at the periphery of the circles are more lush than the plants farther away.[4]

A very vivid explanation comes from N. Juergens who examined the termite population of fairy circles. The sand termite Psammotermes allocerus, their nest and tunnels were the only similarity found in 100 % of the investigated circles and even in young circles. Apparently they feed on plant roots and keep large areas free of water accumulating vegetation which causes also a higher water content in the ground centered beneath the circle.[5]

Only a few years ago, fairy circles were found in Pilbara, Australia similar to those in Africa. Getzin et al. doubt the dependence of the pattern formation from termites or ants since many circles didn’t host any of these insects. They blame pattern-creating plants in water-limited environments, such as in a desert, to be responsible.[6]

– Tatjana Daenzer

Read more:
[2] van Rooyen, J. Arid Environ., 2004, 57, 467–485
[3] Tschinkel, PLOS ONE, 2012, 7, 1–17
[4] Cramer, PLOS ONE, 2013, 8, 1–12
[5] Juergens, Science, 2013, 339, 1618–1622
[6] Getzin, PNAS, 2016, 113, 3551–3556

Jul 032016
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We all know what the color ‘black’ is. If I ask anyone, I will get different responses. From the familiar blackboard in the classroom to the ubiquitous asphalt of the roads. Some might recall, with fondness, it as the color of the little dress on their high-school prom date. Others might be more correct, and remind me that “true” black is the absence of any reflected light. And point me towards the nearest black hole (at the center of the milky way or on the Sagittarius arm of it, depending on what one believes [1]).

Is it Black or is it Grey ?

Is it Black or is it Gray ?

Even then, when I show the above graphic, all (including me) will be unequivocal in declaring the colors to be shades of black. Although those are hues of gray. Such befuddlement ails us all. As Dr. Stephen Westland, professor of color science and technology at Leeds University, is right in saying, “Unless you are looking at a black hole, nobody has actually seen something which has no light.” [2]

Given our feeble attempts at defining and rendering ‘Black’, it becomes quite a challenge to explain Vantablack – the blackest material known [3, 4], where Vanta is an acronym for Vertically Aligned Nano Tube Arrays. Although, NASA might argue that their super-black deserves that title [5]. It is easy to visualize Vantablack as a forest of carbon nano tubes. The tubes are stacked in a vertical orientation, with the length of the individual tubes being much much larger than their diameter.

Vantablack (downloaded from

Vantablack (downloaded from

Yet, that still doesn’t explain why it is the ‘blackest’ of blacks and could rewrite and replace all previous conceptions of black [6]. When light hits the Vantablack surface, it gets trapped in between the carbon nano tubes. The photons undergo a lot of collisions with the walls of these tubes. They lose their energies as heat to the walls and the tiniest amount is reflected back as light, all of 0.035 % [2, 7].

Such properties make it very exciting as future prospects. From manufacturing telescope coatings, where even the tiniest speck of scattered light can seriously affect its contrast and resolving power. To the defense and stealth sectors, who find the material extremely fascinating [7].

Yet, it is still baffling to answer how does it feel to see the blackest material known. We understand a surface by its depth or its topological features. These features change reflectance. But for Vantablack, even when it is crumpled up, it defies perception. “You expect to see the hills and all you can see … it’s like black, like a hole, like there’s nothing there. It just looks so strange”, as Surrey Nanosystems CTO Ben Jensen puts it [2].

Vantablack is the darkest material we have that is as close to perceiving what a black hole would look like. This might be a bit disconcerting for us in the future, expecting to see textures but being greeted with an abyss. “And if you gaze long into an abyss, the abyss also gazes into you.”

-Soham Roy

[4] E. Theocharous et al., Optics Express 2014, 22, 7290-7307.

Jun 122016
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Modern aviation is one of the most important and possibly, also the safest when it comes to transportation and travel. As a result of the increasing need for fast and reliable transfer of resources, airplanes have become increasingly complex and nowadays only a relatively small number of people know how they are operated.

Figure 1: Landing of a modern aircraft.(downloaded from

Figure 1: Landing of a modern aircraft.(downloaded from

In this Question of the Week, we want to focus on one particular detail of aviation: The landing. A typical airplane approaches the airstrip with a speed of around 270 km/h and has to decelerate within a very short time to guarantee a safe landing. So how do you brake an airplane?

To answer this question, we first have to think about how braking works in the case of any wheel-based vehicle. In a nutshell, the braking process always exerts a torque upon the wheels which then use friction with the ground to lose kinetic energy. Friction, however, is massively dependent on the weight that rests on the wheels. In case of landing an airplane, the aerodynamic lift basically nullifies the weight of the plane and therefore makes braking while using the wheels extremely inefficient. As a result, the plane needs other ways to slow down until the aerodynamic lift and speed is sufficiently reduced. In modern aviation, this is done by two different braking systems: The Spoilers and the Reversers, that both are usually operated by a computer, which tries to reach a constant deceleration of convenient magnitude (about 0.17 – 0.3 g).


Figure 2 : Spoilers on an aircraft. (downloaded from

As soon as the wheels get in contact with the ground, the Spoilers (Figure 2) are fully activated. These are flaps located on the back-end of the wings and can significantly reduce the aerodynamic lift as well as increase the drag. These flaps are extremely important for the braking process because without them the friction of the wheels is not sufficient for efficient braking. Basically, wheel brakes and Spoilers together can already be sufficient for slowing down an airplane.


Figure 3 : Reversers on an aircraft. (downloaded from

However, to reduce the amount of stress the wheel brakes have to withstand, there is an additional system: The Reversers (Figure 3). These are mechanisms located at the engines that can be activated to redirect the engine’s exhaust forward, rather than backwards (commonly referred to as thrust reversal). All three systems together can be used by a computer to reach an extremely smooth braking process without putting too much stress on the single components.

As a result, the landing process by itself is extremely complex and depends on many factors. Most of them can be controlled by a computer, however, in case of any unforeseen circumstances, the pilots have to be prepared to take over and land the airplane manually. This (and many other factors) makes the training of pilots one of the most demanding educational processes of our time.

– Kai Litzius

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May 012016
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Have you ever wondered if you are smarter than your parents or grandparents? Actually, that might not be completely unlikely! At least according to the so called Flynn effect, which was first described in 1984 by the political scientist James Robert Flynn [1]. It refers to the observation that a generation scores in average slightly higher on an IQ test* than the generation before. This effect has been investigated for more than 20 industrial countries and for different types of intelligence tests that were specified on problem-solving (fluid intelligence) and knowledge and experience-based questions (crystallized intelligence), respectively.

Many people do not believe in the IQ test as a benchmark for intelligence and therefore seek a different explanation than increasing intelligence for Flynn’s observation. They argue that the measured IQ might just be related to something else, for example a training effect.

Anyways, according to Flynn, statistics seemed convenient. But if we really are getting smarter, the central question that arises is, of course: Why? The discovery heated up the old genes vs. socialization influence debate. Dealing with the latter, different theories were developed in the last decades [2]:

  • Social environment: As the world is getting more and more complex due to modernization and new technologies, people are more often confronted with abstract concepts.
  • Education: Probably there is a connection between intelligence and learning. The education in general has been improved in the last century – schools are getting better equipped and school attendance is compulsory.
  • Dedicated parents: In general, parents are more dedicated to seek for a more inspiring environment for their children, than they had for themselves.
  • Nutrition: Nowadays, people are better nourished compared to earlier generations.

What people obviously have learned from Flynn’s discovery is that there needs to be a regular updating for IQ tests and other tests in order to reset the normal distribution to the average value of 100.

Is the Flynn effect ongoing or is it just describing IQ test results from the first three-quarters of the 20th century ? More recent studies indicate that the test results in Norway are more or less stable since the nineties [3]. Another publication even claimed a recent reversal of the Flynn effect [4]. In 2012, on the other hand, Flynn himself pointed out that there are new statistics leading to an increasing IQ [5].

At least we can agree, that the Flynn effect is a controversial field in psychology and will keep scientists busy for many more years.

*The informative value of an IQ test is widely discussed and a topic for another Question of the Week.

-Jennifer Heidrich

[1] J.R. Flynn. The mean IQ of Americans: Massive gains 1932–1978. Psychological Bulletin. 1984; 95(1): 29–51.
[2] A. Furnham: 50 Psychology Ideas You Really Need to Know, Quercus Publishing Plc, 2009.
[3] J.M. Sundet, D.G. Barlaug, T.M. Torjussen. The end of the Flynn effect?: A study of secular trends in mean intelligence test scores of Norwegian conscripts during half a century, Intelligence, Volume 32, Issue 4, July–August 2004, 349-362.
[4] T.W. Teasdale, D.R. Owen. Secular declines in cognitive test scores: A reversal of the Flynn Effect, Intelligence, Volume 36, Issue 2, March–April 2008, 121-126.
[5] J.R. Flynn. Are We Getting Smarter? Rising IQ in the Twenty-First Century, Cambridge University Press, 2012.

Apr 242016
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Since way back, humankind is looking up into the night sky, observing orbs and wondering about the origin and the look of the cosmos. Is the universe really expanding as we all learn in school? How does the border of the universe (if it exists) look like? Admittedly, a modern scientific approach to this problem is very abstract and not easily explained in layman’s terms.The following explanation therefore spares any detailed mathematical considerations for simplification.

Derived from Einstein’s theory of relativity, there are found different possibilities. In simplified terms, mass warps the space and thus determines its shape. Complex mathematical considerations result in a critical density of the universe. A structure can be assigned from the density parameter, omega, which is the quotient of the average density of the universe and the critical density. Three border cases emerge whose abstract values can be translated into two-dimensional images for a more vivid explanation (Fig. 1):[1,2]

a) The density is bigger than the critical density (omega > 1). The universe is big enough to stop the expansion sometime but after that point it will be shrinking again. This is called “closed universe”.

b) The density is smaller than the critical density (omega < 1). The universe expands forever and its shape is saddle-like. This is called “open universe”.

c) The density has the exact value of the critical density (omega = 1). The expansion rate decelerates over an infinite time-span and the shape is flat and endless.

Fig. 1: Two dimensional illustrations of the universe’s possible shapes: spherical or "closed" universe, saddle-like or "open" universe, and flat universe [3].

Fig. 1: Two dimensional illustrations of the universe’s possible shapes: spherical or
“closed” universe, saddle-like or “open” universe, and flat universe [3].

Another discussed model is the “Picard topology” that defines the universe as a horn which is closed at the end. Here very surreal phenomena would occur depending on whether one is situated at the peak or the broad end [4].

Measurements from the Wilkinson Microwave Anisotropy Probe (WMAP) give hints that the density of the universe equals the critical value. Accordingly, the shape would be flat. Still, with our limited technical possibilities we only can observe a very small area of the universe. No one can yet (or maybe never will?) know with absolute certainty how the universe looks like [2].

-Tatjana Daenzer

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Mar 202016
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All of us are esurient creatures, when it comes to being happy. Everyone wants to be happy. There are myriad paths to happiness as well – religious, spiritual and even rational. The Dalai Lama, once remarked, “Happiness is not something ready made. It comes from your own actions.”

Yet it seems, year after year, that a group of people sharing a small genetic pool end up tops of the “The World Happiness Index” [1]. The Danish, it seems, are genetically endowed when it comes to being happy [2]. A genetic mutation 5-HTTLPR seems to be behind it. This gene variant influences the metabolism of serotonin, the neurotransmitter which affects our moods.

Does it then mean that you cannot be happy if you have not inherited Danish genes? No, there’s more to this story. And that’s where science opens a new door towards happiness.

Whether we are Danish or not, we produce a neurotransmitter called Anandamide [3]. The name of this molecule itself exudes joy, deriving from the Sanskrit word ananda or bliss. But then why aren’t we all equally happy. That depends on the extent to which this “bliss molecule” is metabolized. People who produce less of the enzyme that aids in the metabolization are more prone to be calm and at peace [4].

Prof. Friedman, from the Weill Cornell Medical College, puts it elegantly when he says, “What we really need is a drug that can boost anandamide—our bliss molecule—for those who are genetically disadvantaged.”[5]

Now it seems such a future is not that far off when we can engineer happiness. There are two things that one needs. To understand the genetic factors behind the different neurotransmitters. And how to manipulate them with nano-scale precision. Once we have that information, it will be possible to ingest a pill that carries predesigned nanobots to specific regions of the brain and turn on or off genes at will. This will then lead to a change in the perception of the immediate environment which would have otherwise strained our ability to be happy. Such a future was envisioned a decade back by author James Hughes in his book “Citizen Cyborg”.

So yes, it seems highly likely that our next generation can buy over-the-counter pharmaceuticals that can generate the feeling of satisfaction, joy or bliss. But still to be truly happy and have a satisfying life, it would take more than a drug as after all, happiness “comes more from your own actions”.

– Soham Roy

[3] W.A. Devane et al., Science 1992, 258, 1946-1949.
[4] I. Dincheva et al., Nature Communications 2015, 6, 1-9.