Dig through the JUnQ

Here you find all contributions made by external authors to JUnQ. This includes peer-reviewed articles and editorial board reviewed open questions.

The Spaghetti Turn

 Question of the Month  No Responses »
Jan 052019
 
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Certainly, most of us enjoy an occasional nice bowl of spaghetti. Some of us use a spoon along with the fork, some don’t. Doesn’t matter, as long as you enjoy and don’t make a mess. But have you ever wondered whether there is a preferred direction to turn the fork? And is it related to where you live? We did!
In our last issue (Vol 2, 2018), we launched a survey asking our readers exactly this question (Figure 1).

Figure 1: The Spaghetti Turn survey as it appeared on the webpage.

Our survey was advertised in social media (Facebook, LinkedIn, Twitter, ResearchGate) and via QR codes on flyers. The survey reached a total number of n=160 readers, 132 of them found their way directly to our website. The results are shown in Table 1 and Figure 2.

Table 1: Results of the survey “The Spaghetti Turn”.

Northern hemisphere Southern hemisphere worldwide
n % n % n %
right-handed clockwise 120 75.5 3 60 118 75.0
right-handed counter clockwise 13 7.7 1 20 13 8.1
left-handed clockwise 10 6.5 0 0 10 6.3
left-handed counter clockwise 10 6.5 0 0 10 6.3
both-handed clockwise 0 0 0 0 0 0
both-handed counter clockwise 1 0.6 0 0 1 0.6
shovel 5 2.6 1 20 5 3.1
other 1 0.6 0 0 1 0.6
sum 153 96.9 5 3.1 160 100

 

Figure 2: Worldwide percentage of the preferred direction to turn the fork when eating spaghetti related to the handedness (values in %).

The option „no preferred direction” remained unanswered. One single participant chose “I am right-handed and turn clockwise” and “I am right-handed and turn counter clockwise”, depicted as “other”. Assuming that this is no miss-click one out of a total number of 160 participants has no preferred direction when using the fork with their right hand. This underlines that most people on earth indeed have a favourite direction to screw the fork.
Although there is no clear definition to determine handedness, some publications claim that 70–95 % of human population worldwide are right-handed, 5–30% are left-handed and a small minority is ambidextrous.[1] This is consistent with our findings: the survey was answered by 133 right-handed people, which is 86.9% of all 154 participants who revealed their handedness. 20 participants are left-handed (13.1% of all 154 participants who revealed their handedness). One participant (<1%) is ambidextrous and turns the fork counter clockwise with both hands.
75.0% of all participants are right handed and turn the fork in clockwise direction. Only 8.1% turn it counter clockwise. Surprisingly, there seems to be no preference about the turning direction among left-handed people. Their numbers equal (each ten or 6.3%), while 90.2% of all right-handed people turn clockwise. Fortunately (or shockingly?), 3.1% of spaghetti eaters worldwide shovel.
Unfortunately, we did not reach a significant number of readers from the southern hemisphere. Four participants out of five are right-handed, one shovels. 60% of the right-handed southerners turn the fork clockwise, 20% turn it counter clockwise. Considered that only five participants (3.1% of all) do not represent the whole ~10% of the human population living on the southern hemisphere,[2] the preference of turning counter clockwise shows the same tendency for both hemispheres. There is therefore supposedly no relation to where you live on this planet.
But why is the clockwise direction so obviously favoured?
Time and therefore clocks have a powerful influence in our daily lives. Also, in a lot of cultures texts are written from left to right (as the clockhand moves). Moving and looking to the right is very often linked to the future and openness. An experiment from Sascha Topolinski and Peggy Sparenberg from 2012 suggests, that the preferred direction to turn objects could be determined by one’s conservative or open personality.[3] Or is it just for handling reasons only and it is a little easier to apply force on the edge of the fork while turning it clockwise?
With a simple survey like our’s it is impossible to determine whether the habit to turn the fork left or right is a matter of education, subconsciousness or technique.

Throughout the active survey it was possible to answer the poll via the Facebook “Surveys for Pages” and our webpage. Hence, we cannot entirely assure the integrity of the results. Also, we hope our readers understand humour but also answer the survey genuinely. We simply trust in the scientific spirit of our readers. We also did not consider that for cultural habits in certain cultures spaghetti dishes might not be available or forks might not be part of the traditional cutlery. Although it is very often a cause for heavy crossfires during meals, the use of a spoon along with the fork is discounted in the evaluation of the results too. With this survey we just aim to give a picture about the general turning behaviour of spaghetti eaters. To the best of our knowledge there has not been a similar survey until now.

We are now smarter than before but still missing the details of the big picture. Let’s see what the new year brings…

Tatjana Daenzer, Mariia Filianina, Alexander Kronenberg, Kai Litzius, Adrien Thurotte

The editorial team of the Journal of Unsolved Questions thanks all 160 participants of the survey and wishes Bon Appetit and a very happy start into the year 2019!

Read more:

[1] [https://www.scientificamerican.com/article/why-are-more-people-right/ (last access 31.12.18, 15:20).
[2] https://bigthink.com/strange-maps/563-pop-by-lat-and-pop-by-long?page=all (last access 31.12.18, 15:40).
[3] Sascha Topolinski, Peggy Sparenberg, Social Psychological and Personality Science, 2012, 3, 308–314.

How many colours are needed for a map? And for a plane?

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Dec 042018
 
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When Francis Guthrie took on the task to colour a map of England in 1852 he needed four colours to ensure that no neighbouring shires had the same colour. Is this the case for any map imaginable, he wondered.

As it turns out, five colours do suffice, as mathematically proven in 1890 in the five-colour theorem [1]. That indeed four colours are enough to colour a map if every country is a connected region took until 1967 to prove [2] and required computer assistance. It abstracted the idea to geometric graph theory where regions are represented by vertices connected by an edge if they share a border (see fig. 1).

Fig 1: Illustration of the abstraction of the map colouring problem to graph theory.

The four-colour theorem was then proven by demonstrating the absence of a map with the smallest number of regions requiring at least five colours. In its long history the theorem attracted numerous false proofs and disproofs. The simplest versions of counterexamples focus on painting extensive regions that bordering many others, thereby forcing the other regions to be painted with only three colours. The focus on the large region might cause people’s inability to see that colouring the remaining regions with three colours is actually possible.

Even before the four-colour theorem was proven, the abstraction to graph theory evoked the question as to how many colours would be needed to colour a plane so that no two points on that plane with distance 1 do have the same colour. This is also known as the Hadwiger–Nelson problem. Note that we are not colouring continuous areas in this case, but instead each individual point of the plane, rendering it extremely more complex. In the 1950s it was known that this sought number, the chromatic number of the plane, had to be between four and seven.

The upper border is known from the existing tessellation of a plane by regular hexagons that can be seven-coloured [4] (fig. 2). The maximal distance within one hexagon, the diameter, needs to be smaller than one to comply with the requirement. Additionally one needs to ensure that the distance to the next hexagon of the same colour is larger than one. These constraints imply that the hexagon edge length a has to be between 0.5 and $\sqrt(7)/2$ for an allowed colouring of the plane, where no two points with distance one have the same colour.

Fig. 2: Colouring of a plane in a seven colour tessellation pattern of regular hexagons.

As to the lower border for the chromatic number of the plane, it is obvious that two colours will not suffice to colour even the simple unit-distance path of an equilateral triangle (see fig. 3 a). To demonstrate that three colours do not suffice either and therefore at least four colours a needed, we take a look at the Moser spindle shown in fig. 3 b. The seven vertices (all eleven edges / connections have unit-distance) cannot be coloured with three colours, say green, blue, and yellow. Assigning green to vertex A, its neighbours B and C need to be blue and yellow, respectively, or vice versa, enforcing D to be green again. A’s other neighbouring vertices E and F analogously are assigned blue and yellow, or vice versa, enforcing in turn G to be green. This conflicts with G’s neighbour D to be green, too, thus demonstrating that arbitrary unit-distance graphs require at least four colours.

Fig 3: a) An equilateral triangle as a simple example for a unit-distance graph. b) The Moser spindle is a four-colourable unit distance graph [3].

After many years of intractability only this year there was some significant progress in closing in on the Hadwiger–Nelson problem. It was demonstrated that “the chromatic number of the plane is at least 5” [5], by finding two non-four-colourable unit-distance graphs (with 20425 and 1581 vertices). The smallest unit-distance graph with chromatic number five found this year has 553 vertices [6] and is shown in fig. 4. Whether the chromatic number of the plane is five, six, or seven still remains to be shown.

Fig 4: Five-colourable unit distance graph with 533 vertices. The fifth colour (white) is only used in the centre. [6]

— Alexander Kronenberg

[1] Heawood, (1890), “Map-Colour Theorems”, Quarterly Journal of Mathematics 24, pp. 332–338
[2] Appel, Haken, (1989), “Every Planar Map is Four-Colorable”, Contemporary Mathematics 98, With the collaboration of J. Koch., doi:10.1090/conm/098
[3] Soifer, (2009) “The Mathematical Coloring Book”, Springer
[4] Hadwiger, (1945), “?berdeckung des euklidischen Raumes durch kongruente Mengen”, Portugal. Math. 4 ,pp. 238–242
[5] de Grey, (2018), “The chromatic number of the plane is at least 5”, arXiv:1804.02385
[6] Heule, (2018), “Computing Small Unit-Distance Graphs with Chromatic Number 5”, arXiv:1805.12181

Why do alkali metals actually explode in water?

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Nov 222018
 
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It is one of the most common educational experiments in school and straight from the books: The reaction of an alkali metal with water. During this reaction significant amounts of hydrogen gas are produced, which can ignite and thus explode due to the strongly exothermic reaction – at least that is the explanation one finds pretty much everywhere. However, there is something odd about this reasoning. On the one hand, a complete immersion of the metal within water should then prevent the explosion from happening as no oxygen is present to ignite the hydrogen gas. On the other hand, it is surprising that the solid-liquid interface of this heterogeneous reaction creates enough physical contact to drive the reaction. Additionally, the produced gas tends to separate the educts and therefore stop the reaction. Overall, there are quite a few unclear details in this proposed reaction mechanism.

A study of the Czech Academy of Sciences in Prague and the Technical University of Braunschweig, however, showed that even in presumably clear textbook reactions a lot of surprises may be found sometimes. [1,2] The scientists used drops of sodium-potassium alloy that is liquid at room temperature and filmed the reaction with high speed cameras. They could show that the explosive reaction also happens under water when the metal is completely immersed, thus ruling out the ignition of the hydrogen gas as the main driving mechanism for the explosion. Supported by molecular dynamics simulations, they instead showed what mechanism actually drives the reaction: A Coulomb explosion! During the reaction of a clean metal surface with the adjacent water molecules, electrons move quickly from the metal atoms into the water. This also explains why a solid piece of an alkali metal does not always explode in water: it needs a clean interface without significant oxidation. After the electrons left the metal surface and moved into the water, a strongly charged surface is left. On this surface, the ionized atoms strongly repel each other, and thus open up a path to more inner atoms that have not taken part in the reaction yet. On a time scale of about 0.1 ms, metal dendrites shoot into the water (see figure) and suddenly increase the surface area of the metal. [1-3] This happens extremely fast with giant charge currents flowing in the interface region. The surface tension is pretty much nullified in this case [2,3] and the expanding surface provides more reactive area. As a result, large amounts of hydrogen gas are suddenly produced. Together, these effects drive the explosion, while the ignition of the gas is not directly necessary for the explosion to occur. Instead, the hydrogen gas can also burn off later. [2]

Further results of the study could lead to approaches to avoid metal-water explosions and thus gain application relevance in industry. What is however most unusual about this study is that parts of it got funded by the YouTube science channel of the lead author of the paper, which he explicitly acknowledges. In this exciting case, science and media are really in a close relationship.

As soon as a drop of NaK-alloy gets in contact with water (top left), fine metal fingers are protruding into the water (middle). These are driven by the Coulomb explosion that massively increases the surface area and therefore the reactive interface. As a result, a fast production of hydrogen becomes possible, which further drives the explosion (bottom left). The right column depicts the impact of a water droplet for reference. [1,3]

— Kai Litzius

References:

[1] P. E. Mason et al., Nature Chemistry 7, 250–254 (2015).
[2] https://youtu.be/LmlAYnFF_s8
[3] https://youtu.be/xMfQSV4ygHE

 

The Spaghetti Turn

 Question of the Month  2 Responses »
Sep 282018
 
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Certainly, most of us enjoy an occasional nice bowl of spaghetti. Some of us use a spoon along with the fork, some don’t. Doesn’t matter, as long as you enjoy and don’t make a mess ?

But have you ever wondered if there is a preferred direction to turn the screw? And is it related to where you live? We did!

Please take a minute of your time and participate in our survey to enlighten the world.

Note:
If you are both-handed, please choose your preferred direction for right- and left-handed.
It is irrelevant whether you use a spoon in addition or not.
Please don’t shovel. That’s rude
The results will be published on Spaghetti Day (Jan 4th, 2019) on Junq.info

The Spaghetti Turn

How does a candle burn in zero gravity?

 Question of the Month, Uncategorized  No Responses »
Jul 172018
 
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We are all familiar with the appearance of a candle flame. Warm, bright yellow, and formed like a teardrop it nestles up the wick just to reach far out into the empty above it. This behavior can be easily explained by the rise – the convection – of the less dense air that is heated by the combustion around the wick. While colder, more dense air floats inward, the buoyancy of the warm air lets it move upward and away from the combustion zone. However, this process requires buoyancy, which only exists in an environment with gravity. But what would then happen to a flame in zero gravity?

In so-called microgravity, that is an environment with very little gravity like it is present in the Earth’s orbit, there is no convection since there is no definition of a classical “up and down”. The flame therefore looks significantly different and forms a light blue, spherical shape instead of the familiar teardrops. To understand this behavior, one has to consider the chemistry of the combustion as well as the physics of the gas exchange.

In case of the “normal” candle flame, the bright yellow color stems from soot particles that originate in the (non-perfect) combustion. They rise with the hot air and glow yellow in the upper region on the flame. The lower blue-ish region on the other hand is fed by the stream of fresh oxygen-rich air from below. In case of the flame in microgravity, there is no preference for up and down and therefore it assumes a spherical shape. Due to the lack of conversion, the combustion is fed only by (slow) diffusion of the oxygen into and the fuel out of the central combustion zone. This means that the zero-gravity flame burns much slower and does not produce equally distributed soot particles. Thus it is blue, spherical, and produces much more CO and formaldehyde than CO2, soot, and water.

This behavior, and how to extinguish a flame in microgravity, is under investigation aboard on the International Space Station (ISS) in the so-called FLame Extinguishment Experiment (FLEX). It is carried out on small heptane bubbles that are ignited in a controlled atmosphere. The experiment found that such small flame bubbles are not just exotic to look at, but also can pose a threat to space exploration since they can be much more difficult to extinguish. In this way, research on small bubbly flames can thus help making space exploration a bit safer.

A candle on Earth (left) and in microgravity (right): The different combustion patterns are clearly visible. [3, NASA]

— Kai Litzius

References:

[1] www.nasa.gov/mission_pages/station/research/experiments/666.html
[2] medium.com/@philipbouchard/why-is-a-candle-flame-in-zero-gravity-so-different-than-one-on-earth-1775194cf21a
[3] https://www.youtube.com/watch?v=DmrOzeXWxdw

 

What is the Cause of Sonoluminescence?

 Question of the Month  No Responses »
May 292018
 
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Sonoluminescence is a fascinating, mysterious physical phenomenon, that combines the principles of light and sound.

In the year 1934 H. Frenzel and H. Schultes discovered a luminous effect by ultrasonication of water.[1] The defining moment that leads to sonoluminescence is the emergence of a cavitation in the liquid (figure 1). The high frequency ultrasound leads to the formation of bubbles, that are filled with gas and expand and collapse rapidly like a shock wave. Shortly after the collapse, the energy is released in form of sound and a short lightning, which is barely observable with the bare eye and reaches temperatures up to 10,000 K.[2,3]

Figure 1. Schematic illustration of the formation of sonoluminescence (f.l.t.r.): Growth of a gas bubble in a liquid, collapse or implosion of the bubble and emission of light.[4]

In the 1990s, the causes and impacts that lead to sonoluminescence have been intensively investigated but the real cause of this phenomenon remains unresolved even nearly 85 years after its discovery.[5,6] There are different quantum mechanical approaches, but they are highly controversial.[7,8]

Sonoluminescence is not only a physical phenomenon, it does indeed show capability for an academic application, at least in chemistry: in 1991 Grinstaff et al. were able to generate nearly pure amorphous iron by ultrasonication of an iron pentacarbonyl solution in decane. Compared to crystalline iron this compound shows enhanced catalytic activity when used in the Fischer-Tropsch process.[3]

Sonoluminescence also occurs in wildlife: by snapping their claws, pistol shrimp create a sharp stream of water that does not only kill prey but generates a cavitation bubble and thus a short lightning. Scientists call this special phenomenon “shrimpoluminescence”.[9]

 

— Tatjana Daenzer

 

Bibliography

[1] H. Frenzel, H. Schultes, Z. Phys. Chem. 1934, 27, 421–424.
[2] B. P. Barber, S. J. Putterman, Nature, 1991, 352, 318–320.
[3] K. Suslick, S.-B. Choe, A. A. Cichowias, M. Grinstaff, Nature, 1991, 353, 414–416.
[4] „Creative Commons“ from Dake CC BY-SA 3.0. (https://commons.wikimedia.org/wiki/File:Sonoluminescence.png#/media/File:Sonoluminescence.png) last access: 15.05.2018.
[5] B. P. Barber, C.-C. Wu, R. L?fstedt, P. H. Roberts, S. J. Puttermann, Phys. Rev. Lett. 1994, 72, 1380–1383.
[6] R. Hiller, K. Weninger, S. J. Puttermann, Science, 1994, 266, 248–250.
[7] C. Eberlein, Phys, Rev. Lett. 1996, 76, 3842–3845.
[8] R. P. Taleyerkhan, C. D. West, J. S. Cho, R. T. Lahey Jr., R. I. Nigmatulin, R. C. Block, Science, 2002, 295, 1868–1873.
[9] D. Lohse, B Schmitz, M. Versluis, Nature, 2001, 413, 477–478.

Was the Reformer a Plagiarist?

 Essays, news, and open questions, Question of the Month, Uncategorized  No Responses »
Apr 012018
 
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“Dr.” Martin Luther plagiarized in his dissertation

LutherPlag checks

Theology professor Kim Lee-jung of Luther University in Giheung-gu, Yongin, South Korea, reports that he found the doctoral thesis of Martin Luther. The title: Iocorum Encomium (In Praise of Jokes). This discovery is in itself an epochal event. The sensation beyond that: up to 80 percent of the work is plagiarized.

Martin Luther’s is one of the best-researched lives in German history. So far it has been assumed that the reformer never submitted a dissertation, since he never mentioned such an endeavor in his writings, his letters or his diaries.

According to the trilingual press release of South Korean Luther University (see below), theology professor Kim has discovered and examined the dissertation of Martin Luther. The amazing thing is that Martin Luther apparently plagiarized massively in his dissertation. Whole passages are believed to come from a text by his humanist colleague, the Dutch theologian Erasmus of Rotterdam, says Kim.

On his spectacular find and on the content of Luther’s dissertation professor Kim will publish an article in the American Journal of Protestant Theology. In his article he will also address the question: How could such an upright man as Martin Luther do such a thing?

The Korean professor of theology has noticed that countless monuments in Germany refer to the reformer as “Dr. Martin Luther”, whereas in America the academic title is completely absent in his naming. As a reason for this, Kim suspects a cultural preference that arose in Germany during Luther’s lifetime.

“A doctor’s degree seems to be very important to Germans,” he supposes. Even Martin Luther, perhaps the most German of all Germans, may not have resisted this temptation. His example was later followed, among others, by Doktor Faustus, Doktor Allwissend, Dr. h. c. Erich Honecker, Dr. Karl-Theodor zu Guttenberg.

The news has attracted a lot of attention worldwide. Internet activists have set up LutherPlag and run the text through the plagiarism software. Already, it has been said, up to 80 percent of the text consists of plagiarism.

Meanwhile, at Martin Luther University in Halle-Wittenberg, there are unofficial debates going on whether or not to strip Luther of his academic title. This university is the successor of the University of Wittenberg, where Luther submitted his doctoral thesis on 19 October 1512. What would the divestiture mean? Should the title at the dozens of Luther statues in Germany be removed and all the publications on “Dr. Martin Luther” have an erratum attached?

 

Professor Kim Lee-jung had no idea what consequences his discovery would have. In a telephone conversation with JUnQ, he said: “It is about time, however, that thinking about Martin Luther enters into a postheroic and postmonumental, even into a postdoctoral phase. That’s what I stand for as a scientist, I can do no other.”

Dr. Antje Käßmann for Journal of Unsolved Questions

Mainz, April 1st; 2018

 

Online-Version:

For further information please click here: website.

 

War der Reformator ein Plagiator?

Dr.” Martin Luther hat in seiner Dissertation abgeschrieben – LutherPlag prüft

Der Theologieprofessor Kim Lee-jung von der Luther University in Giheung-gu, Yongin, Südkorea, berichtet, er habe die Doktorarbeit Martin Luthers gefunden. Der Titel: Iocorum encomium (Lob der Scherze). Diese Entdeckung ist an sich ein Jahrhundertereignis. Die Sensation darüberhinaus: bis zu 80 Prozent der Arbeit sollen abgeschrieben sein.

Die Biographie Martin Luthers gehört zu den am besten recherchierten Leben in der deutschen Geschichte. Bisher ist man davon ausgegangen, der Reformator habe nie eine Dissertation vorgelegt, da er weder in seinen Schriften, noch in Briefen oder Tagebüchern ein solches Bemühen erwähnt habe.

Laut der dreisprachigen Pressemitteilung der südkoreanischen Luther University (siehe unten) hat der Theologieprofessor Kim Lee-jung die Dissertation Martin Luthers entdeckt und untersucht. Das Erstaunliche ist, dass Martin Luther in seiner Dissertation anscheinend massiv plagiiert habe. Ganze Textpassagen sollen aus einer Schrift seines humanistischen Kollegen, dem holländischen Theologen Erasmus von Rotterdam stammen, behauptet Kim.

Über den spektakulären Fund und über den Inhalt der Lutherschen Dissertation wird Professor Kim einen Aufsatz im American Journal of Protestant Theology publizieren. Darin wird er sich auch der Frage widmen: Wie konnte ein so geradrückiger Mensch wie Martin Luther so etwas tun?

Dem koreanischen Theologieprofessor ist aufgefallen, dass die unzähligen Denkmale in Deutschland den Reformator stets als „Dr. Martin Luther” ausweisen, wohingegen man in Amerika auf den akademischen Titel bei der Namensnennung komplett verzichtet. Kim vermutet als Grund eine kulturelle Vorliebe, die in Deutschland zu Luthers Lebzeiten aufkam.

„Die Doktorwürde scheint den Deutschen sehr wichtig zu sein”, schätzt er. Selbst Martin Luther als vielleicht Deutschester aller Deutschen habe wohl der Versuchung nicht widerstehen können. Seinem Beispiel folgten später u.a. Doktor Faustus, Doktor Allwissend, Dr. h. c. Erich Honecker, Dr. Karl-Theodor zu Guttenberg.

Die Nachricht hat weltweit große Aufmerksamkeit erregt. Internet-Aktivisten haben LutherPlag eingerichtet und jagen den Text durch die Plagiatssoftware. Schon jetzt wird von einem bis zu 80-prozentigen Plagiat gesprochen.

Inzwischen wird an der Martin-Luther-Universität zu Halle-Wittenberg inoffiziell diskutiert, ob man Luther den akademischen Grad aberkennen müsse. Diese Universität ist die Nachfolgerin der Universität Wittenberg, wo Luther am 19. Oktober 1512 seine Doktorarbeit eingereicht hat. Was würde die Aberkennung bedeuten? Müsste der Titel von den Dutzenden Lutherdenkmälern in Deutschland mechanisch getilgt werden und all den Publikationen über „Dr. Martin Luther” ein Erratum beigefügt werden?

Professor Kim habe nicht geahnt, welche Konsequenzen seine Entdeckung nach sich ziehen würde. In einem Telefonat mit JUnQ sagte er: „Es ist aber an der Zeit, dass der Umgang mit Martin Luther in eine postheroische und postmonumentale, ja sogar in eine postdoktorale Phase eintritt. Dafür stehe ich als Wissenschaftler, ich kann nicht anders.”

 

Dr. Antje Käßmann für Journal of Unsolved Questions

Mainz, 01. April 2018

 

Online-Version:

Für weitere Informationen klicken sie bitte hier: website.

 

Continue reading “Was the Reformer a Plagiarist?” »

When will we be able to hoover with a Dyson sphere?

 Question of the Month, Uncategorized  No Responses »
Mar 152018
 
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Probably never, since a Dyson sphere is not a vacuum cleaner of the same-named famous brand. In fact, until now it is just a thought experiment:

In 1960 Freeman J. Dyson published his theory about the “the long-scale conversion of starlight into far infrared radiation” in Science.[1] He states that aliens with further developed technology than ours must have found an advanced way like this to harvest solar energy.

Such a device could be a shell around the system’s sun at a distance of about two earth orbits, a thickness of 2?3 m, and nearly the mass of Jupiter. All the energy emitted by the star could thus be absorbed and harnessed on the inner surface. Of course, one must first exploit an entire planet to obtain all the mass needed for this device –  a huge technical trouble.

But with his hypothesis Dyson also proposed a way to trace intelligent existence in far-away solar systems that was new up to then. Until the 1960s the search for aliens based on the search for extra-terrestrial radio signals. However, a Dyson sphere would appear as a dark object emitting radiation in the far infrared (about 10 µm).[1] Now, instead for only listening to strange radio noise, scanning the sky for abnormalities in the infrared spectrum became also of importance.

Some years ago mankind seemed to be one step closer to discovering a Dyson sphere (or something similar): the light of the star KIC 8462852 shows an immensely changing intensity as if a huge object is regularly passing by. An orbiting planet would be too small to cause such an eclipse. This evokes suspicions about space-factories or cities and even whole Dyson-like devices. But the shadow could probably also be cast by natural causes like the remains of a burst asteroid or an interstellar cloud.[2]

Until we will be able to construct a Dyson sphere millions of years could pass. We first have to develop advanced methods for space-travel and the technology to destruct a whole planet. Not to speak of the energy we will already have consumed on the way.

But then, of course, we might be able to drive our hoovers (or anything else) with energy from a Dyson sphere 😉

 

— Tatjana Daenzer

 

Read more:

[1] Dyson F. J., Science 1960, 131, 1667-1668.

[2] https://www.seti.org/seti-institute/mysterious-star-kic-8462852 (last access 16.02.2018).

 

 

Two minds, one body and a billion questions.

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Feb 282018
 
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Conjoined twinning is one of the most fascinating and at the same time devastating human malformations. This is an extremely rare phenomenon. The occurrence is estimated to range from 1 in 50,000 births to 1 in 100,000 births [1], when identical twins are born physically connected to each other. They can be joined anywhere—head, chest, abdomen, hips, and so on [2]. In fact, there is a whole spectrum of cases with different degrees of bodily overlapping: from being joined by a thin sliver of skin to being extensively fused. The “fusion” can be so extensive that in some cases, it is no longer correct to talk about “twins” because there is only one individual with some extra organs [3].

Conjoined twins have been known to exist for centuries, yet there is very little understanding of this phenomenon. Common public questions are: How do conjoined twins live together? How do they eat, walk or manage any other daily routine activities? Do they share thoughts and can they read each other’s mind?

The answers to these questions are indeed different for different pairs of conjoined twins. For example, 27-year old Abigail “Abby” and Brittany Hensel are joined at the torso. They have two hearts, two spines, two sets of lungs, two arms and two stomachs. Below the waist, they are more like one body. Each twin controls her half of their body – Brittany, the left twin, can’t feel the right side of her body, and vice versa. Each twin manipulates one arm and one leg.

As infants, the initial learning of physical processes that required bodily coordination, such as clapping, crawling, and walking, required the cooperation of both twins, even standing up takes total coordination. Now as grown-ups they are incredibly well coordinated with this set-up, able to walk with a smooth gait, dribble a basketball, ride a bike, and even drive a car: both steer and Abigail controls the accelerator with her right foot. The really mesmerizing thing is watching them type on a computer, as both girls’ hands fly over the keys, but there is no verbal discussion of what they are writing [4].

For 98 percent of all sets of conjoined twins, each person has their own separate and distinct thoughts and feelings. But in the case of Tatjana and Krista Hogan [5], which occurs in only one in 2.5 million births, they share neural activity because their skulls are connected.

The girls are still too young to investigate their neurological wiring, but from the MRI scans, doctors have determined that there is a “thalamic bridge” that links one sister’s sensory input to the other, creating a conscious loop. Essentially, if one thinks a happy thought, the other can perceive it. When one sees an image through her eyes, the other receives the image milliseconds later.

With a few tens pairs of conjoined twins across the world today Abby and Brittany, Krista and Tatjana are defying the odds. And a fair answer to all the curious questions can be that they are able to do normal things, even though it takes a lot more effort for them than anyone can imagine.

 

— Mariia Filianina

  1. Mutchinick, O.M. Conjoined twins: a worldwide collaborative epidemiological study of the international clearinghouse for birth defects surveillance and research, Am J Med Genet C Semin Med Genet. 0, 274 (2011).
  2. Kaufman, M.H. The embryology of conjoined twins, Child’s Nervous System 20, 508 (2004).
  3. Savulescu, J. and Persson, I. Conjoined twins: philosophical problems and ethical challenges, Medicine and Philosophy 41, 41 (2016).
  4. Abby and Brittany: Joined for Life, BBC.
    Available: http://www.bbc.co.uk/programmes/b01s5b2d
  5. Ryan, D. Through her sister’s eyes: conjoined twins Tatiana and Krista were extraordinary from the beginning. The Vancouver Sun[On-line] (2012). Available: http://www.vancouversun.com/health/Through+sister+eyes+Conjoined+twins+Tatiana+Krista+were+extraordinary+from+beginning/7449226/story.html

 

Is Mycelium the Material of the Future

 Question of the Month  1 Response »
Jan 082018
 
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Is Mycelium the Material of the Future?

No, mycelium is not a recently discovered chemical element. It might be the solution to the question of how to replace petroleum-based materials!

Mycelium is the tenuous web of vegetative fungal cells called hyphae that grows in the soilas shown in figure 1.[1] The parts of fungi that we usually see are just their body fruits (mushrooms, chanterelles, shiitake,…). But mycelium forms a much larger network below the surface that can even spread over several thousand square kilometers.[2] It is one of earth’s most important organisms since it helps nature to “digest”, meaning that it decomposes organic material and turns it into compost.[1]

Figure 1: Microscopic image of a mycelium network (size 1 mm · 1 mm).[3]

But can this bio-based material save our planet? The answer to this question could be easier as you might think. Fungal material is renewable, compostable under certain conditions (moisture and the presence of other organisms), fire resistant, moldable, free from volatile organic compounds (VOCs), dyeable and vegan.[4]

Companies like Ecovative and MycoWorks have already started to produce items from mycelium that can find access to our daily life.[4,5]

Ecovative was founded in 2007 and claims to produce more than 450,000 kg of mycelium material per year. They explain the production process on their webpage:

Agricultural waste is seeded with mycelium from mushrooms like Ganoderma. After some time of incubation, the waste is cut into little particles that are filled into a mold with the desired shape. The mycelium grows a few days until it has filled the mold and can be removed. In a last step the solid material is dried to stop the mycelium from growing. From that process packing material and even decoration can be made.[6] Imagine how many things could be substituted that are still petroleum-based and not compostable.

MycoWorks, founded in 2013, is specializing on replacing leather by mycelium – a relieve for our vegan friends. They claim that “…it feels and performs like leather”.[5] Indeed, recently I had the chance to touch a sample of “mycelium leather” and it does feel quite comfortable!

Mycelium as a full substitute for most of our plastic-based everyday products has still a long way to go. Sure, fugus as fancy packing material is not unusual anymore but customers still have to be convinced to wear clothes made from mushrooms. After all, some fungi are responsible for decay and mould. How will it react on the (moist) skin? Can it be washed without any damage to the fabric? How quickly does it decompose?

There must still be made a lot more research and explanatory work until consumers are convinced to take mycelium as an impeccable material. But maybe one day the world will be greener and we will be producing less eternal waste.

– Tatjana Daenzer

Read more:

[1] https://www.britannica.com/science/fungus, last access: 15.12.2017, 15:33.
[2] Ingraham, John L.: March of the Microbes: Sighting the Unseen, Harvard University Press, Cambridge 2010.
[3] CC BY-SA 3.0, last access 15.12.2017, 16:52.
[4] https://www.ecovativedesign.com/, last access 15.12.2017, 15:58.
[5] https://www.mycoworks.com/, last access 15.12.2017, 16:26.
[6] https://www.ecovativedesign.com/how-it-works, last access 15.12.2017, 16:09.

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