Mass is mass is mass
Digital photograph Max Planck Institute for Physics, Munich
The particle physicists from all over the world who work together at the CERN European accelerator centre in Geneva had great cause for celebration: they finally succeeded in detecting the long-sought Higgs particle. According to the Standard Model of particle physics, this particle gives mass to all other elementary particles. Peter Higgs and François Englert predicted its existence as far back as 1964 – and have now been awarded the Nobel Prize in Physics 2013 for their work. However, direct evidence of the Higgs particle cannot be provided; its existence is calculated from the measurements made at the Large Hadron Collider (LHC), the world’s biggest particle accelerator. The image shows a view of the interior of the Hadronic End-Cap Calorimeter in the ATLAS detector at the LHC: this is one of the measuring devices that record the particle tracks that arise when two opposing proton beams are shot at each other in the ring tunnel of the LHC.
Read more here: Higgs or not Higgs?
Thinking in orderly structures
Diffusion-weighted magnetic resonance imaging (MRI);
depiction via visualisation software Fibernavigator 2
Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig
Ralph Schurade, Alfred Anwander
What is 17 multiplied by 146? Or 111 plus 97? Complex cognitive skills such as calculation wouldn't be possible without complicated connections of neuronal circuits in various brain regions. With the help of diffusion-weighted magnetic resonance imaging (MRI), neuroscientists are able to uncover how these nerve fibre bundles connect different regions of the brain. To this end, the scientists use the natural magnetism of the particles in the brain in order to measure the diffusion movement of water molecules in the tissue. This enables them to draw conclusions on the pathways and signal orientation of the large nerve fibre bundles. The researchers translate the measured diffusion gradients into bright colour patterns, with the colours corresponding to the direction of the fibres (red: left-right; green: front-back; blue: top-bottom).
Reflected-light microscope image in polarised light
Max-Planck-Institut für Eisenforschung GmbH, Düsseldorf
Making high-quality steel is something of an art. To this effect, materials scientists experiment with different alloys. For example, the combination of iron and chrome increases the tensile strength of the steel and its resistance to corrosion and wear. In order to find the optimum mixing ratio, the researchers vary the chrome content and test the hardness of the material with the help of a Brinell impression measurement system. To do this, they apply an exactly defined test force to the surface of the material, using a carbide ball with a diameter of 2.5 millimetres; the size of the resulting indentation is a measure of the material’s hardness. The image shows the microstructure of a chrome-iron alloy. The circular Brinell indentation can be seen on the bottom right. So-called slip lines arise on the edge of the indentation through plastic deformation.
Visualisation of satellite data
Max Planck Institute for Astrophysics, Garching
The keyboard of light extends across numerous octaves. It ranges from long-wave radio radiation to the visible range and high-energy gamma photons. This is precisely what was captured here by a telescope on board the Fermi satellite. What’s more, the image is the product of all of the data collected by the US satellite over a period of around four-and-a-half years. It shows the sky with the heart of the Milky Way in the centre. The galactic disk, in which our sun – just one of 200 billion stars – orbits, extends to the left and right. The north galactic pole is on the upper edge of the image and the south galactic pole on the lower edge. The diffuse structures in the image are part of the Milky Way. Numerous point sources are also visible; some of these belong to our solar system, others belong to remote galaxies. Three bright “stars” are particularly noticeable - the Vela pulsar in the middle of the right hand half of the image and the Geminga and Crab Nebula pulsars on the extreme right side of the picture.
An enzyme that warms the climate
Electron microscopy image, 3D reconstruction
Max Planck Institute of Biophysics, Frankfurt am Main
Methane is over 20 times stronger in its effect as a greenhouse gas than carbon dioxide. It is formed when certain microbes from the Archaea group of bacteria decompose organic material under the exclusion of air – for example, in rice fields, bogs and cows’ stomachs. The enzyme Frh, a hydrogenase, plays a key role in the process: it splits hydrogen, which can then react with carbon dioxide to form the methane. The Frh protein consists of a total of twelve trimers, each of which has three subunits, here in blue green and purple. It contains several iron-sulphur clusters – shown as yellow structures in the image – and nickel and iron in the active centres, where the reaction takes place. The structure and function of this enzyme are not only of interest to climate researchers: the molecule could provide a model for the development of catalysts for hydrogen production.
Read more here: New insight into biochemical methane production
The place to be
Scanning electron microscope image, partly coloured
Max Planck Institute for Developmental Biology, Tübingen
Jürgen Berger, Gáspár Jékely
Whether corals, worms or mussels: Many marine invertebrates begin their lives as part of the plankton. This is also the case with the annelid or ragworm Platynereis dumerilii, which has become an important model organism in evolutionary developmental biology in recent years. The larva controls its movement with the help of a prominent, regularly beating belt consisting of thousands of tiny hairs or cilia. But how does it find a place that can offer the adult worm ideal conditions for its rather stationary existence? A simple organ at the head end of the larva, known as the apical organ, plays a crucial role. Neurons located here perceive environmental stimuli and produce a neuropeptide in response, which alters the beat of the cilia. The larvae start to sink, and then crawl along, surveying the sea floor. They can presumably detect food in this way, and thereby find a suitable habitat.
Read more here: The neurobiology of house-hunting at sea
Sugared with silver
Scanning electron microscope image
Max Planck Institute of Colloids and Interfaces
Bat El Pinchasik
The Roman god Janus served as godfather to these silicon dioxide microparticles. Like the two-headed deity, these particles have two faces. One half is covered with silver, and the other is not. To produce these Janus particles, the researchers fix silicon balls in a soft film and coat the free side with silver. The metal is then chemically reduced and catalytically active silver particles are formed. When the particles are placed in water, they move: the splitting of the hydrogen peroxide causes tiny oxygen bubbles to form on the silver-coated side which lift and propel the particles. A similar kind of propelling mechanism is also found in the animal kingdom: the violet snail, for example, glides through the oceans with the help of small bubbles.
Digital photograph: Fresco von Alessandro Allori, Annunciation, 1560/1564,
Florence, SS. Annunziata, Cappella di San Gerolamo
[Photothek: Inv. Nr. 599129, Dig. Nr. fld0003491]
Kunsthistorisches Institut in Florenz – Max Planck Institute
The Florentine painter Alessandro Allori was commissioned to design the chapel of the Montauti family in the city’s Basilica della Santissima Annunziata in 1560. Allori created a fresco cycle with scenes from the life of Christ, including the Annunciation of the birth of Christ to Mary by the Archangel Gabriel as the ceiling image. The angel is shown here appearing to a humble Mary in a room furnished only with a lectern; an open door provides a view of the distant countryside. As a symbol of the angel’s celestial origin, he is presented floating on a cloud; the white lily with seven blossoms in his hand and the white cloth in which Mary is wrapped, refer to her virginity. Viewers of this Annunciation are struck by the angel’s strongly sculptural male form. The muscular depiction is reminiscent of works by Michelangelo, which provided important models for Allori’s work. This image was produced as part of a photographic project carried out by the Photo Library of the Kunsthistorisches Institut in Florenz on the completion of the chapel restoration project in 2010.
Fish eye in focus
Fluorescence microscope image
Max Planck Institute of Molecular Cell Biology and Genetics, Dresden
Although humans and zebra fish appear to have little in common at a first glance, an astonishing number of parallels can be observed in their development and the structure of their organs. For example, the retina of the eyes in both species is structured very similarly. For this reason, the small fish is a popular model organism for studying the development of our visual organ. The image shows a cross-section of the retina of a three-day-old zebrafish embryo. The researchers made different cell types visible using fluorescent proteins. This enables them to trace the way in which the cells rearrange themselves while the initially simple tissue layer develops into a multi-layered structure. Part of the cell skeleton can be seen here in green, and the cell walls of the photoreceptors and the optic nerve, which conveys information to the brain, are bright pink.
Waves in virtual space
Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Potsdam-Golm
Numerical simulation: Bruno Giacomazzo, Luciano Rezzolla (AEI)
Scientific visualisation: Ralf Kähler (AEI & Zuse Institute Berlin)
Take half a million earths, compress them into a ball of just 20 kilometres in diameter and make it rotate faster than a kitchen mixer. This is precisely what occurs in a neutron star, the remnant of a massive sun that has exploded during a supernova event. Such star corpses sometimes arise in pairs, in other words they circle around a joint centre of gravity. If they come too close to each other, they melt into a black hole in a matter of milliseconds. This process cannot be observed directly in nature. However, researchers can simulate such events in a virtual universe. The computer simulation provides the solution to Einstein’s equations in the form of columns of numbers. To visualise the processes, these data are transformed into graphics, images and films and then coloured. In this way, a clear image is produced of the disaster, during which “spiral” gravitational waves are also released – witnesses of a cosmic dance of death.
Read more here: The ripples in space-time.
Becoming a cellular jack-of-all-trades
Flourescence microscope image
Max Planck Institute for Molecular Biomedicine, Münster
Skin cells, cardiac cells, liver cells - our body cells are specialised to carry out specific tasks. However, under certain circumstances, cells can be reprogrammed in the laboratory into pluripotent stem cells – similar ‘all-rounders’ as embryonic stem cells. A protein called Oct4 is crucial to this process. But Oct4 does not appear to play a major role in early embryonic development: the embryonic node, from which the foetus develops, can also be formed without the Oct4 protein. The images show a normal mouse embryo (left), an embryo without maternal Oct4 (centre) and an embryo that entirely lacks Oct4 (right). The cells of the embryonic node are coloured green, those of the trophoblast, which later become part of the placenta, are bright red. Consequently, nature takes a different route than the stem cell researchers.
Read more here: Two distinct types of reprogramming
Extremely cold and incredibly empty
Max Planck Institute for Nuclear Physics, Heidelberg
Life is difficult for chemical reaction partners in outer space – due to the low temperature and density of mass in the interstellar realm, there are only slim chances of getting together. To gain a better understanding of this special chemistry, researchers use very complex technology to simulate the conditions in space on earth. A new cryogenic storage ring, one of a kind in the world, is currently being constructed in Heidelberg. Even sensitive, highly-charged molecule-ions can be stored for up to several hours and examined in detail in this storage ring, which has a temperature of just 2° above absolute zero and an extremely powerful vacuum with less than one billionth of normal air pressure. The image shows a quadrupole, part of the ion optical elements, which trap the ions to be studied on a defined path. Unlike the usually used magnets, this electrostatic guiding of the ion beam also enables the storage of very large, heavy ions up to biomolecules and clusters. The electrodes of the ion optical elements are gilded to ensure optimal surface quality.
Short-lived beauty at the beach
Max Planck Institute for Meteorology and Klimacampus University of Hamburg
The cover photograph of our Advent Calendar which shows a large ice cave in Iceland,
was also taken by Christian Klepp.
An impressive spectacle can be seen every day in south Iceland: at the foot of the Vatnajökull glacier, there is a large lagoon, in which numerous glaciers swim. At high tide, sea water flows into the glacial lake via a short river and the glaciers rotate in large circles in the current. At low tide, the water flows away again and sweeps even large glaciers with it to the sea. They are battered in the rough waves, but fragments often remain stranded on the jet black lava beach. The turquoise colour of this 2.5 metre-tall block of ice testifies to its advanced age – the snowflakes that formed the ice fell around 1000 years ago on the plateau of Vatnajökull. The cracks in the ice are traces of the enormous pressure and tension to which it was subjected during its journey through the glacier. These are the weak points at which the glacier will disintegrate in the waves of the next high tide. Researchers from Hamburg study precipitation over the oceans from the tropics to the polar regions. Precipitation is an important component of the climate system.
Owls in the sleep laboratory
Max Planck Institute for Ornithology, Seewiesen
The two baby barn owls shown in the image look very much awake, however, like human babies, they still need a lot of sleep. Owls have the same sleeping pattern as mammals: as babies they spend more time in REM sleep (rapid eye movement) than they do as adults. In the REM sleep phase dreams occur and brain activity is similar to that of the waking state. However, scientists remain in the dark about the function of this sleep phase: because it predominates in early life and then declines, they assume that it plays an important role in brain development. Scientists are also baffled by another rather curious phenomenon relating to owls and sleep: the sleeping behaviour of the barn owls is closely linked with the activity of a gene, which is responsible for black spots on the plumage of the adult bird. The scientists would like to discover how sleep, brain development and pigmentation are linked.
Read more here: Baby owls sleep like baby humans
A delicate balance
Confocal microscope image
Max Planck Institute for Biology of Ageing, Cologne
Sara A. Wickström, Alexander Meves
Our skin has an astonishing capacity for regeneration and renews itself continuously throughout our lifetime. To do this, new skin cells must form continually from stem cells. It is important, however, that the number of cells remains constant. The delicate balance between cell renewal and differentiation can be thrown out of kilter, and eczema, psoriasis and tumours can arise as a result. The skin’s regeneration capacity also declines with age, a phenomenon that manifests, for example, in poorer wound healing. The factors that influence this balance and the role aging plays are important questions that researchers are investigating with the help of cytological methods, among others. The image shows a section through a mouse skin sample with three hair follicles. The stem cell area was stained red, the precursor cells of the top layer of skin (epidermis) are bright green. The cell nuclei are labelled blue.
A turbulent mix
Max Planck Institute for Meteorology, Hamburg
Chiel van Heerwaarden
Turbulence arises in the earth’s atmosphere when relatively cold air is found above a warm surface. These whirlwinds form clouds, can cause storms and, as a result, have a major influence on the climate. Max Planck researchers approach the study of turbulent processes in the sky with the help of computer simulations. The image shows a cross-section of the atmosphere that is being heated by two very warm areas on the earth’s surface. These could be cities, for example, which generate much more heat than rural areas, or lakes which are warmer at night than their surroundings. By varying the expansion of the heat sources on the computer, the scientists can reconstruct how changes on earth influence the turbulence in the sky.
Black holes in the virtual laboratory
Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Potsdam
Numerical simulation: C. Reisswig, L. Rezzolla / Scientific visualisation: M. Koppitz
Albert Einstein’s theory of relativity predicts the existence of gravitational waves: minute distortions of space-time. The direct measurement of these gravitational waves is one of the most exciting challenges in modern physics. In order to track down the gravitational waves, Einstein’s equations are solved for the collision of black holes and neutron stars using supercomputers. This image shows the numerical simulation of two inspiralling black holes, which merge to form a new black hole. The horizons of the black holes and the radiated gravitational waves are represented in the image. Simulations like this provide insights into the possible properties of gravitational wave signals and help the scientists in their search for needles in a haystack.
Colourful brain waves
Max Planck Institute for Biological Cybernetics, Tübingen
To enable us to watch a film or read a book, the visual information that reaches our eyes must be transformed into electric currents and transmitted to the brain, where it is processed in the sight centre. However, electric currents can also arise spontaneously in this area of the brain without any visual stimulus. The image shows a spontaneous spiral wave of this kind in a primate’s visual centre. To this end, the scientists used a voltage-sensitive dye that reflects the excitation state of the neurons in different colours. The image is a snapshot from a series of individual shots taken at intervals of four milliseconds. This method enables the researchers to trace the dynamics of the brain activity in almost real time. They would like to find out how the brain, the most complex of organs, functions.
A plasma makes waves
Max Planck Institute for Extraterrestrial Physics, Garching
Contrary to appearance, this wave was not created by a Pointillist painter but by a complex plasma: physicists ionise the noble gas neon to a plasma using a high voltage and inject it into these plastic microspheres. The particles become electrically charged and repel each other. Through the effect of gravity, they also arrange themselves in three layers in order of their size. In this colorized image, the complex plasma flows from the left through a narrow section on the right and fluctuations in the density in the upper layer generate waves in the middle layer. Because the individual microspheres can be observed, researchers use complex plasmas to study, for example, how a laminar flow becomes turbulent, particle by particle. To eliminate the influence of gravity and study the causes of turbulence in pure form, the experiments are also carried out on the International Space Station.
3D printer in action
Max Planck Institute for Evolutionary Anthropology, Leipzig
Ronny Barr and Dennis Reinhardt
The Max Planck Institute for Evolutionary Anthropology in Leipzig studies fossils with the help of modern imaging processes. As the fossils are often incomplete, the scientists record 3D data from the originals using a computer tomograph and then visualise it in the Virtual Reality Laboratory. Individual parts of a fossil can be assembled there like a puzzle and missing parts are calculated by computers. This replica is recreated in its original size or to scale with the help of a 3D printer. For example, the 3D printer can print the replica of a human skull in just 33 seconds. The researchers use these replicas to study the consistency of a fossil or to compare it with other fossils. The valuable original is protected and conserved in this way. The 3D data are made available to researchers all over the world.
A peacock in stone
Niche fragment with peacock & vine branches - part of an inscription
from the Basilica of St Polyeuctos in Constantinople, (Istanbul
Institute of Art History in Florence – Max Planck Institute
The Roman imperial princess Anicia Juliana was an important patron of the arts and sciences in Late Antique Constantinople. The Basilica of St. Polyeuctos, commissioned by her and constructed from 524 to 527, was the city’s most important and magnificent ecclesiastic building until the construction of the Hagia Sophia by Emperor Justinian. Today, only the substructures and fragments of the marble fittings remain. In combining the classical tradition and Sassanid-Persian elements, these capitals, pilasters and niches are an outstanding example of transcultural dynamics in the history of art. Parts of the church, which was abandoned in the 11th century, were used as spolia, that is, re-used in the construction of other buildings. For example, the pillars in front of St. Mark’s Basilica in Venice, which are known as the Pilastri Acritani, originate from St. Polyeuctos – they reached Venice during the fourth crusade in the 13th century.
Confocal microscope image
Max Planck Institute for Molecular Physiology, Dortmund
The human brain consists of approximately 100 billion neurons. In order to be able to communicate with each other, the individual neurons have long extensions. Like telephone cables, these extensions enable the transmission of electrical signals. Researchers try to understand how neurons develop their complex shape and, to this end, they examine the different components of the neuronal cytoskeleton – actin and microtubuli – and the associated proteins. To do this, they cultivate special neurons in the laboratory and make the highly delicate structures visible with the help of fluorescent dyes. They can thus follow the dynamic process live in the living object. This image is a frame from a film. It shows the actin molecules (blue) and the microtubuli-associated protein 2c (gold). This binds to the microtubuli, stabilises them and promotes the formation of long cell extensions.
Oh Christmas tree, Oh Christmas tree
Fluorescent microscope image
Max Planck Institute for Molecular Cell Biology and Genetics, Dresden
What do these Christmas tree-like structures have to do with science? Molecular biologists are sometimes rewarded with unusual sights after peering into the fluorescent microscope for hours on end. Here, the scientists marked two structures in a cell in different colours. The shiny red structures are microtubules, which stabilise the shape of the cell and can make it expand or shrink. They are assisted in this function by microtubule-associated proteins on the sides, which appear green in this image. These proteins are constantly produced and dismantled, a process that the scientists at the Max Planck Institute for Molecular Cell Biology and Genetics in Dresden observed under the microscope. They took a photo every five seconds - and when they superimposed photos taken over a ten-minute period, these Christmas trees emerged.
A wandering star
Computer simulation and montage
Max Planck Institute for Biophysical Chemistry, Göttingen
Timo Graen, Carsten Kutzner, Petra Kellers
This star, which would make a good motif for a Christmas card, is worth closer scrutiny. The tiny individual components, which look like colourful scribbles, are actually snapshots of protein structures. As proteins are among the elementary building blocks of life – from single-celled bacteria to humans – scientists are trying to decode the structures of these proteins and, in this way, gain a better understanding of the tasks they carry out. Up until now, scientists have identified almost 80,000 different biological molecular structures and recorded them in a central database (RCSB Protein Data Bank). Computer simulations like this one help the researchers to decode the function of these amazing biological nanomachines. This image is composed of 85 individual simulations.