Advent Calendar 2018

Our online science advent calendar is back! Each day until December 24, we will open a door of our advent calender for you to dazzle you with images from science and provide the scientific background to the image. Enjoy!

The background picture of our advent calendar shows a glimpse into a cosmic nursery: NGC 602, at about about five million years of age a relatively young cluster of stars, is surrounded by natal stars and dust. It is located in the Small Magellanic Cloud, a satellite galaxy to our Milky Way.
^{© NASA, ESA, and the Hubble Heritage Team (STScI/AURA) – ESA/Hubble Collaboration}

In the eye of the storm

Cyclones grow as they extract energy from the atmosphere and ocean. They originate out of Earth’s inability to otherwise move great amounts of energy efficiently from areas where it accumulates. The best known cyclones are the hurricanes of the North Atlantic, or the Typhoons of the North Pacific. But the tropical cyclones of the Indian Oceans are often perceived as particularly destructive, as they seemingly emerge out of the tranquility of the tropics to unleash their ferocious power in the form of violent winds and torrential rain. However, even the Mediterranean Sea gives rise to the tempests with tropical features. With the help of today’s super computers,researchers can virtually create these storms to better improve forecasts of their development and evolution. This image shows the intensity of winds close to the surface of a cyclone-like storm in the Mediterranean Sea.

Numerical simulation

Max Planck Institute for Meteorology

City in sepia

Historical photographs are often referred to as black and white, but they actually have a broader colour spectrum: the actual colours of the image are converted into a tone scale that depends on the relevant process, while the negative and print assume a certain basic tone. The term 'black and white photography' was first used at the beginning of the 20th century to distinguish previous techniques from the emerging colour photography. This collodion glass negative with the view of Florence was produced between 1860 and 1880. To produce it, an emulsion of collodion was poured onto a glass plate, made light-sensitive by silver halide and exposed in the camera. Around 1880, these elaborately produced negatives were increasingly replaced by industrially produced gelatine dry plates.

Collodion negative with sepia ground sound

Kunsthistorisches Institut in Florenz - Max Planck Institute

Cosmic crash

Space-time ripples? That sounds more like fiction than research. And yet it was Albert Einstein who predicted such a phenomenon more than a century ago. On September 14, 2015, that which the ingenious physicist himself had never believed actually happened: two detectors in the USA caught such ripples, called gravitational waves, for the first time and thus opened up a completely new view of the universe. Two black holes that had melted together in a distant galaxy about 1.3 billion years ago turned out to be the source. The measured data were visualized by scientists, creating this image of the cosmic crash. Since the first discovery a good three years ago, ten more signals have been detected. One of them does not originate from black holes, but from the collision of two neutron stars. Read more: Four new sources of gravitational waves

Scientific visualization of a numerical simulation

Max Planck Institute for Gravitational Physics

A mosaic of the heart

The heart is the first functional organ of a developing infant. Malformations of this organ often lead to the death of the embryo. This is why scientists want to investigate how the development of the healthy heart proceeds in detail. To this end, they are investigating heart development for example, in mice, because the animals’ developmental pathways are very similar to those of humans. The very first cells of the heart are labelled with fluorescent proteins. If these cells divide, they pass the labels on to all descendants - which leads to the characteristic spot patterns on the mouse heart shown here. And although the individual cells behave very differently, the size of the spots follows universal laws - an important finding for the interpretation of these experiments in order to gain a basic understanding of the behaviour of stem cells.

Fluorescence microscopy

Max Planck Institute for the Physics of Complex Systems

In good shape

An astonishing number of leaf shapes have developed in the course of evolution. They enable plants to function in the best possible way under varying climatic conditions. The scientists at the Max Planck Institute for Plant Breeding Research want to find out how the different leaf shapes developed and identify the driving force for this variety. Hairy bittercress (Cardamine hirsuta) forms a basal rosette using composite - so-called plumed - leaves. The colours in the image are the result of artistic licence: The orange-red glow reflects the environmental strain which the plant leaves face every day, e.g. due to fluctuations in temperature, light, humidity and infections.

Digital photography wide-angle close-up lens

Max Planck Institute for Plant Breeding Research

Bon appetit

Since carnivorous plants grow in a low-nutrient environment, they need to consume their food in the form of animals. To catch them, they have developed highly specialized catching and digestion mechanisms, such as the pots from transformed leaves used by the species Nephentes. The variety Nepenthes alata shown here is found in the Philippine rain forest, where it can catch insects and other arthropods in its trap. Bait includes scent and optical stimuli, as well as sweet nectar produced on the edges of the pots, which glows in fluorescent light. But if the prey slips off into the inside of the pot, things no longer look so rosy – acidic liquid awaits which contains a whole cocktail of digestive enzymes.

Digital photography under UV light

Max Planck Institute for Chemical Ecology

Men's best friend

At least 15,000 years ago, humans began domesticating wolves and started to breed dogs. What role these animals played at that time is still shrouded in mystery. Now images carved into rocks, discovered by Max Planck researchers in Saudi Arabia, provide first glimpses into life with animals in early human history. The images show people hunting with dogs - and some of the dogs are wearing leashes. These might be particularly experienced, valuable dogs or young animals that still need to be trained. Or the men may have wished to keep the dogs close to them for their own protection. The image is an excerpt from a hunting scene with a lion and two dogs; further dogs are engraved behind the lion. The carvings were highlighted in white to make the images clearer.
More images can be found here: Max Planck researchers discover the oldest ever images of dogs on leashes

Photography

Max Planck Institute for the Science of Human History

Are identical twins really identical?

Created from one fertilized egg and yet not always identical: Identical twins have the same genetic material - and yet already reveal certain differences in the early stages before implantation in the womb. Researchers at the Max Planck Institute for Molecular Biomedicine are researching what causes these differences based on identical mouse embryos created in the lab - shown here in the blastocysts stage. The cells which show up green and blue under fluorescent light will become extraembryonal tissue during further development, such as the placenta. The future foetuses develop based on the epiblast cells coloured red in this image. However, in this specific case, only one of the two blastocysts has sufficient epiblast cells in order to develop further after the implantation.

Immunofluorescence microscopy

Max Planck Institute for Molecular Biomedicine

Structure is key

Steel is one of the most versatile construction materials ever. Since its properties can be influenced over a wide range by forming, heat treatments, and not least by some clever alloying - i.e. adding different quantities of other elements - tailor-made grades are now available for a wide variety of applications. At the Max-Planck-Institut für Eisenforschung, scientists are exploring the characteristics of various materials down to the atomic level as well as developing new ones. This image shows the crystallographic structure of stainless steel, which is very often used in the food industry due to its chemical resistance. The colours illustrate the crystal orientations, which have a decisive influence on the properties of the material.

Electron microscopy

Max-Planck-Institut für Eisenforschung GmbH

Relativity test at a black hole

At the heart of the Milky Way, there’s a supermassive black hole. This gravitational trap, which has a mass four million times that of our Sun, is surrounded by a small group of stars orbiting around it at high speed. This spring, astronomers were able to observe one of these stars, called S2 with unprecedented detail on its orbit around the black hole. They registered an effect that Albert Einstein predicted in his general theory of relativity more than 100 years ago - the gravitational red shift: When the star approaches the black hole, its light is stretched to longer wavelengths by the very strong gravitational field of the black hole, making it appear red.
More: In the gravity field of the black hole

Illustration

Max Planck Institute for Extraterrestrial Physics

Microbial art

Biofilms are communities of microorganisms that have entrenched themselves in a protective layer of mucus. Since they are difficult to combat, they are a serious problem in medicine. However, the biofilm shown here consists of harmless Escherichia coli bacteria embedded in a fibrous matrix of protein and modified cellulose. The aesthetic pattern is created while the film – in this image dyed - is formed. In order to be able to combat biofilms more efficiently, researchers are trying to understand the architectural principles behind it. This could not only have benefits for our health, for example in the case of implant or tissue infections - biofilms are also an important factor of hygiene in industrial processes such as food production.

Fluorescence imaging with a stereomicroscope

Max Planck Institute of Colloids and Interfaces

Complexity at a glance

Cells are constantly exchanging information with each other. In a developing embryo, for example, immature cells need to know what they will become. In an adult organism, it is important to sound the alarm when something needs to be repaired. Researchers at the Max Planck Institute for Molecular Cell Biology and Genetics are investigating the molecular properties of the signals and receivers that ensure that cells first form tissue and then complex organs - such as the retina of a fruit fly. This picture shows a section through the complex eye of the fly. At the bottom right, the lenses of the single eyes can be seen, at the top left, parts of the brain. The rhabdomers, the light-sensitive structures of the sensory cells, glow blue.

Immunofluorescence microscopy

Max Planck Institute of Molecular Cell Biology and Genetics

Happy Christmas in South East Asia

In the far north of Vietnam, directly on the border to China, the small Catholic community of the provincial capital Lao Cai is preparing for Christmas. Streamers in many different colours and a large star adorn the church building, which was first erected in 1895 during the French colonial rule. For the many market and street traders in Lao Cai, the Christmas season offers additional business opportunities, for example through the sale of Christmas decorations, Santa Claus costumes or sweets. From an ethnological point of view, the border city, which has experienced an enormous economic boom in recent years by brisk trade with China, is an ideal place to explore the complex web of social relations, informal networks and political structures that characterise the everyday lives of many Vietnamese.

Photography

Max Planck Institute for Social Anthropology

Much older than believed

Cultural achievements that are passed down from generation to generation are an important part of what makes humans distinct. Especially the impressive cave paintings, which we know from the late Palaeolithic, were regarded as a unique characteristic of modern humans (Homo sapiens). Using precision uranium-thorium dating, scientists have now proven that Neanderthals created cave art more than 65,000 years ago, more than 20,000 years before the arrival of modern humans in Europe. This handprint of a Neanderthal in the Maltravieso Cave in western Spain (Extremadura) is more than 66,000 years old. The new data suggest that Neanderthals were also able to think symbolically and that their mental abilities were on a par with those of modern humans.

Find out more: Neanderthals thought like we do

Photography (color enhanced)

Max Planck Institute for Evolutionary Anthropology

Cosmic web

It takes a supercomputer to create millions of galaxies in a virtual universe. The electronic brain in question is called Hazel Hen, and researchers have input data about the original status of the cosmos to then simulate the development of the universe over aeons. For just two of the main calculations of this project, which is called IllustrisTNG, a total of 24,000 processors were kept for around two months. The simulation created a cubiform section of the universe with an edge length of approx. one billion light years. Inside the cube, the broad structure of the universe was presented as a blue web of gas and stars. This glowing web reflects the underlying backbone of the dark matter shown in yellow and white, the constituent of around a quarter of space.

Max Planck Institute for Astrophysics

A protected space

Omnis cellula e cellula - every cell stems from another cell as the pathologist Rudolf Virchow already knew in 1885. But how did the first cells came into being and what makes a cell? Well, some four billion years ago, life began to encapsulate itself. The first cells were probably simple, water-filled small bubbles of fatty acids that encapsulated genetic information in the form of RNA. More complex molecules were then able to form in this protected space. In order to investigate how the first primitive cells developed and how the exchange of genetic material between them might have worked, scientists at the Max Planck Institute for Biochemistry use artificially produced giant vesicles that contain red or green stained DNA. When the vesicles are frozen and defrosted, the contents and thus also the colours mix. This is exactly what our image shows. Corresponding environmental conditions could also have enabled the early cells to exchange genetic information - a decisive step in evolution.

Fluorescence microscopy

Max Planck Institute of Biochemistry

Cuckoo eggs?

Phalaropes, small Arctic-breeding wading birds, have reversed avian sex roles: the males incubate the eggs and raise the offspring - a rare behavior in the animal kingdom. After all, males can never be completely sure whether they are related to all their chicks or whether they invest in "cuckoo children". In order to examine the kinship without disturbing the young chicks and their father in the nest, scientists from the Max Planck Institute for Ornithology swapped the real eggs for real-looking plastic versions (shown here). The real eggs were hatched in the incubator. Before the newly hatched chicks were brought back to the nest in an unobserved moment, the researchers took a small blood sample from them to compare them with samples from the parents who had mated before the eggs were laid. The paternity analysis showed that the females are usually very faithful to the caring fathers of their chicks.

Photography

Max Planck Institute for Ornithology

Tailor-made light

Electrons move at breathtaking speed. If you want to observe them, you need ultra-short light pulses. In order to control the particles beyond that, "ultra-white" laser light is required. It includes not only all colours of the visible spectrum, but also infrared and ultraviolet waves. But that's not all: the waves oscillating at different speeds must also be combined appropriately. Scientists have developed a so-called "light wave synthesizer" that splits the white laser light into three colour channels and then reassembles them in a modified form. This produces laser pulses with complex but finely adjustable waveforms. The pulses can then even consist of less than one full oscillation and last only about two femtoseconds (one femtosecond is one millionth of a billionth of a second). This enables the precise control of electron movements.
Photography

Max Planck Institute of Quantum Optics

Genome parasites

Large parts of the genetic material of plants and animals - including humans - is made up of small, repeating gene sections which multiply and fit themselves to ever new positions in the genome. These justifiably deserve to be called genome parasites. The purpose of these gene sequences, which are called the transposable element or TE, is not yet clear - some scientists suspect that they keep the genome flexible in order to promote evolution. These parasite genes need special proteins in order to achieve integration at ever new positions in the genome. These proteins can be crystallized and their spatial structure can be investigated. Our image shows these TE protein crystals.
Find out more: Genes as parasites

Light microscopy with pole filter

Max Planck Institute for Developmental Biology

From the point of view of a cell

Where humans use a folding rule to capture their environment, cells use surface receptors. They measure the traction force of compounds with their environment. To measure these forces, researchers offer the cells artificial surfaces - in this case a hydrogel with embedded gold particles to which the cells can dock (the "purple beads" on the picture). Depending on the distance between the particles, receptors transmit different forces so that the cell can "feel" and "read" the mechanical environment. Since the cell pulls more or less strongly at the surface and deforms it, this can be measured with an appropriately equipped microscope. Invasive cancer cells show particularly high tensile forces - possibly an indication that they "see" their environment differently than normal cells

Traction Force Microscopy

Max Planck Institute for Medical Research

A comet spews dust

Capturing the right moment and the right mood - this applies not only to photographers on Earth, but also to robots in space. Just at the moment when the sun rose over the Imhotep region of comet 67P/Churyumov-Gerasimenko, warming up the surface of the dirty ice ball, leading to dust being blown into space, the Rosetta space probe came along this scence. And by chance, the OSIRIS camera system pointed exactly at the point on the surface where the fountain originated: a round region about ten meters in diameter within a depression where frozen water exists. The Earth scout's mission is long over - Rosetta fell on the comet's nucleus on 30 September 2016 - but the analysis of the collected data is still in progress today. And who knows: sometimes true treasures can be found...!

Max Planck Institute for Solar System Research

View of a city

Maps don't just map spaces, they create them. Not only the present, but also the past play a role in the image we create of a city. And for which city could this be any truer than for Rome? This image shows an excerpt from the oldest known map of Rome in post-antiquity; commissioned around 1320 by Paolino Minorita. Its "universal history" combines chronological tables, continuous text and maps to show the history from the creation of the world to the (then) present in an accessible manner. Clearly visible are the city walls, the Pantheon (with its striking dark vestibule), the Colosseum (below right with dome) as well as the Tiber, which meanders through the city, past an ancient circus (Circo) - which, however, no longer existed in the 14th century . The aim of the map is to integrate historical knowledge in the image and to thus project history into the space.

Bibliotheca Hertziana - Max Planck Institute for Art History

Orderly arrangements

The nerve cells in the brain are arranged in clearly defined layers. These nerve cell layers and their connections form the basis for the organised processing of information. Using specific staining techniques, scientists can visualise the different layers, as shown here in the brain section of a mouse (only a part of it is shown). Parts of the nerve cell layer 6 of the cerebral cortex and the hippocampus can be seen. This layer is crucial for the communication between the neocortex - the developmentally newer part of the brain - and older brain structures. Using antibody staining, the researchers have marked a specific protein that ensures the proper development of the nerve cell processes in this layer. Cells containing this protein glow red, those without it green.

Fluorescence microscopy

Max Planck Institute of Neurobiology

Climate archive in the Far North

The CO₂ in the atmosphere has not been as high as it is today for hundreds of thousands of years. Scientists at the Max Planck Institute for Chemistry are taking a look back into the past in order to better understand current climate change and predict our future climate: Where Greenland's ice bar breaks off, layers of ice from the last 20,000 years are being revealed. They contain information about past climatic conditions just like a giant climate archive. Researchers can deduce based on ice cores and the gaseous bubbles contained in them what the atmosphere was like at a given time, and what affected the climate and life on Earth.

Digital photography

Max Planck Institute for Chemistry