Research in Hamburg

Research in Hamburg

Keywords

Gravity, Big Bang, dark matter, dark energy, Higgs boson, top quark, symmetry, supersymmetry, superstrings, extra dimensions, technology, future, Big Data, artificial intelligence, particle accelerator, tunnel, underground, universe, space-time, from the very big to the very small, home-made, Hamburg contributions, innovation, applications, ...

The perfect wave

German research groups were involved in one of the biggest physics events of recent years: the discovery of gravitational waves.

As predicted by Einstein, gravitational waves are generated when extreme things happen in space: collisions of black holes and neutron stars, for example, or supernovae, stars that end their lives in a huge explosion. These extreme events disrupt space-time and send waves in all directions. These waves contain information about their origin and possibly about the nature of gravity itself. Researchers just need the right tools to read this information.

The right tool was the Laser Interferometer Gravitational-Wave Observatory (LIGO) in the USA. On 14 September 2015, LIGO observed a gravitational wave from the depths of the universe for the first time. Around 1,000 scientists worldwide were involved, including from the Universität Hamburg and the Albert Einstein Institute in Hanover. The signal was first seen in Hanover, because it was morning and the colleagues in the USA were still asleep. Sometimes luck is on your side!

Since 2015, LIGO and the European-Italian-French Virgo Observatory have recorded 70 gravitational waves. The first scientific finding of many in the meantime was that there are significantly more black holes in the universe than previously thought.

In 2017, Rainer Weiss, Kip Thorne and Barry Barish, who founded and later led LIGO in 1992, were awarded the Nobel Prize in Physics for the first observation.

ATLAS and CMS at the LHC

The research groups from the Universität Hamburg and DESY are among the largest of the huge international collaborations operating the ATLAS and CMS detectors at the LHC at CERN. They develop, build and test new components, control the quality of the data and, of course, analyse it.

The absolute highlight of the data analysis at ATLAS and CMS so far was the discovery of a new particle, the Higgs boson, in 2012, with the active participation of physicists from Hamburg. This discovery was awarded the Nobel Prize in Physics in 2013.

Incidentally, ATLAS is the largest detector ever built at a particle accelerator. It is 40 metres long and 25 metres wide and high. That would put it right up against the portico of the Brandenburg Gate.

CMS, on the other hand, is the heaviest detector ever built at a particle accelerator. It weighs 12,500 tonnes and is thus more than one and a half times as heavy as the Eiffel Tower.

With their many high-tech detector layers, ATLAS and CMS record all the particles created in the collisions in the accelerator.

What a beauty: the BELLE experiment

Particle beams consisting of electrons and their antiparticles (positrons) collide in the new high-performance particle accelerator SuperKEKB. The resulting particles are measured and analysed in the Belle II experiment. The entire Belle II detector is about 10 metres wide, just as high and weighs a total of 1,500 tonnes. Physicists from Hamburg are also involved in Belle II, an international experiment. The aim is to observe time-dependent matter-antimatter asymmetry effects and thus understand the excess of matter in our universe today.

Dark Matter Detective Agency

Researchers are also on the trail of dark matter here in Hamburg. Experiments at DESY and Universität Hamburg focus on very special dark matter candidates consisting of extremely light particles such as the so-called axion. These particles call for completely new search concepts, which are being implemented in Hamburg in experiments called MADMAX, BRASS, WISPFI or WISPLC. In addition, ALPS II is attempting to generate and detect dark matter particle candidates itself. An experiment called BabyIAXO is looking for corresponding particles that could be produced in the centre of the Sun.

However, dark matter could also be produced in particle collisions, for example at the Large Hadron Collider. So far, however, it has eluded every search ...

The axion

The basic principle of the axion searches in Hamburg is usually very similar: when axions enter a strong magnetic field, they can transform into light. Researchers are therefore searching for light that is created virtually out of nothing in a completely light-tight space as soon as it is flooded by a magnetic field. However, the technical challenges are enormous: extreme magnetic fields are needed and the expected low light intensities are at the limit of what is technically detectable.

Oscillating loops

With the superstring theory, physicists and mathematicians, also from the Universität Hamburg and DESY, try to describe the conditions shortly after the Big Bang. The elementary components are ultra-short loops ("strings") that behave like vibrating strings, and different particles result from the many different forms of vibration of these strings. However, they need more than just our three spatial dimensions to describe them – up to six dimensions more. Their expansions, however, cannot yet be resolved with current measuring instruments.

One of the advantages of superstring theory is that it can describe all four basic forces of nature even at very small distances, and researchers are trying to understand why the gravitational force is so different from the other three forces. And superstring theory is on the trail of yet another mystery: why is the observed expansion of the universe accelerating today? How can the dark energy that Einstein suspected behind it be reconciled with the laws of superstring theory?

day-to-day in science

keywords

Meetings, postdocs, students, exams, lectures, job interviews, grant applications, screens, zoom, after-work beers, inspiration, colleagues, self-motivation, curiosity, joy, night shifts, on-call duty, publications, work-life balance, excellence cluster, company kindergarten, sports field, active breaks, physics parties, ideas

All in a day's work ...

At Hamburg's universities and research institutes, several hundred students and scientists are searching for the great secrets every day. But groundbreaking discoveries or revolutionary flashes of genius do not happen every day, of course. Nevertheless, there is more than enough to do for everyone.

If you ask them about a typical day, most will answer that they sit at their computers, have lots of meetings and sometimes go on business trips to conferences. Perhaps this sounds familiar to you?

In fact, the tasks these researchers have to do are very diverse. Theorists develop models, make predictions for experiments and calculate hypotheses about properties and processes that the experimenters investigate. In the reverse direction, theory also tries to develop models to explain experimentally measured data. Research facilities have to be designed, built, tested, operated in shifts and kept up to date for the experiments. The incoming data is collected, stored, analysed and published. In addition, new technologies have to be developed, third-party funding has to be raised, the next generation of researchers has to be trained and, as in this exhibition, the fascination of research has to be passed on to the public.

Technology and science

keywords

PET scan, cancer therapy, self-driving cars, WorldWideWeb, Teflon pan, materials research, touch screen, proton therapy, MRI, solar cells, intercultural, international, problem-oriented, room temperature superconductors, vacuum, art history, artificial intelligence

In search of the big secrets – and what's in it for me?

Shouldn't the money that is invested in fundamental research be better spent on other things? This thought is perfectly understandable because fundamental research has no direct benefit for humans – except, of course, to satisfy people's natural curiosity and to push the boundaries of knowledge and make it freely available to everyone.

However, this fundamental research requires a lot of specialised and precise high technology that cannot be bought anywhere. It is developed in universities and laboratories, and the developers often discover ways to use these technologies in everyday life. The world wide web is probably the outcome from research that has most fundamentally changed our lives. But we also benefit from medical developments – detectors and accelerators from particle physics, for example, help to detect tumours better and to treat them more precisely.

Physics meets medicine

Despite breathtaking advances in medicine, there are still "blind spots", i.e. questions that remain unanswered. One example is the behaviour of the different subtypes of immune cells in immune-mediated inflammatory diseases, such as Crohn's disease. In a joint effort between the Department of Physics at the Universität Hamburg and the University Medical Center Hamburg-Eppendorf (UKE), research is being done on precisely this question, with the physics team at the UHH using innovative methods of biomedical imaging at particle accelerators to conduct novel studies together with the UKE team. Both sides hope that this will provide new insights into our immune system with the prospect of using them to develop new therapeutic methods.

Technology and science

Research not only requires creative minds, but also many tools and materials, most of which fulfil very special requirements and therefore have to be developed from scratch. Once successfully tested and used in science, they can often be extended to other areas of use. Detector technology, for example, helps in space missions, in nuclear power plants or in the screening of goods. New materials for improved aircraft parts are developed with the help of accelerators, pictures of old masters are gently X-rayed and reconstructed and solar cells are further developed with the help of the vacuum know-how of physics research. In addition, computational methods from particle physics – machine learning, for example – help in areas as diverse as warehouse logistics or self-driving cars.

Ultimately, it is actually the creative minds themselves who contribute the most back to society. Only a few of the young people stay in research, the rest enrich the workplace with the skills learned in research – being able to solve problems, being creative, team players and tolerant, thinking logically and proceeding methodically to solve problems together in the large international collaborations.

The birthplace of the World Wide Web

The world wide web was born in 1989 at CERN. CERN employee Sir Tim Berners-Lee developed it at the time to make it easier for scientists scattered all over the world to exchange information. CERN made his development available to the world free of charge in 1993, but even before that, IT experts from DESY, which works in close cooperation with CERN, had learnt how to use the new system and thus created Germany's first website.

what does the future hold?

keywords

Future Circular Collider, International Linear Collider, Einstein Telescope, artificial intelligence, machine learning, collaboration, peaceful, innovation, plasma accelerator, superconductivity, LISA, ALPS, climate change, interdisciplinary

Is the future linear?

Particle collision experiments with electrons and their antiparticles, positrons, stand out for their extremely high precision. The planned International Linear Collider (ILC) is a linear electron-positron accelerator that can reach energies of 250 – 1,000 billion electron volts and is expected to be 20 – 50 kilometres long. DESY and Universität Hamburg are substantially involved in the development of the ILC technology, which is already being used successfully at the European XFEL in Schenefeld. A technical innovation is the use of polarised electron and positron beams, which provide special additional information about the properties of the particles produced. The ILC allows measurements of all particles – for example the Higgs boson – with unrivalled precision and reveals even tiny traces of new physics. The construction of the ILC is being intensively discussed as an international project in Japan.

Surfing the plasma wave

The study of our world and the fundamental building blocks it is made of relies on particle collisions at the very highest energies. Scientific progress is directly linked to the development of new types of particle accelerators that open up ever new energy scales.

Plasma-based accelerators promise to revolutionise particle physics accelerators, as they can accelerate charged particles with field strengths thousands of times greater than traditional acceleration techniques based on metal structures. They are therefore much smaller while providing the same particle energy.

In plasmas, either high-intensity laser flashes or extremely dense particle beams excite strong plasma waves on which particle bunches can ride like surfers and be accelerated to the very highest energies.

DESY and Universität Hamburg are among the world's innovation drivers in the development of plasma-based technologies.

FCC – the 100-kilometre tunnel

The Future Circular Collider (FCC) is another planned particle accelerator intended to be the grand successor to the LHC at CERN. When the 27-kilometre-long LHC goes out of operation around 2040, the 100-kilometre-long FCC is to replace it. The larger circumference will make it possible to achieve particle collisions with extremely high energy, namely 50 tera-electronvolts, which is four times the energy of the LHC. Scientists hope to discover new heavy particles and to answer many unsolved questions in the world of particle physics.

The FCC is designed for various types of particle collisions, for example protons on protons, electrons on positrons and protons on electrons. Extremely strong dipole magnets, which have not yet been developed, are needed to keep the particles, which will have almost the speed of light, in their orbit. If these magnets are successfully developed, the technology could be used in many other industrial fields, medicine and materials research. At the moment, many scientists all over the world are discussing whether and how the FCC can be realised.

The European "Einstein telescope"

The gravitational wave observatories LIGO and Virgo now observe on average significantly more than one gravitational wave per week. This has been made possible by further improvements to the technology, which was also developed in Germany: Laser light with squeezed (reduced) quantum fuzziness. Groups from Germany are also significantly involved in another future gravitational wave project that is currently being discussed, the so-called "Einstein telescope".