Earlier this month, Roger Penrose, Reinhard Genzel, and Andrea Ghez split the 2020 physics Nobel Prize for decades of work on black holes. Click here to learn more about their monumental achievement and about the history of our understanding of these exotic objects in space.
From prow to stern, this little boat measures 30 micrometers, about a third of the thickness of a hair. It has been 3D-printed by Leiden physicists Rachel Doherty, Daniela Kraft and colleagues.
The image was made using an electron microscope and can be found in their article about 3D printing synthetic microswimmers in the scientific journal Soft Matter.
Black holes are perhaps the most mysterious objects in nature. They warp space and time in extreme ways and contain a mathematical impossibility, a singularity – an infinitely hot and dense object within. But if black holes exist and are truly black, how exactly would we ever be able to make an observation?
This morning the Nobel Committee announced that the 2020 Nobel Prize in physics will be awarded to three scientists – Sir Roger Penrose, Reinhard Genzel and Andrea Ghez – who helped discover the answers to such profound questions. Andrea Ghez is only the fourth woman to win the Nobel Prize in physics.
Robert Penrose is a theoretical physicist who works on black holes, and his work has influenced not just me but my entire generation through his series of popular books that are loaded with his exquisite hand-drawn illustrations of deep physical concepts.
Posted in biotech/medical, cosmology, physics
It’s unbelievable all that’s going on at the moment in astronomy” — DER SPIEGEL — international.
DER SPIEGEL: Wherever black holes are discussed, that picture is shown. And you are now telling us that we don’t really even know what it is?
Genzel: Exactly. It could be that we are looking at the shadow of a black hole, as it is commonly portrayed. But it could also be the outer wall of a jet that is coming directly at us at the speed of light. To know for sure, we need additional measurements. But we have a problem at the moment: the corona pandemic. Most Earth-based telescopes have been switched off.
DER SPIEGEL: Tell us a little bit about your research. What is the importance of a black hole at the center of the Milky Way?
Much of the ‘memory’ of the world and all our digital activities are based on media, hard disks, where the information is encoded thanks to magnetism, by orienting the spin of electrons in one direction or the opposite.
An international team of scientists led by the Italian physicist Stefano Bonetti, professor at Ca’ Foscari University of Venice and the Stockholm University, has managed for the first time to observe the ‘nutation’ of these spins in magnetic materials, i.e. the oscillations of their axis during precession. The measured nutation period was of the order of one picosecond: one thousandth of a billionth of a second. The discovery was recently published by Nature Physics.
The axis of a spin performs nutation and precession, as with any object that revolves, from spinning tops to planets. In this research, physicists observed experimentally that the nutation of the magnetic spin axis is 1000 times faster than precession, a curiously similar ratio to that of Earth.
In 1999, the Egyptian chemist Ahmed Zewail received the Nobel Prize for measuring the speed at which molecules change their shape. He founded femtochemistry using ultrashort laser flashes: the formation and breakup of chemical bonds occurs in the realm of femtoseconds.
Now, atomic physicists at Goethe University in Professor Reinhard Dörner’s team have for the first time studied a process that is shorter than femtoseconds by magnitudes. They measured how long it takes for a photon to cross a hydrogen molecule: about 247 zeptoseconds for the average bond length of the molecule. This is the shortest timespan that has been successfully measured to date.
The scientists carried out the time measurement on a hydrogen molecule (H2) which they irradiated with X-rays from the X-ray laser source PETRA III at the Hamburg accelerator facility DESY. The researchers set the energy of the X-rays so that one photon was sufficient to eject both electrons out of the hydrogen molecule.
A major new milestone has just been achieved in the quest for superconductivity. For the first time, physicists have achieved the resistance-free flow of an electrical current at room temperature — a positively balmy 15 degrees Celsius (59 degrees Fahrenheit).
This has smashed the previous record of −23 degrees Celsius (−9.4 degrees Fahrenheit), and has brought the prospect of functional superconductivity a huge step forward.
“Because of the limits of low temperature, materials with such extraordinary properties have not quite transformed the world in the way that many might have imagined,” physicist Ranga Dias of the University of Rochester said in a press statement.
The comparison of distant atomic clocks is foundational to international timekeeping, global positioning and tests of fundamental physics. Optica l-fibre links allow the most precise optical clocks to be compared, without degradation, over intracontinental distances up to thousands of kilometres, but intercontinental comparisons remain limited by the performance of satellite transfer techniques. Here we show that very long baseline interferometry (VLBI), although originally developed for radio astronomy and geodesy, can overcome this limit and compare remote clocks through the observation of extragalactic radio sources. We developed dedicated transportable VLBI stations that use broadband detection and demonstrate the comparison of two optical clocks located in Italy and Japan separated by 9,000 km. This system demonstrates performance beyond satellite techniques and can pave the way for future long-term stable international clock comparisons.
Congratulations from Ogba Educational Clinic.
The 2020 Nobel Prize for Physics has been awarded to Roger Penrose, Reinhard Genzel and Andrea Ghez for their work on black holes.
The prize is worth 10 million Swedish krona (about $1.1 million) and half goes to Penrose, with Genzel and Ghez sharing the other half of the prize.
The Nobel Committee cites Penrose “for the discovery that black hole formation is a robust prediction of the general theory of relativity”, and Genzel and Ghez “for the discovery of a supermassive compact object at the centre of our galaxy”.
Physicists have reached a long-sought goal. The catch is that their room-temperature superconductor requires crushing pressures to keep from falling apart.
