Quarter of #schools in England lack a #physics teacher, analysis finds Institute of Physics says ‘critical’ shortage means 700,000 pupils are deprived of a subject specialist
Random Tuesday thought (but not really!): I thought it was bad enough that we had a rogue star here on earth, but today I learnt that that there are 675 rogue stars between our Milky Way galaxy and the Andromeda galaxy and that there are over a trillion in Virgo! Moreover, there’s such a thing as rogue black holes, which totally sucks. I hope someone’s tracking them.
This was a fun episode with lots of talk of #darkmatter, particle #physics, #astrophysics, and what life is like when you dedicate your career to making new discoveries in these areas! Dr. Djuna Croon is a fantastic researcher and science communicator, and I enjoyed our chat! 👩🔬 🧪
Today on #arxiv : the giant "fossil" lobe of relativistic electrons in the Ophiucus cluster of galaxies, observed in the radio band from 1.3Ghz town to 120MHz, by S. Giacintucci et al.
interesting and complex configuration in which the diffuse blob of electrons also host narrow filaments, in which electrons apparently aged faster than the rest!
Evolution from z=10 to z=0 of the magnetic field intensity along the line of sight (left) and Faraday Rotation Measure for the same volume of 85 cubic Megaparsec (right).
Type 1a supernovae are agreed to be explosions of white dwarf stars, the remains of stars similar in mass to our Sun. They’re thought to be triggered when extra mass — from a nearby companion star, for example — triggers a runaway fusion reaction in their carbon and oxygen, elements that white dwarfs generally don’t have enough mass to successfully fuse. The runaway fusion then blows the star apart.
But there’s another theory — demonstrated through numerical simulations — that suggests an alternate mechanism: a small explosion on the star’s surface could compress the interior enough to trigger fusion of the heavier elements there, thereby triggering a second detonation. The two explosions would happen in quick succession, making them difficult to detect, but astronomers predicted that each explosion could create a shell of calcium; given enough time, those two shells could drift apart, allowing …
Double Detonation in Type 1a Supernovae
Type 1a supernovae are agreed to be explosions of white dwarf stars, the remains of stars similar in mass to our Sun. They’re thought to be triggered when extra mass — from a nearby companion star, for example — triggers a runaway fusion reaction in their carbon and oxygen, elements that white dwarfs generally don’t have enough mass to successfully fuse. The runaway fusion then blows the star apart.
But there’s another theory — demonstrated through numerical simulations — that suggests an alternate mechanism: a small explosion on the star’s surface could compress the interior enough to trigger fusion of the heavier elements there, thereby triggering a second detonation. The two explosions would happen in quick succession, making them difficult to detect, but astronomers predicted that each explosion could create a shell of calcium; given enough time, those two shells could drift apart, allowing astronomers to see a shell of sulfur between them.
The team looked to a supernova remnant about 300 years old, and using a spectrograph from the Very Large Telescope, they were able to image — as predicted — a two shells of calcium, separated by sulfur, supporting the double-detonation hypothesis.
The impact of double-detonation in Type 1a supernovae could be far-reaching. Right now, the intensity of these objects seems to be consistent enough that astronomers use their brightness to estimate their distance. Over the years, those distance estimates have been used to measure the universe’s expansion and provide evidence for the existence of dark matter. But if Type 1a supernovae are not all the same intensity, we may need to reevaluate their use as a universal yardstick. (Image credit: ESO/P. Das et al.; research credit: P. Das et al.; via Ars Technica)
Happy birthday to mathematician and NASA scientist Katherine Johnson (née Coleman; 1918 – 2020). One of the first Black women employed as a NASA scientist (and its predecessor NACA), she was known for her mastery of complex manual calculations of orbital mechanics and played a pivotal role in the success of the US crewed spaceflights from the beginning. Her work included calculating the trajectories, 🧵1/
Happy days! I ordered a book on the fundamentals of astrophysics from Amazon (I live in the country, in France so don’t judge) and it arrived damaged. I started the return process and it said keep the book! Yay. It’s not cheap! Yay!!🥳 Now I’ll just have to get out the tape and some glue.
Attention s’il vous plaît : it’s time for me to read Bely’s Petersburg novel now - chapter the sixth. It’s one of the most complex novels on earth after Ulysses. I need to concentrate. So no posting of super interesting things for the next four hours please. 🙏
Max Planck reluctantly founded quantum physics in 1900 while trying to solve a mundane problem about lightbulb efficiency. He called his own revolutionary discovery ‘an act of desperation’ and spent years trying to disprove it! #physics#science
The simulated dance of two remnant lobes of relativistic electrons (pink) ejected in the gas (green) in between the galaxies of a large group, by radio jets from a black hole accretion region.
The clouds of electrona first undergo turbulent mixing via Rayleigh -Taylor instabilities (same of nuclear mushrooms) and later on get dispersed on larger scales by turbulent motions present in the cluster because of continuous gas accretions.
Had today a long meeting finally in person with a colleague in #physics who lives and works in the West Bank (Nablus) and periodically come to Europe and #CERN with the family. I want to contribute if possible to his plan to spread #STEM students who fled from #Gaza for a few months in EU universities (and we will keep speaking of this 🤞) but above all it was important and deeply moving to have him telling the (unbearable) reality of how life and academia go on in #Palestine.
