This Is Why Quantum Field Theory Is More Fundamental Than Quantum Mechanics
“But the motivation for quantizing the field is more fundamental than that the argument between those favoring perturbative or non-perturbative approaches. You need a quantum field theory to successfully describe the interactions between not merely particles and particle or particles and fields, but between fields and fields as well. With quantum field theory and further advances in their applications, everything from photon-photon scattering to the strong nuclear force was now explicable.”
What’s wrong with quantum mechanics? It might surprise you to hear that the answer is, “it isn’t quantum enough.” The enormous differences between the quantum and the non-quantum Universe are so striking, as we replace:
* continuous matter with discrete particles, * ideal points with dual-nature wave/particle quanta, * and observable properties like position and momentum with quantum mechanical operators containing an inherent uncertainty.
But it’s still not enough. For one, the original (Schroedinger) equation of quantum mechanics doesn’t play nice with relativity, but even the relativistically invariant versions don’t describe reality fully. Why not? Because only the particles are quantized in quantum mechanics. To reveal the full behavior, you need to quantize their fields and interactions, too.
For decades, astronomers searched the cosmos for what is thought to be the first kind of molecule to have formed after the Big Bang. Now, it has finally been found. The molecule is called helium hydride. It’s made of a combination of hydrogen and helium. Astronomers think the molecule appeared more than 13 billion years ago and was the beginning step in the evolution of the universe. Only a few kinds of atoms existed when the universe was very young. Over time, the universe transformed from a primordial soup of simple molecules to the complex place it is today — filled with a seemingly infinite number of planets, stars and galaxies. Using SOFIA, the world’s largest airborne observatory, scientists observed newly formed helium hydride in a planetary nebula 3,000 light-years away. It was the first ever detection of the molecule in the modern universe. Learn more about the discovery:
Helium hydride is created when hydrogen and helium combine.
Since the 1970s, scientists thought planetary nebula NGC 7027—a giant cloud of gas and dust in the constellation Cygnus—had the right environment for helium hydride to exist.
But space telescopes could not pick out its chemical signal from a medley of molecules.
Enter SOFIA, the world’s largest flying observatory!
By pointing the aircraft’s 106-inch telescope at the planetary nebula and using a tool that works like a radio receiver to tune in to the “frequency” of helium hydride, similar to tuning a radio to a favorite station…
…the molecule’s chemical signal came through loud and clear, bringing a decades-long search to a happy end.
The discovery serves as proof that helium hydride can, in fact, exist in space. This confirms a key part of our basic understanding of the chemistry of the early universe, and how it evolved into today’s complexity. SOFIA is a modified Boeing 747SP aircraft that allows astronomers to study the solar system and beyond in ways that are not possible with ground-based telescopes. Find out more about the mission at www.nasa.gov/SOFIA
How to Understand the Image of a Black Hole | Veritasium
We are about to see the first image of a black hole, the supermassive black hole Sagittarius A* at the center of the Milky Way galaxy. But what is that image really showing us? This is an awesome paper on the topic by J.P. Luminet: Image of a spherical black hole with thin accretion disk Astronomy and Astrophysics, vol. 75, no. 1-2, May 1979, p. 228-235 https://ve42.co/luminet
The first picture of a black hole opens a new era of astrophysics
This is what a black hole looks like.
A world-spanning network of telescopes called the Event Horizon Telescope zoomed in on the supermassive monster in the galaxy M87 to create this first-ever picture of a black hole.
“We have seen what we thought was unseeable. We have seen and taken a picture of a black hole,” Sheperd Doeleman, EHT Director and astrophysicist at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., said April 10 in Washington, D.C., at one of seven concurrent news conferences. The results were also published in six papers in the Astrophysical Journal Letters.
“We’ve been studying black holes so long, sometimes it’s easy to forget that none of us have actually seen one,” France Cordova, director of the National Science Foundation, said in the Washington, D.C., news conference. Seeing one “is a Herculean task,” she said.
That’s because black holes are notoriously hard to see. Their gravity is so extreme that nothing, not even light, can escape across the boundary at a black hole’s edge, known as the event horizon. But some black holes, especially supermassive ones dwelling in galaxies’ centers, stand out by voraciously accreting bright disks of gas and other material. The EHT image reveals the shadow of M87’s black hole on its accretion disk. Appearing as a fuzzy, asymmetrical ring, it unveils for the first time a dark abyss of one of the universe’s most mysterious objects.
“It’s been such a buildup,” Doeleman said. “It was just astonishment and wonder… to know that you’ve uncovered a part of the universe that was off limits to us.”
TheEvent Horizon Telescope is releasing its results on April 10th - including, we hope, the first picture of a black hole’s event horizon. The group has been analysing data for two years.
Video: “Observational appearance of an accretion disk in a General Relativistic Magnetohydrodynamics simulation at a radio wavelength.” - Dr. Hotaka Shiokawa, EHT media resources
Today’s FYFD video tells a story I’ve wanted to share for a couple of years now. It’s about the life and work of Agnes Pockels, a woman born in the mid-nineteenth century who, despite a lack of formal scientific training, made major contributions to the understanding of surface tension and to the experimental apparatuses and methodologies used in surface chemistry in general. She accomplished all of this not in a scientific lab, but from her kitchen.
Pockels’ story is one of curiosity, determination, and meticulous scientific inquiry. Chances are that you’ve never heard of her, but you really should. Check out the full video below to learn more! (Image and video credit: N. Sharp)
Topological spin textures in magnetic systems are intriguing objects that exhibit exotic physics and have potential applications in information storage and processing. The most fundamental and exemplary topological spin texture is called the skyrmion, which is a nanoscale circular domain wall carrying a nonzero integer topological charge. The skyrmion texture in magnetic materials was theoretically predicted in the late 1980s, and it was experimentally observed in chiral magnets a decade ago. Since the first observation of magnetic skyrmions, the skyrmion community has focused on a series of topological spin textures evolved from the skyrmion, such as the skyrmionium and bimeron.
In a recent theoretical work carried out by an international team from China, Japan, Australia, Russia, and France. The authors introduced a new type of topological spin textures, which is called the bimeronium. The bimeronium exists in magnets with in-plane magnetization. It is a topological counterpart of skyrmionium in perpendicularly magnetized magnets and can be seen as a combination of two bimerons with opposite topological charges. Therefore, the bimeronium carries a topological charge of zero, like the skyrmionium.
All of these samples were collected at Hogen Camp Mine, Harriman State Park, NY. The first image is a reflected light image of the ore vein. The ore vein formed as a result of dextral shear which ultimately created large fractures. Shortly after this, hydrothemal alteraltion occured of the metavolcanic gneiss in the region (image 2 and 3). The metavolcanic gneiss is rich in iron. Due to this, the highly acidic metamorphic fluids began to precipitate in the fractures. The process yeilded magnetite, clinopyroxene, and less common biotite within the fractures occuring at Hogen Camp Mine. The clinopyroxene and biotite are highly rich in iron.
Image 3 and 4 is the local pink pegmatites that occured in the region around 923 Ma. The pegmatitic dikes formed post-Ottawan orogeny. Composition includes: alkali feldspar with minor constituents of clinopyroxene and quartz.
This rock is a quartzofeldspathic gneiss from Surebridge Mine in Harriman State Park, NY. What’s so cool about this is you can see the hydrothermal process which alters biotite to chlorite. The large brown grain being biotite, and the purple/blue/green in the center being chlorite. (10x XPL)
Working on polishing my samples for reflective light microscopy. This sample is a pyroxenite from Hogen Camp Mine in the Hudson Highlands region of New York. The area was once a lead producer of iron ore and magnetite for the east coast.
Alkali Feldspar crystals are large in this thin section. The alkali feldspar have subhedral crystals. The quartzy matrix in some areas is intergrown at the edge of the alkali feldspar crystal faces. The muscovite crystallized in the interstitial space and have anhedral crystal faces. To differentiate between the muscovite and the biotite pleochroism comes into effect. The biotite is darker amber under PPL and muscovite is tan/light brown. Both are pleochroic under PPL.
This rock is composed predominantly of plagioclase feldspar that are large euhedral crystals suggesting that they formed first in the melt. In the interstitial space there is clinopyroxene which suggests that the clinopyroxene formed after the plagioclase. The larger crystals do not have any form of twinning, so at first glance they look like quartz. After using the bertrand lens, the big crystals have an optic sign of biaxial which help conclude that the crystals are plagioclase and not quartz. The fractures in the big crystals have clinopyroxene crystals present. The rock is most likely an anorthosite/tonalite.
(For future posts #optmin is the tag to see all my original content!)
The plagioclase in this thin section has polysynthetic twinning. The orthopyroxene also has twinning present in most grains. The clinopyroxene is filling voids in the rock and have an anhedral structure, filling interstitial space, compared to to the plagioclase and orthopyroxene which range from subhedral to euhedral. The rock is a gabbronorite due to the presence of both orthopyroxene and clinopyroxene.
This rock is predominantly composed of quartz, alkali feldspar, and plagioclase. The alkali feldspar grains are large and take up a decent amount of the slide. The perthite is mainly one grain that is large and is about 11mm. The plagioclase has polysynthetic twinning.The muscovite is pleochroic under PPL and has clinopyroxene embayed in the core. Clinopyroxene is present because the melt reacted with the clinopyroxene and create muscovite. Leucite is also present in a minimal quantity. The leucite is embayed in the alkali feldspar. This happened when the alkali feldspar started to crystalize. The silica content was too great and the leucite reacted with the melt to form alkali feldspar. Due to the composition the rock would just be classified as a granite. (leucite in 2nd pic)
Composition includes: biotite, muscovite, chlorite, feldspars, oxides, and quartz. Feldspar poikiloblasts with inclusions of quartz and oxides are prominent throughout much of the sample. Most poikiloblasts occurred synkinematic to the 1st deformation event (D1) and rotation occurred. D1 had a direct effect on the foliation (S1) of minerals that already crystallized. D2 led to crystallization of quartz which is seen in quartz ribbons and pressure fringes throughout the sample.
This thin section shows an amygdule in a sample of amygdaloid basalt. The rock formed due to an eruption of gaseous, low viscous magma which resulted in vesicles throughout much of the rock. The rock then underwent hydrothermal alteration and low temperature alteration minerals formed in the once vesicles, forming amygdules. The amygdules are composed of quartz, celadonite (a type of mica) and epidote.
