Quantum entanglement of two macroscopic objects is the Physics World 2021 Breakthrough of the Year: https://physicsworld.com/a/quantum-entanglement-of-two-macroscopic-objects-is-the-physics-world-2021-breakthrough-of-the-year/

James Webb: A $10bn machine in search of the end of darkness: https://www.bbc.com/news/science-environment-59476869.amp

NASA's James Webb Space Telescope launch: Live updates: https://www.space.com/news/live/james-webb-space-telescope-updates

NASA OFFICIALLY TOUCHES THE SUN — AND SOLVES A SOLAR MYSTERY

This is the closest encounter between our species and the Sun ever.

IN A FIRST for humanity, a manmade spacecraft has kissed the Sun.

“Not only does this milestone provide us with deeper insights into our Sun’s evolution and its impacts on our Solar System, but everything we learn about our own star also teaches us more about stars in the rest of the universe,” Thomas Zurbuchen, the associate administrator for the Science Mission Directorate, says in a press release.

WHAT’S NEW — NASA’s audacious Parker Solar Probe achieved the scientific first after three years and five Venus flybys, entering the Sun’s atmosphere on April 28, 2021.

The achievement was announced at a press conference at the American Geophysical Meeting Fall Meeting in New Orleans this week.

So why are we only learning about this incredible feat now? Well, NASA needed the intervening months to confirm they had actually done it — analyzing energy interactions recorded by the probe to try and mark the moment.

Ultimately, the signature of the Sun’s magnetic field was the smoking gun that verified we had really, actually, touched the Sun.

Since then, the probe has encountered the Sun twice more — once in August and once in November.

WHAT THEY FOUND — Already, this achievement is serving up serious insight into the Sun.

The first paper detailing fresh results from the probe was published Tuesday in Physical Review Letters, and there is another paper set to be published in The Astrophysical Journal soon.

The liminal space between the Sun’s atmosphere and space is called the Alfvén critical surface. Prior to the mission, physicists knew this dividing line was there but didn’t know precisely where.

Best estimates put it at 4.3 and 8.6 million miles above the surface of the Sun. But the Solar Probe complicates matters.

In April, the probe entered the Sun’s corona (another word for the atmosphere) at an altitude of 8.1 million miles above the surface of the Sun.

In doing so, the probe confirmed the Sun’s atmosphere isn’t uniform in shape — it is not some big sphere encasing the burning orb. Rather, it flows with peaks and valleys that the probe passed through repeatedly. At its closest approach, the probe came within 6.5 million miles of the surface of the Sun.

NEW DISCOVERIES — In its fly-through, the probe discovered two strange solar weather phenomena:

-A source of solar wind, known as switchbacks
-A pseudostreamer

Switchbacks are streams of charged particles that escape the Sun in a zig-zag-like pattern. Parker’s flyby proved that the photosphere — or surface — of the Sun generates these solar winds for the first time, although other regions of the Sun can generate them, too.

A pseudostreamer is a name given to huge structures that come forth from the Sun.

The agency compared it to the “eye of a storm,” because these structures are relatively calm compared to the surrounding environment.

As Parker Solar Probe passed through the corona on encounter nine, the spacecraft flew by structures...

WHAT IS THE PARKER SOLAR PROBE?

The Parker Solar Probe isn’t the first NASA mission to study the Sun. ESA also has a Sun-orbiter named Solar Orbiter (hopefully they didn’t spend too long on that name), but it has yet to have a close encounter — thus far, it’s only made it within 48 million miles, which wouldn’t even put it past Mercury’s orbit.

Parker wasn’t designed just to come near the Sun — it was designed to enter its atmosphere to settle the mystery of why the upper reaches of the corona are hotter than the surface of the Sun.

To do that, the probe is outfitted with a shield of carbon bricks able to withstand the unfathomably searing temperatures — up to 1.8 million degrees Fahrenheit.

To reach the Sun, the probe will go through a total of seven Venus flybys, which act like gravity slingshots to drop it close enough to the Sun to get inside the atmosphere.

A flyby in January will bring the craft within the corona again. The next Venus flyby is slated for 2023.

These initial results are just the tip of the iceberg (plasmaberg?) for Parker, which will eventually reach 3.83 million miles from the Sun’s surface.

Thanks to the new insight gained, the mission team will be able to further unlock the mysteries of our home star.

Source: https://www.inverse.com/science/we-touched-the-sun

Exotic six-quark particle predicted by supercomputers

The predicted existence of an exotic particle made up of six elementary particles known as quarks by RIKEN researchers could deepen our understanding of how quarks combine to form the nuclei of atoms.

Quarks are the fundamental building blocks of matter. The nuclei of atoms consist of protons and neutrons, which are in turn made up of three quarks each.

Particles consisting of three quarks are collectively known as baryons.

Scientists have long pondered the existence of systems containing two baryons, which are known as dibaryons.

Only one dibaryon exists in nature—deuteron, a hydrogen nucleus made up of a proton and a neutron that are very lightly bound to each other.

Glimpses of other dibaryons have been caught in nuclear-physics experiments, but they had very fleeting existences.

"Although the deuteron is the only known stable dibaryon, many more dibaryons may exist," says Takuya Sugiura of the RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program.

"It's important to study which pairs of baryons form dibaryons and which do not because this provides valuable insights into how quarks form matter."

Quantum chromodynamics is a highly successful theory that describes how quarks interact with each other.

But the strong coupling that occurs between quarks in baryons complicates quantum chromodynamics calculations. The computations become even more complex when considering bound states of baryons such as dibaryons.

Now, by calculating the force acting between two baryons each containing three charm quarks (one of the six types of quarks), Sugiura and his co-workers have predicted the existence of a dibaryon they called the charm di-Omega.

For this calculation, the team solved quantum chromodynamics with large-scale numerical calculations.

Since the calculations involved a vast number of variables, they used two powerful supercomputers: the K computer and the HOKUSAI supercomputer.

"We were extremely fortunate to have had access to the supercomputers, which dramatically reduced the cost and time to perform the calculations," says Sugiura.

"But it still took us several years to predict the existence of the charm di-Omega."

Despite the complexity of the calculations, the charm di-Omega is the simplest system for studying interactions between baryons. Sugiura and his team are now studying other charmed hadrons using the supercomputer Fugaku, which is the K computer's more powerful successor.

"We're especially interested in interactions between other particles containing charmed quarks," says Sugiura.

"We hope to shed light on the mystery of how quarks combine to form particles and what kind of particles can exist."

The research was published in Physical Review Letters.

Source: https://phys.org/news/2021-12-exotic-six-quark-particle-supercomputers.amp

Quantum physics requires imaginary numbers to explain reality

Theories based only on real numbers fail to explain the results of two new experiments

Imaginary numbers might seem like unicorns and goblins — interesting but irrelevant to reality.

But for describing matter at its roots, imaginary numbers turn out to be essential. They seem to be woven into the fabric of quantum mechanics, the math describing the realm of molecules, atoms and subatomic particles.

A theory obeying the rules of quantum physics needs imaginary numbers to describe the real world, two new experiments suggest.

Imaginary numbers result from taking the square root of a negative number. They often pop up in equations as a mathematical tool to make calculations easier.

But everything we can actually measure about the world is described by real numbers, the normal, nonimaginary figures we’re used to (SN: 5/8/18).

That’s true in quantum physics too. Although imaginary numbers appear in the inner workings of the theory, all possible measurements generate real numbers.

Quantum theory’s prominent use of complex numbers — sums of imaginary and real numbers — was disconcerting to its founders, including physicist Erwin Schrödinger.

“From the early days of quantum theory, complex numbers were treated more as a mathematical convenience than a fundamental building block,” says physicist Jingyun Fan of the Southern University of Science and Technology in Shenzhen, China.

Some physicists have attempted to build quantum theory using real numbers only, avoiding the imaginary realm with versions called “real quantum mechanics.”

But without an experimental test of such theories, the question remained whether imaginary numbers were truly necessary in quantum physics, or just a useful computational tool.

A type of experiment known as a Bell test resolved a different quantum quandary, proving that quantum mechanics really requires strange quantum linkages between particles called entanglement (SN: 8/28/15).

“We started thinking about whether an experiment of this sort could also refute real quantum mechanics,” says theoretical physicist Miguel Navascués of the Institute for Quantum Optics and Quantum Information Vienna.

He and colleagues laid out a plan for an experiment in a paper posted online at arXiv.org in January 2021 and published December 15 in Nature.

In this plan, researchers would send pairs of entangled particles from two different sources to three different people, named according to conventional physics lingo as Alice, Bob and Charlie.

Alice receives one particle, and can measure it using various settings that she chooses. Charlie does the same.

Bob receives two particles and performs a special type of measurement to entangle the particles that Alice and Charlie receive.

A real quantum theory, with no imaginary numbers, would predict different results than standard quantum physics, allowing the experiment to distinguish which one is correct.

Fan and colleagues performed such an experiment using photons, or particles of light, they report in a paper to be published in Physical Review Letters.

By studying how Alice, Charlie and Bob’s results compare across many measurements, Fan, Navascués and colleagues show that the data could be described only by a quantum theory with complex numbers.

Another team of physicists conducted an experiment based on the same concept using a quantum computer made with superconductors, materials which conduct electricity without resistance.

Those researchers, too, found that quantum physics requires complex numbers, they report in another paper to be published in Physical Review Letters.

“We are curious about why complex numbers are necessary and play a fundamental role in quantum mechanics,” says quantum physicist Chao-Yang Lu of the University of Science and Technology of China in Hefei, a coauthor of the study.

But the results don’t rule out all theories that eschew imaginary numbers, notes theoretical physicist Jerry Finkelstein of Lawrence Berkeley National Laboratory in California, who was not involved with the new studies.

The study eliminated certain theories based on real numbers, namely those that still follow the conventions of quantum mechanics. It’s still possible to explain the results without imaginary numbers by using a theory that breaks standard quantum rules.

But those theories run into other conceptual issues, making them “ugly,” he says. But “if you’re willing to put up with the ugliness, then you can have a real quantum theory.”

Despite the caveat, other physicists agree that the quandaries raised by the new findings are compelling.

“I find it intriguing when you ask questions about why is quantum mechanics the way it is,” says physicist Krister Shalm of the National Institute of Standards and Technology in Boulder, Colo.

Asking whether quantum theory could be simpler or if it contains anything unnecessary, “these are very interesting and thought-provoking questions.”

Source: https://www.sciencenews.org/article/quantum-physics-imaginary-numbers-math-reality

NASA confirms next Friday for Webb Space Telescope launch

NASA Administrator Bill Nelson confirmed Friday that the James Webb Space Telescope will attempt to blast off on Dec. 24. A European Ariane rocket will provide the lift from South America's French Guiana.

The $10 billion Webb—considered the successor to the Hubble Space Telescope—was supposed to soar Saturday, but was jolted by a clamp during launch preparations, resulting in a four-day delay.

Then a bad communication link on the rocket had to be fixed, postponing the launch another two days.

U.S. and European space officials signed off Friday on the launch date, following one last round of testing.

Nelson expects a smaller crowd at the launch site because of the holidays. Liftoff is scheduled for 7:20 a.m. EST.

"Since it's Christmas Eve, all the congressional delegations that were going down, all of that has evaporated," he told The Associated Press. Even the NASA and contractor team has dwindled, he noted. But he'll be there.

Already years late in flying, Webb will look back to almost the beginning of time, to when the first stars and galaxies were forming, while also examining the atmospheres of planets orbiting stars closer to home.

NASA is partnering with the European and Canadian space agencies on the mega project.

"There's so much riding on this," Nelson said, "opening up just all kinds of new understanding and revelations about the universe."

Is there a better Christmas present than seeing the telescope launch? Nelson answered by breaking into song: "All I want for Christmas are not my two front teeth, but for the success of JWST"—referring to the telescope by its acronym.

Source: https://phys.org/news/2021-12-nasa-friday-webb-space-telescope.html

https://www.youtube.com/watch?v=n9MxqFfBTzQ&feature=youtu.be

A001:
What is the Fermi Paradox?

The Fermi Paradox asks "Where is everybody?"

The Fermi Paradox refers to the dichotomy between the high probability that extraterrestrial intelligence exists and the fact that we have no evidence for such aliens.
...

Source: https://www.livescience.com/fermi-paradox

Have you heard of the dark forest hypothesis?

IMAliyu:

Have you heard of the dark forest hypothesis?

No, what's it all about?

This thread is the best
Op tell me more about Feynman

A001:

No, what's it all about?

A rather disturbing possible answer to the Femi paradox.

Kurzgesagt made an interesting video on it.

https://www.youtube.com/watch?v=xAUJYP8tnRE

A001:

Should I drop digits on Christmas Day?


I am recuperating from a serious fever.

I work in a place where workers are on recess during this period.


I can't afford loans online.

NASA's Webb Telescope Launches to See First Galaxies, Distant Worlds

NASA’s James Webb Space Telescope launched at 7:20 a.m. EST Saturday on an Ariane 5 rocket from Europe’s Spaceport in French Guiana, South America.

A joint effort with ESA (European Space Agency) and the Canadian Space Agency, the Webb observatory is NASA’s revolutionary flagship mission to seek the light from the first galaxies in the early universe and to explore our own solar system, as well as planets orbiting other stars, called exoplanets.

NASA’s James Webb Space Telescope launched Dec. 25 at 7:20 a.m. EST on an Ariane 5 rocket from Europe’s Spaceport in French Guiana, on the northeastern coast of South America.

“The James Webb Space Telescope represents the ambition that NASA and our partners maintain to propel us forward into the future,” said NASA Administrator Bill Nelson.

“The promise of Webb is not what we know we will discover; it’s what we don’t yet understand or can’t yet fathom about our universe. I can’t wait to see what it uncovers!”

Ground teams began receiving telemetry data from Webb about five minutes after launch. The Arianespace Ariane 5 rocket performed as expected, separating from the observatory 27 minutes into the flight.

The observatory was released at an altitude of approximately 870 miles (1,400 kilometers). Approximately 30 minutes after launch, Webb unfolded its solar array, and mission managers confirmed that the solar array was providing power to the observatory.

After solar array deployment, mission operators will establish a communications link with the observatory via the Malindi ground station in Kenya, and ground control at the Space Telescope Science Institute in Baltimore will send the first commands to the spacecraft.

Engineers and ground controllers will conduct the first of three mid-course correction burns about 12 hours and 30 minutes after launch, firing Webb’s thrusters to maneuver the spacecraft on an optimal trajectory toward its destination in orbit about 1 million miles from Earth.

“I want to congratulate the team on this incredible achievement – Webb’s launch marks a significant moment not only for NASA, but for thousands of people worldwide who dedicated their time and talent to this mission over the years,” said Thomas Zurbuchen, associate administrator for the Science Mission Directorate at NASA Headquarters in Washington.

“Webb’s scientific promise is now closer than it ever has been. We are poised on the edge of a truly exciting time of discovery, of things we’ve never before seen or imagined.”

The world’s largest and most complex space science observatory will now begin six months of commissioning in space.

At the end of commissioning, Webb will deliver its first images. Webb carries four state-of-the-art science instruments with highly sensitive infrared detectors of unprecedented resolution. Webb will study infrared light from celestial objects with much greater clarity than ever before.

The premier mission is the scientific successor to NASA’s iconic Hubble and Spitzer space telescopes, built to complement and further the scientific discoveries of these and other missions.

“The launch of the Webb Space Telescope is a pivotal moment – this is just the beginning for the Webb mission,” said Gregory L. Robinson, Webb’s program director at NASA Headquarters.

“Now we will watch Webb’s highly anticipated and critical 29 days on the edge. When the spacecraft unfurls in space, Webb will undergo the most difficult and complex deployment sequence ever attempted in space.
Once commissioning is complete, we will see awe-inspiring images that will capture our imagination.”

The telescope’s revolutionary technology will explore every phase of cosmic history – from within our solar system to the most distant observable galaxies in the early universe, to everything in between.

Webb will reveal new and unexpected discoveries and help humanity understand the origins of the universe and our place in it.

NASA Headquarters oversees the mission for the agency’s Science Mission Directorate. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages Webb for the agency and oversees work on the mission performed by the Space Telescope Science Institute, Northrop Grumman, and other mission partners. In addition to Goddard, several NASA centers contributed to the project, including the agency’s Johnson Space Center in Houston, Jet Propulsion Laboratory in Southern California, Marshall Space Flight Center in Huntsville, Alabama, Ames Research Center in California’s Silicon Valley, and others.

Source: https://www.nasa.gov/press-release/nasas-webb-telescope-launches-to-see-first-galaxies-distant-worlds

Meet the Launch Team of NASA's James Webb Space Telescope.

The team worked together for the success of JWST at the Jupiter Mission Control Centre.

Congratulations to the great team for accomplishing this milestone.

Their efforts have paved a way for JWST to commence the journey into the deep space.

We are waiting for the outcome of the mission in the next six months.

✍� Charles Nwali

�©️ESA

#JamesWebbSpaceTelescope #UnfoldTheUniverse #JWST #deepspace

The JWST will be parked at the Lagrangian points (L2 in the figure above), about one million miles above the Earth.

But What is a Lagrange Point?

Lagrange points are positions in space where objects sent there tend to stay put. At Lagrange points, the gravitational pull of two large masses precisely equals the centripetal force required for a small object to move with them.

These points in space can be used by spacecraft to reduce fuel consumption needed to remain in position.


https://www.youtube.com/watch?v=foyJzvpeaBE

Lagrange Points are positions in space where the gravitational forces of a two body system like the Sun and the Earth produce enhanced regions of attraction and repulsion.

These can be used by spacecraft to reduce fuel consumption needed to remain in position.

Lagrange points are named in honor of Italian-French mathematician Josephy-Louis Lagrange.

There are five special points where a small mass can orbit in a constant pattern with two larger masses.

The Lagrange Points are positions where the gravitational pull of two large masses precisely equals the centripetal force required for a small object to move with them.

This mathematical problem, known as the "General Three-Body Problem" was considered by Lagrange in his prize winning paper (Essai sur le Problème des Trois Corps, 1772).

Of the five Lagrange points, three are unstable and two are stable. The unstable Lagrange points - labeled L1, L2 and L3 - lie along the line connecting the two large masses.

The stable Lagrange points - labeled L4 and L5 - form the apex of two equilateral triangles that have the large masses at their vertices. L4 leads the orbit of earth and L5 follows.

The L1 point of the Earth-Sun system affords an uninterrupted view of the sun and is currently home to the Solar and Heliospheric Observatory Satellite SOHO.

The L2 point of the Earth-Sun system was the home to the WMAP spacecraft, current home of Planck, and future home of the James Webb Space Telescope.

L2 is ideal for astronomy because a spacecraft is close enough to readily communicate with Earth, can keep Sun, Earth and Moon behind the spacecraft for solar power and (with appropriate shielding) provides a clear view of deep space for our telescopes.

The L1 and L2 points are unstable on a time scale of approximately 23 days, which requires satellites orbiting these positions to undergo regular course and attitude corrections.

NASA is unlikely to find any use for the L3 point since it remains hidden behind the Sun at all times. The idea of a hidden planet has been a popular topic in science fiction writing.

The L4 and L5 points are home to stable orbits so long as the mass ratio between the two large masses exceeds 24.96.

This condition is satisfied for both the Earth-Sun and Earth-Moon systems, and for many other pairs of bodies in the solar system.

Objects found orbiting at the L4 and L5 points are often called Trojans after the three large asteroids Agamemnon, Achilles and Hector that orbit in the L4 and L5 points of the Jupiter-Sun system.

(According to Homer, Hector was the Trojan champion slain by Achilles during King Agamemnon's siege of Troy).

There are hundreds of Trojan Asteroids in the solar system.

Most orbit with Jupiter, but others orbit with Mars. In addition, several of Saturn's moons have Trojan companions.

In 1956 the Polish astronomer Kordylewski discovered large concentrations of dust at the Trojan points of the Earth-Moon system.

The DIRBE instrument on the COBE satellite confirmed earlier IRAS observations of a dust ring following the Earth's orbit around the Sun.

The existence of this ring is closely related to the Trojan points, but the story is complicated by the effects of radiation pressure on the dust grains.

In 2010 NASA's WISE telescope finally confirmed the first Trojan asteroid (2010 TK7) around Earth's leading Lagrange point.

Finding the Lagrange Points

The easiest way to understand Lagrange points is to think of them in much the same way that wind speeds can be inferred from a weather map.

The forces are strongest when the contours of the effective potential are closest together and weakest when the contours are far apart.

Source: https://solarsystem.nasa.gov/resources/754/what-is-a-lagrange-point/

"ALWAYS LOOK UP
In the image Galileo Galilei, the mathematician, physicist and astronomer considered the father of science and pioneer of modern astronomy, showed his telescope to the Duke of Venice and the entire Senate of that Republic.

"Over 412 years of technology evolution, scientists send the James Webb telescope to space, science’s greatest effort to discover the secrets and wonders of the Universe.
Two different telescopes, two totally different eras.

"And the same human longing to know and know."

©Fresco de Giuseppe Bertini (1825-1898). Public domain.
Scientists of the JWST project ©️ NASA

This is quite easily one of the the best threads on NL imo. Awesome work man! It's pleasantly surprising and refreshing to see this level of enthusiam and dedication to science and astronomy especially here in Nigeria. I haven't quite been active on NL for sometime but I wonder why I've not stumbled upon this gem. Anyways,I'm currently following. Premium memes btw,I already had some of them in storage but still highlights the quality of the meme theme.

Random question tho,have you been to able to fully understand Eisteins "General theory of Relativity"?. Just theoretically. I have a few applications and effects that I'm curious about especially those that newtonian gravity could quite easily explain.

EmperorHarry:
This is quite easily one of the the best threads on NL imo. Awesome work man! It's pleasantly surprising and refreshing to see this level of enthusiam and dedication to science and astronomy especially here in Nigeria. I haven't quite been active on NL for sometime but I wonder why I've not stumbled upon this gem. Anyways,I'm currently following. Premium memes btw,I already had some of them in storage but still highlights the quality of the meme theme.

Random question tho,have you been to able to fully understand Eisteins "General theory of Relativity"?. Just theoretically. I have a few applications and effects that I'm curious about especially those that newtonian gravity could quite easily explain.

Yes, but I'm always willing to learn more. What are those applications and effects?

A001:

Yes, but I'm always willing to learn more. What are those applications and effects?

Well it's mostly when you try to understand theory of relativity on Earth or on planet surfaces. Matter or energy distorts space-time and that as a result creates paths(geodesics) that other masses follow when within the range of distorted space-time by the greater mass or energy. So I have some questions from the perspective of our home planet
1. How does geodesics account for objects thrown up in the air and it falls down in a straight line? Do we have straight line geodesics in distorted space-time?
2.How do planets stay in orbit if they are constantly falling towards the "well" created by the sun? Is it because they have velocities?
I only recently tried to really understand general theory of relativity beyond surface knowledge and time dilations. So I not quite certain about the terms I used but I'd like to understand it sufficiently

EmperorHarry:

Well it's mostly when you try to understand theory of relativity on Earth or on planet surfaces. Matter or energy distorts space-time and that as a result creates paths(geodesics) that other masses follow when within the range of distorted space-time by the greater mass or energy. So I have some questions from the perspective of our home planet
1. How does geodesics account for objects thrown up in the air and it falls down in a straight line? Do we have straight line geodesics in distorted space-time?
2.How do planets stay in orbit if they are constantly falling towards the "well" created by the sun? Is it because they have velocities?
I only recently tried to really understand general theory of relativity beyond surface knowledge and time dilations. So I not quite certain about the terms I used but I'd like to understand it sufficiently

1. Contrary to how falling objects are visualized as traveling in a line theoretically, objects don't fall down in a straight line in reality because their motion is disrupted by air resistance or drag force unless during a free fall (devoid of air resistance), which is also a theoretical scenario at least on Earth.

2. From the Newtonian (classical) worldview, planets are kept in orbits round the Sun due to the Sun's immense gravitational pull on these planets.

But gravity, as defined relativistically by Einstein, isn't a force but a distortion of space and time by mass and energy.

The sun's gravity is still what keeps the planets in orbit here as it warps (or distorts) the spacetime around the Sun by an immense amount since the Sun is the largest object in the solar system.

The planets take the shortest path (or geodesic) through the spacetime around the Sun, and this explains their orbits.

The distortion of spacetime by the Sun, in other words gravity, is what creates the "well".