The 2020 Nobel prize in physics has been jointly awarded to Roger Penrose, Reinhart Genzel, and Andrea Ghez for their contributions to our understanding of black holesthe Universes most mysterious and compact objects. Whilst Genzel and Ghez claim their share of the most celebrated prize in physics for the discovery of a supermassive compact object at the centre of our galaxyan object that we would later come to realize was a supermassive black hole which was later named Sagittarius A* (Sgr A*)Penrose is awarded his share for an arguably more fundamental breakthrough.

The Nobel is awarded to Penrose based on a 1965 paper in which he mathematically demonstrated that black holes arise as a direct consequence of the mathematics of Einsteins theory of General Relativity. Not only this; but for a body of a certain mass, the collapse into a singularity wasnt just possible, or even probable. If that collapse could not be halted, singularity formation, Penrose argued, is inevitable.

For the discovery, that black hole formation is a robust prediction of the general theory of relativity

The fact that Penrose showed that black holes mathematically emerge from general relativity may seem even more revolutionary when considering that the developer of general relativitya geometric theory of gravity that suggests mass curves the fabric of spacetimeAlbert Einstein did not even believe that black holes actually existed.

It was ten years after Einsteins death in April 1955 when Penrose showed that singularities form as a result of the mathematics of general relativity and that these singularities act as the heart of the black hole. At this centralor gravitationalsingularity, Penrose argued, all laws of physics displayed in the outside Universe ceased to apply.

The paper published in January 1965just eight years after Penrose earned his Ph.D. from The University of CambridgeGravitational Collapse and Spacetime Singularities is still widely regarded as the second most important contribution to general relativity after that of Einstein himself.

Yet, Penrose wasnt the first physicist to mathematically unpick general relativity and discover a singularity. Despite this, his Penrose Singularity Theorem is still considered a watershed moment in the history of general relativity.

A black hole is to be expected when a large massive body reaches a stage where internal pressure forces are insufficient to hold the body apart against the relentless inward pull of its own gravitational influence.

Black holes are generally regarded as possessing two singularities; a coordinate singularity and an actual gravitational singularity. Penroses work concerned the actual singularity, so named because unlike the coordinate singularity, it could not be removed with a clever choice of coordinate measurement.

That doesnt mean, however, that the coordinate singularity is unimportant or even easy to dismiss. In fact, you may already be very familiar with the coordinate singularity, albeit under a different namethe event horizon. This boundary marks the point where the region of space defined as a black hole begins, delineating the limit at which light can no longer escape.

The discovery of the event horizon occurred shortly after the first publication of Einsteins theory of general relativity in 1915. In 1916, whilst serving on the Eastern Front in the First World War astrophysicist Karl Schwarzschild developed the Schwarzschild solution, which described the spacetime geometry of an empty region of space. One of the interesting features of this solutiona coordinate singularity.

The coordinate singularityalso often taking a third more official name as the Schwarzschild radius (Rs)exists for all massive bodies at r =Rs = 2GM/c. This marks the point where the escape velocity of the body is such that not even light can escape its grasp. For most cosmic bodies the Schwarzschild radius falls well within its own radius (r). For example, the Suns Rs occurs at a radius of about 3km from the centre compared to an overall radius of 0.7 million km.

Thus, the Schwarzschild radius or event horizon marks the boundary of a light-trapping surface. A distant observer could see an event taking place at the edge of this surface, but should it pass beyond that boundaryno signal could ever reach our observer. An observer falling with the surface, though, would notice nothing about this boundary.

The passing of Rs would just seem a natural part of the fall to them despite it marking the point of no return. To the distant observer the surface would freeze and become redder and redder thanks to the phenomena of gravitational redshiftalso the reason the event horizon is sometimes referred to as the surface of infinite redshift.

The very definition of a black hole is a massive body whose surface shrinks so much during the gravitational collapse that its surface lies within this boundary. But, what if this collapse continues? When does it reach a central singularity at the heart of the black holer= 0 for the mathematically inclined?

We see that the matter continues to collapse inwards through the surface called the event horizon, where the escape velocity indeed becomes the speed of light. Thereafter, no further information from the star itself can reach any outside observer, and a black hole is formed.

Penrose and other researchers have found that the equations of general relativity open the possibility that a body may undergo a complete gravitational collapseshrinking to a point of almost infinite densityand become a black hole.

In order for this to happen, however, a series of limits have to be reached and exceeded. For example, planets are unable to undergo this gravitational collapse as the mass they possess is insufficient to overcome the electromagnetic repulsion between their consistent atomsthus granting them stability.

Likewise, average-sized stars such as the Sun should also be resistant to gravitational collapse. The plasma found at the centre of stars in this solar-mass range is believed to be roughly ten times the density of lead protecting from complete collapse, whilst the thermal pressure arising from nuclear processes and radiation pressure alone would be sufficient to guarantee a star of low to intermediate-mass stability.

For older, more evolved stars in which nuclear reactions have ceased due to a lack of fuel. Its a different story. Especially if they have a mass ten times greater than the Sun.

It was suggested as early as the 1920s that small, dense starswhite dwarf starswere supported against collapse by phenomena arising from quantum mechanics called degeneracy.

This degeneracy pressure arises from the Pauli exclusion principle, which states that fermions such as electrons are forbidden from occupying the same quantum state. This led a physicist called Subrahmanyan Chandrasekhar to question if there was an upper limit to this protection.

In 1931, Chandrasekhar proposed that above 1.4 times the mass of the Sun, a white dwarf would no longer be protected from gravitational collapse by degeneracy pressure. Beyond this boundaryunsurprisingly termed the Chandrasekhar limitgravity overwhelms the Pauli exclusion principle and gravitational collapse continues unabated.

The discovery of neutronsthe neutral partner of protons in atomic nucleiin 1932 led Russian theorist Lev Landau to speculate about the possibility of neutron stars. The outer part of these stars would contain neutron-rich nuclei, whilst the inner sections would be formed from a quantum-fluid comprised of mostly neutrons.

Again, neutron stars would be protected against gravitational collapse by degeneracy pressurethis time provided by this neutron fluid. In addition to this, the greater mass of the neutron in comparison to the electron would allow neutron stars to reach a greater density before undergoing collapse.

To put this into perspective, a white dwarf with the mass of the Sun would be expected to have a millionth of our stars volumegiving it a radius of5000 km roughly that of the Earth. A neutron star of a similar mass though, that would have a radius of about 20kmroughly the size of a city.

By 1939, Robert Oppenheimer had calculated that the mass-limit for neutron stars would be roughly 3 times the mass of the Sun. Above that limitagain, gravitational collapse wins. Oppenheimer also used general relativity to describe how this collapse appears to a distant observer. They would consider the collapse to take an infinitely long time, the process appearing to slow and freeze as the stars surface shrinks towards the Schwarzschild radius.

So long as Einsteins picture of classical spacetime can be maintained, acting in accordance with Einsteins equation then a singularity will be encountered within a black hole. The expectation is that Einsteins equation will tell us that this singularity cannot be avoided by any matter in the hole

For Penrose, the mathematical proof of a physical singularity at the heart of a black hole arising from this complete collapse was not enough. He wanted to demonstrate the singularity and the effects on a spacetime that would arise there. He did so with the use of light cones travelling down a geodesican unerringly straight line. In the process, he unveiled the anatomy of the black hole.

A light cone is most simply described as the path that a flash of light created by a single event and travelling in all directions would take through spacetime. Light cones can be especially useful when it comes to physicists calculating which events can be causally linked. If a line cant be drawn between the two events that fits in the light cone, one cannot have caused the other.

We call a line emerging from a lightcone a world-linethese move from the central event out through the top of the conethe future part of the diagram. The worldline shows the possible path of a particle or signal created by the event at the origin of the lightcone. Throwing a light cone at a black hole demonstrates why passing the event horizon means a merger with the central singularity is inevitable.

Penrose considered what would happen to a light cone as it approached and passed the event horizon of what is known as a Kerr black hole. This is a black hole that is non-charged and rotating. Its angular momentum drags spacetime along with it in an effect researchers call frame dragging.

Far from the black hole, light is free to travel with equal ease in any direction. The lightcones here have a traditionally symmetrical appearance which represents this.

However, towards the static limitthe point at which the black hole starts to drag spacetime around with itthe lightcones begin to tip towards the singularity and in the direction of rotation and narrow. Thus the static limit represents the point at which light is no longer free to travel in any direction. It must move in a direction that doesnt oppose the rotation of the black hole. Particles at this limit can no longer sit stillhence the name static limit.

Yet, despite the fact the dragging effect is so strong, here that not even light can resist it, signals can escape this regionit isnt the event horizonbut they can only do so by travelling in the direction of the rotation.

Interestingly, Penrose suggests that particles entering the static limit and decaying to two separate particles may result in energy leaching from the black hole in what is known as the Penrose process, but thats a discussion for another time.

So as our light cone moves toward the event horizon, it begins to narrow and tip. But, something extraordinary happens when it passes this boundary. As long as one is using so-called Swartzchild coordinates, once inside the black hole proper, the lightcone flips on its side, with the future end of the cone pointed towards the singularity.

This can mean only one thing for the worldline of that event, it points to the central singularity signalling that an encounter with that singularity is evitable.

It is generally believed that the spacetime singularities of gravitational collapse will necessarily always lie within an event horizon, to that whatever happens to be the extraordinary physical effects at such a singularity, these will be hidden from the view of any external observer.

Black holes arent particularly complex in construction and posses only three properties mass, electric charge, and angular momentumbut physicists working with light cones were able to determine the layers of their anatomyand crucially, the bounded surfaces that exist within them.This is what was revolutionary about Penroses concepts, they introduced the concept of bounded surfaces to black holes.

Looking back on this from an era in which a black hole has been imaged for the first time and gravitational waves are beginning to be routinely measured from the mergers of such objects, its important to not underestimate the importance of Penroses findings.

Before any practical developments surround black holes could even be dreamed of, Roger Penrose provided the mathematical basis to not just suggest the existence of black holes, but also laying the groundwork for their anatomy, and the effect they have on their immediate environment.

Thus, what Penroses Nobel award can really be seen as a recognition of moving these objectsor more accurately, spacetime eventsfrom the realm of speculation to scientific theory.

Penrose. R., Gravitational Collapse and Space-Time Singularities, Physical Review Letters, vol. 14, Issue 3, pp. 57-59, [1965]

Penrose. R., The Road to Reality, Random House, 2004

Senovilla. J. M. M., Garfinkle. G., The 1965 Penrose Singularity Theorem, Classical and Quantum Gravity, [2015].

Relativity, Gravitation and Cosmology,Robert J. Lambourne, Cambridge Press, 2010.

Relativity, Gravitation and Cosmology: A basic introduction, Ta-Pei Cheng, Oxford University Press, 2005.

Extreme Environment Astrophysics,Ulrich Kolb, Cambridge Press, 2010.

Stellar Evolution and Nucleosynthesis,Sean G. Ryan, Andrew J. Norton, Cambridge Press, 2010.

Cosmology,Matts Roos, Wiley Publishing, 2003.

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Singularity Minded: The Black Hole Science that Won a Nobel Prize - ZME Science

When did something like us first appear on the planet? It turns out theres remarkably little agreement on this question. Fossils and DNA suggest people looking like us, anatomically modern Homo sapiens, evolved around 300,000 years ago. Surprisingly, archaeologytools, artifacts, cave artsuggest that complex technology and cultures, behavioral modernity, evolved more recently: 50,000 to 65,000 years ago.

Some scientists interpret this as suggesting the earliest Homo sapiens werent entirely modern. Yet the different data tracks different things. Skulls and genes tell us about brains, artifacts about culture. Our brains probably became modern before our cultures.

Key physical and cultural milestones in modern human evolution, including genetic divergence of ethnic groups. Image credit: Nick Longrich / author provided

For 200,000 to 300,000 years after Homo sapiens first appeared, tools and artifacts remained surprisingly simple, little better than Neanderthal technology, and simpler than those of modern hunter-gatherers such as certain indigenous Americans. Starting about 65,000 to 50,000 years ago, more advanced technology started appearing: complex projectile weapons such as bows and spear-throwers, fishhooks, ceramics, sewing needles.

People made representational artcave paintings of horses, ivory goddesses, lion-headed idols, showing artistic flair and imagination. A bird-bone flute hints at music. Meanwhile, arrival of humans in Australia 65,000 years ago shows wed mastered seafaring.

This sudden flourishing of technology is called the great leap forward, supposedly reflecting the evolution of a fully modern human brain. But fossils and DNA suggest that human intelligence became modern far earlier.

Bones of primitive Homo sapiens first appear 300,000 years ago in Africa, with brains as large or larger than ours. Theyre followed by anatomically modern Homo sapiens at least 200,000 years ago, and brain shape became essentially modern by at least 100,000 years ago. At this point, humans had braincases similar in size and shape to ours.

Assuming the brain was as modern as the box that held it, our African ancestors theoretically could have discovered relativity, built space telescopes, written novels and love songs. Their bones say they were just as human as we are.

300,000 ya skull, Morocco. Image credit: NHM

Because the fossil record is so patchy, fossils provide only minimum dates. Human DNA suggests even earlier origins for modernity. Comparing genetic differences between DNA in modern people and ancient Africans, its estimated that our ancestors lived 260,000 to 350,000 years ago. All living humans descend from those people, suggesting that we inherited the fundamental commonalities of our species, our humanity, from them.

All their descendantsBantu, Berber, Aztec, Aboriginal, Tamil, San, Han, Maori, Inuit, Irishshare certain peculiar behaviors absent in other great apes. All human cultures form long-term pair bonds between men and women to care for children. We sing and dance. We make art. We preen our hair, adorn our bodies with ornaments, tattoos and makeup.

We craft shelters. We wield fire and complex tools. We form large, multigenerational social groups with dozens to thousands of people. We cooperate to wage war and help each other. We teach, tell stories, trade. We have morals, laws. We contemplate the stars, our place in the cosmos, lifes meaning, what follows death.

The details of our tools, fashions, families, morals and mythologies vary from tribe to tribe and culture to culture, but all living humans show these behaviors. That suggests these behaviorsor at least, the capacity for themare innate. These shared behaviors unite all people. Theyre the human condition, what it means to be human, and they result from shared ancestry.

We inherited our humanity from peoples in southern Africa 300,000 years ago. The alternativethat everyone, everywhere coincidentally became fully human in the same way at the same time, starting 65,000 years agoisnt impossible, but a single origin is more likely.

Archaeology and biology may seem to disagree, but they actually tell different parts of the human story. Bones and DNA tell us about brain evolution, our hardware. Tools reflect brainpower, but also culture, our hardware and software.

Just as you can upgrade your old computers operating system, culture can evolve even if intelligence doesnt. Humans in ancient times lacked smartphones and spaceflight, but we know from studying philosophers such as Buddha and Aristotle that they were just as clever. Our brains didnt change, our culture did.

That creates a puzzle. If Pleistocene hunter-gatherers were as smart as us, why did culture remain so primitive for so long? Why did we need hundreds of millennia to invent bows, sewing needles, boats? And what changed? Probably several things.

First, we journeyed out of Africa, occupying more of the planet. There were then simply more humans to invent, increasing the odds of a prehistoric Steve Jobs or Leonardo da Vinci. We also faced new environments in the Middle East, the Arctic, India, Indonesia, with unique climates, foods and dangers, including other human species. Survival demanded innovation.

Many of these new lands were far more habitable than the Kalahari or the Congo. Climates were milder, but Homo sapiens also left behind African diseases and parasites. That let tribes grow larger, and larger tribes meant more heads to innovate and remember ideas, more manpower, and better ability to specialize. Population drove innovation.

Beijing from space. Image credit: NASA

This triggered feedback cycles. As new technologies appeared and spreadbetter weapons, clothing, sheltershuman numbers could increase further, accelerating cultural evolution again.

Numbers drove culture, culture increased numbers, accelerating cultural evolution, on and on, ultimately pushing human populations to outstrip their ecosystems, devastating the megafauna and forcing the evolution of farming. Finally, agriculture caused an explosive population increase, culminating in civilizations of millions of people. Now, cultural evolution kicked into hyperdrive.

Artifacts reflect culture, and cultural complexity is an emergent property. That is, its not just individual-level intelligence that makes cultures sophisticated, but interactions between individuals in groups, and between groups. Like networking millions of processors to make a supercomputer, we increased cultural complexity by increasing the number of people and the links between them.

So our societies and world evolved rapidly in the past 300,000 years, while our brains evolved slowly. We expanded our numbers to almost eight billion, spread across the globe, reshaped the planet. We did it not by adapting our brains but by changing our cultures. And much of the difference between our ancient, simple hunter-gatherer societies and modern societies just reflects the fact that there are lots more of us and more connections between us.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Image credit: Wikimedia Commons

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When Did We Become Fully Human? What Fossils and DNA Tell Us About the Evolution of Modern Intelligence - Singularity Hub

ARTIFICIAL INTELLIGENCE

A Radical New Technique Lets AI Learn With Practically No DataKaren Hao | MIT Technology ReviewShown photos of a horse and a rhino, and told a unicorn is something in between, [children] can recognize the mythical creature in a picture book the first time they see it. Now a new paper from the University of Waterloo in Ontario suggests that AI models should also be able to do thisa process the researchers call less than one-shot, or LO-shot, learning.

Artificial General Intelligence: Are We Close, and Does It Even Make Sense to Try?Will Douglas Heaven | MIT Technology ReviewA machine that could think like a person has been the guiding vision of AI research since the earliest daysand remains its most divisive idea. So why is AGI controversial? Why does it matter? And is it a reckless, misleading dreamor the ultimate goal?

The Race for a Super-Antibody Against the CoronavirusApoorva Mandavilli | The New York TimesDozens of companies and academic groups are racing to develop antibody therapies. But some scientists are betting on a dark horse: Prometheus, a ragtag group of scientists who are months behind in the competitionand yet may ultimately deliver the most powerful antibody.

How to Build a Spacecraft to Save the WorldDaniel Oberhaus | WiredThe goal of the Double Asteroid Redirection Test, or DART, is to slam the [spacecraft] into a small asteroid orbiting a larger asteroid 7 million miles from Earth. It should be able to change the asteroids orbit just enough to be detectable from Earth, demonstrating that this kind of strike could nudge an oncoming threat out of Earths way. Beyond that, everything is just an educated guess, which is exactly why NASA needs to punch an asteroid with a robot.

Inside Gravitys Daring Mission to Make Jetpacks a RealityOliver Franklin-Wallis | WiredThe first time someone flies a jetpack, a curious thing happens: just as their body leaves the ground, their legs start to flail. Its as if the vestibular system cant quite believe whats happening. This isnt natural. Then suddenly, thrust exceeds weight, andtheyre aloft. Its that moment, lift-off, that has given jetpacks an enduring appeal for over a century.

Inside Singapores Huge Bet on Vertical FarmingMegan Tatum | MIT Technology Reviewto cram all [of Singapores] gleaming towers and nearly 6 million people into a land mass half the size of Los Angeles, it has sacrificed many things, including food production. Farms make up no more than 1% of its total land (in the United States its 40%), forcing the small city-state to shell out around $10 billion each year importing 90% of its food. Here was an example of technology that could change all that.

The Effort to Build the Mathematical Library of the FutureKevin Hartnett | QuantaDigitizing mathematics is a longtime dream. The expected benefits range from the mundanecomputers grading students homeworkto the transcendent: using artificial intelligence to discover new mathematics and find new solutions to old problems.

Image credit:Kevin Mueller /Unsplash

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This Week's Awesome Tech Stories From Around the Web (Through October 17) - Singularity Hub

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.

As a graduate student in the 1990s at Penn State, where Penrose holds a visiting position, I had many opportunities to interact with him. For many years I was intimidated by this giant in my field, only stealing glimpses of him working in his office, sketching strange-looking scientific drawings on his blackboard. Later, when I finally got the courage to speak with him, I quickly realized that he is among the most approachable people around.

Sir Roger Penrose won half the prize for his seminal work in 1965 which proved, using a series of mathematical arguments, that under very general conditions, collapsing matter would trigger the formation of a black hole.

This rigorous result opened up the possibility that the astrophysical process of gravitational collapse, which occurs when a star runs out of its nuclear fuel, would lead to the formation of black holes in nature. He was also able to show that at the heart of a black hole must lie a physical singularity an object with infinite density, where the laws of physics simply break down. At the singularity, our very conceptions of space, time and matter fall apart and resolving this issue is perhaps the biggest open problem in theoretical physics today.

Penrose invented new mathematical concepts and techniques while developing this proof. Those equations that Penrose derived in 1965 have been used by physicists studying black holes ever since. In fact, just a few years later, Stephen Hawking, alongside Penrose, used the same mathematical tools to prove that the Big Bang cosmological model our current best model for how the entire universe came into existence had a singularity at the very initial moment. These are results from the celebrated Penrose-Hawking Singularity Theorem.

The fact that mathematics demonstrated that astrophysical black holes may exactly exist in nature is exactly what has energized the quest to search for them using astronomical techniques. Indeed, since Penroses work in the 1960s, numerous black holes have been identified.

The remaining half of the prize was shared between astronomers Reinhard Genzel and Andrea Ghez, who each lead a team that discovered the presence of a supermassive black hole, 4 million times more massive than the Sun, at the center of our Milky Way galaxy.

Genzel is an astrophysicist at the Max Planck Institute for Extraterrestrial Physics, Germany and the University of California, Berkeley. Ghez is an astronomer at the University of California, Los Angeles.

The location of the black hole in the Milky Way galaxy relative to our solar system. Johan Jarnestad/The Royal Swedish Academy of Sciences, CC BY-NC

Genzhel and Ghez used the worlds largest telescopes (Keck Observatory and the Very Large Telescope) and studied the movement of stars in a region called Sagittarius A* at the center of our galaxy. They both independently discovered that an extremely massive 4 million times more massive than our Sun invisible object is pulling on these stars, making them move in very unusual ways. This is considered the most convincing evidence of a black hole at the center of our galaxy.

This 2020 Nobel Prize, which follows on the heels of the 2017 Nobel Prize for the discovery of gravitational waves from black holes, and other recent stunning discoveries in the field such as the the 2019 image of a black hole horizon by the Event Horizon Telescope serve as great recognition and inspiration for all humankind, especially for those of us in the relativity and gravitation community who follow in the footsteps of Albert Einstein himself.

This article is republished from The ConversationbyGaurav Khanna, Professor of Physics, University of Massachusetts Dartmouthunder a Creative Commons license. Read the original article.

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Black holes at the center of 2020 Nobel Prize in physics astrophysicist explains why its a big deal - The Next Web

If youve seen the movie The Martian, you no doubt remember the rescue scene, in which (spoiler alert!) Matt Damon launches himself off Mars in a stripped-down rocket in hopes of his carefully-calculated trajectory taking him just close enough to his crew for them to pluck him from the void of outer space and bring him safely home to Earth. Theres a multitude of complex physics involved, and who knows how true-to-science the scene is, but getting the details right to successfully grab something in space certainly isnt easy.

So it will be fascinating to watch NASA aim to do just that, as its OSIRIS-REx spacecraft attempts to pocket a fistful of rock and dust from an asteroid called Bennu then ferry it back to Earthwith the whole endeavor broadcast live on NASAs website starting Tuesday, October 20 at 5pm Eastern time. Here are some details to know in advance.

Bennus full name is 101955 Bennu, and its close enough to Earth to be classified as a near-Earth object, or NEOthat means it orbits within 1.3 AU of the sun. An AU is equivalent to the distance between Earth and the sun, which is about 93 million miles. The asteroid orbits the sun at an average distance of 105 million miles, which is just (just being a relative term here!) 12 million miles farther than Earths average orbital distance from the sun.

Every six years, Bennu comes closer to Earth, getting to within 0.002 AU. Scientists say this means theres a high likelihood the asteroid could impact Earth sometime in the late 22nd century. Luckily, an international team is already on the case (plus, due to Bennus size and composition, it likely wouldnt do any harm).

Bennu isnt solid, but rather a loose clump of rock and dust whose density varies across its area (in fact, up to 40 percent of it might just be empty space!). Its shape is more similar to a spinning top than a basketball or other orb, and its not very bigabout a third of a mile wide at its widest point. Since its small, it spins pretty fast, doing a full rotation on its axis in less than four and a half hours. That fast spinning also means its likely to eject material once in a while, with chunks or rock and other regolith dislodging and being flung into space.

OSIRIS-REx stands for Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer. Yeahthats a lot. Its the size of a large van (bigger than a minivan, smaller than a bus), and looks sort of like a box with wings and one long arm. Its been orbiting Bennu for about two years (since 2018) after taking two years to get there (it was launched in 2016).

The spacecrafts arm is called TAGSAM, which stands for Touch-And-Go Sample Acquisition Mechanism. Its 11 feet long and has a round collection chamber attached to its end.

OSIRIS-REx doesnt have any legs to land on, but thats for a good reason: landing isnt part of the plan. Which brings us to

As far as plans go, this one is pretty cool. The spacecraft will approach the asteroid, and its arm will reach out to tap the surface. A pressurized canister will shoot out some nitrogen gas to try to dislodge some dust and rock from Bennu, and the collection chamber on the spacecrafts arm will open up to grab whatever it can; scientists are hoping to get at least 60 grams worth of material (thats only 4 tablespoons! Its less than the cup of yogurt you eat in the morning!).

And thats not even the wildest detail; if the mission goes as planned and OSIRIS-REx scoops up those four tablespoons of precious cargo, scientists on Earth still wont see them for almost three more years; the spacecraft is scheduled for a parachute landing in the Utah desert on September 24, 2023.

The NASA team working on this project thinks its likely theyll find organic material in the sample collection, and it may even give them clues to the origins of life on Earth.

Does the mission have better odds of success than Matt Damons rescue in The Martian? Tune in on Tuesday to see for yourself.

Image Credit: NASA

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NASA's About to Try Grabbing a Chunk of Asteroid to Bring to Earthand You Can Watch - Singularity Hub

Lost within a YouTube hole, I came across a silly, animated science video about black holes by Kurzgesagt In a Nutshell. A lot of what I heard went over my head, but I knew that the idea of black holes made me feel anxious, the way I feel in the ocean at night: so immensely swallowed that I lose myself.

These past seven months have left me reeling in a similar limbo. It feels as though there is no acting force of gravity keeping me on track. Time goes on and on and on and I am infinitely in disarray.

***

Some days I am exponentially radiating outward in all directions and there are endless possibilities. On other days I am taught that there is a limit to growth that is called Logistical and is Shaped like a Crooked Spine.

But what if I could just grow larger and larger and larger until the point of implosion, upon which all of that denseness of thought and energy and pure being could shrink into the size of a dust grain? Not diminished, but concentrated.

A black hole is a star that grew so massive iron bubbled up inside its core. The star, with its iron heart, sank and sank until its body couldnt hold up its burden. The child within me could read it as a story: The Star Who Got Too Big for its Britches, or maybe just the star who got lonely despite all of its mass and gravity.

Out and then in, like a giant breath.

I lie awake in bed, tense between the shoulder blades, finding breathing insufficient. I think about the giant stars that give in to their burdens and instead of release are brought into a concentrated agony. It is and isnt like drowning and waking on a cold mountain peak.

***

Located in the center of a black hole is whats known as a gravitational singularity, in which a huge mass exists in an infinitely small space. This gives the point infinite density and gravity, and it warps the curvature of the universe.

If we looked at a black hole, we wouldnt really see it. It is hidden behind the event horizon: a sphere of absolute darkness out of which nothing, not even light, escapes.

***

When I was younger my understanding of darkness was nothing more than fear of my own imagination, like when the lights turned off and I had to count the number of steps to my bed because there were unnamed terrors in the corners of the room. But my mother would come in and I would find that the monsters and dragons and ghouls were nothing but shadows playing on the wall, or a jacket hanging from the doorframe.

Darkness has changed since childhood. Now, Im not afraid of the monsters but of the emptiness when I reach my hand out and feel nothing. Its scarier when you find out your imagination is foolish and that darkness is mostly empty.

But black holes dont represent my cynical view of darkness. They arent emptiness or absence. A single point at the center of a black hole, so small it has a hypothetical volume of zero, holds multiple infinities. Why did I grow up to think my imagination was insufficient?

***

In reality, if I was to enter a black hole my body would be stretched out into a long string of plasma as it is drawn closer to the singularity. I would be funneled. The gravitational funnel inside a black hole is so strong that if a star were to stray too close, its entire mass could be ripped apart.

I think about the giant stars that give in to their burdens and instead of release are brought into a concentrated agony.

Nothing can escape a black hole once it passes the horizon, because turning back around would require a moving velocity faster than the speed of light. Incapable of turning back or to the side, you are committed to what seems a lot like fate. Rapid descent toward the point from which there is no return. Like tripping through the looking glass into an unavoidable future.

For spectators watching you enter a black hole, the time it takes to cross the event horizon seems infinite because they are never given the signal that you are gone. The phantom image of yourself reflects back on them for an infinite amount of time long after you have edged past the lip of blackness.

I could disappear with nobody knowing where and when I had gone. In thinking of this I feel lonely. And disconnected.

***

Stephen Hawking came up with a theory to describe how black holes lose energy. Its called Hawking Radiation, and it describes how black holes evaporate.

Over time, they lose an extremely tiny amount of matter, and for the largest black hole in our universe, it might take 10,100 years, at which point it would explode with an eruption energy 1,000 times the total nuclear capacity on Earth.

But at its cease, would the knowledge of that original star and all other matter caught within the event horizon really be lost? That seems sad to me.

Black holes seem like one of those indefatigable forces of the world. It is enough to know they are up there somewhere, a virginal presence, impenetrable. But even they, with their multitudes and carefully folded legs, cannot last forever. And here I was thinking that infinity was the same as eternity.

***

It is not particles that make up our universe, but information. Information arranges the elementary particles of existence. If you lose information, you lose the possibility of creation.

The conservation of quantum information or the no-hiding theorem states that information can neither be created nor destroyed. But for black holes, the line is blurry.

It was originally thought that information was lost forever in a black holes interminable void. But Hawking also came up with what is called the information paradox, and the thinking is as follows: What if, when something enters a black hole, it leaves behind a holographic projection of its life on the screen of the event horizon before it pushes through and into the funnel toward singularity?

It would be nice, I think, to leave behind my life, with all of its tangles, on the event horizon and have the molecules and elementary particles of my physical body enter the cosmic hodgepodge of singularity.

And what if every time a particle leaves the black hole thanks to Hawking Radiation it takes information away with it? Like walking into a library filled with trillions of books and walking away having read only one.

This theory would make black holes a movie of the universe. Fractaling toward origin or maybe infinity.

These days, its easier to think of myself in the third person, as if I was watching a film reel of the moments that would be harder to bear than to watch. It would be nice, I think, to leave behind my life, with all of its tangles, on the event horizon and have the molecules and elementary particles of my physical body enter the cosmic hodgepodge of singularity. I imagine it would be a lot like giving in. Like reincarnation into something whose existence is a lot more straightforward, or maybe just different.

***

But, alas, the nearest event horizon is 1,000 light-years from my room. My haphazard trail of thought isnt showing me any cosmic truth.

Our knowledge of black holes is nothing but logical conjecture, based on the absolutes we rely on to feel safe and comfortable.

We feel better knowing that science is reliable and that there are fundamental laws of our universe scrawled out on blackboards by geniuses with chalk on their slacks.

But logic makes breathing feel robotic, absolutes have failed me and safety is temporal.

***

I prefer to wonder about the unknown because maybe then I can stay hopeful. Maybe that black hole 1,000 light-years away contains worlds where I could be happy and held and something completely different from who I am here and now. I could be woman or otherwise, I could be two-dimensional and have no need to breathe and feel breathless. I could be a system of veins or connective tissue: a building block for something much larger than myself. I could be all my past lives all at once. I could be a supermodel or a supernova, a fetus or a mother of stars.

Contact Aliya Haas Blinman at [emailprotected].

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