Taylor Willett. Music. Food. 23. SoCal.
TAYLOR.
What the Sight of a Black Hole Means to a Black Hole Physicist
The astrophysicist Janna Levin reflects on the newly unveiled, first-ever photograph of a black hole.
“At this historic moment, the world has paused to take in the sight of humanity’s first image of the strangest phenomenon in the known universe, a remarkable legacy of the general theory of relativity: a black hole. I am moved not just by the image; overwhelmingly I am moved by the significance of sharing this experience with strangers around the globe. I am moved by the image of a species looking at an image of a curious empty hole looming in space.
I am at the National Press Club, in Washington, D.C., a hive of excitement. Scientists with the Event Horizon Telescope aspired for years to take the first-ever picture of a supermassive black hole, so when they gathered journalists and scientists together today for a press conference, there wasn’t much doubt as to what we were here to see.
But still, there are surprises.
At the podium is Sheperd Doeleman, the director of the Event Horizon Telescope. He welcomes us, ‘black hole enthusiasts.’ I have the strongest memory of standing at the chalkboard in an otherwise empty classroom at the Massachusetts Institute of Technology with Shep, my funny friend with his funny, unmistakable, burnt-mahogany hair. Covered in chalk dust, we acquired the hard-earned mathematics of Albert Einstein’s theory of relativity.
We knew the words already, the standard lore: All forms of matter and energy bend space and time, and light and matter follow those curves. The words have to be taken on trust. But the mathematics we could acquire. It would belong to us. When Einstein conceived of relativity, he gave us a gift that has been passed from person to person around the world. Relativity, defying its name, is true for all of us.
Maybe my memory of that particular board is so crisp precisely because that moment defines the cusp between before and after acquiring relativity. Now I cannot imagine my own mind without it. Relativity permeates my thoughts so that I think in relativity the way writers think in their natural language. Since that time at MIT, Shep and I have both found our way via relativity to the most remarkable of its predictions, black holes.
Black holes were conceived of as a thought experiment, a fantastical imagining. Imagine matter crushed to a point. Don’t ask how. Just imagine that. While enlisted in the German army during World War I, Karl Schwarzschild discovered this possible solution to Einstein’s newly published theory of relativity, apocryphally between calculating ballistic trajectories from the trenches on the Russian front. Schwarzschild inferred that space-time effectively spills toward the crushed center. Racing at its absolute speed, even light gets dragged down the hole, casting a shadow on the sky. That shadow is the event horizon, the stark demarcation between the outside and anything with the misfortune to have fallen inside.
Einstein thought nature would protect us from the formation of black holes. To the contrary, nature makes them in abundance. When a dying star is heavy enough, gravity overcomes matter’s intrinsic resistance and the star collapses catastrophically. The event horizon is left behind as an archaeological record while the stellar material continues to fall inward to an unknown fate. In our own Milky Way galaxy there could be billions of black holes.
Supermassive black holes, millions or even billions of times the mass of the sun, anchor the centers of nearly all galaxies, though nobody yet knows how they formed or got so heavy. Maybe they formed from dead stars that merged and escalated in size, or maybe they directly collapsed out of more primordial material in a younger universe. However they formed, there are as many supermassive black holes as there are galaxies — hundreds of billions in the observable universe.
We had never seen a black hole before today. No telescope had ever taken a picture of one. We have indirectly inferred the presence of black holes when they’ve cannibalized companion stars, powered energetic jets in twisted magnetic fields, and captured stars in their orbit. We have even heard black holes collide and merge, ringing space-time like mallets on a drum.
We had never taken a direct picture of a black hole before because black holes are tiny, despite their dramatic reputation as weapons of mayhem and destruction (yes, the Nova film I hosted was called ‘Black Hole Apocalypse’). A black hole the mass of the sun would have an event horizon a mere 6 kilometers across. Compare that to the 1.4-million-kilometer breadth of the sun itself. The supermassive black hole at the center of the Milky Way, dubbed Sagittarius A*, is 4 million times the mass of the sun but only about 17 times wider.
Consider the challenge of capturing a portrait of an entirely dark object only 17 times the width of an ordinary star at a distance of 26,000 light-years. Resolving an image of Sagittarius A* is comparable to resolving the image of a piece of fruit on the moon.
To resolve such a minuscule image requires a telescope the size of the entire Earth. Since those days in that chalk-dusted classroom at MIT, my funny, utterly unconventional friend has been determined to capture the image of a supermassive black hole all the same.
During our years in graduate school, Shep’s hair was an allegory for his mind — wild and spirited. I admired the freedom I sensed in the way he thought, always forging unexpected connections, sometimes at the expense of the required lesson. His shocked eyes would warn me that a crazy idea had struck him just at that precise moment, as though he was as surprised as I was by the thought.
The Event Horizon Telescope is a testament to bold ideas, as well as scientific ingenuity and collaboration. Exploiting large radio telescopes around the globe — relying on the newest, most sophisticated observatories and reviving some that were nearly defunct — EHT became a composite telescope the size of the Earth. As the planet spins and orbits, the target black holes rise into the field of view of component telescopes around the planet. To render a precise image, the telescopes need to operate as one, which involves sensitive time corrections so that one global eye looks toward the black hole.
Combining telescopes for better resolution was the basis of Shep’s doctoral thesis in the ’90s. By 2008, he led a small team that imaged structures comparable in size to nearby supermassive black holes. That proof of concept drove the EHT project, whose team was now confident that the required resolution was in reach. In the decade since, EHT had to address challenges the data posed and advance technologically, and Shep is quick to credit the international team for their stamina and for the cleverness of their collective contributions.
Our supermassive black hole, Sagittarius A*, became the obvious target to pursue. Despite the abundance of supermassive black holes in galaxies, all others are too far away to resolve even with a telescope the size of the Earth. There is one exception. Messier 87, or M87, is an enormous elliptical galaxy 55 million light-years away that is known to harbor a staggering supermassive black hole somewhere between 3.5 billion and 7.2 billion times the mass of the sun. At the small end of that range, M87 would be an impossible target for EHT. At the high end, it is possibly suitable. So M87 became a secondary target in the heated pursuit of Sagittarius A*.
A black hole against the dark backdrop of empty space would be truly invisible. Sagittarius A* and M87 are helpfully illuminated by debris caught in hot disks orbiting very near their event horizons. The path of the light from the luminous orbiting material is bent along the curved space so that even light behind a black hole gets redirected our way. The disk appears to surround the black hole, allowing for a bright contrast against which its shadow is visible.
EHT actually sees an area slightly outside the event horizon itself — a region defined by the location closest to the black hole where a beam of light could orbit on a circle, known as the ‘last photon orbit.’ (Were you to float there, you could see light reflected off the back of your head after completing a round trip. Or, if you turned around quickly enough, you might see your own face.) Closer than that, all the light falls in.
We are gathered here, black hole theorists and observers, journalists and friends, in this room together to share an image we could already pretty well imagine and were excited to celebrate. But this was the surprise on hearing the announcement: It’s not Sagittarius A* they saw. It’s not our black hole. It’s M87!
The image is unmistakable — a dark shadow the size of our solar system, enveloped by a bright, beautiful blob.
While the scientific implications will take time to unpack, some of the anthropological impact feels immediate. The light EHT collected from M87 headed our way 55 million years ago. Over those eons, we emerged on Earth along with our myths, differentiated cultures, ideologies, languages and varied beliefs. Looking at M87, I am reminded that scientific discoveries transcend those differences. We are all under the same sky, all of us bound to this pale blue dot, floating in the sparse local territory of our solar system’s celestial bodies, under the warmth of our yellow sun, in a sparse sea of stars, in orbit around a supermassive black hole at the center of our luminous galaxy.
When asked his thoughts at the moment he first saw the image of the black hole in M87, Shep replied, ‘We saw something so true.’ And it’s true for all of us.”
(Source: quantamagazine.org, via s-c-i-guy)
Think you’re totally in control of your thoughts? Maybe not as much as you think, according to a new San Francisco State University study that examines how thoughts that lead to actions enter our consciousness.
While we can “decide” to think about certain things, other information — including activities we have learned like counting — can enter our subconscious and cause us to think about something else, whether we want to or not. Psychologists call these dispositions “sets,” explains SF State Associate Professor of Psychology Ezequiel Morsella, one of four authors on a new study that examines how sets influence what we end up thinking about.
Morsella and the other researchers conducted two experiments with SF State students. In the first experiment, 35 students were told beforehand to not count an array of objects presented to them. In 90 percent of the trials, students counted the objects involuntarily. In a second experiment, students were presented with differently colored geometric shapes and given the option of either naming the colors (one set) or counting the shapes (a different set). Even though students chose one over the other, around 40 percent thought about both sets.
“The data support the view that, when one is performing a desired action, conscious thoughts about alternative plans still occupy the mind, often insuppressibly,” said Morsella.
Understanding how sets work could have implications for the way we absorb information — and whether we choose to act or not. We think of our conscious minds as private and insulated from the outside world, says Morsella. Yet our “insulation” may be more permeable than we think.
“Our conscious mind is the totality of our experience, a kind of ‘prime real estate’ in the cognitive apparatus, influencing both decision-making and action,” Morsella said.
The new study demonstrates that it’s actually quite easy to activate sets in people and influence what occupies the brain’s “prime real estate.”
“The research shows that stimuli in the environment are very important in determining what we end up thinking about and that once an action plan is strongly activated its many effects can be difficult to override,” said Morsella.
The study’s findings support Morsella’s passive frame theory, which posits that most thoughts enter our brains as a result of subliminal processes we don’t totally control.
(Source: news.sfsu.edu, via neurosciencestuff)
Dogs are capable of understanding the emotions behind an expression on a human face. For example, if a dog turns its head to the left, it could be picking up that someone is angry, fearful or happy. If there is a look of surprise on a person’s face, dogs tend to turn their head to the right. The heart rates of dogs also go up when they see someone who is having a bad day, say Marcello Siniscalchi, Serenella d'Ingeo and Angelo Quaranta of the University of Bari Aldo Moro in Italy. The study in Springer’s journal Learning & Behavior is the latest to reveal just how connected dogs are with people. The research also provides evidence that dogs use different parts of their brains to process human emotions.
By living in close contact with humans, dogs have developed specific skills that enable them to interact and communicate efficiently with people. Recent studies have shown that the canine brain can pick up on emotional cues contained in a person’s voice, body odour and posture, and read their faces.
In this study, the authors watched what happened when they presented photographs of the same two adults’ faces (a man and a woman) to 26 feeding dogs. The images were placed strategically to the sides of the animals’ line of sight and the photos showed a human face expressing one of the six basic human emotions: anger, fear, happiness, sadness, surprise, disgust or being neutral.
The dogs showed greater response and cardiac activity when shown photographs that expressed arousing emotional states such as anger, fear and happiness. They also took longer to resume feeding after seeing these images. The dogs’ increased heart rate indicated that in these cases they experienced higher levels of stress.
In addition, dogs tended to turn their heads to the left when they saw human faces expressing anger, fear or happiness. The reverse happened when the faces looked surprised, possibly because dogs view it as a non-threatening, relaxed expression. These findings therefore support the existence of an asymmetrical emotional modulation of dogs’ brains to process basic human emotions.
“Clearly arousing, negative emotions seem to be processed by the right hemisphere of a dog’s brain, and more positive emotions by the left side,” says Siniscalchi.
The results support that of other studies done on dogs and other mammals. These show that the right side of the brain plays a more important part in regulating the sympathetic outflow to the heart. This is a fundamental organ for the control of the ‘fight or flight’ behavioural response necessary for survival.
(Source: springer.com, via neurosciencestuff)
Just the two of us: Holding hands can ease pain, sync brainwaves
Reach for the hand of a loved one in pain and not only will your breathing and heart rate synchronize with theirs, your brain wave patterns will couple up too, according to a new study.
The study, by researchers with CU Boulder and University of Haifa and published in the journal Proceedings of the National Academy of Sciences (PNAS), also found that the more empathy a comforting partner feels for a partner in pain, the more their brainwaves fall into sync. And the more those brain waves sync, the more the pain goes away.
“We have developed a lot of ways to communicate in the modern world and we have fewer physical interactions,” said lead author Pavel Goldstein, a postdoctoral pain researcher in the Cognitive and Affective Neuroscience Lab at CU Boulder. “This paper illustrates the power and importance of human touch.”
The study is the latest in a growing body of research exploring a phenomenon known as “interpersonal synchronization,” in which people physiologically mirror the people they are with. It is the first to look at brain wave synchronization in the context of pain, and offers new insight into the role brain-to-brain coupling may play in touch-induced analgesia, or healing touch.
Goldstein came up with the experiment after, during the delivery of his daughter, he discovered that when he held his wife’s hand, it eased her pain.
“I wanted to test it out in the lab: Can one really decrease pain with touch, and if so, how?”
He and his colleagues at University of Haifa recruited 22 heterosexual couples, age 23 to 32 who had been together for at least one year and put them through several two-minute scenarios as electroencephalography (EEG) caps measured their brainwave activity. The scenarios included sitting together not touching; sitting together holding hands; and sitting in separate rooms. Then they repeated the scenarios as the woman was subjected to mild heat pain on her arm.
Merely being in each other’s presence, with or without touch, was associated with some brain wave synchronicity in the alpha mu band, a wavelength associated with focused attention. If they held hands while she was in pain, the coupling increased the most.
Researchers also found that when she was in pain and he couldn’t touch her, the coupling of their brain waves diminished. This matched the findings from a previously published paper from the same experiment which found that heart rate and respiratory synchronization disappeared when the male study participant couldn’t hold her hand to ease her pain.
“It appears that pain totally interrupts this interpersonal synchronization between couples and touch brings it back,” says Goldstein.
Subsequent tests of the male partner’s level of empathy revealed that the more empathetic he was to her pain the more their brain activity synced. The more synchronized their brains, the more her pain subsided.
How exactly could coupling of brain activity with an empathetic partner kill pain? More studies are needed to find out, stressed Goldstein. But he and his co-authors offer a few possible explanations. Empathetic touch can make a person feel understood, which in turn - according to previous studies - could activate pain-killing reward mechanisms in the brain.
“Interpersonal touch may blur the borders between self and other,” the researchers wrote.
The study did not explore whether the same effect would occur with same-sex couples, or what happens in other kinds of relationships. The takeaway for now, Pavel said: Don’t underestimate the power of a hand-hold.
“You may express empathy for a partner’s pain, but without touch it may not be fully communicated,” he said.
this is still the funniest fucking thing i remember being 7 and almost throwing up watching this and now im 20 puking onto my rug
(via pikamans)
