Black Holes Aren’t Black After All, Say Theoretical Physicists
Collapsed stars are just too big to trap light forever
Black holes are a crucial part of the great cultural legacy of Einstein’s theory of general relativity. They have fascinated scientists and laypeople alike since they entered the public consciousness in the latter half of the 20th century.
But it may be time to say goodbye to the notion of regions of space so dense that even light becomes trapped within them. In the last year or so, an intense debate about the paradoxical properties of black holes has left a number of theoretical physicists, including Stephen Hawking, suggesting that black holes might not exist at all, at least not in the form that anyone had imagined.
"A scientific colleague tells me about a recent trip to the New Guinea highlands where she visited a stone age culture hardly contacted by Western civilization. They were ignorant of wristwatches, soft drinks, and frozen food. But they knew about Apollo 11. They knew that humans had walked on the moon. They knew the names of Armstrong and Aldrin and Collins. They wanted to know who was visiting the moon these days." - Carl Sagan
After traveling four days and more than 238,900 miles, the Lunar Module Eagle began its descent to the surface of the Moon. Very early on, however, it became clear to Aldrin and Armstrong that their telemetry was incorrect as they recognized lunar landmarks were being passed too early. At approximately 6,000 miles above the surface, numerous guidance computer program alarms distracted the crew as they communicated with flight controllers. Mission Control engineers soon reassured the Eagle to continue with the descent as it was determined that their system was being overloaded with extra tasks not necessary to land on the Moon. After looking out of the window a few moments later, Armstrong was forced to take semi-manual control as he noticed that the navigational systems were guiding them towards an area comprised of boulders and an uneven landing surface. This manual override would require Aldrin to call out velocity and altitude data before landing fuel ran out. After a somewhat frantic period, the Lunar Module safely landed on the moon on July 20th, 1969 — with about 25 seconds of fuel remaining.
As an estimated 600 million people watched, Neil Armstrong became the first ambassador of the planet Earth to walk on another world. For over 2.5 hours, he and Buzz Aldrin captured the imagination of our species as they performed various scientific and geological experiments. Along with planting an American flag, a commemorative plaque marking this monumental human achievement was mounted to the Apollo 11 Lunar Module — and remains as a relic of humanity’s first journey on the Moon.
“We came in peace for all mankind. That statement really to me was a very symbolic one — not just of our mission, but of the entire Apollo effort.” - Buzz Aldrin, Apollo 11 Lunar Module Pilot
Apollo 11 was arguably our most exciting adventure, and over the span of three years, NASA sent a total of 12 astronauts to explore the Moon. However, not since 1972 have human beings been beyond low-Earth orbit. Please watch our video, The Spirit of Apollo, and consider what raising the NASA budget will once again do for our society.
If anyone else wants to keep tabs on what’s happening in Gaza in real time, here’s a live-stream cam:
I’ll let you know if I find any others.
When people get together in groups, unusual things can happen — both good and bad. Groups create important social institutions that an individual could not achieve alone, but there can be a darker side to such alliances: Belonging to a group makes people more likely to harm others outside the group.
“Although humans exhibit strong preferences for equity and moral prohibitions against harm in many contexts, people’s priorities change when there is an ‘us’ and a ‘them,’” says Rebecca Saxe, an associate professor of cognitive neuroscience at MIT. “A group of people will often engage in actions that are contrary to the private moral standards of each individual in that group, sweeping otherwise decent individuals into ‘mobs’ that commit looting, vandalism, even physical brutality.”
Several factors play into this transformation. When people are in a group, they feel more anonymous, and less likely to be caught doing something wrong. They may also feel a diminished sense of personal responsibility for collective actions.
Saxe and colleagues recently studied a third factor that cognitive scientists believe may be involved in this group dynamic: the hypothesis that when people are in groups, they “lose touch” with their own morals and beliefs, and become more likely to do things that they would normally believe are wrong.
In a study that recently went online in the journal NeuroImage, the researchers measured brain activity in a part of the brain involved in thinking about oneself. They found that in some people, this activity was reduced when the subjects participated in a competition as part of a group, compared with when they competed as individuals. Those people were more likely to harm their competitors than people who did not exhibit this decreased brain activity.
“This process alone does not account for intergroup conflict: Groups also promote anonymity, diminish personal responsibility, and encourage reframing harmful actions as ‘necessary for the greater good.’ Still, these results suggest that at least in some cases, explicitly reflecting on one’s own personal moral standards may help to attenuate the influence of ‘mob mentality,’” says Mina Cikara, a former MIT postdoc and lead author of the NeuroImage paper.
Cikara, who is now an assistant professor at Carnegie Mellon University, started this research project after experiencing the consequences of a “mob mentality”: During a visit to Yankee Stadium, her husband was ceaselessly heckled by Yankees fans for wearing a Red Sox cap. “What I decided to do was take the hat from him, thinking I would be a lesser target by virtue of the fact that I was a woman,” Cikara says. “I was so wrong. I have never been called names like that in my entire life.”
The harassment, which continued throughout the trip back to Manhattan, provoked a strong reaction in Cikara, who isn’t even a Red Sox fan.
“It was a really amazing experience because what I realized was I had gone from being an individual to being seen as a member of ‘Red Sox Nation.’ And the way that people responded to me, and the way I felt myself responding back, had changed, by virtue of this visual cue — the baseball hat,” she says. “Once you start feeling attacked on behalf of your group, however arbitrary, it changes your psychology.”
Cikara, then a third-year graduate student at Princeton University, started to investigate the neural mechanisms behind the group dynamics that produce bad behavior. In the new study, done at MIT, Cikara, Saxe (who is also an associate member of MIT’s McGovern Institute for Brain Research), former Harvard University graduate student Anna Jenkins, and former MIT lab manager Nicholas Dufour focused on a part of the brain called the medial prefrontal cortex. When someone is reflecting on himself or herself, this part of the brain lights up in functional magnetic resonance imaging (fMRI) brain scans.
A couple of weeks before the study participants came in for the experiment, the researchers surveyed each of them about their social-media habits, as well as their moral beliefs and behavior. This allowed the researchers to create individualized statements for each subject that were true for that person — for example, “I have stolen food from shared refrigerators” or “I always apologize after bumping into someone.”
When the subjects arrived at the lab, their brains were scanned as they played a game once on their own and once as part of a team. The purpose of the game was to press a button if they saw a statement related to social media, such as “I have more than 600 Facebook friends.”
The subjects also saw their personalized moral statements mixed in with sentences about social media. Brain scans revealed that when subjects were playing for themselves, the medial prefrontal cortex lit up much more when they read moral statements about themselves than statements about others, consistent with previous findings. However, during the team competition, some people showed a much smaller difference in medial prefrontal cortex activation when they saw the moral statements about themselves compared to those about other people.
Those people also turned out to be much more likely to harm members of the competing group during a task performed after the game. Each subject was asked to select photos that would appear with the published study, from a set of four photos apiece of two teammates and two members of the opposing team. The subjects with suppressed medial prefrontal cortex activity chose the least flattering photos of the opposing team members, but not of their own teammates.
“This is a nice way of using neuroimaging to try to get insight into something that behaviorally has been really hard to explore,” says David Rand, an assistant professor of psychology at Yale University who was not involved in the research. “It’s been hard to get a direct handle on the extent to which people within a group are tapping into their own understanding of things versus the group’s understanding.”
The researchers also found that after the game, people with reduced medial prefrontal cortex activity had more difficulty remembering the moral statements they had heard during the game.
“If you need to encode something with regard to the self and that ability is somehow undermined when you’re competing with a group, then you should have poor memory associated with that reduction in medial prefrontal cortex signal, and that’s exactly what we see,” Cikara says.
Cikara hopes to follow up on these findings to investigate what makes some people more likely to become “lost” in a group than others. She is also interested in studying whether people are slower to recognize themselves or pick themselves out of a photo lineup after being absorbed in a group activity.