smparticle2
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Latest Posts by smparticle2
Unusual Insects Taking Off
What do you do when you’re an insect researcher with a high-speed camera? Why, film all sorts of unusual insects from your backyard as they take off and fly! (Image and video credit: Ant Lab/A. Smith; via Colossal) Read the full article
To keep pain in check, count down
Diverse cognitive strategies affect our perception of pain. Studies by LMU neuroscientist Enrico Schulz and colleagues have linked the phenomenon to the coordinated activity of neural circuits located in different brain areas.
Is the heat still bearable, or should I take my hand off the hotplate? Before the brain can react appropriately to pain, it must evaluate and integrate sensory, cognitive and emotional factors that modulate the perception and processing of the sensation itself. This task requires the exchange of information between different regions of the brain. New studies have confirmed that there is a link between the subjective experience of pain and the relative levels of neural activity in functional structures in various sectors of the brain. However, these investigations have been carried out primarily in contexts in which the perception of pain was intensified either by emotional factors or by consciously focusing attention on the painful stimulus. Now, LMU neuroscientist Enrico Schulz, in collaboration with colleagues at the University of Oxford, has asked how cognitive strategies that affect one’s subjective perception of pain influence the patterns of neural activity in the brain.
In the study, 20 experimental subjects were exposed to a painful cold stimulus. They were asked to adopt one of three approaches to attenuating the pain: (a) counting down from 1000 in steps of 7, (b) thinking of something pleasant or beautiful, and (c) persuading themselves – by means of autosuggestion – that the stimulus was not really that bad. During the experimental sessions, the subjects were hooked up to a 7T magnetic resonance imaging (MRI) scanner to visualise the patterns of neural activity in the brain, which were later analysed in detail.
In order to assess the efficacy of the different coping strategies, participants were also asked to evaluate the subjective intensity of the pain on a scale of 0 to 100. The results revealed that the countdown strategy was the most effective of the three methods. “This task obviously requires such a high level of concentration that it distracts the subject’s attention significantly from the sensation of pain. In fact some of our subjects managed to reduce the perceived intensity of pain by 50%,” says Schulz. “One participant later reported that she had successfully adopted the strategy during the most painful phase of childbirth.”
In a previous paper published in the journal Cortex in 2019, the same team had already shown that all three strategies help to attenuate the perception of pain, and that each strategy evoked a different pattern of neural activity. In the new study, Schulz and his collaborators carried out a more detailed analysis of the MRI scans, for which they divided the brain into 360 regions. “Our aim was to determine which areas in the brain must work together in order to successfully reduce the perceived intensity of the pain,” Schulz explains. “Interestingly, no single region or network that is activated by all three strategies could be identified. Instead, under each experimental condition, neural circuits in different brain regions act in concert to varying extents.”
The attenuation of pain is clearly a highly complex process, which requires a cooperative response that involves many regions distributed throughout the brain. Analysis of the response to the countdown technique revealed close coordination between different parts of the insular cortex, among other patterns. The imaginal distraction method, i.e. calling something picturesque or otherwise pleasing to mind, works only when it evokes intensive flows of information between the frontal lobes. Since these structures are known to be important control centres in the brain, the authors believe that engagement of the imaginative faculty may require a greater degree of control, because the brain needs to search through more ‘compartments’ – to find the right memory traces, for instance. Comparatively speaking, counting backwards stepwise – even in such awkward steps – is likely to be a more highly constrained task. “To cope with pain, the brain makes use of a recipe that also works well in other contexts,” says Anne Stankewitz, a co-author of the new paper: “success depends on effective teamwork.” Her team now plans to test whether their latest results can be usefully applied to patients with chronic pain.
How to Build a More Resilient Brain
Your executive control center has helped your mental health survive the pandemic thus far. Here’s how to strengthen it for the future.
A Lot has been written (including by this reporter) about the mental health toll of the pandemic, and for good reason. The latest numbers from the National Pulse Survey, a weekly mental health screen conducted by the National Center for Health Statistics and the U.S. Census Bureau, estimate that nearly 40% of Americans are currently experiencing symptoms of either anxiety or depression, a 50% increase over pre-pandemic times.
In some ways, though, it’s surprising that this number isn’t even higher given the stress, trauma, loss, and loneliness of the past year. The vast majority of people have spent the last 12 months locked inside their homes, terrified of catching a deadly virus, and trying not to kill their spouse, children, or roommates — in more ways than one. People living alone have marked births, deaths, graduations, and layoffs with no one to hug but our pillows. And yet the majority of Americans seem to have made it through with their mental health still intact. How?
If the root of much of the mental illness that’s emerged during the pandemic is unrelenting chronic stress, the opposite is also true: Resilience to trauma lies in the ability to adapt positively to stress.
“Resilience is really this ability to bounce back in the face of adversity,” says Steven Southwick, MD, an emeritus professor of psychiatry at Yale University. “From a biological standpoint, it’s the ability to modulate and hopefully constructively harness the stress response.”
In the brain, resilience means protecting against many stress-induced changes, particularly in regard to the size, activity, and connectivity of the amygdala, hippocampus, and prefrontal cortex — the brain’s fear, memory and mood, and executive control centers, respectively.
How does one prevent these neural changes? Some of it is genetic — gene variants affect the levels and activity of circulating stress hormones, as well as the hormones that counteract them. But perhaps more importantly, behavioral interventions can also build resilience and serve as a buffer against stress for those important brain systems.
“Resilience is not an on-off switch,” says Deborah Marin, MD, a professor of psychiatry and director of the Mount Sinai Center for Stress, Resilience, and Personal Growth, which was launched in 2020 to help health care workers cope with pandemic stress. “Some people may be born with more resilience, there may be some genetic component there, but there’s a lot of environmental interaction at play — everything from poverty, access to health care, education, community support.”
Southwick has been studying resilience for decades, interviewing countless combat veterans and other trauma survivors with and without post-traumatic stress disorder. Based on these conversations, he, along with collaborator Dennis Charney, MD, dean of the Icahn School of Medicine at Mount Sinai, developed a rubric of 10 behaviors and traits that contribute to people’s resilience.
“We and many others believe that a big part of resilience is knowing how to regulate the stress response,” Southwick says. “Resilience, in many ways, is a set of skills that can be learned, and pretty much any of us can, to some significant degree, learn these skills.”
Several of these skills, along with a few other strategies, are outlined below, but the basic premise is to engage in activities that strengthen your brain’s executive control center (the prefrontal cortex) so that it doesn’t get overrun by the brain’s fear and arousal center (the amygdala) during times of stress.
Optimism and cognitive flexibility
Negative emotions — fear, anger, disgust — prepare the body to fight or to flee through activation of the sympathetic nervous system, which narrows people’s focus and restricts our behaviors to those actions. Positive emotions, on the other hand, lower arousal levels, broaden attention, and increase creativity, which helps people be more flexible in their thoughts and behaviors.
While some people are naturally more optimistic than others, you can train yourself to think more positively through the skill of cognitive reappraisal. During times of stress, this means seeing a threat not as an insurmountable problem but as a challenge to be solved. For example, many people have tried to see the bright side of the extra time spent at home during the pandemic, viewing it as an opportunity to learn a new skill or pick an old hobby back up. It doesn’t change the outcome of the pandemic, but it does make the best of a bad situation. Instead of being bored at home and lamenting the loss of your social life, you might have learned a new language or started playing the guitar again now that you have more free time.
Southwick calls this type of reframing “realistic optimism.” “The realistic optimist basically has a future-oriented attitude and the belief that things will turn out okay,” he says. “The realistic optimist actually tends to see as much of the negative information that a more pessimistic person might, but they don’t remain focused or glued to this negative perception, and they have the ability to rapidly disengage, particularly from those negative perceptions that are not solvable. And they tend to be pretty darn good at turning their attention to solvable problems.”
This type of cognitive flexibility is associated with activity in the prefrontal cortex, and stronger executive control from the region, particularly over the threat response triggered by the amygdala, is important for not letting stress and anxiety run wild. Chronic stress can damage the connection between the prefrontal cortex and the amygdala, taking the brakes off of the brain’s alarm system and potentially leading to anxiety and PTSD. Having a stronger prefrontal network that can protect against this negative effect of chronic stress may help support resilience.
Meditation
Another resilience strategy that exercises the prefrontal cortex is meditation, which can largely be thought of as a practice of attention. Every time your mind wanders while you meditate, it requires cognitive control exerted by your prefrontal cortex to bring it back to focusing on your breath. And just like working out your biceps will make them stronger, so will working out a brain region in this way. Activate an area enough times, and your neurons start to wire new connections there, making the thought process more automatic.
“Our brain structure is changing from moment to moment. It’s much more plastic than we ever thought; it’s like a muscle, you can strengthen it or weaken it,” Southwick says. “It’s called ‘use-dependent neuroplasticity’ — the more I practice accurately, the more my brain will respond, and it will be less effortful in the future.”
On a more immediate time scale, taking a few deep breaths in a moment of stress can turn on the parasympathetic nervous system — the counterpart to the fight-or-flight response — and start to undo some of the body’s stress response. Deep breathing also lowers levels of noradrenaline, a brain chemical that increases arousal, which is also released in response to stress.
Stress inoculation and facing your fears
You can also train your brain to handle stress better through exposure to smaller stressors, particularly early in life. Scientists call this stress inoculation: Just like exposure to a tiny amount of a virus will educate your immune system on how to respond to it better next time, learning how to deal with mild stressors teaches your brain how to handle bigger stressors later.
“There’s some evidence that exposure to chronic stress early in life can actually make you resilient to stress later in life. Like that initial experience changes your resilience capacity,” says James Herman, PhD, a professor of psychiatry and behavioral neuroscience at the University of Cincinnati and director of the Laboratory of Stress Neurobiology. “You have all of these stressors that are present all the time, but if you’re used to them, you become resilient to them. They can help you later on in life, and they might even be beneficial.”
Part of this process is facing your fears, which, again, involves the prefrontal cortex overcoming the alarm bells ringing from the amygdala.
“Fear is completely natural. It’s, in many ways, a signal or something that is warning us, it’s a guide,” Southwick says. “But if you allow fear to hang around too long, it might evolve into panic. And when someone’s panicked, there tends to be a flooding of noradrenaline to the prefrontal cortex, which has a tendency to take the prefrontal cortex offline, which means that I’m now operating much more via my amygdala because my prefrontal cortex is no longer inhibiting the amygdala to the same degree that it normally does.”
Practicing facing your fears in lower stakes situations teaches your brain how to maintain control during stressful scenarios so that fear doesn’t turn into panic and spiral out of control. This isn’t something you can magically do right now to help you deal with the rest of the pandemic, but as things quiet down, consider it to help build your resilience for the future. Maybe challenge yourself to sign up for a class you’ve been intimidated to take or speak up in a meeting if normally you stay silent. In clinical settings, facing your fears is called exposure therapy and is used to treat anxiety disorders, particularly phobias and PTSD. With it, you gradually build up your exposure to the thing you’re afraid of while practicing relaxation techniques to prevent your amygdala and sympathetic nervous system from running out of control. The goal is ultimately to desensitize yourself to your fear, but the therapy can help you learn how to remain calm in any stressful situation.
Exercise and sleep
Maintaining good physical health is also critical for your mental capabilities. If you’ve heard it once, you’ve heard it a million times: Exercise is one of the best things you can do for your brain. Physical activity helps the brain grow new connections between brain cells and maybe even new neurons themselves. Much of this growth takes place in, you guessed it, the prefrontal cortex, as well as in the hippocampus, an area involved in regulating mood and memory. The new growth can help offset the loss of connections that occurs in those regions with chronic stress. Exercise also boosts levels of the feel-good neurochemicals dopamine and serotonin, both of which are depleted in people with depression.
On the flip side, lack of sleep can exacerbate many of the problems seen in the brain with chronic stress. One study from 2019 showed that sleep deprivation can cause a decrease in activity in the prefrontal cortex, while the amygdala becomes more reactive after a poor night’s sleep. This shift in activity correlated with people’s feelings of anxiety.
Social support
A crucial resilience strengthener experts bring up again and again is social support. In many ways, social connection counters the stress response from the sympathetic nervous system. Being with a friend or family member, especially during a stressful situation, dampens the activity of noradrenaline and cortisol. It also activates the reward center of the brain, providing a boost in dopamine.
“Human beings have many, many sources of resilience, but I think the most important is our relationships and social support and the way that we can help each other,” says Ann Masten, PhD, a psychologist and professor of child development at the University of Minnesota. “Feelings of belonging and support are powerful protective factors for many different kinds of situations.”
This aspect of resilience can be tricky during a pandemic when physical distancing from people outside of your household is necessary for safety. However, just knowing you have people in your corner who love and support you‚ even if you can’t currently be with them, still has a protective effect.
“The perception that you have others you can count on, even if they’re not presently there, has been shown to buffer some of the physiological effects [of stress],” says Julianne Holt-Lunstad, PhD, a professor of psychology and neuroscience at Brigham Young University. “[We’ve shown that] people who simply have more supportive people in their social network are less cardiovascularly reactive to a stressor task. Other studies have shown that even just thinking about someone who is very supportive is enough to buffer some of those physiological responses.”
Purpose and self-efficacy
Another key protective factor is having a sense of purpose and not feeling like you’re helpless in the stressful situation you’re facing. Similar to cognitive reappraisal, viewing the stressful scenario as an opportunity and that you have something to contribute provides a powerful sense of self-efficacy, which can prevent people from despairing. Scientists have known for decades that a feeling of helplessness is strongly tied to the development of depression, while having a sense of control is linked to resilience.
This factor is particularly relevant for frontline health care workers who have seen some of the greatest trauma during the pandemic. While roughly half of doctors, nurses, and other hospital staff are understandably experiencing depression, PTSD, and anxiety as a consequence, the other half have remained resilient. One reason may be because they can directly impact the course of the pandemic and have the ability to save people’s lives.
“Even if you’re working really hard, [if you’re] able to feel that your work has a sense of meaning and purpose, and that sense of meaning and purpose is aligned and shared by your colleagues and your institution, then you can tolerate an incredible amount of stress,” says Ronald Epstein, MD, a professor of family medicine at the University of Rochester Medical Center who has studied physician burnout.
If you’re not a frontline worker, it may be a little harder to feel like you have a role to play or any control over the situation. However, just because you can’t change the larger course of the pandemic doesn’t mean that you can’t take steps to control your own risk and the day-to-day unfolding of your life within it. Staying home for a year and forgoing social interactions and a normal life has been hard on everyone, but keep in mind that you’re doing it for a really important purpose — you’re potentially saving a life, maybe even your own. Every time you wear a mask, you’re taking your health into your own hands. Even just making and sticking to a daily schedule that slots in exercise or meditation can give you back some semblance of control.
“The pandemic and catastrophes like this can give you a sense that everything is out of control,” Masten says. “We don’t have a lot of control over what’s happening at a global level, but in our own lives, day by day, we can plan, take things one step at a time, and we can give ourselves a sense of accomplishment just in daily planning and setting manageable goals that provide us with a sense of self-efficacy.”
Preparation
Another reason that there isn’t more mental illness among health care workers is that they’ve trained for these types of situations. If someone was pulled off the street to work a day in the intensive care unit, their stress levels would go through the roof and they could very quickly become overwhelmed by the pressure and high stakes of the work, not to mention being exposed to so much suffering and death. But health care workers deal with this every day as part of their jobs.
Notably, many of the health care workers who did develop symptoms of depression or anxiety said that they had been transferred to a different department during the pandemic. In other words, they wound up doing a job that they had not been trained for. For example, nurses and doctors who normally work in rehabilitation were redeployed to the intensive care unit, where they saw much more death than they were used to. Some health care workers had to use ventilators for the first time since graduating from medical school, a skill they may not have felt as competent at.
“Redeployment was definitely a factor that contributed to having more symptomatology, either depression or anxiety or PTSD,” says Marin, the Mount Sinai psychiatrist who directs the Center for Stress, Resilience, and Personal Growth. “That probably is because when you’re redeployed, you’re doing a new skill set that you haven’t been doing or you’re used to, and you’re removed from an environment that may have your own community resilience.”
Virtually no one was prepared for the pandemic and all that it threw at us (how could you be?), and many people — and systems — broke down as a result. But there are at least lessons to be learned should disaster strike again in the future. Perhaps you still have a cache of beans and toilet paper stocked away that can give you a little peace of mind if there’s another stress on grocery store chains. Maybe you finally got to know your neighbors, and now you know who on your street might need a little more help getting groceries, or who has kids around the same age as yours. Or if your pandemic hobby was gardening or hiking or spending more time outdoors, maybe you developed some new survival or self-sufficiency skills you can keep in your back pocket to feel a little more competent and confident going forward.
Hopefully, government and institutions have also learned how to better support under-resourced groups, including parents, the elderly, and the unemployed. “I think this pandemic is a wake-up call for a lot of disasters that probably are going to come in the future, either other pandemics or climate disasters related to weather,” says Masten. “I think we need to think about how do we organize work and cities, and how do we support families with enough child care and financial support to give us flexibility?” These are big complicated questions, but many organizations, particularly those focused on public health, are starting to ask them, which is an important first step.
The past year has turned our lives upside down. People have lost loved ones, jobs, social lives, and any sense of normalcy. It’s entirely understandable, and even expected, that living through a year of a deadly pandemic would take a toll on mental health. But it’s also important to remember that depression, anxiety, and PTSD aren’t an inevitable result, although it does take some work to protect against them.
“As humans, we have this immense capacity to get through transient stresses,” Epstein says. “That’s why humans have survived — we’re not physically strong creatures, and we don’t have a lot of natural protection, so we rely on our ability to adapt to different circumstances.”
Epstein, who leads resilience workshops for health care workers, advises people to embed small habits into their day that can help relieve their stress, at least temporarily. This could be a five-minute meditation or breathing exercise when you feel yourself getting worked up; a quick walk around the block every day at lunch; a standing text or phone check-in with a friend; or a daily gratitude list you make at bedtime.
“Try to find something really, really small that you can do every day that will improve your own sense of positive potential, gratitude, community presence, your ability to be attentive — something that will actually make you feel a bit more aware and in control of your own inner life,” he says. “There’s a whole catalog of things that people can do that are awfully simple, easily accomplished, and doable, it’s just a question of reminding yourself and making that commitment.”
It’s also important to keep in mind that you don’t have to go through this alone. Again, social support is one of the most beneficial factors when it comes to resilience, so reach out to a friend or colleague if you’re struggling — they probably need to talk just as much as you do.
“Yes, we each can take actions, we each can be optimistic or practice meditation by ourselves to help deal with trauma. But a lot of the capacity for human resilience comes from the ways we interact with each other in relationships, in our friendships, in our congregating in cultural practices,” says Masten. “Human beings have a lot of capabilities to come up with ideas and share them of how to deal with whatever current issues are coming up with the pandemic or other kinds of struggles.”
She continues, “We’re great at ingenuity, and you can see […] as the challenges unfold, the mobilization unfolding at the same time. We respond when we’re challenged.”
By Dana G Smith Ph.D., (Medium). Illustration: Carolyn Figel
Spinal Stimulators Repurposed to Restore Touch in Lost Limb
Imagine tying your shoes or taking a sip of coffee or cracking an egg but without any feeling in your hand. That’s life for users of even the most advanced prosthetic arms.
Although it’s possible to simulate touch by stimulating the remaining nerves in the stump after an amputation, such a surgery is highly complex and individualized. But according to a new study from the University of Pittsburgh’s Rehab Neural Engineering Labs, spinal cord stimulators commonly used to relieve chronic pain could provide a straightforward and universal method for adding sensory feedback to a prosthetic arm.
For this study, published in eLife, four amputees received spinal stimulators, which, when turned on, create the illusion of sensations in the missing arm.
“What’s unique about this work is that we’re using devices that are already implanted in 50,000 people a year for pain — physicians in every major medical center across the country know how to do these surgical procedures — and we get similar results to highly specialized devices and procedures,” said study senior author Lee Fisher, Ph.D., assistant professor of physical medicine and rehabilitation, University of Pittsburgh School of Medicine.
The strings of implanted spinal electrodes, which Fisher describes as about the size and shape of “fat spaghetti noodles,” run along the spinal cord, where they sit slightly to one side, atop the same nerve roots that would normally transmit sensations from the arm. Since it’s a spinal cord implant, even a person with a shoulder-level amputation can use this device
Fisher’s team sent electrical pulses through different spots in the implanted electrodes, one at a time, while participants used a tablet to report what they were feeling and where.
All the participants experienced sensations somewhere on their missing arm or hand, and they indicated the extent of the area affected by drawing on a blank human form. Three participants reported feelings localized to a single finger or part of the palm.
“I was pretty surprised at how small the area of these sensations were that people were reporting,” Fisher said. “That’s important because we want to generate sensations only where the prosthetic limb is making contact with objects.”
When asked to describe not just where but how the stimulation felt, all four participants reported feeling natural sensations, such as touch and pressure, though these feelings often were mixed with decidedly artificial sensations, such as tingling, buzzing or prickling.
Although some degree of electrode migration is inevitable in the first few days after the leads are implanted, Fisher’s team found that the electrodes, and the sensations they generated, mostly stayed put across the month-long duration of the experiment. That’s important for the ultimate goal of creating a prosthetic arm that provides sensory feedback to the user.
“Stability of these devices is really critical,” Fisher said. “If the electrodes are moving around, that’s going to change what a person feels when we stimulate.”
The next big challenges are to design spinal stimulators that can be fully implanted rather than connecting to a stimulator outside the body and to demonstrate that the sensory feedback can help to improve the control of a prosthetic hand during functional tasks like tying shoes or holding an egg without accidentally crushing it. Shrinking the size of the contacts — the parts of the electrode where current comes out — is another priority. That might allow users to experience even more localized sensations.
“Our goal here wasn’t to develop the final device that someone would use permanently,” Fisher said. “Mostly we wanted to demonstrate the possibility that something like this could work.”
Seeing stable topology using instabilities
We are most familiar with the four conventional phases of matter: solid, liquid, gas, and plasma. Changes between two phases, known as phase transitions, are marked by abrupt changes in material properties such as density. In recent decades a wide body of physics research has been devoted to discovering new unconventional phases of matter, which typically emerge at ultra-low temperatures or in specially-structured materials. Exotic “topological” phases exhibit properties that can only change in a quantized (stepwise) manner, making them intrinsically robust against impurities and defects.
In addition to topological states of matter, topological phases of light can emerge in certain optical systems such as photonic crystals and optical waveguide arrays. Topological states of light are of interest as they can form the basis for future energy-efficient light-based communication technologies such as lasers and integrated optical circuits.
However, at high intensities light can modify the properties of the underlying material. One example of such a phenomenon is the damage that the high-power lasers can inflict on the mirrors and lenses. This in turn affects the propagation of the light, forming a nonlinear feedback loop. Nonlinear optical effects are essential for the operation of certain devices such as lasers, but they can lead to the emergence of disorder from order in a process known as modulational instability, as is shown in Figure 1. Understanding the interplay between topology and nonlinearity is a fascinating subject of ongoing research.
Read more.
5 Cookie Pro Tips from TED-Ed (and Science)
1. Cookies are for everyone. But everyone has cookie preferences. When you slide that cookie tray into the oven, you’re setting off a series of chemical reactions that transform one substance - dough - into another - cookies! The better you understand ‘Cookie Chemistry’, the better equipped you will be to create the cookies you crave.
2. Lots goes on in that oven, but one of science’s tastiest reactions occurs at 310º. Maillard reactions result when proteins and sugars breakdown and rearrange themselves into ring like structures which reflect light in a way that gives foods their distinctive, rich brown color. As this reaction occurs, it produces a range of flavor and aroma compounds, which also react with each other forming even more complex tastes and smells.
3. The final reaction to take place inside your cookie is caramelization and it occurs at 356º. Caramelization is what happens when sugar molecules breakdown under high heat, forming the sweet, nutty and slightly bitter flavor compounds that define…caramel! So if your recipe calls for a 350º oven - caramelization will never happen.
So, if your ideal cookie is barely browned - 310º will do. But if you want a tanned, caramelized cookie, crank up the heat! Caramelization continues up to 390º degrees.
4. No need to check that oven like a fiend. You don’t even really need a kitchen timer - when you smell the nutty, toasty aromas of the Maillard reaction and caramelization, your cookies are ready!
5. Baking is chemistry, friends! That’s right - PURE. SCIENCE. Check carefully before altering those recipes - chances are some of those ingredients and quantities are there for a reason.
Curious what else happens in that oven? Check out the TED-Ed Lesson The chemistry of cookies - Stephanie Warren
Animation by Augenblick Studios
“That is the one unforgivable sin in any society. Be different and be damned!” -Rhett Butler
How we determine who’s to blame
How do people assign a cause to events they witness? Some philosophers have suggested that people determine responsibility for a particular outcome by imagining what would have happened if a suspected cause had not intervened.
This kind of reasoning, known as counterfactual simulation, is believed to occur in many situations. For example, soccer referees deciding whether a player should be credited with an “own goal” — a goal accidentally scored for the opposing team — must try to determine what would have happened had the player not touched the ball.
This process can be conscious, as in the soccer example, or unconscious, so that we are not even aware we are doing it. Using technology that tracks eye movements, cognitive scientists at MIT have now obtained the first direct evidence that people unconsciously use counterfactual simulation to imagine how a situation could have played out differently.
“This is the first time that we or anybody have been able to see those simulations happening online, to count how many a person is making, and show the correlation between those simulations and their judgments,” says Josh Tenenbaum, a professor in MIT’s Department of Brain and Cognitive Sciences, a member of MIT’s Computer Science and Artificial Intelligence Laboratory, and the senior author of the new study.
Tobias Gerstenberg, a postdoc at MIT who will be joining Stanford’s Psychology Department as an assistant professor next year, is the lead author of the paper, which appears in the Oct. 17 issue of Psychological Science. Other authors of the paper are MIT postdoc Matthew Peterson, Stanford University Associate Professor Noah Goodman, and University College London Professor David Lagnado.
Follow the ball
Until now, studies of counterfactual simulation could only use reports from people describing how they made judgments about responsibility, which offered only indirect evidence of how their minds were working.
Gerstenberg, Tenenbaum, and their colleagues set out to find more direct evidence by tracking people’s eye movements as they watched two billiard balls collide. The researchers created 18 videos showing different possible outcomes of the collisions. In some cases, the collision knocked one of the balls through a gate; in others, it prevented the ball from doing so.
Before watching the videos, some participants were told that they would be asked to rate how strongly they agreed with statements related to ball A’s effect on ball B, such as, “Ball A caused ball B to go through the gate.” Other participants were asked simply what the outcome of the collision was.
As the subjects watched the videos, the researchers were able to track their eye movements using an infrared light that reflects off the pupil and reveals where the eye is looking. This allowed the researchers, for the first time, to gain a window into how the mind imagines possible outcomes that did not occur.
“What’s really cool about eye tracking is it lets you see things that you’re not consciously aware of,” Tenenbaum says. “When psychologists and philosophers have proposed the idea of counterfactual simulation, they haven’t necessarily meant that you do this consciously. It’s something going on behind the surface, and eye tracking is able to reveal that.”
The researchers found that when participants were asked questions about ball A’s effect on the path of ball B, their eyes followed the course that ball B would have taken had ball A not interfered. Furthermore, the more uncertainty there was as to whether ball A had an effect on the outcome, the more often participants looked toward ball B’s imaginary trajectory.
“It’s in the close cases where you see the most counterfactual looks. They’re using those looks to resolve the uncertainty,” Tenenbaum says.
Participants who were asked only what the actual outcome had been did not perform the same eye movements along ball B’s alternative pathway.
“The idea that causality is based on counterfactual thinking is an idea that has been around for a long time, but direct evidence is largely lacking,” says Phillip Wolff, an associate professor of psychology at Emory University, who was not involved in the research. “This study offers more direct evidence for that view.”
(Image caption: In this video, two participants’ eye-movements are tracked while they watch a video clip. The blue dot indicates where each participant is looking on the screen. The participant on the left was asked to judge whether they thought that ball B went through the middle of the gate. Participants asked this question mostly looked at the balls and tried to predict where ball B would go. The participant on the right was asked to judge whether ball A caused ball B to go through the gate. Participants asked this question tried to simulate where ball B would have gone if ball A hadn’t been present in the scene. Credit: Tobias Gerstenberg)
How people think
The researchers are now using this approach to study more complex situations in which people use counterfactual simulation to make judgments of causality.
“We think this process of counterfactual simulation is really pervasive,” Gerstenberg says. “In many cases it may not be supported by eye movements, because there are many kinds of abstract counterfactual thinking that we just do in our mind. But the billiard-ball collisions lead to a particular kind of counterfactual simulation where we can see it.”
One example the researchers are studying is the following: Imagine ball C is headed for the gate, while balls A and B each head toward C. Either one could knock C off course, but A gets there first. Is B off the hook, or should it still bear some responsibility for the outcome?
“Part of what we are trying to do with this work is get a little bit more clarity on how people deal with these complex cases. In an ideal world, the work we’re doing can inform the notions of causality that are used in the law,” Gerstenberg says. “There is quite a bit of interaction between computer science, psychology, and legal science. We’re all in the same game of trying to understand how people think about causation.”
The Myth of Prometheus
Before the creation of humanity, the Greek gods won a great battle against a race of giants called the Titans. Most Titans were destroyed or driven to the eternal hell of Tartarus. But the Titan Prometheus, whose name means foresight, persuaded his brother Epimetheus to fight with him on the side of the gods.
As thanks, Zeus entrusted the brothers with the task of creating all living things. Epimetheus was to distribute the gifts of the gods among the creatures. To some, he gave flight; to others, the ability to move through water or race through grass. He gave the beasts glittering scales, soft fur, and sharp claws.
Meanwhile, Prometheus shaped the first humans out of mud. He formed them in the image of the gods, but Zeus decreed they were too remain mortal and worship the inhabitants of Mount Olympus from below. Zeus deemed humans subservient creatures vulnerable to the elements and dependent on the gods for protection. However, Prometheus envisioned his crude creations with a greater purpose. So when Zeus asked him to decide how sacrifices would be made, the wily Prometheus planned a trick that would give humans some advantage. He killed a bull and divided it into two parts to present to Zeus. On one side, he concealed the succulent flesh and skin under the unappealing belly of the animal. On the other, he hid the bones under a thick layer of fat. When Zeus chose the seemingly best portion for himself, he was outraged at Prometheus’s deception.
Fuming, Zeus forbade the use of fire on Earth, whether to cook meat or for any other purpose. But Prometheus refused to see his creations denied this resource. And so, he scaled Mount Olympus to steal fire from the workshop of Hephaestus and Athena. He hid the flames in a hollow fennel stalk and brought it safely down to the people. This gave them the power to harness nature for their own benefit and ultimately dominate the natural order.
With fire, humans could care for themselves with food and warmth. But they could also forge weapons and wage war. Prometheus’s flames acted as a catalyst for the rapid progression of civilization. When Zeus looked down at this scene, he realized what had happened. Prometheus had once again wounded his pride and subverted his authority.
Furious, Zeus imposed a brutal punishment. Prometheus was to be chained to a cliff for eternity. Each day, he would be visited by a vulture who would tear out his liver and each night his liver would grow back to be attacked again in the morning. Although Prometheus remained in perpetual agony, he never expressed regret at his act of rebellion. His resilience in the face of oppression made him a beloved figure in mythology. He was also celebrated for his mischievous and inquisitive spirit, and for the knowledge, progress, and power he brought to human hands.
He’s also a recurring figure in art and literature. In Percy Bysshe Shelley’s lyrical drama “Prometheus Unbound,” the author imagines Prometheus as a romantic hero who escapes and continues to spread empathy and knowledge. Of his protagonist, Shelley wrote, “Prometheus is the type of the highest perfection of moral and intellectual nature, impelled by the purest and the truest motives to the best and noblest ends.” His wife Mary envisaged Prometheus as a more cautionary figure and subtitled her novel “Frankenstein: The Modern Prometheus.” This suggests the damage of corrupting the natural order and remains relevant to the ethical questions surrounding science and technology today. As hero, rebel, or trickster, Prometheus remains a symbol of our capacity to capture the powers of nature, and ultimately, he reminds us of the potential of individual acts to ignite the world.
From the TED-Ed Lesson The myth of Prometheus - Iseult Gillespie
Animation by Léa Krawczyk ( @lea–krawczyk )
Mathematical processes in the brain influenced by language
People can intuitively recognise small numbers up to four, however when calculating they are dependent on the assistance of language. In this respect, the fascinating research question ensues: how do multilingual people solve arithmetical tasks presented to them in different languages of which they have a very good command? This situation is the rule for students with Luxembourgish as their mother tongue, who were first educated in German and then attended further schooling in French as teaching language.
This question was investigated by a research team led by Dr Amandine Van Rinsveld and Professor Christine Schiltz from the Cognitive Science and Assessment Institute (COSA) at the University of Luxembourg. For the purpose of the study, the researchers recruited subjects with Luxembourgish as their mother tongue, who successfully completed their schooling in the Grand Duchy of Luxembourg and continued their academic studies in francophone universities in Belgium. Thus, the study subjects mastered both the German and French languages perfectly. As Luxembourger students, they took maths classes in primary schools in German and then in secondary schools in French.
In two separate test situations, the study participants had to solve very simple and a bit more complex addition tasks, both in German and French. In the tests, it became evident that the subjects were able to solve simple addition tasks equally well in both languages. However, for complex addition in French, they required more time than with an identical task in German. Moreover, they made more errors when attempting to solve tasks in French.
The bilingual brain calculates differently depending on the language used
During the tests, functional magnetic resonance imaging (fMRI) was used to measure the brain activity of the subjects. This demonstrated that, depending on the language used, different brain regions were activated.
With addition tasks in German, a small speech region in the left temporal lobe was activated. When solving complex calculatory tasks in French, additional parts of the subjects’ brains responsible for processing visual information, were involved. During the complex calculations in French, the subjects additionally fell back on figurative thinking. The experiments do not provide any evidence that the subjects translated the tasks they were confronted with from French into German, in order to solve the problem.
While the test subjects were able to solve German tasks on the basis of the classic, familiar numerical-verbal brain areas, this system proved not to be sufficiently viable in the second language of instruction, in this case French. To solve the arithmetic tasks in French, the test subjects had to systematically fall back on other thought processes, not observed so far in monolingual persons.
The study documents for the first time, with the help of brain activity measurements and imaging techniques, the demonstrable cognitive “extra effort” required for solving arithmetic tasks in the second language of instruction. The research results clearly show that calculatory processes are directly affected by language.
For the Luxembourg school system, these findings are somewhat groundbreaking, given the well-known fact that, upon moving from primary school to secondary school, the language of instruction for math changes from the primary teaching language (German) to the secondary teaching language (French). This is compounded by the fact that a much smaller proportion of today’s student population in the Grand Duchy has a German-speaking background compared to previous generations, and it can be assumed that they already have to perform visual translation tasks in German-speaking math classes in primary school.
SoCal, home.
The Beauty of Webb Telescope’s Mirrors
The James Webb Space Telescope’s gold-plated, beryllium mirrors are beautiful feats of engineering. From the 18 hexagonal primary mirror segments, to the perfectly circular secondary mirror, and even the slightly trapezoidal tertiary mirror and the intricate fine-steering mirror, each reflector went through a rigorous refinement process before it was ready to mount on the telescope. This flawless formation process was critical for Webb, which will use the mirrors to peer far back in time to capture the light from the first stars and galaxies.
The James Webb Space Telescope, or Webb, is our upcoming infrared space observatory, which will launch in 2019. It will spy the first luminous objects that formed in the universe and shed light on how galaxies evolve, how stars and planetary systems are born, and how life could form on other planets.
A polish and shine that would make your car jealous
All of the Webb telescope’s mirrors were polished to accuracies of approximately one millionth of an inch. The beryllium mirrors were polished at room temperature with slight imperfections, so as they change shape ever so slightly while cooling to their operating temperatures in space, they achieve their perfect shape for operations.
The Midas touch
Engineers used a process called vacuum vapor deposition to coat Webb’s mirrors with an ultra-thin layer of gold. Each mirror only required about 3 grams (about 0.11 ounces) of gold. It only took about a golf ball-sized amount of gold to paint the entire main mirror!
Before the deposition process began, engineers had to be absolutely sure the mirror surfaces were free from contaminants.
The engineers thoroughly wiped down each mirror, then checked it in low light conditions to ensure there was no residue on the surface.
Inside the vacuum deposition chamber, the tiny amount of gold is turned into a vapor and deposited to cover the entire surface of each mirror.
Primary, secondary, and tertiary mirrors, oh my!
Each of Webb’s primary mirror segments is hexagonally shaped. The entire 6.5-meter (21.3-foot) primary mirror is slightly curved (concave), so each approximately 1.3-meter (4.3-foot) piece has a slight curve to it.
Those curves repeat themselves among the segments, so there are only three different shapes — 6 of each type. In the image below, those different shapes are labeled as A, B, and C.
Webb’s perfectly circular secondary mirror captures light from the 18 primary mirror segments and relays those images to the telescope’s tertiary mirror.
The secondary mirror is convex, so the reflective surface bulges toward a light source. It looks much like a curved mirror that you see on the wall near the exit of a parking garage that lets motorists see around a corner.
Webb’s trapezoidal tertiary mirror captures light from the secondary mirror and relays it to the fine-steering mirror and science instruments. The tertiary mirror sits at the center of the telescope’s primary mirror. The tertiary mirror is the only fixed mirror in the system — all of the other mirrors align to it.
All of the mirrors working together will provide Webb with the most advanced infrared vision of any space observatory we’ve ever launched!
Who is the fairest of them all?
The beauty of Webb’s primary mirror was apparent as it rotated past a cleanroom observation window at our Goddard Space Flight Center in Greenbelt, Maryland. If you look closely in the reflection, you will see none other than James Webb Space Telescope senior project scientist and Nobel Laureate John Mather!
Learn more about the James Webb Space Telescope HERE, or follow the mission on Facebook, Twitter and Instagram.
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Henry Cabot Lodge Jr. presenting “The Thing” to the Security Council at the United Nations. 26 May 1960.
via reddit
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Packing numerous books and papers that he plans to read over winter break, the grad student deludes himself.
Earlier this fall, I attempted my first corn maze. It didn’t work out very well. Early on I unknowingly cut through an area meant to be impassable and thus ended up missing the majority of the maze. Soap, as it turns out, is a much better maze-solver, taking nary a false turn as it heads inexorably to the exit. The secret to soap’s maze-solving prowess is the Marangoni effect.
Soap has a lower surface tension than the milk that makes up the maze, which causes an imbalance in the forces at the surface of the liquid. That imbalance causes a flow in the direction of higher surface tension; in other words, it tends to pull the soap molecules in the direction of the highest milk concentration. But that explains why the soap moves, not how it knows the right path to take. It turns out that there’s another factor at work. Balancing gravitational forces and surface tension forces shows that the soap tends to spread toward the path with the largest surface area ahead. That’s the maze exit, so Marangoni forces pull the soap right to the way out! (Video credit: F. Temprano-Coleto et al.)
Major Research Instrumentation Program
Credit: Photo by Lance Long; courtesy Electronic Visualization Laboratory, University of Illinois at Chicago
The Major Research Instrumentation program has helped to fund pieces of research equipment ranging from scanning probe microscopes, which have helped to visualize and characterize nano-scale biological tools, to nuclear magnetic resonance (NMR) spectrometers, which allow chemists to identify the individual molecules they make. Not only does this instrumentation help scientists advance their own research, it’s also used to train the next generation of scientists. For example, an X-ray diffractometer at Utah State University allowed Joan Hevel and Sean Johnson to teach four high school students in their lab about protein crystallization. Learn more.
Behind a TED-Ed Lesson: Animation + Inspiration
To celebrate George Seurat’s birthday today, we thought we’d do a deep dive behind the scenes of one of our animated lessons, How do schools of fish swim in harmony?, which is about the concept of ‘emergence’ and whose animated style just so happens to have been largely influenced by the paintings of George Seurat and his contemporaries.
Emergence refers to the spontaneous creation of sophisticated behaviors and functions from large groups of simple elements, and can be used to explain the movements of ants, fish, and birds, as well as how the tiny cells in your brain give rise to the complex thoughts, memories, and consciousness that are you.
A Sunday Afternoon on the Island of La Grande Jatte, George Seurat (1884–86)
It’s kind of like a pointillist painting. When you zoom in real close, it’s just a collection of chaotic brush strokes. But take a few steps back, and you’ll see that all of those brush strokes are working together to illustrate a complex and detailed scene.
Pointillism stems from Impressionism, and depending on the artist’s technique, the size of the brush strokes vary, but are always visible. For example, Vincent van Gogh’s The Starry Night uses larger brush strokes in the night sky. Both the above and below concept designs show the animator of this lesson testing out how different brushstrokes interact to create depth within a scene. She decided that the swirling waters would make sense as large brushstrokes, which also offered contrast to allow the small fish to stand out.
George Seurat also employed a technique called ‘divisionism’, sometimes known as ‘chromoluminarism’, in which colors were separated into individual dots or patches which interacted optically. So, rather than relying on mixing colors, painters like Seurat and Paul Signac juxtaposed contrasting colors to allow for optical mixing - which in theory would produce more vibrant and pure colors than the traditional process of mixing pigments.
Circus Sideshow (Parade de Cirque), George Seurat (1887–88)
While designing this TED-Ed lesson, George Seurat and Paul Signac’s paintings provided inspiration not just for the brushstroke technique, but also for the color palette.
This GIF of the brain and it’s neural connections draws many of its colors from Seurat’s circus series palette, while the brighter colors - such as the ones used in the title GIF above - are drawn from the more vibrant colors commonly used by Paul Signac, like in the painting below.
Notre-Dame-de-la-Garde (La Bonne-Mère), Marseilles, Paul Signac (1905-06)
Animating this lesson was an opportunity to renew a sense of wonder in our ever complex universe, whether studying it up close or from afar. We hope that watching it might do the same for you!
From the TED-Ed Lesson How do schools of fish swim in harmony? - Nathan S. Jacobs
Animation by TED-Ed // Lisa LaBracio
More art, less pollution
Week in Brief (27 November – 1 December)
Credit: Christine Daniloff/MIT
Artists can now paint with ink made from polluted air. Start-up company Graviky Labs has developed a device that attaches to the exhaust systems of diesel generator chimneys, catching emissions, which are then converted into inks, called Air-Ink.
The devices – known as KAALINK devices – are currently being trialled across India. So far more than 200 gallons of Air-Ink have been produced from collected emissions. KAALINK relies on static electricity, whereby energised materials attract particles. Inside the device are cartridges filled with high-energy plasma, which is triggered by a voltage to attract emission particles.
The disposable cartridges, which need to be emptied after 15–20 days, are then sent to Graviky Labs collection units. From these, they are sent to the start-up’s lab for treatment, where heavy metals and toxins are removed.
Graviky Lab’s Anirudh Sharma, an Interdisciplinary researcher at MIT Media Lab, commented, ‘Other processes convert air pollution into water pollution, and essentially generate more waste. We minimise the process and create a recycling stream from particulate matter waste that would have otherwise gone into our lungs.’
Credit: Graviky Labs
To find out more visit, bit.ly/2hXCRgX
In other news:
– Co-op and Iceland have backed a potential bottle deposit scheme
– A mission testing methods to clean-up space junk is preparing for launch
– Siemens, Rolls-Royce and Airbus are to collaborate on the development a of hybrid-electric aircraft
To find out more on materials science, packaging and engineering news, visit our website IOM3 at or follow us on Twitter @MaterialsWorld for regular news updates.
Earlier this year, The Lutetium Project explored how microfluidic circuits are made, and now they are back with the conclusion of their microfluidic adventures. This video explores how microfluidic chips are used and how microscale fluid dynamics relates to other topics in the field. Because these techniques allow researchers very fine control over droplets, there are many chemical and biological possibilities for microfluidic experiments, some of which are shown in the video. Microfluidics in medicine are also already more common than you may think. For example, test strips used by diabetic patients to measure their blood glucose levels are microfluidic circuits! (Video and image credit: The Lutetium Project; submitted by Guillaume D.)
Measuring Cosmic Rays at the Edge of Space
It’s a bird! It’s a plane! It’s a… SuperTIGER?
No, that’s not the latest superhero spinoff movie - it’s an instrument launching soon from Antarctica! It’ll float on a giant balloon above 99.5% of the Earth’s atmosphere, measuring tiny particles called cosmic rays.
Right now, we have a team of several scientists and technicians from Washington University in St. Louis and NASA at McMurdo Station in Antarctica preparing for the launch of the Super Trans-Iron Galactic Element Recorder, which is called SuperTIGER for short. This is the second flight of this instrument, which last launched in Antarctica in 2012 and circled the continent for a record-breaking 55 days.
SuperTIGER measures cosmic rays, which are itty-bitty pieces of atoms that are zinging through space at super-fast speeds up to nearly the speed of light. In particular, it studies galactic cosmic rays, which means they come from somewhere in our Milky Way galaxy, outside of our solar system.
Most cosmic rays are just an individual proton, the basic positively-charged building block of matter. But a rarer type of cosmic ray is a whole nucleus (or core) of an atom - a bundle of positively-charged protons and non-charged neutrons - that allows us to identify what element the cosmic ray is. Those rare cosmic-ray nuclei (that’s the plural of nucleus) can help us understand what happened many trillions of miles away to create this particle and send it speeding our way.
The cosmic rays we’re most interested in measuring with SuperTIGER are from elements heavier than iron, like copper and silver. These particles are created in some of the most dynamic and exciting events in the universe - such as exploding and colliding stars.
In fact, we’re especially interested in the cosmic rays created in the collision of two neutron stars, just like the event earlier this year that we saw through both light and gravitational waves. Adding the information from cosmic rays opens another window on these events, helping us understand more about how the material in the galaxy is created.
Why does SuperTIGER fly on a balloon?
While cosmic rays strike our planet harmlessly every day, most of them are blocked by the Earth’s atmosphere and magnetic field. That means that scientists have to get far above Earth - on a balloon or spacecraft - to measure an accurate sample of galactic cosmic rays. By flying on a balloon bigger than a football field, SuperTIGER can get to the edge of space to take these measurements.
It’ll float for weeks at over 120,000 feet, which is nearly four times higher than you might fly in a commercial airplane. At the end of the flight, the instrument will return safely to the ice on a huge parachute. The team can recover the payload from its landing site, bring it back to the United States, repair or make changes to it, if needed, and fly it again another year!
There are also cosmic ray instruments on our International Space Station, such as ISS-CREAM and CALET, which each started their development on a series of balloons launched from Antarctica. The SuperTIGER team hopes to eventually take measurements from space, too.
Why do we launch from Antarctica?
McMurdo Station is a hotspot for all sorts of science while it’s summer in the Southern Hemisphere (which is winter here in the United States), including scientific ballooning. The circular wind patterns around the pole usually keep the balloon from going out over the ocean, making it easier to land and recover the instrument later. And the 24-hour daylight in the Antarctic summer keeps the balloon at a nearly constant height to get very long flights - it would go up and down if it had to experience the temperature changes of day and night. All of that sunlight shining on the instrument’s array of solar cells also gives a continuous source of electricity to power everything.
Antarctica is an especially good place to fly a cosmic ray instrument like SuperTIGER. The Earth’s magnetic field blocks fewer cosmic rays at the poles, meaning that we can measure more particles as SuperTIGER circles around the South Pole than we would at NASA scientific ballooning sites closer to the Earth’s equator.
The SuperTIGER team is hard at work preparing for launch right now - and their launch window opens soon! Follow @NASABlueshift for updates and opportunities to interact with our scientists on the ice.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
Making glass invisible: A nanoscience-based disappearing act
If you have ever watched television in anything but total darkness, used a computer while sitting underneath overhead lighting or near a window, or taken a photo outside on a sunny day with your smartphone, you have experienced a major nuisance of modern display screens: glare. Most of today’s electronics devices are equipped with glass or plastic covers for protection against dust, moisture, and other environmental contaminants, but light reflection from these surfaces can make information displayed on the screens difficult to see.
Now, scientists at the Center for Functional Nanomaterials (CFN) – a U.S. Department of Energy Office of Science User Facility at Brookhaven National Laboratory – have demonstrated a method for reducing the surface reflections from glass surfaces to nearly zero by etching tiny nanoscale features into them.
Whenever light encounters an abrupt change in refractive index (how much a ray of light bends as it crosses from one material to another, such as between air and glass), a portion of the light is reflected. The nanoscale features have the effect of making the refractive index change gradually from that of air to that of glass, thereby avoiding reflections. The ultra-transparent nanotextured glass is antireflective over a broad wavelength range (the entire visible and near-infrared spectrum) and across a wide range of viewing angles. Reflections are reduced so much that the glass essentially becomes invisible.
Read more.
Spacewalk Recap Told in GIFs
Friday, Oct. 20, NASA astronauts Randy Bresnik and Joe Acaba ventured outside the International Space Station for a 6 hour and 49 minute spacewalk. Just like you make improvements to your home on Earth, astronauts living in space periodically go outside the space station to make updates on their orbiting home.
During this spacewalk, they did a lot! Here’s a recap of their day told in GIFs…
All spacewalks begin inside the space station. Astronauts Paolo Nespoli and Mark Vande Hei helped each spacewalker put on their suit, known as an Extravehicular Mobility Unit (EMU).
They then enter an airlock and regulate the pressure so that they can enter the vacuum of space safely. If they did not regulate the pressure safely, the astronauts could experience something referred to as “the bends” – similar to scuba divers.
Once the two astronauts exited the airlock and were outside the space station, they went to their respective work stations.
Bresnik replaced a failed fuse on the end of the Dextre robotic arm extension, which helps capture visiting vehicles.
During that time, Acaba set up a portable foot restraint to help him get in the right position to install a new camera.
While he was getting set up, he realized that there was unexpected wearing on one of his safety tethers. Astronauts have multiple safety mechanisms for spacewalking, including a “jet pack” on their spacesuit. That way, in the unlikely instance they become untethered from the station, the are able to propel back to safety.
Bresnik was a great teammate and brought Acaba a spare safety tether to use.
Once Acaba secured himself in the foot restraint that was attached to the end of the station’s robotic arm, he was maneuvered into place to install a new HD camera. Who was moving the arm? Astronauts inside the station were carefully moving it into place!
And, ta da! Below you can see one of the first views from the new enhanced HD camera…(sorry, not a GIF).
After Acaba installed the new HD camera, he repaired the camera system on the end of the robotic arm’s hand. This ensures that the hand can see the vehicles that it’s capturing.
Bresnik, completed all of his planned tasks and moved on to a few “get ahead” tasks. He first started removing extra thermal insulation straps around some spare pumps. This will allow easier access to these spare parts if and when they’re needed in the future.
He then worked to install a new handle on the outside of space station. That’s a space drill in the above GIF.
After Acaba finished working on the robotic arm’s camera, he began greasing bearings on the new latching end effector (the arm’s “hand”), which was just installed on Oct. 5.
The duo completed all planned spacewalk tasks, cleaned up their work stations and headed back to the station’s airlock.
Once safely inside the airlock and pressure was restored to the proper levels, the duo was greeted by the crew onboard.
They took images of their spacesuits to document any possible tears, rips or stains, and took them off.
Coverage ended at 2:36 p.m. EDT after 6 hours and 49 minutes. We hope the pair was able to grab some dinner and take a break!
You can watch the entire spacewalk HERE, or follow @Space_Station on Twitter and Instagram for regular updates on the orbiting laboratory.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
Entering the house owned by a friend working in the private sector, the grad student anxiously reassesses many of his life choices.
Why Webb Needs to Chill
Our massive James Webb Space Telescope is currently being tested to make sure it can work perfectly at incredibly cold temperatures when it’s in deep space.
How cold is it getting and why? Here’s the whole scoop…
Webb is a giant infrared space telescope that we are currently building. It was designed to see things that other telescopes, even the amazing Hubble Space Telescope, can’t see.
Webb’s giant 6.5-meter diameter primary mirror is part of what gives it superior vision, and it’s coated in gold to optimize it for seeing infrared light.
Why do we want to see infrared light?
Lots of stuff in space emits infrared light, so being able to observe it gives us another tool for understanding the universe. For example, sometimes dust obscures the light from objects we want to study – but if we can see the heat they are emitting, we can still “see” the objects to study them.
It’s like if you were to stick your arm inside a garbage bag. You might not be able to see your arm with your eyes – but if you had an infrared camera, it could see the heat of your arm right through the cooler plastic bag.
Credit: NASA/IPAC
With a powerful infrared space telescope, we can see stars and planets forming inside clouds of dust and gas.
We can also see the very first stars and galaxies that formed in the early universe. These objects are so far away that…well, we haven’t actually been able to see them yet. Also, their light has been shifted from visible light to infrared because the universe is expanding, and as the distances between the galaxies stretch, the light from them also stretches towards redder wavelengths.
We call this phenomena “redshift.” This means that for us, these objects can be quite dim at visible wavelengths, but bright at infrared ones. With a powerful enough infrared telescope, we can see these never-before-seen objects.
We can also study the atmospheres of planets orbiting other stars. Many of the elements and molecules we want to study in planetary atmospheres have characteristic signatures in the infrared.
Because infrared light comes from objects that are warm, in order to detect the super faint heat signals of things that are really, really far away, the telescope itself has to be very cold. How cold does the telescope have to be? Webb’s operating temperature is under 50K (or -370F/-223 C). As a comparison, water freezes at 273K (or 32 F/0 C).
How do we keep the telescope that cold?
Because there is no atmosphere in space, as long as you can keep something out of the Sun, it will get very cold. So Webb, as a whole, doesn’t need freezers or coolers - instead it has a giant sunshield that keeps it in the shade. (We do have one instrument on Webb that does have a cryocooler because it needs to operate at 7K.)
Also, we have to be careful that no nearby bright things can shine into the telescope – Webb is so sensitive to faint infrared light, that bright light could essentially blind it. The sunshield is able to protect the telescope from the light and heat of the Earth and Moon, as well as the Sun.
Out at what we call the Second Lagrange point, where the telescope will orbit the Sun in line with the Earth, the sunshield is able to always block the light from bright objects like the Earth, Sun and Moon.
How do we make sure it all works in space?
By lots of testing on the ground before we launch it. Every piece of the telescope was designed to work at the cold temperatures it will operate at in space and was tested in simulated space conditions. The mirrors were tested at cryogenic temperatures after every phase of their manufacturing process.
The instruments went through multiple cryogenic tests at our Goddard Space Flight Center in Maryland.
Once the telescope (instruments and optics) was assembled, it even underwent a full end-to-end test in our Johnson Space Center’s giant cryogenic chamber, to ensure the whole system will work perfectly in space.
What’s next for Webb?
It will move to Northrop Grumman where it will be mated to the sunshield, as well as the spacecraft bus, which provides support functions like electrical power, attitude control, thermal control, communications, data handling and propulsion to the spacecraft.
Learn more about the James Webb Space Telescope HERE, or follow the mission on Facebook, Twitter and Instagram.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
Dead Poets Society (1989)
Director - Peter Weir, Cinematography - John Seale
“Boys, you must strive to find your own voice. Because the longer you wait to begin, the less likely you are to find it at all. Thoreau said, "Most men lead lives of quiet desperation.” Don’t be resigned to that. Break out!“
Building microfluidic circuits is generally a multi-day process, requiring a clean room and specialized manufacturing equipment. A new study suggests a quicker alternative using fluid walls to define the circuit instead of solid ones. The authors refer to their technique as “Freestyle Fluidics”. As seen above, the shape of the circuit is printed in the operating fluid, then covered by a layer of immiscible, transparent fluid. This outer layer help prevent evaporation. Underneath, the circuit holds its shape due to interfacial forces pinning it in place. Those same forces can be used to passively drive flow in the circuit, as shown in the lower animation, where fluid is pumped from one droplet to the other by pressure differences due to curvature. Changing the width of connecting channels can also direct flow in the circuits. This technique offers better biocompatibility than conventional microfluidic circuits, and the authors hope that this, along with simplified manufacturing, will help the technique spread. (Image and research credit: E. Walsh et al., source)
“People who never met her except across the footlights did not realize how, in her private life, she had such compassion and interest in everyone. After I returned from Hong Kong I was ill with a virus and she rang me up reproachfully later to say, ‘Why didn’t you let me know? I would have come and sit with you.’ Giving flowers to sick people is easy. Giving that precious commodity time is far more expensive for someone who had such a full life. But she always found time for everyone.” -Godfrey Winn
When a porous solid retains its properties in liquid form
Known for their exceptional porosity that enables the trapping or transport of molecules, metal-organic frameworks (MOFs) take the form of a powder, which makes them difficult to format. For the first time, an international team led by scientists from the Institut de recherche de Chimie Paris (CNRS/Chimie ParisTech ), and notably involving Air Liquide, has evidenced the surprising ability of a type of MOF to retain its porous properties in the liquid and then glass state. Published on October 9, 2017 in Nature Materials website, these findings open the way towards new industrial applications.
Metal-organic frameworks (MOFs) constitute a particularly promising class of materials. Their exceptional porosity makes it possible to store and separate large quantities of gas, or to act as a catalyst for chemical reactions. However, their crystalline structure implies that they are produced in powder form, which is difficult to store and use for industrial applications. For the first time, a team of scientists from the CNRS, Chimie ParisTech, Cambridge University, Air Liquide and the ISIS (UK) and Argonne (US) synchrotrons has shown that the properties of a zeolitic MOF were unexpectedly conserved in the liquid phase (which does not generally favor porosity). Then, after cooling and solidification, the glass obtained adopted a disordered, non-crystalline structure that also retained the same properties in terms of porosity. These results will enable the shaping and use of these materials much more efficiently than in powder form.
Read more.