DR. GARRETT REISMAN: The thing that was probably the most impactful and surprising to me was when I looked at the horizon of the Earth and I saw how thin the atmosphere was. That was actually really scary. It was shocking. When you look at the atmosphere from Earth orbit it looks incredibly fragile. It's this little tiny thin blue line that separates the sunlit Earth from the black void of space. And compared to the diameter of the Earth it's tiny. I mean, you could hold up your pinky and block the whole thing out very easily. It looks terribly fragile. It looks like a gust of wind could come by and just strip the thing away. The next time, in fact, if you're home right now at your computer please open up a browser, put this on pause, open up a browser and just Google 'Earth from space' and then go to the images. And just look at any picture we took of the horizon of the Earth from space and you'll see that thin blue line. Look for yourself at just how think that is. When you compare the thickness of the atmosphere to the diameter of the Earth it's like the same dimension or fraction or ratio I should say as the shell on an egg or the skin on an apple. It's incredibly thin and that gives you a real visceral impression of just how fragile this planet is. And by the way, this happened to me. I had this experience and then about a week later I was looking out the window and I was looking down at the Earth and I saw what you see most of the time which is the ocean. When you look at the ocean I thought to myself well gee, how think is that? I could see the atmosphere. I could see how thin that is. What about the ocean? How deep is it? And the answer is that the ocean is ten times less deep than the atmosphere is high. The atmosphere, we draw an arbitrary line at 100 kilometers. We call that the Karman line and we say okay, that's where the atmosphere ends and that's where space begins. And that's kind of, again that's kind of made up, but it's about where, the blue line you see in those photographs is probably about 80 kilometers, but let's say about 100 kilometers. That's a nice round number. That's about 300,000 feet. The deepest part of the ocean like the Marianas Trench, Challenger Deep. The very deepest part that's about 35,000 feet deep. So that's ten times thinner than the atmosphere. So when you see that tiny thin blue line and when you look at those photographs think for a moment that the ocean is ten times thinner than that. And then think about the fact as I talked about before about how this planet is perfect for us, how it provides everything we need. All the food we need, all the air we need to breathe, the water we need to drink. It's where all of our friends and family live. It's where all the animals are, and the plants, and rainbows, and mountain ranges, and whales in the ocean. All that stuff that makes this our home, it's somewhere between the bottom of the ocean and the top of the atmosphere. And that's tiny. It's so tiny. What we have is a giant planet and sure, if you look out the window of the Space Shuttle, the Space Station it covers your whole view. It's monstrous this planet, but the part that matters to us is this tiny little bit. Just a tiny sliver on top. It's like we have a massive planet that's a big, giant dead rock with an incredibly precious surface coating.
CHRIS HADFIELD: As astronauts we train more than anybody knows. I had photographers train me. Hasselblad cameras with 70 millimeter film, and Aeroflex cameras, and I became an IMAX cameraman and helped make two IMAX movies, and Linhof cameras, and the whole gamut of complex photography with all of those photographers talking about not just portraiture and not just inside, but how to take a good picture of the world and what parts of the world we haven't seen yet. Some places have a lot of cloud cover and maybe one day you'll get a great picture of the Panama Canal or a part of the Amazon that's never been photographed because it's always so cloudy. So you are hyper prepared to be one of the world's photographers up there. You're really trying to make sure that you're technically competent with the camera, but you're also artistically capable of understanding how to compose a picture, how to frame it properly, how to recognize something that's worth taking a picture of. And you don't always get it right. I mean the National Geographic photographers they take thousands of pictures for every one that makes it into the magazine. Same for us, but the world is a very generous photography subject and you have the best tripod in existence, so it's a great place to take pictures.
RON GARAN: So I've been very fortunate. I've had a lot of perspective shifting experiences. I lived on the bottom of the ocean for three weeks in Aquarius, the only undersea laboratory. I flew once on the U.S. Space Shuttle on a two-week construction mission aboard the International Space Station, and I spent about half a year, half of 2011, living and working onboard the International Space Station after launching from Kazakhstan on a Russian rocket with a couple of Russian crewmates. When it was time to depart the Space Station and return home my Russian crewmates and I climbed into our Soyuz spacecraft, the same one we launched from five-and-a-half months earlier. We wiggled into our seats. We had our spacesuits on. We strapped ourselves in. It's really tight. It's like three guys in the trunk of a car. Our knees are in our chest. We undock from the Space Station and I had a window. I was sitting in the right seat. I had a window right by my head and I strained as best I could to see the Space Station as we were departing it because I knew quite likely that would be the last time I ever saw this magnificent sight. After we undocked we did a couple of laps around the planet, and as we passed the south tip of South America we fishtailed our spacecraft around to point the engines backwards. I remember when we did this I saw this crescent moon go by the window. It was just absolutely breathtaking. We fired our engines just a little bit at precisely the right moment to have us enter the upper atmosphere. And as we entered the upper atmosphere we started to develop drag. We had this fiery violent ride through the atmosphere. It was really amazing. Once you got down to a lower altitude the speed really becomes amazing. I remember seeing oh, there goes Africa as we whiz by the continent. And the parachutes open, they throw us all over the place. Shortly thereafter we smashed into the ground. We bounced, we flipped, we rolled over. And when we rolled over we rolled on the right side and now my window was pointing at the ground. I remember looking out of the window and seeing a rock, a flower and a blade of grass. And I remember thinking to myself distinctly that I'm home. And what was really amazing about that thought was that I was in Kazakhstan. And so for me at that moment my home was no longer Houston, Texas where I live with my family or Yonkers, New York where I was born and grew up. My home was Earth and it was really a perspective shifting moment for me. I think the big thing is to understand the framework that we've built to view the world in. Now, we live as we all know in a very, very complicated world. There's so many horrors, there's terrorism, there's poverty, there's almost a billion people that don't have access to clean water. There's so many ills that our global society face, but our world also has compassion and love and ingenuity and creativity and self-sacrifice. And so it becomes very complicated and what we tend to do, myself included, we tend to build a more simplified framework through which to view the world, through which to view our global society. And when we do that we tend to build cubbyholes and put people and groups into certain cubbyholes. It just makes it easier and more palpable to understand the events, the current events of the day. But what that does is it also creates barriers and walls. We box ourselves into these cubbyholes which at sometimes prevents us from dialogue, prevents us from recognizing any merit in the position, in another person's position, in another group's position because we've written off whole groups of people, whole countries, whole cultures as not worth our time, not worth our, there's no value in the problem solving process to engage those people. And I think once we realize that and we can step outside of it. And I don't just mean people and organizations. There's political parties. A good example is the political process in the U.S. right now where we've become so divided and to the point where one side will refuse to recognize any merit whatsoever in the position of the other side. If they win, we lose. If they gain, we lose. And so I think that is a recipe for disaster. It's a recipe for not being able to have progress. It's a barrier to us being able to tackle the big problems. And so I think you don't have to go to space to realize that. You don't have to go to space to realize that each and everyone of us is riding through the universe together on this spaceship that we call Earth. That we're all interconnected, that we're all in this together and that we're all family. I think one of the big things that the world perspective teaches us is there are no passengers on spaceship Earth. We're all crewmates. And as crewmates we have a responsibility to mind the ship and take care of our fellow crewmates.
CHRIS HADFIELD: Flying in space is a huge amount of work. It's decades of work getting all of the university degrees and life experience so that NASA will even look at you when they're selecting astronauts. In the last astronaut selection, 18,300 people applied for 12 positions. So how do you even get your foot in the door? But if you've done enough things in your life that you're competent enough that maybe they'll look at you and then they phone you and say we'd like you to be an astronaut. Now suddenly you're starting a whole new phase of life. You come over this watershed and now there's probably 10 or 15 years of work ahead of you to get ready and be competent enough to be trusted to fly a spaceship. And then someday you get into a rocket and it takes you above the atmosphere and the engines shut off and you're there. And you're doing all your work and flying the rocket and docking with the space station, but at the end of it what do you do with that experience? Now you've done all of these incredibly complex and extremely dangerous things in order to push back the edge of human capability and of our understanding of the world itself. But now what do you do with the sequence of things that have turned you into who you are and the things that have come in through your eyeballs and you've tried to understand? And I think part of the continuing responsibility of being one of the world's astronauts is not to keep it to yourself, but to try and let as many people benefit from what you've done. Let people see the world through your eyes. Try and understand the ideas behind it through your words so that hopefully they can go far further than you ever did or that I ever did.
LELAND MELVIN: Grace has a way of appreciating the people that are around you, the things that are around you and how you interact with them in a way that's meaningful, that's purposeful, that's intentional. You live an intentional way. You don't just hey, write someone off and just keep moving. Everyone has a purpose on this planet and we can learn something from everyone. I mean I learn something every day from my dog. I learn patience. I learn things from people that I would never have expected to learn something, the janitor or whomever it is, and so moving through life in this graceful way of embracing everything around you. Before I could read my mother read to me every night two books. "The Little Engine That Could." I think I can, I think I can. And "Curious George." Looking up curiosity. And I'll never forget, I was this little kid on the football team, the smallest kid probably. I could run fast but no one ever expected me to play in the NFL and I never imagined to play in the NFL because I was just this small little kid. But having this never give up, I think I can, I think I can mentality is a gritty way of ensuring that you're going to reach the dreams and goals that you have. Sometimes people don't have expectations for you because they see you are from a certain neighborhood or a certain zip code or whatever and you're looked at as this kid that well, you're never going to be an astronaut because you're from that zip code. I think we need to make sure that we look at every child as a potential president, astronaut, whatever that thing is and we give them the resources to be that.
- Being able to call yourself a former astronaut is a distinction that not many people on Earth have. Studying or reading about space from the ground is one thing, but getting to experience it firsthand is to join the universe's most exclusive club.
- This video brings together the voices of former astronauts Garrett Reisman, Chris Hadfield, Ron Garan, and Leland Melvin as they each share a personal anecdote about what they saw, felt, and learned during their training and their time in space.
- From Reisman's memories of seeing Earth's atmosphere from above for the first time, to Hadfield's extensive camera photography training, these space stories offer unique insights into a cool and very complex profession.
- How I overcame disability to become a NASA astronaut - Big Think ›
- Long spaceflights change astronaut brain structure - Big Think ›
Elephants dilate their nostrils to create more space in their trunks, allowing them to store up to 5.5 liters (1.45 gallons) of water, according to their new study.
They can also suck up three liters (0.79 gallons) per second—a speed 30 times faster than a human sneeze (150 meters per second/330 mph), the researchers found.
The researchers wanted to better understand the physics of how elephants use their trunks to move and manipulate air, water, food, and other objects. They also wanted to learn if the mechanics could inspire the creation of more efficient robots that use air motion to hold and move things.
Photo by David Clode on Unsplash
While octopuses use jets of water to propel themselves and archer fish shoot water above the surface to catch insects, elephants are the only animals able to use suction both on land and underwater.
"An elephant eats about 400 pounds of food a day, but very little is known about how they use their trunks to pick up lightweight food and water for 18 hours, every day," says lead author Andrew Schulz, a mechanical engineering PhD student at the Georgia Institute of Technology. "It turns out their trunks act like suitcases, capable of expanding when necessary."
Sucking up tortilla chips without breaking them
Schulz and his colleagues worked with veterinarians at Zoo Atlanta, studying elephants as they ate various foods. For large rutabaga cubes, for example, the animal grabbed and collected them. It sucked up smaller cubes and made a loud vacuuming sound, like the sound of a person slurping noodles, before transferring the vegetables to its mouth.
To learn more about suction, the researchers gave elephants a tortilla chip and measured the applied force. Sometimes the animal pressed down on the chip and breathed in, suspending the chip on the tip of its trunk without breaking it, similar to a person inhaling a piece of paper onto their mouth. Other times the elephant applied suction from a distance, drawing the chip to the edge of its trunk.
Elephants inhale at speeds comparable to Japan's 300 mph bullet trains.
"An elephant uses its trunk like a Swiss Army knife," says David Hu, Schulz's advisor and a professor in Georgia Tech's School of Mechanical Engineering. "It can detect scents and grab things. Other times it blows objects away like a leaf blower or sniffs them in like a vacuum."
By watching elephants inhale liquid from an aquarium, the team was able to time the durations and measure volume. In just 1.5 seconds, the trunk sucked up 3.7 liters (just shy of 1 gallon), the equivalent of 20 toilets flushing simultaneously.
Soft robots and elephant conservation
The researchers used an ultrasonic probe to take trunk wall measurements and see how the trunk's inner muscles work. By contracting those muscles, the animal dilates its nostrils up to 30%. This decreases the thickness of the walls and expands nasal volume by 64%.
"At first it didn't make sense: an elephant's nasal passage is relatively small and it was inhaling more water than it should," Schulz says. "It wasn't until we saw the ultrasonographic images and watched the nostrils expand that we realized how they did it. Air makes the walls open, and the animal can store far more water than we originally estimated."
Based on the pressures applied, Schulz and the team suggest that elephants inhale at speeds comparable to Japan's 300-mph bullet trains.
Schulz says these unique characteristics have applications in soft robotics and conservation efforts.
"By investigating the mechanics and physics behind trunk muscle movements, we can apply the physical mechanisms—combinations of suction and grasping—to find new ways to build robots," Schulz says.
"In the meantime, the African elephant is now listed as endangered because of poaching and loss of habitat. Its trunk makes it a unique species to study. By learning more about them, we can learn how to better conserve elephants in the wild."
The paper appears in the Journal of the Royal Society Interface. The US Army Research Laboratory and the US Army Research Office 294 Mechanical Sciences Division, Complex Dynamics and Systems Program, funded the work. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the view of the sponsoring agency.
Source: Georgia Tech
Original Study DOI: 10.1098/rsif.2021.0215
Reprinted with permission of Futurity. Read the original article.
As he described it, “In my mind's eye I saw many, many things: children that I hadn't even had yet, friends that I had never seen but are now my friends. The thing that really stuck in my mind was playing an instrument". Then Tony landed on his head and lost consciousness.
When he came to at the hospital, he felt like a different person and didn't want to return to his previous life. Over the following weeks, the images kept flashing back into his mind. He felt that he was “being shown something" and that the images represented his future.
Later, Tony saw a picture of a saxophone and recognized it as the instrument he'd seen himself playing. He used his compensation money from the accident to buy one. Now, Tony Kofi is one of the UK's most successful jazz musicians, having won the BBC Jazz awards twice, in 2005 and 2008.
Though Tony's belief that he saw into his future is uncommon, it's by no means uncommon for people to report witnessing multiple scenes from their past during split-second emergency situations. After all, this is where the phrase “my life flashed before my eyes" comes from.
But what explains this phenomenon? Psychologists have proposed a number of explanations, but I'd argue the key to understanding Tony's experience lies in a different interpretation of time itself.
When life flashes before our eyes
The experience of life flashing before one's eyes has been reported for well over a century. In 1892, a Swiss geologist named Albert Heim fell from a precipice while mountain climbing. In his account of the fall, he wrote is was “as if on a distant stage, my whole past life [was] playing itself out in numerous scenes".
More recently, in July 2005, a young woman called Gill Hicks was sitting near one of the bombs that exploded on the London Underground. In the minutes after the accident, she hovered on the brink of death where, as she describes it: “my life was flashing before my eyes, flickering through every scene, every happy and sad moment, everything I have ever done, said, experienced".
In some cases, people don't see a review of their whole lives, but a series of past experiences and events that have special significance to them.
Explaining life reviews
Perhaps surprisingly, given how common it is, the “life review experience" has been studied very little. A handful of theories have been put forward, but they're understandably tentative and rather vague.
For example, a group of Israeli researchers suggested in 2017 that our life events may exist as a continuum in our minds, and may come to the forefront in extreme conditions of psychological and physiological stress.
Another theory is that, when we're close to death, our memories suddenly “unload" themselves, like the contents of a skip being dumped. This could be related to “cortical disinhibition" – a breaking down of the normal regulatory processes of the brain – in highly stressful or dangerous situations, causing a “cascade" of mental impressions.
But the life review is usually reported as a serene and ordered experience, completely unlike the kind of chaotic cascade of experiences associated with cortical disinhibition. And none of these theories explain how it's possible for such a vast amount of information – in many cases, all the events of a person's life – to manifest themselves in a period of a few seconds, and often far less.
Thinking in 'spatial' time
An alternative explanation is to think of time in a “spatial" sense. Our commonsense view of time is as an arrow that moves from the past through the present towards the future, in which we only have direct access to the present. But modern physics has cast doubt on this simple linear view of time.
Indeed, since Einstein's theory of relativity, some physicists have adopted a “spatial" view of time. They argue we live in a static “block universe" in which time is spread out in a kind of panorama where the past, the present and the future co-exist simultaneously.
The modern physicist Carlo Rovelli – author of the best-selling The Order of Time – also holds the view that linear time doesn't exist as a universal fact. This idea reflects the view of the philosopher Immanuel Kant, who argued that time is not an objectively real phenomenon, but a construct of the human mind.
This could explain why some people are able to review the events of their whole lives in an instant. A good deal of previous research – including my own – has suggested that our normal perception of time is simply a product of our normal state of consciousness.
In many altered states of consciousness, time slows down so dramatically that seconds seem to stretch out into minutes. This is a common feature of emergency situations, as well as states of deep meditation, experiences on psychedelic drugs and when athletes are “in the zone".
The limits of understanding
But what about Tony Kofi's apparent visions of his future? Did he really glimpse scenes from his future life? Did he see himself playing the saxophone because somehow his future as a musician was already established?
There are obviously some mundane interpretations of Tony's experience. Perhaps, for instance, he became a saxophone player simply because he saw himself playing it in his vision. But I don't think it's impossible that Tony did glimpse future events.
If time really does exist in a spatial sense – and if it's true that time is a construct of the human mind – then perhaps in some way future events may already be present, just as past events are still present.
Admittedly, this is very difficult to make sense of. But why should everything make sense to us? As I have suggested in a recent book, there must be some aspects of reality that are beyond our comprehension. After all, we're just animals, with a limited awareness of reality. And perhaps more than any other phenomenon, this is especially true of time.
Steve Taylor, Senior Lecturer in Psychology, Leeds Beckett University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
A Florida student figured out a way to more accurately measure the size of one of the largest fish that ever lived – the extinct megalodon shark – and found that it was even larger than previously estimated.
The megalodon (officially named Otodus megalodon, which means "Big Tooth") lived between 3.6 and 23 million years ago and was thought to be about 34 feet long on average, reaching the maximum length of 60 feet. Now a new study puts that number at up to 65 feet (20 meters).
Homework assignment leads to a discovery
The study, published in Palaeontologia Electronica, used new equations extrapolated from the width of megalodon's teeth to make the improved estimates. The paper's lead author, Victor Perez, developed the revised methodology while he was a doctoral student at the Florida Museum of Natural History. He got the idea while teaching students, noticing a range of discrepancies in the results they were getting.
Students were supposed to calculate the size of megalodon based on the ancient fish's similarities to the modern great white shark. They utilized the commonly accepted method of linking the height of a shark's tooth to its total body length. As the press release from the Florida Museum of Natural History expounds, this method involves locating the anatomical position of a tooth in the shark's jaw, measuring the tooth "from the tip of the crown to the line where root and crown meet," and using that number in an appropriate equation.
But while carrying out calculations in this way, some of Perez's students thought the shark would have been just 40 feet long, while others were calculating 148 feet. Teeth located toward the back of the mouth were yielding the largest estimates.
"I was going around, checking, like, did you use the wrong equation? Did you forget to convert your units?" said Perez, currently the assistant curator of paleontology at the Calvert Marine Museum in Maryland. "But it very quickly became clear that it was not the students that had made the error. It was simply that the equations were not as accurate as we had predicted."
Found in North Carolina, these 46 fossils are the most complete set of megalodon teeth ever excavated.Credit: Jeff Gage/Florida Museum
The new approach
Perez's math exercise demonstrated that the equations in use since 2002 were generating different size estimates for the same shark based on which tooth was being measured. Because megalodon teeth are most often found as standalone fossils, Perez focused on a nearly complete set of teeth donated by a fossil collector to design a new approach.
Perez also had help from Teddy Badaut, an avocational paleontologist in France, who suggested using tooth width instead of height, which would be proportional to the length of its body. Another collaborator on the revised method was Ronny Maik Leder, then a postdoctoral researcher at the Florida Museum, who aided in the development of the new set of equations.
The research team analyzed the widths of fossil teeth that came from 11 individual sharks of five species, which included megalodon and modern great white sharks, and created a model that connects how wide a tooth was to the size of the jaw for each species.
"I was quite surprised that indeed no one had thought of this before," shared Leder, who is now director of the Natural History Museum in Leipzig, Germany. "The simple beauty of this method must have been too obvious to be seen. Our model was much more stable than previous approaches. This collaboration was a wonderful example of why working with amateur and hobby paleontologists is so important."
Why use teeth?
In general, almost nothing of the super-shark survived to this day, other than a few vertebrae and a large number of big teeth. The megalodon's skeleton was made of lightweight cartilage that decomposed after death. But teeth, with enamel that preserves very well, are "probably the most structurally stable thing in living organisms," Perez said. Considering that megalodons lost thousands of teeth during a lifetime, these are the best resources we have in trying to figure out information about these long-gone giants.
Researchers suggest megalodon's large jaws were very thick, made for grabbing prey and breaking its bones, exerting a bite force of up to 108,500 to 182,200 newtons.
Megalodon tooth compared to two great white shark teeth. Credit: Brocken Inaglory / Wikimedia.
Limitations of the new model
While the new model is better than previous methods, it's still far from perfect in precisely figuring out the sizes of animals which lived so long ago and left behind few if any full remains. Because individual sharks come in a variety of sizes, Perez warned that even their new estimates have an error range of about 10 feet when it comes to the largest animals.
Other ambiguities may affect the results, such as the width of the megalodon's jaw and the size of the gaps between its teeth, neither of which are accurately known. "There's still more that could be done, but that would probably require finding a complete skeleton at this point," Perez pointed out.
How did the megalodon go extinct?
Environmental changes that led to fluctuations in sea levels and disturbed ecosystems in the oceans likely led to the demise of these enormous ancient sharks. They were just too big to be sustained by diminishing food resources, says the ReefQuest Centre for Shark Research.
A 2018 study suggested that a supernova 2.6 million years ago hit Earth's atmosphere with so much cosmic energy that it resulted in climate change. The cosmic rays that included particles called muons might have caused a mass extinction of giant ocean animals ("the megafauna") that included the megalodon by causing mutations and cancer.
Scientists, led by Adrian Melott, professor emeritus of physics and astronomy at the University of Kansas, estimated that "the cancer rate would go up about 50 percent for something the size of a human — and the bigger you are, the worse it is. For an elephant or a whale, the radiation dose goes way up," as he explained in a press release.
