Chris Hadfield: When the very first balloon was launched that could carry people it was in Paris in the late 1700s and it was Montgolfier the brothers, they had hydrogen balloons and hot air balloons and it was the cutting edge of science. It was the cutting edge of technology. We just learned how to capture a gas like hydrogen that would be lighter than air as you could take a balloon and the first balloon rose and Ben Franklin was there and it was huge and magnificent, all of those scientists. And it rose but it got out of control and it went and landed out in the countryside 15 miles away from Paris and the peasants there attacked it with pitchforks because they thought it was an alien coming from space. The schism between learned understanding and scientific pursuit and the common perception of what was normal was that close just 15 miles away. It was an enormous gap between what we knew and what we were doing and what a lot of folks knew yet or what had become part of common knowledge. So there's nothing new about the speed with which we're inventing things and the ability for people to understand what's going on. There's a recent populous sort of wave of anti-science as if that's something new. It's mostly because social media has given everybody what appears to be an equal voice. On the corner of Hyde Park in London there's Speakers Corner and that used to be the Internet where you could go stand there and yell any stupid thing you wanted and if people wanted to gather around and listen that was their choice, but if you weren't interested in whatever that person was spouting then you didn't need to listen. But now the Internet has sort of turned everything into the Speakers Corner so you really have to just decide what are you going to listen to and what aren't you. And if someone decides to put forward some stupid idea that is patently false like if somebody says the sky is orange, you can have an argument about it if you want, but it's obviously not true so there's really no point in even engaging in conversation. Or if somebody says the world is flat, it's patently untrue so there's no point in engaging in conversation because all you're doing is giving that person credibility for something that we've known for thousands of years to not be truth. I don't even worry about it. The world is full of fascinating interesting new discoveries and we're pushing the very boundaries of what we know. Stephen Hawking, who just recently died, the work that he did in trying to understand how the universe works the original thinking there's so many brilliant motivated people around that's why would you engage with someone who is being deliberately ignorant? I don't mind people that just don't know when they're just in the process of learning, but if someone has chosen to take the facts and be deliberately stupid about them then I think they've discounted themselves from rational conversation so I don't bother. If you wrestle with a pig the best you can be is a pig wrestler; I want to do better than that. So just because somebody says something, no matter how big their megaphone is, it doesn't mean that they deserve conversation. Just use your own brain, that's why we each have one, and choose who you're going to disregard.
To the average person, there appears to be a growing number of people who believe — somehow — that the world is actually flat and that we are all being "lied" to by world governments. Canadian astronaut Chris Hadfield has actually been to space and has seen that the world is round, but is unphased by these so-called "flat-earthers." He flatly (pun intended) denies a global conspiracy, and says that perhaps the best way to deal with such willful ignorance is just to ignore it. After all, he posits, "if you wrestle with a pig, the best you can be is a pig wrestler." It's folky wisdom like that which puts Chris into another stratosphere of intelligence. Chris Hadfield is the author of An Astronaut's Guide to Life on Earth: What Going to Space Taught Me About Ingenuity, Determination, and Being Prepared for Anything
and features in the new docuseries One Strange Rock
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.
