Shark Intestines Operate Like Nikola Tesla’s Valve
Shark intestines (in this case of the Pacific spiny dogfish shark Squalus suckleyi) have a spiral shape, whose structure has only been revealed using CT scans. Food here would move from left to right. Image Credit: Samantha Leigh/California State University, Dominguez Hills
Just two months after physicists proved a century-old invention by Nikola Tesla works better than anyone realised it turns out someone else got there first, by a few hundred million years. 3D images of shark intestines show they use Tesla’s technique, apparently for most of the time they have ruled the oceans.
Sharks innards have often been examined to learn if they had anything to do with somebody’s one way trip into the ocean, or more exotic demise. However, this is much more convenient after the shark is dead, leaving zoologists little opportunity to see how the intestines operate when the shark is alive. "Intestines are so complex, with so many overlapping layers, that dissection destroys the context and connectivity of the tissue,” said Professor Adam Summers of the University of Washington in a statement. “It would be like trying to understand what was reported in a newspaper by taking scissors to a rolled-up copy. The story just won't hang together."
Dr Samantha Leigh of California State University, Dominguez Hills sought to go beyond flat sketches of expired sharks’ innards and published her results in Proceedings of the Royal Society B. "It's high time that some modern technology was used to look at these really amazing spiral intestines of sharks," Leigh said. "We developed a new method to digitally scan these tissues and now can look at the soft tissues in such great detail without having to slice into them."
The method required CT scans but wheeling a shark into a hospital might raise eyebrows, Fortunately Summers’ lab has one, used to reveal many animals’ innards.
Leigh and Summers concluded spiral-shaped organs in sharks digestive system slow the movement of food through giving sharks more time to scavenge nutrients while requiring less energy to do so. Like many apex predators, some sharks consume very large meals but then can go a long time between feeds.
Top view of a shark intestine from a CT scan. Samantha Leigh/California State University, Dominguez Hills
A digestive system that uses the intervening time well is a major asset, one that presumably helped sharks not only fight their way to the top of the food chain, but survive mass extinctions that wiped out many formidable competitors. Similar structures were found within representatives of 22 families of sharks, rays and skates, and appears independent of diet, indicating the structure dates back to the very origins of Selachimorpha.
A combination of gravity and rhythmic gut muscle contractions to force food in the direction it needs to go, while the spirals prevent its return during any sudden maneuvers. These operate in a similar manner to Tesla’s valve, which pushes fluids in one direction while preventing their movement the other way.
Like many of Tesla’s other inventions, the valve was largely ignored when first patented. He had, after all, many great failures along with his immense feats in engineering. However, as Tesla’s status has grown his “valvular conduit” has achieved an online cult following, with its harnessing of turbulent flows only recently attracting scientific explanation. That discovery was accompanied by the suggestion the Tesla’s Valve might have overlooked applications, and it seems the sharks were way ahead of us.
The intestines could act as an inspiration for some novel uses for Tesla Valves, such as wastewater treatment mechanisms that maximize pollutant removal. "We need to look harder at sharks and, in particular, we need to look harder at parts other than the jaws, and the species that don't interact with people." Summers said.
5 fascinating shark facts
Sharks have called the Earth's oceans home for hundreds of millions of years and adapted to thrive in harsh environments.
© naturepl.com / Doug Perrine / WWF The population of hammerhead sharks in the Sea of Cortez, between Baja California and the Mexican mainland, has seen a steep decline due to overfishing.
While these top hunters of the deep blue have evolved to survive cold and dark climates, sharks are no match for the ultimate predator -- humans.
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That's why Shark Week, running from July 11 through July 18, was launched 33 years ago by Discovery Channel to encourage shark conservation and educate the public on these underwater predators.
The world's shark and ray populations plummeted 70% from 1970 to 2018, with overfishing as a primary cause, according to a 2019 study published in the journal Nature.
Of the 31 oceanic species of sharks and rays, 24, or over three-quarters, of the species are now threatened with extinction due to their steep drop in numbers, the study said.
With Hollywood blockbusters like "Jaws" and "The Meg" fanning the flames of fear and paranoia in humans, these underwater animals have suffered a serious image problem.
However, sharks play a crucial role in their environment and keep the animal kingdom in check.
Sharks balance the food chain
As sharks were killed off from overfishing in the Sea of Cortez, located between Baja California and the Mexican mainland, other creatures swooped in to take their place on the food chain.
Wahoo and hammerhead sharks, along with other fish species like marlin and swordfish, have seen a steep decline in population due to commercial and local fishing in the area.
Scientists believe the decline in sharks is one of the reasons the Humboldt squid now call the Baja home in greater numbers. The creature can grow up to 7 feet (2.1 meters) long and weigh over 100 pounds (45.4 kilograms).
The squid only live for a couple years, but they reproduce at a much faster rate than sharks.
Some sharks are partially warm-blooded
Despite having a reputation of being cold-blooded, some sharks -- like the great white and the salmon shark -- are able to internally regulate their temperature, according to a June study published by the British Ecological Society.
The study found endothermic fish, which are able to regulate their own body temperature, swam over one-and-a-half times faster than ectotherms, animals that rely on the outside temperature to regulate their body heat.
Researchers weren't able to make any conclusions on how the warm-bloodedness could be helpful to sharks, but they hypothesized that it could help them when searching for food or migrating.
Sharks can live for hundreds of years
Sharks tend to have one of the longest life spans of creatures in the animal kingdom.
Using radiocarbon dating to estimate how old Greenland sharks were for a 2016 study, researchers discovered the underwater creatures lived to be at least 272 years old, with the largest of the group clocking in at around 392 years old.
The animals don't reach maturity until the ripe age of 150 years old, and they are the longest-lived vertebrate known to humans.
Some can glow in the dark
A small number of sharks are bioluminescent and glow hundreds of feet below the ocean's surface, according to a February study published in Frontiers in Marine Science.
One of the sharks is the kitefin shark (Dalatias licha), which spans nearly 6 feet (1.8 meters). It's also the world's largest known bioluminescent shark.
Very little is known about sharks that glow because the sharks mostly roam in the deep sea, which begins over 656 feet (200 meters) below the ocean surface.
Researchers also discovered the southern lanternshark (Etmopterus granulosus) and blackbelly lanternshark (Etmopterus lucifer) have bioluminescent abilities.
They nearly went extinct millions of years ago
Despite having the reputation as an apex predator, sharks died off at alarming rates millions of years ago.
Over 90% of open-ocean sharks disappeared from the planet around 19 million years ago, scientists said.
Researchers said they could not confirm what caused the near-mass extinction event, and it could have lasted from a single day to 100,000 years.
Based on current research, there was no climate or ecosystem crisis during this time, which leaves a gaping hole of knowledge for scientists to do more research on and unlock the mystery.
7 Eccentric Inventions by Nikola Tesla That Were Never Built
From artificial tidal wave machine to a thought camera, Tesla had interesting ideas.
Nikola Tesla is one of history’s greatest inventors, whose work has captured the imaginations of the generations living in the world he helped to build. As the holder of more than 270 patents in 27 countries—including 112 in the US alone—Tesla rightfully earned his place in history. However, not every one of Tesla's inventions made it to production. With that in mind, we combed through the records and found seven of Tesla’s most eccentric inventions that were never built.
Wireless Energy Transmission
As someone almost completely associated with electricity, it shouldn’t be surprising that many of Tesla’s patents are in the field of electricity generation and transmission. What a lot of people don’t know is that Tesla also tried to build a tower that would transmit electricity through the air. He even got American financier J.P. Morgan to finance the building of Wardenclyffe Tower on the North Shore of Long Island, which Tesla hoped to adapt to transmit electricity to New York City.
Morgan balked at the cost of the electricity transmission scheme and refused to fund the rest of the project, which Tesla had to abandon in 1906, tearing down Wardenclyffe Tower a decade later in 1917.
Supersonic Airships Powered by Ground-Based, Wireless Electrical Towers
Source: Frank R. Paul/Wikimedia Commons
When wireless charging was introduced, it felt revolutionary. Nikola Tesla, meanwhile, would chide us all for thinking so small. In 1919, Tesla described his idea for a supersonic airship powered entirely by wireless electrical transmission from ground-based towers that could fly 40,000 ft (12,192 meters) off the ground and at a speed of 1,000 mph (1,609 km/h), making the trip from New York to London in under four hours.
Remote Controlled Navies
Source: Public Domain/Engadget
While Tesla is best known for his work with electricity, this isn’t the only area in which he worked. Another major area of work for Tesla was military technology. Like Alfred Nobel, Tesla believed that the best way to prevent war was to make it either utterly pointless or so catastrophic for the participants that no one would be mad enough to go to war again.
With this in mind, Tesla invented a small boat that he could start, stop, and steer with radio signals. He hoped that by removing humans from the equation, “battle ships [sic] will cease to be built and the most tremendous artillery afloat will be of no more use than so much scrap iron.”
The Thought Camera
Source: kalerkantho
One of Tesla’s most outlandish ideas was that it would be possible to photograph one's thoughts.
In 1933, he told reporters at the Kansas City Journal-Post,
“In 1893, while engaged in certain investigations, I became convinced that a definite image formed in thought, must by reflex action, produce a corresponding image on the retina, which might be read by a suitable apparatus.
“Now if it be true that a thought reflects an image on the retina, it is a mere question of illuminating the same property and taking photographs and then using the ordinary methods which are available to project the image on a screen.
“If this can be done successfully, then the objects imagined by a person would be clearly reflected on the screen as they are formed, and in this way, every thought of the individual could be read. Our minds would then, indeed, be like open books.”
Obviously, this is not how thought processes work, but there is so much we don’t know about the biological mechanism of human thought and consciousness that we cannot say for certain that Tesla wasn’t on to something.
The Earthquake Machine
In 1893, Tesla was granted a patent for his steam-powered mechanical oscillator whose vibration could be utilized to generate electricity. As he would later tell reporters, while calibrating this machine for an experiment, it began to shake his New York City laboratory so violently that it almost brought the building down.
“Suddenly all the heavy machinery in the place was flying around. I grabbed a hammer and broke the machine. The building would have been down about our ears in another few minutes.
“Outside in the street, there was pandemonium. The police and ambulances arrived. I told my assistants to say nothing. We told the police it must have been an earthquake. That's all they ever knew about it.”
This gave Tesla the inspiration for his telegeodynamic oscillator—an earthquake machine—which could be used by scientists to discover the geological properties of the Earth and for engineers and prospectors to locate mineral and metal ore deposits underground. He never got to build his earthquake machine, but scientists and engineers use the same principle today to do exactly as Tesla imagined.
Artificial Tidal Waves
Over the course of his life, Tesla conceived of weapons of such destructive magnitude that they would rival the atom bomb in their devastating power—had they been built and put to use.
One such weapon was the Artificial Tidal Wave, which he believed would be the ultimate defense against enemy navies. Tesla’s hope was to make the largest battleship any nation could produce useless, so countries would not bother to build navies. To do this, Tesla envisioned “telautomatons” that would pilot several tons of high-explosive material near an enemy navy and detonate it.
Tesla calculated that the collapsing gas bubble produced by the explosion would produce tidal waves more than 100 feet (30 meters) high, enough to sweep away the largest dreadnoughts of the era.
Tidal waves don’t quite work that way, however, as the United States and Soviet Union learned when they performed underwater nuclear bomb testing in the 1940s and 1950s.
The Death Ray
Source: Wellcome Collection, Edited by John Loeffler for Interesting Engineering
Or the Peace Ray, as Tesla called it.
Tesla believed that by accelerating mercury isotopes to 48 times the speed of sound, the resulting beam would produce enough energy to destroy entire armies at a distance, limited only by the curvature of the Earth.
Tesla apparently tried to shop this idea around to several governments in the years before his death, including the United States, but the Soviet Union was the only one to experiment with it at all, and it never produced the kind of results Tesla hoped.
Which is probably a good thing, all things considered.