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In harmony with nature - in harmony with yourself, Mexico City (2025)

28/02/2023

"We realized that the ice is forcing the water up the hill, squeezing the water backward," Bell said.

There are other instances in which water has naturally run uphill. For example, an 8.0-magnitude earthquake shook southeastern Missouri so hard that the Mississippi River temporarily flowed backward, Live Science previously reported. In addition, a 2006 study in the journal Physical Review Letters showed that small amounts of water put on a hot surface — a scalding pan, for instance — can "climb" tiny stairs made out of v***r if the water is hot enough, Live Science reported.

28/02/2023

Hawaii's Kilauea volcano, located on the southern shore of the Big Island, has been actively erupting for decades. Shown here is Pu’u ‘O’o, a typical cinder cone spattering a fountain of lava in irregularly shaped globs that fall down in a heap around the vent. (© United States Geological Survey; Photo by G.E. Ulrich)

Mount St. Helens

The explosive eruption of Mount St. Helens in the spring of 1980 produced a ball of ash rising through the clouds, as shown in this photo taken on July 22 of that year. The eruption blasted off the top portion of the volcano. The volcanic activity is caused by the subduction of the Juan de Fuca plate off the western coast of North America. Scientists say Mount St. Helens is the most likely volcano in the continental United States to erupt again in the future, according to the USGS. (Image © United States Geologic Survey; Photo by Jim Vallance)

Hurricane Dean

Hurricane Dean was the strongest hurricane of the 2007 Atlantic hurricane season. It struck downtown Kingston, Jamaica on August 19, 2007, battering the city's waterfront boulevard with strong winds and heavy rains. (Image: © Andres Leighton/AP Photo)

Campo tornado

About three quarters of all tornadoes take place in a part of the central United States known as Tornado Alley. The violent winds and funnel-shaped clouds are formed when warm, humid air from the Gulf of Mexico meets cool, dry air from the north, producing thunderstorms. The conditions create an average of 600 tornadoes per year. This 2010 tornado touched down in Colorado and swept into Oklahoma. (Image: © Willoughby Owen)

Shake-it-up interactive

23/02/2023

Known as the fastest land animals, cheetahs (Acinonyx jubatus) are members of the big cat family, which includes tigers, jaguars, lions, leopards, snow leopards and pumas. Their name comes from the Hindi word "chita," which means "spotted one," according to the book "Cheetahs: Biology and Conservation(opens in new tab)" (Elsevier, 2018).

With aerodynamic bodies, long legs, and blunt, semi-retractable claws, cheetahs are formidable carnivores that can sprint at speeds of 60 to 70 mph (96 to 112 km/h), according to the Smithsonian's National Zoo & Conservation Biology Institute(opens in new tab).

WHAT DO CHEETAHS LOOK LIKE?
Adult cheetahs are, on average, 2.5 feet (0.8 meter) tall at the shoulder and up to 5 feet (1.5 m) long from head to rump, with their tails adding another 26 to 33 inches (66 to 84 centimeters). Typically, these large cats weigh between 75 and 140 pounds (34 to 64 kilograms), according to the Smithsonian.

Like leopards (Panthera pardus) and jaguars (Panthera onca), cheetahs have black spots scattered across their tan coats. But whereas leopard and jaguar spots are arranged in rosette (rose-like) patterns, cheetahs' spots are solid and fairly uniform in size, and are evenly distributed across the whole body, except for the white throat and belly, the Smithsonian notes. Cheetahs' spotted coats help them blend into the environment when resting, stalking prey and hiding from predators. Much like human fingerprints, these markings are unique to each cat.

Cheetahs also have signature black "tear stains" on their faces — one trailing from the inner corner of each eye, down to the mouth.

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HOW FAST DO CHEETAHS RUN?
Cheetahs' long, slender bodies; powerful legs; and flexible spines enable them to fully stretch their bodies when they sprint and to cover significant ground — around 20 to 22 feet (6 to 6.7 m) per stride, according to the San Diego Zoo(opens in new tab).

Cheetahs have been known to accelerate from 0 to 45 mph (72 km/h) in just 2.5 seconds, according to the Smithsonian. For comparison, the fastest cars in the world can accelerate from 0 to 60 mph (97 km/h) in 3.5 seconds, according to Consumer Reports(opens in new tab). As noted by Guinness World Records(opens in new tab), the peak speed of the fastest human on Earth, Usain Bolt, was 27.34 mph (44 km/h), which he achieved in a race in 2009. That means it's impossible for a person to outrun a cheetah on foot.

Related: The world's fastest animals

CHEETAH TAXONOMY
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Felidae
Genus and species: Acinonyx jubatus

Cheetahs can execute quick turns even while in midair, thanks to their long tails, which counter their body weight, according to the San Diego Zoo. Their semi-retractable claws, which are more dog-like than cat-like, provide great traction during sprints and sudden changes in direction.

photo of a cheetah mid-sprint in a field

Cheetahs can sprint at speeds of 60 to 70 mph (96 to 112 km/h). (Image credit: Mike Powles via Getty Images)
WHERE DO CHEETAHS LIVE?
Cheetahs are native to Africa and Asia, although the Asiatic cheetah (Acinonyx jubatus venaticus) has become all but extinct, according to The Times of Israel(opens in new tab).

According to the African Wildlife Foundation(opens in new tab) (AWF), cheetahs currently inhabit only about 10% of their historic range. The animals are now found primarily in North Africa, the Sahel (the region between the Sahara desert and the savanna of Sudan), East Africa (Kenya and Tanzania) and southern Africa (Namibia and Botswana), according to the Smithsonian.

A small population of Asiatic cheetahs also lives in Iran, where the animals are critically endangered. In January 2022, Iranian officials reported that only a few cheetahs remained in the country, The Times of Israel reported.

Cheetahs don't have one home location where they seek shelter day in and day out. Instead, these nomadic cats have home territories or ranges — expanses of grasslands, savannas, forest land and mountainous terrain, ranging from about 5 to 370 square miles (13 to 958 square kilometers), which they regularly roam, according to the Smithsonian. When not actively hunting, they prefer to sleep and rest in tall grasses, under trees or on rocky outposts.

23/02/2023

If terms like "bird brain" and "harebrained" are any indication, animal brains present fascinating and diverse examples of one of the most complex organs known to science. Animal brains differ not only in overall size but also in their size relative to the animal's body mass.

At 18 pounds (8 kilograms), on average, the s***m whale (Physeter macrocephalus) has the largest brain, but has an overall body mass of 45 tons (40 metric tons), giving it a brain-to-body-mass ratio of 1:5,100. But which animal has the biggest brain relative to its body size?

A 2009 study in the journal Brain, Behavior and Evolution(opens in new tab) found that an especially tiny genus of ant has the largest brain for its body size. Brachymyrmex has an average body mass of up to 0.049 milligrams and an average brain mass of 0.006 milligram. That means its brain is roughly 12% of its body mass, giving it a brain-to-body-mass ratio of about 1:8.

Related: Why do our brains have folds?

Why do animals evolve larger brains?
In absolute terms, animals' brain size tends to increase with the size of the animal. Bigger brains are typically related to three factors: "maternal investment, complexity of behavior and the sheer size of the body," said Sophie Scott, a professor of cognitive neuroscience at University College London.

"Having a bigger body means needing to control that more," Scott told Live Science. "Apex predators tend to be big. And because of a need for more complex behavior, like being able to outwit your prey, they benefit from having a bigger brain."

But, brain size isn't a perfect predictor of animal intelligence. The brain of an African elephant (Loxodonta africana) weighs 10 pounds (4.6 kg), on average, according to a 2014 study in the journal Frontiers in Neuroanatomy(opens in new tab), three times larger than the human brain. Their large brain size is due in part to their massive cerebellum, used to coordinate the muscle activity in their trunk and ears, according to Scott.

Colonia of Small Adult Rover Ant of the Genus Brachymyrmex with winged ants and white pupae.

Ants in the genus Brachymyrmex have a 1:8 brain-to-body-mass ratio. (Image credit: vinisouza128 / 500px via Getty Images)
Just as absolute brain size isn't a good predictor of animal intelligence, comparing brain-to-body mass ratios can also be a red herring. Humans and rodents have a roughly similar brain-to-body mass ratio (1:40), according to a 2009 study in the journal Frontiers in Human Neuroscience(opens in new tab). However, the same study argues that if a rat were human-size, it wouldn't be as intelligent because it has a smaller cerebral cortex (the outermost area of the brain, which is associated with the most complex mental functions) and fewer neurons there than humans do.

"If you look at the brain of a rabbit, a cat and a small monkey, they're not that different in size, but their behavior is going to be very different because of the nature of the brain cells," Scott said. "By the time you get to the monkey, you're seeing a primate brain, with proportionally larger frontal lobe areas and more curiosity-driven behavior."

Scott explained that evolutionary adaptations change the brain's structure to increase the size of certain areas and favor certain neural connections. In humans, the size of our cerebral cortex and the density of cortical neurons (the number of neurons present there) explain our intelligence more than the size of our brains relative to our bodies. Compared with other animals "we have quite a small body for the size of our brains," Scott said.

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—How many calories can the brain burn by thinking?

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—What animal has the largest ears?

When comparing brains of different species, it's important to consider brain architecture as well as brain size. Because brain-to-body-mass ratio does not take into account the evolutionary development of the cerebral cortex and the density of neural connections found there, scientists look to encephalization quotient (EQ) as a more accurate measure of animal intelligence. The encephalization quotient is the relative brain size observed in a particular species, compared with the expected brain size of other species of a similar body size. One key factor in EQ is the relative size of the cortex compared with the rest of the brain. Comparing animals based on their EQ provides a more accurate view of their intelligence than brain-to-body-mass-ratio, according to the Encyclopedia of Behavioral Neuroscience(opens in new tab), though not as accurate as measuring the absolute size and interaction of individual brain regions.

Related: Are cats or dogs smarter?

Then, there's a concept known as Haller's rule: The bigger the animal is, the smaller the brain-to-body ratio will be. "Because brain size scales relative to body size, the smallest animals have relatively the largest brains," Wulfila Gronenberg, a professor of neurobiology at the University of Arizona, told Live Science.

For example, ants have relatively small brains compared with other hymenoptera, a class that includes bees, wasps, hornets and sawflies. "We think this is because … ant workers don't fly," Gronenberg said. Flying requires a lot of visual processing, so many flying insects typically have large eyes, thus leading to larger optical lobes. "In some insects, like a dragonfly, visual processing is more than half of their entire brain," Gronenberg said.

In harmony with nature - in harmony with yourself

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