Tiny crab robots are so small they can walk on top of a US penny

Yet at its most elusive, hope still resides within the human spirit — a force that is capable of growth and change.

It’s the same perpetual motion that has propelled innovation on our planet for thousands of years and made the impossible possible.

It’s inspiring to think of what we’re capable of when we work together, and “we all shine on, like the moon and the stars and the sun.”

Trailblazers

A tiny robotic crab stands on the edge of a US penny.

If you tried to play a game of “I Spy” with these robots, you might lose.

The world’s smallest remote-controlled walking robots are more miniscule than the thickness of a United States penny.

Engineers at Northwestern University created the tiny robots, which resemble crabs, inchworms and crickets. Made from shape-memory alloy, the robots start out as flat as a piece of paper. Heat from lasers allow the robots to come to life and move around.

These little critter bots are still in development, but the researchers envision a future that could include minimally invasive surgeries or even flight.

Dino-mite!

Dinosaurs like the towering T. rex and lumbering Brachiosaurus were hot-blooded (and scientists checked it to see).

Early on, paleontologists grouped dinosaurs with reptiles, which are cold-blooded. But modern researchers have come to the consensus that dinos were much more like birds.

Now, a groundbreaking study has found some dinosaurs were warm-blooded like birds and mammals. So what’s the difference? Warm-blooded animals require lots of oxygen and calories to maintain their body temperature, while cold-blooded animals breathe and eat less.

The researchers also revealed that other dinosaurs like Triceratops and Stegosaurus evolved to be more like cold-blooded animals — and that could change the way we understand their evolution.

A long time ago

This is Burnswark Hill fort in southwest Scotland, where Roman legions tried to push their boundary northward.

Archaeologists have uncovered 134 previously unknown Iron Age settlements during a survey of the region north of Hadrian’s Wall in the United Kingdom.

These sites likely belonged to Indigenous communities during the Roman occupation — and the discovery of the farmsteads could tell a new side of this story.

Much is known about the Roman quest for control, but written sources from the time period, and perspectives of the locals, are scarce. Just what did Indigenous people think about these invaders as they tried to push into modern-day Scotland?

A new project called “Beyond Walls” aims to shed light on who lived at these settlements and their relationship with the well-armed Roman legions, who were never quite able to control northern Britain.

Across the universe

The Hubble Space Telescope has helped astronomers make great strides in unlocking the secrets of the universe.

One of the main goals for the observatory when it launched was to measure the expansion rate of the universe. Hubble data has allowed scientists to discover and refine that accelerating rate. But in the process, they have stumbled upon an unusual wrinkle.

There is a difference between the expansion rate of the local universe and that of the distant universe right after the big bang — and scientists don’t know why. This weird mystery could require brand-new physics to unravel.

And speaking of weird things witnessed by telescopes, the Landsat 9 satellite spied an undersea volcano, dubbed “Sharkcano,” erupting in the Pacific Ocean near the Solomon Islands.

Wild kingdom

A greater one-horned rhinoceros is seen grazing in India's Kaziranga National Park.

The Indian rhinoceros, once on the verge of extinction, is rebounding in a big way.

The population of this animal, also called the greater one-horned rhino, has reached its highest level since the 1980s. The horned mammal lives in India and Nepal and experienced a “baby boom” during the pandemic while protected areas were closed to visitors.

The governments of India and Nepal have also worked on conservation efforts to protect the vulnerable animals from poaching and provide them with room to roam.

The Indian rhino is poised to be a comeback kid, but experts say there is still work to be done.

Explorations

Take a closer look:

— For the first time, scientists sequenced the genome of a man who died after the eruption of Mount Vesuvius in 79 AD, and the Pompeii victim’s DNA revealed some unexpected insights.

— Previously sunken boats are emerging at Lake Mead as water levels at the nation’s largest reservoir dropped below 1,050 feet elevation for the first time.

— The InSight lander has shared its final selfie from the surface of Mars — and it’s easy to see in the photo why the mission is coming to an end.

One more note before you go. Summer unofficially begins for many in the US this weekend. Be prepared: Hurricane season starts next week, and this year NOAA forecasts above-average activity that includes several major hurricanes.

Like what you’ve read? Oh, but there’s more. Sign up here to receive in your inbox the next edition of Wonder Theory, brought to you by CNN Space and Science writer Ashley Strickland, who finds wonder in planets beyond our solar system and discoveries from the ancient world.

source: cnn.com