Categories
Science TECH

Study: Trapping atoms in a laser beam offers a new way to measure gravity

Trapping atoms in a laser beam may offer scientists a new way to study gravity.

According to a newly published study in Nov. 8 Science, scientists could better probe the gravitational forces exerted by small objects via lasers. The discovery may provide scientists with new insights into gravity and help test Einstein’s theory of gravity.

“Very impressive,” says physicist Alan Jamison of MIT. “It’s quite a challenge to work on these drop experiments, where you have a 10-meter-long tower,” he says. “Magnetic fields are hard to shield, and the environment produces them all over the place — all the electrical systems in your building, and so forth. Working in a smaller volume makes it easier to avoid those environmental noises.”

The discovery provides scientists with a solution to interference from stray magnetic fields. With a new tabletop setup, physicists can gauge the strength of Earth’s gravity by monitoring atoms suspended a couple millimeters in the air by laser light.

Categories
Science

Running just once a week may help you outpace an early death

Running a marathon may save your life, according to a new study.

A new study finds that people running as rarely as once a week have a lower risk of early death compared with people who don’t run at all.

A study published November 4 in the British Journal of Sports Medicine finds running was associated with a 27 percent lower risk of premature death.

“This is good news for the many adults who find it hard to find time for exercise,” says Elaine Murtagh, an exercise physiologist at Mary Immaculate College in Limerick, Ireland, who was not involved in the study. “Any amount of running is better than none.”

While this conclusion might seem obvious to runners, the science has been fairly mixed, says public health researcher Željko Pedišić of Victoria University in Melbourne, Australia. “Some studies found a significant benefit of running, but others did not,” he says.

Categories
NONE SCI Science

Archaeologists unearth long-lost Aztec tower of skulls

Archaeologists digging in Mexico City have unearthed the long-fabled Huey Tzompantli — a tower of human skulls thought to measure about 200 feet in diameter.

The tower was described in contemporary accounts of the Spanish conquistadores when they captured the Aztec capital of Tenochtitlan, which later became Mexico City.

The tower is located at the edge of the Templo Mayor, an edifice dedicated to the Aztec god of sun, war, and human sacrifice, according to a report by The Atlantic.

In the account of Andres de Tapia, a Spanish follower of Hernan Cortes during his conquest of Mexico in 1521, the tower was constructed of tens of thousands of skulls “placed on a very large theater made of lime and stone, and on the steps of it were many heads of the dead stuck in the lime with the teeth facing outward.”

What the archaeologists did not expect to find were so many skulls belonging to women and children. Researchers previously believed that young male warriors were mostly chosen as sacrificial victims. As a result, the discovery is raising new questions about the Aztec Empire’s culture of human sacrifice.

“We were expecting just men,” said Rodrigo Bolanos, a biological anthropologist working on the dig, in a report by Reuters, adding, “Something is happening that we have no record of, and this is really new, a first in the Huey Tzompantli.”

So far, researchers have discovered more than 650 skulls that were covered in lime to cement them together. Only a quarter of the excavation is completed.

Categories
NONE SCI Science

Archaeologists find slave quarters of Sally Hemings at Monticello

Archaeologists have discovered the living quarters of Sally Hemings — the enslaved African American woman who bore six of Thomas Jefferson’s children — at Jefferson’s Monticello estate. The room, 13 feet long and just under 15 feet wide, was adjacent to Jefferson’s bedroom.

Thomas Jefferson wrote the Declaration of Independence and was the third president the United States.

“This discovery gives us a sense of how enslaved people were living,” said Gardiner Hallock, director of restoration for Monticello, in a report by NBC News. “Some of Sally’s children may have been born in this room.”

Historians hit on a possible location for Hemings’ living quarters by studying a description related by one of Jefferson’s grandsons, who said Hemings’ room was in Monticello’s south wing.

Monticello’s director of archaeology, Fraser Neiman, said digging revealed the original brick fireplace, hearth, and early 19th century floors.

“This room is a real connection to the past,” Neiman said. “We are uncovering and discovering and we’re finding many, many artifacts.”

Gayle Jessup White is Sally Hemings’ great-great-great-great niece and also works at Monticello’s Community Engagement Officer.

“As an African American descendant, I have mixed feelings — Thomas Jefferson was a slave holder,” White said, in the NBC News report. I am appreciative of the work that my colleagues are doing at Monticello because this is an important American story. But for too long our history has been ignored. Some people still don’t want to admit that the Civil War was fought over slavery. We need to face history head-on and face the blemish of slavery and that’s what we’re doing at Monticello.”

Categories
NONE SCI Science

5.7-million-year-old “human footprints” stun paleontologists

An analysis of a set of human-like footprints in ancient rock beneath Crete has researchers baffled due to one critical detail: The rock is 5.7 million years old. There were not supposed to be fully evolved humans in Crete—or anywhere on Earth, for that matter—until less than a million years ago, according to the scientific consensus.
Gerard Gierlinski of the Polish Geological Institute found the footprints in 2002 and spent the next decade-and-a-half analyzing them before publishing the results just this month in the latest edition of Proceedings of the Geologists’ Association. The study notes numerous human-like features in the footprint: five toes, including a big toe similar to ours, as well as a distinct ball on the sole. There is also evidence of an upright posture and toenails instead of claws.
None of these features were supposed to appear for another four million years, at least, according to researchers. Also, there were not supposed to be any humans or apelike ancestors of humans anywhere outside Africa.
Until now, the earliest known footprints of hominids that show upright posture date back 3.7 million years ago and are located in present-day Tanzania. There is an earlier set of footprints dating back 4.4 million years ago, but its discoverers said that it very closely resembles an ape’s footprint and shows none of the human-like traits of Gierlinski’s find.
Gierlinski posits that there was another human-like creature that was roaming the Earth eons before any of the known hominids. This creature might have likewise made it to present-day Crete long before any currently known hominids left the African savanna.
“As Crete is some distance outside the known geographical range of pre-Pleistocene (2.5 million to 11,700 years ago) hominins we must also entertain the possibility that they represent a hitherto unknown late Miocene primate that convergently evolved human-like foot anatomy,” the study states.

Categories
NONE SCI Science

African dogs use sneezes to make pack decisions

African wild dogs use sneezing as a way to determine how many members of the pack are ready to move and hunt, according to a new study published in the Proceedings of the Royal Society B.

There are many ways animals communicate, but there is no doubt this is one of the more unusual. Researchers first noted the behavior while conducting a separate study on the dog’s characteristics.

Researchers found that the more sneezes — or “audible rapid nasal exhalations” — the dogs emitted, the more likely the pack would be to set out on its next hunt. The team came to this conclusion after watching five packs in Botswana engage in a total of 68 gatherings.

Not only are the sneezes used for communication, but they differ based on an individual dog’s social standing as well.

“Rallies never failed when a dominant…individual initiated and there were at least three sneezes, whereas rallies initiated by lower ranking individuals required a minimum of 10 sneezes to achieve the same level of success,” stated the study’s authors, according to NPR.

However, while this process is interesting, the sneezes are hard to properly analyze because they do not count as true votes. This is because each dog is not limited to one sneeze and scientists are not sure if each one is voluntary or some are a natural reaction.

Even so, the findings are important because they shed light on a new process. While the dominant members of a pack hold more power than others, every member has a say in certain decisions depending on how many sneezes they can muster.

African wild dogs are not the only species that makes unique sounds to help with decision making, but they are the only one that uses sneezing as their voting method. Researchers seek to follow up on the study by looking at other animals, and they hope the new findings will bring light to the canines, which are one of the most endangered species in the world.

“They’re absolutely gorgeous animals focused on cooperation and their pack family unit,” says study co-author Reena Walker, a student at Brown University, according to National Geographic. “The more people who are aware [of] how amazing these animals are, the better.”

Categories
HEALTH NONE SCI Science

A first: Micromotors used to treat stomach infection

For the first time, nanoengineers have successfully used micromotors — tiny magnesium-based engines no bigger than half the width of a human hair — to treat a bacterial infection in the stomach, according to a statement by the University of California at San Diego’s Jacobs School of Engineering.

The findings are published in the Aug. 16 issue of the journal Nature Communications.

The micromotors are released into the stomach where they swim about rapidly neutralizing gastric acid and releasing antibiotics. Each micromotor has a round magnesium core and is fueled by the reaction of gastric acid with the magnesium, which produces a blast of tiny hydrogen bubbles that propels the micromotor around inside the stomach.

The micromotors are biodegradable and the magnesium cores along with their binding polymer layers are dissolved by the stomach’s gastric acid without harmful effects.

Delivery of drugs to neutralize gastric acid and treat bacterial infections, such as ulcers, by micromotors avoids the use of proton pump inhibitors, which currently are employed to suppress gastric acid production but have several unwanted side effects, including diarrhea, headaches, and depression.

“It’s a one-step treatment with these micromotors, combining acid neutralization with therapeutic action,” said co-first author Berta Esteban-Fernández de Avila, a postdoctoral scholar at UC-San Diego.

The researchers tested the micromotors — loaded with a dose of the antibiotic clarithromycin — in mice infected with Heliobacter pylori. They gave the mice one antibiotic-filled micromotor once daily for five consecutive days.

Once the treatment regimen was complete, analysis of the bacterial count in each mouse’s stomach showed that treatment with micromotors was slightly more effective than conventional treatment using proton pump inhibitors.

While the work is still at an early stage, the results look promising, according to the researchers, who say their work opens the door to the use of micromotors as delivery vehicles for the treatment of diseases.

Categories
NONE SCI Science

5.7 million-year-old fossil footprints from Crete shake up theories of human evolution

Scientists working on the Greek island of Crete have found distinctly human-like footprints that are 5.7 million years old — a discovery that is challenging accepted theories of human evolution because they date back long before human ancestors are thought to have left Africa.

The footprints, found embedded in rock in an area called Trachilos in western Crete, show that the creature was bipedal, had five toes, and sported an especially human-like big toe that is similar to those of modern humans in size, shape, and position.

The research is published in the journal Proceedings of the Geologists’ Association.

“Human feet have a very distinctive shape, different from all other land animals,” wrote Uppsala University, in a statement. “The combination of a long sole, five short forward-pointing toes without claws, and a hallux (“big toe”) that is larger than the other toes, is unique.”

By contrast, the 3.7 million-year-old Laetoli footprints from Tanzania, believed to have been made by Australopithecus, lack arches and have narrower heels than modern humans, while the 4.4 million-year-old Ardipithecus ramidus from Ethiopia has a more ape-like foot.

“What makes this controversial is the age and location of the prints,” says co-author Prof. Per Ahlberg of Uppsala University, in the statement.

When the Trachilos footprints were made, during the late Miocene, Crete was still attached to the Greek mainland and savannah-like environments stretched from North Africa around the eastern Mediterranean.

“This discovery challenges the established narrative of early human evolution head-on and is likely to generate a lot of debate,” says Ahlberg. “Whether the human origins research community will accept fossil footprints as conclusive evidence of the presence of hominids in the Miocene of Crete remains to be seen.”

Categories
Science

Birds can “see” magnetic fields, study reports

Two newly published papers show that birds likely use a special protein in their eyes to navigate around the world.

While birds have been the subject of study for centuries, researchers have never fully understood how they travel around the world with such ease. To shed light on that mystery, scientists at Lund University and the Carl von Ossietzky University Oldenburg found evidence that the protein known as Cry4 might be responsible for avian navigation.

Cry4 is from a protein class known as cryptochromes. Such molecules are sensitive to blue light.and help regulate circadian rhythms. Now, researchers have cause to believe they help birds detect magnetic fields as well.

Past research shows that the cryptochromes in birds’ eyes allows the animals to orient themselves through a process known as magnetoreception. Scientists also know that birds can only sense magnetic fields if certain wavelengths are available.

To follow up on such research, the teams behind the two new studies looked at both zebra finches and Europeans robins. They looked at the birds by analyzing gene expression of the cryptochromes, Cry1, Cry2, and Cry4.

That showed, while Cry1 and Cry2 fluctuated each day, Cry4 — which expressed at constant levels — was the most likely candidate for magnetoreception. That held true for both zebra finches and robins.

“We also found that Cry1a, Cry1b, and Cry2 mRNA display robust circadian oscillation patterns, whereas Cry4 shows only a weak circadian oscillation,” the researchers wrote in their study, according to Science Alert.

In addition, the teams also discovered that Cry4 sits in a region of the retina that receives a lot of light. That further adds credence to the idea that it is used for magnetoreception. In addition, European robins have increased their Cry4 expression over time.

While both teams believe more research is needed before anyone can definitively say that Cry4 is responsible for magnetoreception, the evidence laid out in the two studies is quite strong. The next step is to analyze birds with non-functioning Cry4 and see how they perceive magnetic fields. Only then will teams be able to tell just how important the protein is.

The two studies are published in the Journal of the Royal Society Interface, and Current Biology.

Categories
PHYS Physics SCI Science

Star, black hole interaction further proves Einstein’s theory

For the first time in history scientists have used a supermassive black hole’s gravitational field to confirm Einstein’s theory of general relativity, a new study in Astronomy & Astrophysics reports.

To do this, a team of international researchers analyzed the black hole at the center of the Milky Way — known as Sagittarius A — and a star in its orbit known as S2.

Using a combination of technology, mathematics, and observations, they studied the pair and observed S2 move close to the black hole. During that event, the fiery body acted exactly as predicted by the theory of relativity. 

“This is the second time that we have observed the close passage of S2 around the black hole in our galactic center,” said study co-author Reinhard Genzel, a researcher at the Max Planck Institute for Extraterrestrial Physics, according to Science Alert. “But this time, because of much improved instrumentation, we were able to observe the star with unprecedented resolution.”

Three S-stars orbit Sagittarius A, and S2 gets extremely close to the hole every now and then. In the recent study, it moved within just 17 light-hours of the formation.

That is significant because, according to Einstein’s theory, the event should have stretched S2’s light into long wavelengths through a process known as gravitational redshifting.

While it is not easy to observe S2, high-tech telescopes analyzed the star and revealed its light did behave in that way.

The finding falls in line with other recent studies that set out — and failed — to disprove the popular theory.

However, such trials are important because if the theory ever does fail it would drastically alter the way scientists view and understand both the universe and the field of physics. 

“What we hope is at some point we will see something in the galactic centre that we can’t explain with Einstein’s theory – that would be really, really exciting,” said study co-author Odele Straub, a researcher at the Paris Observatory in France, according to BBC News. “Because then we could go back to the drawing board and come up with something better.”