Category: 7. Science

Using cannabis could make changes to your body’s epigenetic code, research has discovered. The findings, which were published in a study in 2023, suggest that using marijuana in any way can affect the code that your body uses to switch on and off different genes. This research is vital to fully understanding the effects marijuana use has on the body and could open the door to further research down the line.

As one of the most used drugs in the world, the way that marijuana affects the human body is still not fully understood. We have some understanding of its impact, but this research shows that it has a much longer reach than scientists might have previously expected. One of the markers found during the research ties directly to the markers seen in tobacco use, suggesting a much closer association between the use of tobacco and marijuana.

Further, the researchers wanted to see how using cannabis changes the epigenetic code, as fully understanding this could help them ascertain whether it has any directly negative or positive effects on human health. Most notably, they wanted to see how it might affect the genes associated with aging, which are typically controlled by the body’s epigenetic code. Understanding changes to the body’s epigenetic code can help us understand how heat affects aging, as well as what the body’s epigenetic age is.

To conduct their research, the scientists used data gathered from willing participants that had their use of cannabis surveyed over the years. The researchers looked at blood samples taken five years apart, and compared the blood based on factors like consecutive cannabis use, as well as whether or not they had used the drug recently.

Together, the data showcased just how much using cannabis changes the epigenetic code. They found several markers that could be tied to both consecutive and recent use. However, the researchers note that additional research is needed to truly understand the connections and how far they reach throughout the code. For now, though, this research has at least provided some novel insights into the association between using marijuana and epigenetic factors.

If you live in the Northern Hemisphere and look up during July evenings, you’ll see the brilliant star Vega shining overhead. Did you know that Vega is one of the most studied stars in our skies? As one of the brightest summer stars, Vega has fascinated astronomers for thousands of years.

Vega is the brightest star in the small Greek constellation of Lyra, the harp. It’s also one of the three points of the large “Summer Triangle” asterism, making Vega one of the easiest stars to find for novice stargazers. Ancient humans from 14,000 years ago likely knew Vega for another reason: it was the Earth’s northern pole star! Compare Vega’s current position with that of the current north star, Polaris, and you can see how much the direction of Earth’s axis changes over thousands of years. This slow movement of axial rotation is called precession, and in 12,000 years, Vega will return to the northern pole star position.

Bright Vega has been observed closely since the beginning of modern astronomy and even helped to set the standard for the current magnitude scale used to categorize the brightness of stars. Polaris and Vega have something else in common, besides being once and future pole stars: their brightness varies over time, making them variable stars. Variable stars’ light can change for many different reasons. Dust, smaller stars, or even planets may block the light we see from the star. Or the star itself might be unstable with active sunspots, expansions, or eruptions changing its brightness. Most stars are so far away that we only record the change in light, and can’t see their surface.

NASA’s TESS satellite has ultra-sensitive light sensors primed to look for the tiny dimming of starlight caused by transits of extrasolar planets. Their sensitivity also allowed TESS to observe much smaller pulsations in a certain type of variable star’s light than previously observed. These observations of Delta Scuti variable stars will help astronomers model their complex interiors and make sense of their distinct, seemingly chaotic pulsations. This is a major contribution towards the field of astroseismology: the study of stellar interiors via observations of how sound waves “sing” as they travel through stars. The findings may help settle the debate over what kind of variable star Vega is. Find more details on this research, including a sonification demo that lets you “hear” the heartbeat of one of these stars, at: bit.ly/DeltaScutiTESS

In 2024, the James Webb Space Telescope revisited the Vega system to reveal a 100-billion-mile-wide disk of dust around this star. While the debris disk is confirmed, there is no evidence of planets as of today.

Originally posted by Dave Prosper: June 2020

Last Updated by Kat Troche: July 2025

Astronomers have discovered that radiation emitted by a rapidly spinning neutron star, or “pulsar,” is dominated by the impact of its powerful particle winds — and not by the material it strips from a companion star.

The pulsar in question is PSR J1023+0038 (J1023), which sits in a binary system located 4,500 light-years away from Earth. This binary consists of a “dead star,” or neutron star that spins around 600 times a second, as well as a low-mass star upon which the neutron star “feeds.”

Physicists with the USC Dornsife College of Letters, Arts and Sciences, Cornell University and collaborating institutions have created a microscopic device that can both detect and control the rapid “dance” of electron spins in antiferromagnetic materials — a leap that could enable a new generation of ultrafast, energy-efficient electronics.

The work was published this month in Science.

• Antiferromagnetic materials are solids in which electrons spin in opposite directions, canceling each other’s This zero-magnetism makes them fast, stable and immune to outside magnetic interference.
• Until now, scientists could only detect this quantum behavior using bulky lab equipment — making it hard to imagine practical uses in everyday tech.

Why it matters: Antiferromagnets can operate at mind-boggling speeds — trillions of cycles per second — and could support real-world applications that include:

• Ultra-secure, lightning-fast wireless communications, well beyond 5G speeds.
• Ultra-high-resolution medical imaging.
• Safer airport security scanning without X-rays.
• Nano-oscillators that convert a static voltage to high-frequency signals, useful in a wide range of applications, including advanced computers and sensors.

And it does all of this with a device just a few atoms thick, using only electric signals — no room-sized equipment required.

The work was made possible by funding from the National Science Foundation and the U.S. Department of Energy — two key supporters of fundamental research driving tomorrow’s technology.

The breakthrough: The team built a microscopic structure called a “tunnel junction” made of three, ultra-thin stacked layers of materials. This tiny device can do two key things:

1. Detect antiferromagnetic resonance — the natural vibration of opposing electron spins.
2. Tune that resonance electrically using a force called spin-orbit torque, which nudges the electron spins into motion.

What they’re saying: “This gives us a quantum-scale stethoscope and control knob in one,” said Kelly Luo, co-corresponding author and Gabilan Assistant Professor of Physics and Astronomy, Chemistry, and Chemical Engineering and Materials Science at USC Dornsife. “We’re able to listen to the spin dynamics — and then dial them up or down — using nothing but electric current.”

How it’s different: Previous methods for detecting antiferromagnetic behavior relied on bulky lab equipment and relatively large materials. This new device works at the micron scale — roughly 1,000 times smaller — making it the most compact, electrically tunable platform yet.

• “We’ve shrunk the technology down to a size that makes practical applications possible,” said Daniel Ralph, co-corresponding author and R. Newman Professor of Physics in Cornell’s College of Arts and Sciences. “That’s what makes this so exciting.”

A clever twist: At first, the team couldn’t tell which of the two magnetic layers was responsible for the signal — their behaviors were too closely linked.

Their solution? Twist the layers ever so slightly to break the symmetry. That allowed them to target just one layer with electric current while leaving the other unaffected.

“It was like trying to separate the sound of two violins playing the same note,” said lead author Thow Min Jerald Cham, formerly at Cornell and now David and Ellen Lee Postdoctoral Scholar at Caltech. “That tiny shift helped us tell them apart and control each one individually.”

What’s next? The researchers plan to develop nano-oscillators based on their device — tiny components that generate ultra-fast signals for applications in medical imaging, scientific instruments, telecommunications, quantum computing and more.

• They also want to explore “negative damping” — a phenomenon where, instead of fading out, the spin oscillations actually gain energy. That could allow the device to act as a powerful, terahertz radiation source in a footprint smaller than a grain of sand.

About the study

In addition to Luo, Ralph and Cham, study authors include Xiaoxi Huang of Cornell; Daniel Chica and Xavier Roy of Columbia University; and Kenji Watanabe and Takashi Taniguchi of Japan’s National Institute for Materials Science.

Read more on the Cornell University College of Letters, Arts and Sciences’ news website.

Editor’s Note: Darrin S. Joy and Jim Key contributed to this article along with Linda B. Glaser of Cornell.

The largest piece of Mars ever found on Earth was sold for just over $5 million at an auction of rare geological and archaeological objects in New York on Wednesday, while a juvenile dinosaur skeleton went for more than $30 million.

The 54-pound (25-kilogram) rock named NWA 16788 was discovered in the Sahara Desert in Niger by a meteorite hunter in November 2023, after having been blown off the surface of Mars by a massive asteroid strike and traveling 140 million miles (225 million kilometers) to Earth, according to Sotheby’s. The estimated sale price before the auction was $2 million to $4 million.

READ MORE: NASA rover Perseverance observes first aurora at Mars visible to the human eye

The identity of the buyer was not immediately disclosed. The final bid was $4.3 million. Adding various fees and costs, the official bid price was about $5.3 million.

Two advance bids of $1.9 million and $2 million were submitted. The live bidding went slower than for many other objects that were sold, with the auctioneer trying to coax more offers and decreasing the $200,000 to $300,000 bid intervals to $100,000 after the proposals hit $4 million.

The red, brown and gray meteorite is about 70% larger than the next largest piece of Mars found on Earth and represents nearly 7% of all the Martian material currently on this planet, Sotheby’s says. It measures nearly 15 inches by 11 inches by 6 inches (375 millimeters by 279 millimeters by 152 millimeters).

It was also a rare find. There are only 400 Martian meteorites out of the more than 77,000 officially recognized meteorites found on Earth, the auction house says.

“This Martian meteorite is the largest piece of Mars we have ever found by a long shot,” Cassandra Hatton, vice chairman for science and natural history at Sotheby’s, said in an interview before the auction. “So it’s more than double the size of what we previously thought was the largest piece of Mars.”

It’s not clear exactly when the meteorite was blasted off the surface of Mars, but testing showed it probably happened in recent years, Sotheby’s says.

READ MORE: ‘Dinosaur highway’ dating back 166 million years discovered in England

Hatton said a specialized lab examined a small piece of the red planet remnant and confirmed it was from Mars. It was compared with the distinct chemical composition of Martian meteorites discovered during the Viking space probe that landed on Mars in 1976, she said.

The examination found that it is an “olivine-microgabbroic shergottite,” a type of Martian rock formed from the slow cooling of Martian magma. It has a course-grained texture and contains the minerals pyroxene and olivine, Sotheby’s says.

It also has a glassy surface, likely due to the high heat that burned it when it fell through Earth’s atmosphere, Hatton said. “So that was their first clue that this wasn’t just some big rock on the ground,” she said.

The meteorite previously was on exhibit at the Italian Space Agency in Rome. Sotheby’s did not disclose the owner.

Bidding for the juvenile Ceratosaurus nasicornis dinosaur skeleton started with a high advance bid of $6 million, then escalated with offers $500,000 higher than the last and later $1 million higher than the last before ending at $26 million. The official sale price was $30.5 million with fees and costs. The original estimate was $4 million to $6 million.

READ MORE: What mud cracks on Mars tell us about whether life could have formed on the planet

Parts of the skeleton were found in 1996 near Laramie, Wyoming, at Bone Cabin Quarry, a gold mine for dinosaur bones. It’s more than 6 feet (2 meters) tall and nearly 11 feet (3 meters) long.

Specialists assembled nearly 140 fossil bones with some sculpted materials to recreate the skeleton and mounted it so it’s ready to exhibit, Sotheby’s says.

The juvenile Ceratosaurus nasicornis skeleton is displayed during a preview of Sotheby’s Natural History auction in New York City on July 8, 2025. Photo by Eduardo Munoz/ Reuters

The skeleton is believed to be from the late Jurassic period, about 150 million years ago, Sotheby’s says.

Ceratosaurus dinosaurs were bipeds with short arms that appear similar to the Tyrannosaurus rex, but smaller. Ceratosaurus dinosaurs could grow up to 25 feet (7.6 meters) long, while the Tyrannosaurs rex could be 40 feet (12 meters) long.

READ MORE: Fossils reveal dinosaur forerunner smaller than a cellphone

The skeleton was acquired last year by Fossilogic, a Utah-based fossil preparation and mounting company.

Wednesday’s auction was part of Sotheby’s Geek Week 2025 and featured 122 items, including other meteorites, fossils and gem-quality minerals.

A new study published this month has issued an urgent call for future endeavors in space exploration to take nuclear space travel seriously. Similar to a previous study which called for scientists to take terraforming Mars seriously, this new study suggests that focusing on nuclear advancements to power new rockets could drastically improve our chances of deep space exploration.

It’s not a hard argument to follow by any means, and I’m honestly surprised we haven’t seen more urging from the scientific community in regards to it. But what makes this new study so interesting is the fact that the researchers involved have offered three different options to help support in-space demonstrations of nuclear technology.

One of the biggest problems surrounding nuclear space travel is the fact that nobody has really seen any breakthroughs for decades at this point. As Spacenews.com reports, NASA hasn’t seen anything but fizzling projects since the 1960s. That’s an insanely long amount of time for no breakthroughs to take place.

But there are several factors that could end that streak, according to Bhavya Lal, a former NASA associate administrator for technology, policy, and strategy. Lal, who co-authored the new study, says that geopolitical competition could be a major driver in the push to actually make working nuclear space engines. One big part of that driving force could be China’s continued developments in space travel.

Much like here on Earth, most see space as being a “the first movers make the laws” kind of battleground. That means if America falls behind and China makes more advancements — like settling the Moon or even Mars first — then that country (or any other country involved) could make rules and laws before America can even get a foundation set. As such, Lal and the other authors of the study argue it is time for America to take nuclear space travel seriously.

Of course, saying that and actually making it happen are two entirely different things. Sure, we’ve seen some good ideas about what nuclear-powered spacecraft might be able to accomplish, but we have yet to really see anything take off and succeed.

Two of the approaches offered up in the study include a “Go Big or Go Home” option, which would look to develop a government-owned and operated reactor that can produce between 100 to 500 kilowatts of power. Such a reactor would cost around $3 billion to develop, the study suggests, and could see ground tests as early as 2028, with a flight demonstration by 2030.

The second approach is a “Chessmaster’s Gambit,” which would involve two private partnerships working to create reactors that can generate between 10 to 100 kilowatts of power. None of these would be looking at creating megawatt-capable nuclear reactors yet, as Lal says they need to start small to keep costs down and drive breakthroughs.

On July 15, a solar filament erupted from the Sun’s upper left side, ejecting a powerful blast of plasma and magnetic fields into space. The resulting explosion was so massive that it seared a deep, fiery scar of hot plasma and debris onto the star’s visible surface.

While filament eruptions aren’t uncommon, astronomers had already been watching an unusually large filament—cold, dense ribbons of gas suspended above the Sun’s surface—that they spotted days before the explosion. When the filament inevitably collapsed, they had the Solar Dynamics Observatory at the ready to capture the violent ripple of plasma caused by small instabilities in the Sun’s magnetic field.

The resulting explosion carved a gargantuan “canyon of fire” more than 250,000 miles (400,000 kilometers) long, with a height of at least 12,400 miles (20,000 km), reported Tony Phillips, an astronomer who manages Spaceweather.com, a site that tracks solar activity and other space weather events. “A grand canyon, indeed,” he wrote in a brief update of the event.

One practical reason astronomers monitor filaments is that eruptions can sometimes cause coronal mass ejection events (CMEs), or intense bursts of plasma and magnetic fields. When CMEs reach Earth, they can trigger geomagnetic storms that shock power grids and network systems. For astronauts in space, these storms may expose them to dangerously high levels of radiation, impacting their health.

Fortunately, follow-up observations by the Solar and Heliospheric Observatory and the National Oceanic and Atmospheric Administration confirmed that this CME appears to be headed away from Earth. As to how long the filament’s scar will last on the Sun, we’ll just have to see.

Two of the strangest structures in the galaxy just got even stranger.

Ballooning above and below the Milky Way’s center like a massive hourglass, the mysterious Fermi bubbles loom large over our galaxy. These enormous twin orbs of superheated plasma have been gushing out of the galactic center for millions of years. Today, they span some 50,000 light-years from tip to tip, collectively making them half as tall as the Milky Way is long.

Now, scientists studying the perplexing bubbles with the U.S. National Science Foundation Green Bank Telescope in West Virginia have discovered something shocking: Nestled deep within the superhot bubbles are gargantuan clouds of cold hydrogen gas that have inexplicably survived in an extreme environment.

According to the researchers, these bewildering clouds are likely the remnants of much larger structures that puffed out of the galaxy’s center several million years ago.

Where did the world’s most devastating weapon come from? In a four-part series, we go behind the scenes at America’s nuclear laboratories to understand how a scientific-mystery story about the ingredients of matter led to a world-changing (and second-world-war-ending) bomb less than five decades later.

Nuclear weapons have been central to geopolitical power ever since. Now America is seeking to modernise its stockpile and, in doing so, its scientists are pushing the frontiers of extreme physics, materials science and computing.

In episode one, we look at the birth of nuclear physics—the science that emerged early in the 20th century to answer a mystery: what is an atom actually made of?

Host: Alok Jha, The Economist’s science and technology editor. Contributors: Frank Close, a physicist and author of “Destroyer of Worlds”, a history of the birth of nuclear physics; Cheryl Rofer, a chemist who used to work at the Los Alamos National Laboratory (LANL); and Nicholas Lewis, a historian at LANL.

This episode features archive from the Atomic Heritage Foundation.

Listen on: Apple Podcasts | Spotify

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Stars are born in clusters, and the early days in these clusters are messy. Stars move chaotically and haven’t settled into regular routines. Inevitably, some stars are kicked out of their birth clusters through all of the gravitational interactions.

The Large Magellanic Cloud, though much less massive than the Milky Way, is home to a very unusual star cluster named NGC 2070. NGC 2070 is a large open star cluster within the Tarantula Nebula in the LMC. NGC 2070’s central cluster makes astronomers sit up and take notice. It’s called R136, and it holds an extremely dense concentration of massive O-type stars and Wolf-Rayet stars. O-type stars are very hot, and very rare, but since they’re so luminous they’re not difficult to spot. Wolf-Rayet stars are also massive, hot, and highly luminous.

The extraordinary luminosity of the stars in R136, which altogether have about 60,000 solar masses, provides most of the energy that illuminates the entire Tarantula Nebula. For this reason, it’s called a starburst region. It contains many of the most massive and luminous stars astronomers know of.

This JWST image of the Tarantula Nebula highlights the brilliant central cluster R136. This tightly-packed region of extremely luminous stars lights up the nebula. Image Credit: NASA, ESA, CSA, STScI, Webb ERO Production Team

R136 is very young, only about one or two million years old. The region is extremely chaotic, and in 2024, astronomers found 55 massive runaway stars coming from the cluster in two waves. A 2024 paper reporting these findings also discovered that 23–33% of the most luminous stars initially born in R136 are runaways.

New research published in Physical Review Letters examined what’s behind some of these stellar ejections, focusing on a binary star named Mel 34. It’s titled “Origin of the Most Recently Ejected OB Runaway Star from the R136 Cluster.” The lead author is Simon Portegies Zwart, Professor of Numerical Star Dynamics at Leiden University in the Netherlands.

The 2024 paper used data from the ESA’s Gaia mission to show that three of R136’s ejected stars were evicted from the core about 60,000 years ago. However, what caused the triple ejection was unknown. In the new research, Portegies Zwart and his co-researchers reconstructed their ejection, showing that there were five stars involved in the expulsion.

Mel 39 is a binary star with two massive stars, one with 140 solar masses, and the other with 80. Mel 39 is travelling away from the R136 cluster at 64 km/s. It’s in the same orbital plane as Mel 34, the other ejected binary. Mel 34 is one of the most massive known binaries, with the larger of the pair having 139 solar masses, and the other one with 127 solar masses. When combined with VFTS 590, the other star involved, and its 46 solar masses, the five stars constitute more than 530 solar masses.

The researchers relied on Gaia’s precise astrometry to untangle the backstory of these five stars and their ejection from R136. Mel 34 was the last of the stars to be ejected, and tracing it backwards in time and space helped the researchers reconstruct the interactions that led up to the ejection.

“Because of the Gaia satellite’s outstanding precision, we can now retrace the most recently ejected binary star, Mel 34, back to the center of R136 and reconstruct the events that 52 000 years ago led to its removal from R136,” the authors write. “The deterministic nature of the Newtonian dynamics in the scattering enables us to reconstruct the encounter that ejected Mel 34.”

Gravitational interactions follow Newton’s laws of motion, which are deterministic. That means the same starting conditions always produce the same results, unlike quantum laws. So by measuring Mel 34’s trajectory, position, and velocity, the researchers ‘mathematically reversed’ Mel 34’s path, and recovered a picture of the expulsion of the stars. In a sense, each star is like a fossil record of its origins that allows backwards tracing.

Runaway stars stand out from the background due to their trajectories and velocities. In 2010, the Hubble Space Telescope found another star ejected from a different part of the Tarantula Nebula. The heavyweight star, called 30 Dor #016, is 90 times more massive than the Sun and is travelling at more than 400,000 kilometers per hour from its home. Image Credit: By NASA, ESA, J. Walsh (ST-ECF) Acknowledgment: Z. Levay (STScI) Credit for ESO image: ESO Acknowledgments: J. Alves (Calar Alto, Spain), B. Vandame, and Y. Beletski (ESO) Processing by B. Fosbury (ST-ECF) – http://www.spacetelescope.org/news/heic1008/, CC BY 3.0.

“We then predict that Mel 39 is a binary star with an 80⁢𝑀⊙ companion star that orbits within ∼1° in the same plane as Mel 34 and escapes the cluster with a velocity of ∼64  km/s,” the authors explain.

The reconstruction simulations show that the ejection involved five stars, the Mel 34 and Mel 39 binaries and VFTS 590. Since two are binaries, the system acts like a triple star, where VFTS 590 and Mel 34 orbit Mel 39. These results were unexpected, according to the authors. “The participation of five stars is unexpected because runaway stars were not expected to result from triple interactions,” they explain in their paper.

These stars are travelling rapidly away from R136 due to the interactions, but there fates are sealed. All five of these massive stars will eventually explode as supernovae in a few million years. “The five stars will undergo supernova explosions in the coming 5 Myr at a distance of ∼180–332  pc from their birth location (R136),” the researchers explain in their paper.

“The resulting black hole binaries, however, are not expected to merge within a Hubble time,” they conclude.

The ejected stars in this study aren’t R136’s only runaway stars. Its 55 runaway stars paint a picture of R136 as an extreme, dynamically active region. With all of these ejected stars, many of them extremely bright, the star cluster is an excellent natural laboratory to study how massive clusters like this one evolve.