Category: 7. Science

For decades, scientists believed the universe would expand forever, driven endlessly outward by a mysterious force known as dark energy. But a new study has upended that view with a provocative idea: the cosmos may one day stop expanding and instead collapse in on itself in a cataclysmic event called the “Big Crunch.” According to the research, which is currently in preprint and awaiting peer review, this reversal could happen in about 20 billion years. Based on new models and fresh astronomical data, scientists are rethinking the fate of everything we know.

The universe may not expand forever

The traditional model of the universe’s fate was built on the assumption that dark energy is constant and positive, a force pushing galaxies apart faster over time. But researchers analysing data from the Dark Energy Survey (DES) and the Dark Energy Spectroscopic Instrument (DESI) found evidence that dark energy might not be constant after all. Instead, it could vary over time, as proposed by a new theoretical framework called the axion-dark energy (aDE) model.One of the most striking findings in the new study is the possibility that the cosmological constant — which reflects the energy density of space itself — may be negative. If true, this would mean that gravity could eventually overpower expansion. Over time, this shift would cause the universe’s growth to slow, stop, and then reverse into a contraction phase.

What is the Big Crunch

If contraction occurs, all matter and energy could eventually be compressed into a single, dense point — an event known as the Big Crunch. This would be the reverse of the Big Bang. According to the aDE model, the total lifespan of the universe would be about 33.3 billion years, and we are already 13.8 billion years into that span. That leaves approximately 20 billion years before the predicted collapse.

Not a final verdict yet

Although the findings are significant, scientists caution that this new model is not confirmed. It is based on observational trends and evolving theoretical physics. Further investigation using next-generation telescopes and deeper space surveys will be needed to determine whether dark energy truly changes over time and whether a cosmic collapse is on the horizon.

Is the end really the end

Even if the Big Crunch occurs, it might not mark the permanent end of everything. Some theories propose that a collapsing universe could eventually lead to a rebirth — a new Big Bang triggering a fresh universe cycle. While these ideas remain speculative, the study has opened a bold new chapter in understanding how — and when — our universe might end.

When we think of sea animals, we usually picture dolphins, whales, or sharks. But there’s one sea creature that’s quietly amazing– the octopus. With its soft body, eight bendy arms, and smart behaviour, it’s truly one of a kind.

Scientists have studied octopuses for years, and the more they learn, the more fascinating these creatures become. Here are some fun and surprising facts that show just how special octopuses really are:

Overpumping groundwater, worsening droughts and more rapid evaporation due to higher temperatures have caused a drastic decline in the amount of available freshwater, according to a new study.

“Continental drying” has redirected the planet’s total water to the oceans to such degree that it has now surpassed melting ice sheets as the biggest contributor to global sea level rise, the research found.

Losses of land-based water could have profound implications for access to safe drinking water and the ability to grow food in some of the world’s richest agricultural regions.

“We use a lot of water to grow food,” said Jay Famiglietti, a professor at Arizona State University’s School of Sustainability and one of the authors of the study. “If things don’t change, we’ll see impacts on our food security and just our general water availability.”

The findings “should be of paramount concern to the general public, to resource managers, and to decision-makers around the world,” the researchers wrote in the study, adding that the identified trends “send perhaps the direst message on the impact of climate change to date.”

“The continents are drying, freshwater availability is shrinking, and sea level rise is accelerating,” they wrote.

The study, published Friday in the journal Science Advances, assessed changes in terrestrial water sources, such as lakes, underground aquifers and moisture in soil, over the past two decades. The researchers found that several factors, including climate change, are disrupting Earth’s natural water cycle, upsetting how moisture circulates between the ground, oceans and atmosphere.

The researchers used data from a suite of four NASA satellites to analyze changes in terrestrial water storage over the past 22 years. The satellites were designed to track the movement of Earth’s water, including changes to the planet’s ice sheets, glaciers and underground reservoirs.

The researchers found, for instance, that parts of the world that are already dry have been rapidly getting drier since 2014. These drought-ridden regions increased by an area twice the size of California each year, Famiglietti said.

In several cases, drought-ridden hotspots expanded to create giant, interconnected “mega-drying” regions, according to the study. One such area covers parts of Central America, Mexico, California, the southwestern United States, the lower Colorado River basin and the southern High Plains.

“The key message here is that water is really a key driver of the changes we see both on land and in the ocean,” said Benjamin Hamlington, a research scientist in the Earth Sciences Section at NASA’s Jet Propulsion Laboratory who served on the science team for the NASA missions that produced the decades of data used in the new study.

The study found that every large land mass, except for Greenland and Antarctica, has experienced unprecedented drying since 2002.

Widespread continental drying is expected to have major consequences for people. Three quarters of the world’s population lives in countries where freshwater resources are being depleted, according to the researchers.

Meanwhile, rising seas threaten to creep up on coastal regions around the globe, making them less habitable and adding to the mounting pressures caused by extreme storms and floods. In the U.S., severe weather has helped trigger an insurance crisis in coastal cities that are prone to extreme weather events.

The link between sea-level rise and the loss of water locked up in the ground is a consequence of throwing the planet’s water cycle into chaos. Many of these changes, such as overpumping groundwater, are thought to be permanent — or, at the very least, irreversible for thousands or tens of thousands of years, said Alexander Simms, a professor in the Department of Earth Science at the University of California, Santa Barbara, who was not involved with the study.

“If you pull water off the continents, the only place it has to go is in the ocean,” he said. “Water goes in the atmosphere, then 88% of that water rains down on Earth and ends up in the ocean.”

Simms said the study was fascinating in its ability to estimate the global scale of these water losses, but he was skeptical of the claim that water loss from the continents has now surpassed ice sheet melt as the biggest contributor to sea level rise.

Still, Hamlington said the study shows how the movement of water around the planet has enormous ripple effects. It also suggests that the consequences could intensify in the future, if groundwater is further depleted, freshwater resources shrink and drought conditions worsen.

“This kind of tracking of terrestrial water storage is a critical piece of the puzzle,” he said. “If we can track that water, if we know where it’s going, we can improve our understanding of future drought, flooding and water resource availability over land.”

A collaboration among Oregon Health & Science University and three other universities has produced mathematical models that could begin to unlock how groups of cells will respond to various cancer therapy combinations.

Laura Heiser, Ph.D. (OHSU)

The findings, published today in the journal Cell, have broad implications across cancer-related specialties, giving researchers the keys to developing digital models designed to test and predict cell behavior.

“That’s the long-term goal,” said Laura Heiser, Ph.D., vice chair of biomedical engineering, OHSU School of Medicine, and associate director of complex systems modeling in the Cancer Early Detection Advanced Research Center program, OHSU Knight Cancer Institute.

“This research gives us a tool to begin to predict multicellular behavior. We’re not there yet, but it puts us firmly on the road to being able to identify treatment combinations predicted to work best across cancer types, enabling development of novel treatment strategies.”

Being able to do this, and do it as soon as possible, is critical for patients with cancer. Customized treatments, also called personalized or precision medicine, deliver better results, fewer side effects and hopes for improving clinical outcomes.

Young Hwan Chang, Ph.D. (OHSU)

Heiser and Young Hwan Chang, Ph.D., associate professor of biomedical engineering, School of Medicine, and Knight Cancer Institute Interim Director Lisa Coussens, Ph.D., collaborated with researchers from Indiana University, University of Maryland and Johns Hopkins University. In all, four OHSU faculty members and two graduate student trainees took part in the research.

A Grassroots Effort

The effort began in 2020, when Heiser and Chang were conducting research into mechanisms of therapeutic resistance in breast cancer and began collaborating with Paul Macklin, Ph.D. A researcher from Indiana University, Macklin is the lead developer of PhysiCell, a software designed to create computational models of cells and tissues.

Macklin already had ongoing collaborations with Elana Fertig, Ph.D., from University of Maryland, who was focused on pancreatic cancer, and Johns Hopkins University’s Genevieve Stein-O’Brien, Ph.D., who was researching brain development. In other studies, Fertig collaborated with Coussens to understand epigenetic mechanisms impacting therapy response in breast cancer regulated by macrophages, a type of immune cell.

Thanks to philanthropic and National Institutes of Health funding, the multi-institutional group of scientists began collaborating to harness the various scientific approaches across their five labs.

For the last two years, they have been meeting every Friday to present their findings and share updates. Their goal? To develop rational rules based on significant biologic responses, which could then inform mathematical prediction models for therapy responses.

For Heiser, the Friday meetings became a highlight of her week.

“I would really look forward to them,” she says. “I think we all became very invested in the time spent and in the commitment, we had to each other and to developing our ideas.”

Using validated preclinical biology, the group was able to develop and replicate computational models for cells in multiple types of cancer — a milestone and a moment when the group knew they had a novel approach that could significantly impact patients with cancer.

“There wasn’t one a-ha moment; there were many. It was a very grassroots effort,” Heiser said. “And we were fortunate to be able to build off of strong research that already existed within OHSU’s biomedical engineering and cancer biology-focused departments and within the Knight Cancer Institute.”

The group leveraged the following:

• Twenty years of in vivo breast cancer modeling in the Coussens Lab, which demonstrated that a group of immune cells called macrophages and T cells significantly impact how cancer cells progress into lethal tumors.
• 2022 research from the Heiser Lab, which developed a detailed map of how breast cells respond to extracellular signals. This helped create a computational model — a test done on a computer instead of in a lab — to better understand how those cells behave.
• Research from the Chang lab, focused on developing advanced analytics for imaging data.

The findings open the door for next steps — new research questions that now can be asked and answered with greater accuracy and speed.

Lisa Coussens, Ph.D. (Courtesy)

“The collaboration and team-science approach provides a foundational platform to predict the effects of various cell types embedded within tumors expressing different therapeutic targets, based on biological findings, without having to do 20 years’ worth of in vivo biological studies,” Coussens said.

For Heiser and the entire group, working together from a multidisciplinary standpoint has been not only effective, but gratifying.

“We really need a multidisciplinary view if we’re going to cure cancer,” Heiser said. “Our ultimate goal is always to improve outcomes for patients, and to do that, we have to tackle these questions from many different angles.

“It’s a multifaceted disease, so it makes sense that the approach needs to be multifaceted as well. We have been able to demonstrate that the work we’ve been doing these past several years and over these many Fridays has yielded something that can be useful to the broader cancer research community, and that is really very meaningful.”

Research reported in this publication was supported by the Jayne Koskinas Ted Giovanis Foundation for Health and Policy, the National Foundation for Cancer Research and the Susan G Komen Foundation. The content is solely the responsibility of the authors and does not necessarily represent the official views of the various foundations.

Despite what the movies tell us, dinosaurs probably didn’t roar at their prey. It’s more likely that they chirped like birds, based on a well-preserved new fossil with an intact voice box.

A team of researchers from the Chinese Academy of Sciences discovered an almost-complete skeleton of a new dinosaur species in northeastern China.

This two-legged, 72 centimeter (2.4 foot) long herbivore was named Pulaosaurus qinglong after Pulao, a tiny dragon from Chinese mythology that, the story goes, cries out loudly.

Related: The Raptor Noises in Jurassic Park Are Mating Tortoises

That namesake is no coincidence – Pulaosaurus is one of very few dinosaurs for which we have some idea of the noises it could have made.

That’s because the fossil is extremely well-preserved. Not only are most of the bones present and accounted for, but so are parts we don’t usually find, including structures in the larynx. There’s even some impressions of what could be its final meal visible in its gut.

Leaf-shaped, cartilaginous structures in the larynx are very similar to modern birds, the researchers write, which suggests that Pulaosaurus could have communicated through complex chirps and calls. Sadly, don’t expect to be able to listen to a reproduction any time soon.

“Due to the compression of the Pulaosaurus mandible, the exact width of the mandible is unknown, so acoustic calculations of Pulaosaurus cannot be made,” the researchers write.

Finding a fossilized larynx in a dinosaur is extremely rare – in fact, this is only the second time one has been identified. The other was in a very different type of dinosaur: an armored ankylosaur known as Pinacosaurus.

Intriguingly, these two examples are very distantly related and separated by about 90 million years of evolution. That means this kind of larynx structure could have been widespread among dinosaurs.

So why haven’t we found more? The team suggests that either these fragile structures don’t fossilize very often, or perhaps they’re being mistakenly classified as other parts of the throat.

“Reanalysis of vocal anatomy within non-avian dinosaurs needs to be carried out to assess the accuracy of identification among curated specimens,” the researchers write.

Maybe with more examples we’ll get a better understanding of how dinosaurs really sounded.

The research was published in the journal PeerJ.

SpaceX just took a big step toward its next astronaut launch.

The company announced Thursday (July 24) that it has moved its Crew Dragon capsule “Endeavour” to the hangar at historic Pad 39A at NASA’s Kennedy Space Center in Florida.

Endeavour is scheduled to launch atop a Falcon 9 rocket from Pad 39A — the liftoff site of most Apollo moon missions, including Apollo 11 — on July 31, kicking off SpaceX’s Crew-11 mission to the International Space Station (ISS) for NASA.

Crew-11 will send four people to the ISS for a six-month stint: NASA astronauts Zena Cardman and Mike Fincke, along with Japan’s Kimiya Yui and Oleg Platonov of Russia’s space agency Roscosmos. It will be the first spaceflight for Cardman and Platonov, the second for Yui and the fourth for Fincke.

The camera on NASA’s Juno spacecraft was in trouble. Known as JunoCam, it had survived over 50 orbits around Jupiter, capturing stunning images of the planet and its moons. But by late 2023, things took a turn for the space camera.

Radiation had started to wear it down. The photos coming back were almost unusable – full of static, streaks, and distortion.

The camera had been exposed to Jupiter’s brutal radiation environment for years. With one of its most important missions approaching – a close flyby of Jupiter’s volcanic moon Io – the team needed a fix. And they had to do it from over 400 million miles away.

Camera repair in deep space

A team of experts, including scientists from the Southwest Research Institute in San Antonio, took a shot in the dark. The experts believed the problem stemmed from radiation damage to a voltage regulator inside JunoCam. Their only remaining option was to try something risky – heat up the camera.

The process, called annealing, involves raising the temperature of a material to change it at a microscopic level. It’s a method used in electronics but rarely attempted in deep space.

Jacob Schaffner is the Managing Engineer at Malin Space Science Systems, which designed and developed JunoCam and is part of the team that operates it.

“We knew annealing can sometimes alter a material like silicon at a microscopic level but didn’t know if this would fix the damage,” said Schaffner.

“We commanded JunoCam’s one heater to raise the camera’s temperature to 77 degrees Fahrenheit – much warmer than typical for JunoCam – and waited with bated breath to see the results.”

Cranking up the heat on JunoCam

The first results were promising. The camera began producing clearer images again – but that didn’t last. Quality started to slip again.

“After orbit 55, our images were full of streaks and noise,” said JunoCam instrument lead Michael Ravine of Malin Space Science Systems. “We tried different schemes for processing the images to improve the quality, but nothing worked.”

“With the close encounter of Io bearing down on us in a few weeks, it was Hail Mary time: The only thing left we hadn’t tried was to crank JunoCam’s heater all the way up and see if more extreme annealing would save us.”

They gave it everything. The heater was turned up further, hoping that higher temperatures might realign the silicon and bring the camera back to life.

At first, it didn’t look like it worked. Test images were still noisy. But as Juno closed in on Io, the pictures began to improve – rapidly. By December 30, 2023, during its closest flyby yet – just 930 miles from Io’s surface – the images were crisp and detailed.

The camera captured towering mountains dusted with sulfur dioxide frost and active lava flows from Io’s uncharted volcanoes. It was official – JunoCam was back.

Beyond space camera repair

The team didn’t stop there. They have now applied versions of the annealing fix to other systems on the spacecraft – both science instruments and engineering subsystems.

Since its launch, Juno has made 74 orbits of Jupiter. During its most recent pass, image noise crept in again. But now the team has a tool – and some confidence – that they can respond.

“Juno is teaching us how to create and maintain spacecraft tolerant to radiation, providing insights that will benefit satellites in orbit around Earth,” said Scott Bolton, Juno’s principal investigator.

“I expect the lessons learned from Juno will be applicable to both defense and commercial satellites as well as other NASA missions.”

Lessons from a space camera

The lesson from this mission isn’t just about salvaging a camera. It’s about improvising when there’s no manual. It’s about learning how to keep hardware working long past its expected limits — under some of the harshest conditions in the solar system.

Space is punishing. JunoCam wasn’t built to last forever. But thanks to some smart thinking and a little heat, it got a second chance. And it’s still taking pictures.

Image Credit: NASA/JPL-Caltech/SwRI/MSSS. Image processing by Gerald Eichstädt

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MADISON — When a multimillion-dollar extraterrestrial vehicle gets stuck in soft sand or gravel — as did the Mars rover Spirit in 2009 — Earth-based engineers take over like a virtual tow truck, issuing a series of commands that move its wheels or reverse its course in a delicate, time-consuming effort to free it and continue its exploratory mission.

While Spirit remained permanently stuck, in the future, better terrain testing right here on terra firma could help avert these celestial crises.

Using computer simulations, University of Wisconsin–Madison mechanical engineers have uncovered a flaw in how rovers are tested on Earth. That error leads to overly optimistic conclusions about how rovers will behave once they’re deployed on extraterrestrial missions.

An important element in preparing for these missions is an accurate understanding of how a rover will traverse extraterrestrial surfaces in low gravity to prevent it from getting stuck in soft terrain or rocky areas.

On the moon, the gravitational pull is six times weaker than on Earth. For decades, researchers testing rovers have accounted for that difference in gravity by creating a prototype that is a sixth of the mass of the actual rover. They test these lightweight rovers in deserts, observing how it moves across sand to gain insights into how it would perform on the moon.

It turns out, however, that this standard testing approach overlooked a seemingly inconsequential detail: the pull of Earth’s gravity on the desert sand.

Through simulation, Dan Negrut, a professor of mechanical engineering at UW–Madison, and his collaborators determined that Earth’s gravity pulls down on sand much more strongly than the gravity on Mars or the moon does. On Earth, sand is more rigid and supportive — reducing the likelihood it will shift under a vehicle’s wheels. But the moon’s surface is “fluffier” and therefore shifts more easily — meaning rovers have less traction, which can hinder their mobility.

“In retrospect, the idea is simple: We need to consider not only the gravitational pull on the rover but also the effect of gravity on the sand to get a better picture of how the rover will perform on the moon,” Negrut says. “Our findings underscore the value of using physics-based simulation to analyze rover mobility on granular soil.”

The team recently detailed its findings in the Journal of Field Robotics .

The researchers’ discovery resulted from their work on a NASA-funded project to simulate the VIPER rover , which had been planned for a lunar mission. The team leveraged Project Chrono, an open-source physics simulation engine developed at UW–Madison in collaboration with scientists from Italy. This software allows researchers to quickly and accurately model complex mechanical systems — like full-size rovers operating on “squishy” sand or soil surfaces.

While simulating the VIPER rover, they noticed discrepancies between the Earth-based test results and their simulations of the rover’s mobility on the moon. Digging deeper with Chrono simulations revealed the testing flaw.

The benefits of this research also extend well beyond NASA and space travel. For applications on Earth, Chrono has been used by hundreds of organizations to better understand complex mechanical systems — from precision mechanical watches to U.S. Army trucks and tanks operating in off-road conditions.

“It’s rewarding that our research is highly relevant in helping to solve many real-world engineering challenges,” Negrut says. “I’m proud of what we’ve accomplished. It’s very difficult as a university lab to put out industrial-strength software that is used by NASA.”

Chrono is free and publicly available for unfettered use worldwide, but the UW–Madison team puts in significant ongoing work to develop and maintain the software and provide user support.

“It’s very unusual in academia to produce a software product at this level,” Negrut says. “There are certain types of applications relevant to NASA and planetary exploration where our simulator can solve problems that no other tool can solve, including simulators from huge tech companies, and that’s exciting.”

Since Chrono is open source, Negrut and his team are focused on continually innovating and enhancing the software to stay relevant.

“All our ideas are in the public domain and the competition can adopt them quickly, which is drives us to keep moving forward,” he says. “We have been fortunate over the last decade to receive support from the National Science Foundation, U.S. Army Research Office and NASA. This funding has really made a difference, since we do not charge anyone for the use of our software.”

Co-authors on the paper include Wei Hu of Shanghai Jiao Tong University, Pei Li of UW-Madison, Arno Rogg and Alexander Schepelmann of NASA, Samuel Chandler of ProtoInnovations, LLC, and Ken Kamrin of MIT.