Science

A new material for high density data storage can be erased and recycled in a more efficient and sustainable way, providing a potential alternative to hard disk drives, solid-state drives and flash memory in future. The low-cost polymer stores data as 'dents', making a miniscule code in patterns, with the indents just nanometers in size -- promising to store more data than typical hard disk drives.

Another advance has been made by experts in nano-scale chemistry to propel further development of sustainable and efficient generation of hydrogen from water using solar power. Experts have now identified a novel solar cell process to potentially use in future technologies for photocatalytic water splitting in green hydrogen production.

Microgravity is known to alter the muscles, bones, the immune system and cogni tion, but little is known about its specific impact on the brain. To discover how brain cells respond to microgravity, scientists sent tiny clumps of stem-cell derived brain cells called 'organoids' to the International Space Station.

Even if you knew nothing about astronomy, you’d understand that exploding stars are forceful and consequential events. How could they not be? Supernovae play a pivotal role in the Universe with their energetic, destructive demises.

There are different types of supernovae exploding throughout the Universe, with different progenitors and different remnants. The Zwicky Transient Facility has detected 100,000 supernovae and classified 10,000 of them.

The Zwicky Transient Facility (ZTF) is a wide-field astronomical survey named after the prolific Swiss astronomer Fritz Zwicky. In the early 1930s, Zwicky and his colleague Walter Baade coined the term ‘supernova’ to describe the transition of normal main sequence stars into neutron stars. In the 1940s, Zwicky and his colleague developed the modern supernova classification system. The ZTF bears his name because of these and many other scientific contributions. (Zwicky was also a humanitarian and a philosopher.)

The ZTF observes in both optical and infrared and was built to detect transients with the Samuel Oschin Telescope at the Palomar Observatory in San Diego County, California. Transients are objects that change brightness rapidly or objects that move. While supernovae (SN) don’t move, they definitely change brightness rapidly. They can outshine their entire host galaxy for months.

In 2017, the ZTF began its Bright Transient Survey (BTS), an effort dedicated to the search for supernovae (SNe). It’s by far the largest spectroscopic SNe survey ever conducted. The BTS has discovered 100,000 potential SNe, and more than 10,000 of them have been confirmed and classified according to distance, type, rarity, and brightness. These types of astronomical surveys create a rich dataset that will aid researchers well into the future.

“There are trillions of stars in the universe, and about every second, one of them explodes. Reaching 10,000 classifications is amazing, but what we truly should celebrate is the incredible progress we have made in our ability to browse the universe for transients, or objects that change in the sky, and the science our rich data will enable,” said Christoffer Fremling, a staff astronomer at Caltech. Fremling leads the ZTF’s Bright Transient Survey (BTS).

The effort to catalogue supernovae dates back to 2012 when astronomical databases began officially tracking them. Since then, astronomers have detected nearly 16,000 of them, and the ZTF is responsible for more than 10,000 of those detections.

The first documented SNe discovery was in 185 AD when Chinese astronomers recorded the appearance of a ‘guest star’ in the sky that shone for eight months. In the nearly two millennia since then, we’ve seen many more. 1987 was a watershed year for supernovae science when a massive star exploded in the nearby Large Magellanic Cloud. Named SN 1987A. it was the first supernova explosion since the telescope was invented. This was also the first direct detection of neutrinos from a supernova, and the detection is considered by many to be the beginning of neutrino astronomy.

A timeline of important events in the history of supernova astronomy. Click to enlarge. Image Credit: ZTF/Caltech/NSF

Each night, the ZTF detects hundreds of thousands of events, including everything from small, simple asteroids in our inner Solar System to powerful gamma-ray bursts in the distant Universe. The ZTF uses a pair of telescopes that act as a kind of ‘triage’ facility for supernovae and transients. The Samuel Oschin Telescope has a 60-megapixel wide field camera that images the visible sky every two nights. Astronomers detect new transient events by subtracting images of the same portion of the sky from subsequent scans.

Then, members of the ZTF team study these images and send the most promising to the other ZTF telescope, the Spectral Energy Distribution Machine (SEDM). This robotic spectrograph operates on the Palomar 60-inch telescope.

“We combine the brightness information from the ZTF camera with the data from the SEDM to correctly identify the origin and type of a transient, a process astronomers call transient classification,” said Yu-Jing Qin, a postdoc at Caltech, who is running much of the daily operations of the BTS survey.

ZTF Detections are also sent to other observatories around the world who can examine transients with other spectroscopic facilities. About 30% of the ZTF transients have been confirmed this way.

ZTF detects so many transients that it’s difficult for astronomers to keep up. In recent years, Caltech has made an effort to develop machine-learning tools that can examine SEDM spectroscopic data, classify the transients, and send them to the Transient Name Server. In 2023, the BTSBot system was employed to help manage the flow of detections.

“Since BTSbot began operation it has found about half of the brightest ZTF supernovae before a human,” said PhD student Nabeel Rehemtulla from Northwestern University, developer of the BTSBot. “For specific types of supernovae, we have automated the entire process and BTSbot has so far performed excellently in over a hundred cases. This is the future of supernova surveys, especially when the Vera Rubin Observatory begins operations.”

Though every supernova discovery is scientifically valuable, there are some highlights among all these detections.

The ZTF has detected thousands of Type 1a supernovae. They occur in binary systems where one star is a white dwarf. The white dwarf draws gas away from its companion and the gas gathers on the white dwarf. Eventually, this causes a supernova explosion. SN 2022qmx is one of these Type 1a supernovae that appeared to be way brighter than it should be. It turns out that an interceding galaxy was gravitationally lensing the SN’s light, making it appear 24 times brighter.

The ZTF is also responsible for detecting the closest and most distant SNe (with help from the JWST).

Some highlights from the ZTF’s 10,000 supernovae. Click the image to enlarge. Image Credit: ZTF/Caltech/NSF

“Back when we started this project, we didn’t know how many astronomers would follow up on our detections,” said Caltech’s Fremling. “To see that so many have is a testament to why we built ZTF: to survey the whole sky for changing objects and share those data as rapidly as possible with astronomers around the world. That’s the purpose of the Transient Name Server (TNS).”

The TNS is where the global astronomical community announces the detection and classification of transients so that work isn’t duplicated. Since 2016, the TNS has handled over 150,000 reported transients and over 15,000 reported supernovae.

“Everything is public in hopes that the community will come together and make the most of it,” said Fremling. “This way, we don’t have, say, 10 telescopes across the world doing the same thing and wasting time.”

Soon, the ZTF will have a powerful partner in time-domain astronomy. The Vera Rubin Observatory (VRO) should see its first light in the next few months and then begin its 10-year Legacy Survey of Space and Time (LSST). The LSST will also detect transients but is far more sensitive than the ZTF. It’s expected to detect millions of supernovae, and handling all of those detections will require a machine-learning tool similar to the BTSbot.

“The machine learning and AI tools we have developed for ZTF will become essential when the Vera Rubin Observatory begins operations,” said Daniel Perley, an astronomer at Liverpool John Moores University in the UK who developed the search and discovery procedures for the BTS. “We have already planned to work closely with Rubin to transfer our machine learning knowledge and technology,” added Perley.

Astronomical surveys like the ones performed by ZTF and the VRO provide foundational data that researchers will use for years. It’s impossible to know how it will be used in every case or what discoveries it will lead to. Even better, the ZTF and the VRO will overlap.

According to Caltech astronomy professor Mansi Kasliwal, who will lead ZTF in the coming two years, this will be a very important and exciting time in time-domain astronomy.

“The period in 2025 and 2026 when ZTF and Vera Rubin can both operate in tandem is fantastic news for time-domain astronomers,” said Kasliwal. “Combining data from both observatories, astronomers can directly address the physics of why supernovae explode and discover fast and young transients that are inaccessible to ZTF or Rubin alone. I am excited about the future,” added Kasliwal.

The post Zwicky Classifies More Than 10,000 Exploding Stars appeared first on Universe Today.

It seems that we are completely alone in the universe. But simple reasoning suggests that there should be an abundance of alien civilizations. Maybe they’re all out there, but they are keeping their distance. Welcome to the zoo (hypothesis).

The story goes that in the summer of 1950, eminent physicist Enrico Fermi was visiting colleagues at Los Alamos National Laboratory. It was the initial peak of UFO mania, and naturally the physicists brought it up over lunch. After a short while, Fermi went silent. Later, well after the conversation had turned to other topics, he exclaimed “Where is everybody?”

Everybody knew what he meant. We know that the universe is capable of producing intelligent life. We’re literally living proof of that. But the cosmos tends to not do things just once. If life happened here, it likely also happened elsewhere. In fact, given the extraordinary age of the universe and the incredible number of stars and planetary systems in any given galaxy, the Milky Way should be abuzz with intelligent space-faring civilizations.

Humanity itself is right on the cusp of developing a sustained interplanetary presence, and our species is still in its youth, at least as cosmic reckoning is concerned. We should see evidence for other intelligent species everywhere: radio signals, megastructures, wandering probes, and so on.

But we’ve got nothing. So where is everybody?

Perhaps the strangest possible solution to Fermi’s paradox, as this conundrum came to be known, is known as the zoo hypothesis. In this idea, alien life is indeed common, as is intelligence. There really is no huge barrier to intelligent creatures developing spaceflight capabilities and spreading themselves throughout the galaxy.

But the reason that we don’t see anybody is that they are intentionally hiding themselves from us. Through their sophisticated observations, they can easily tell that we are intelligent ourselves, but also somewhat dangerous. After all, we have peaceful space rockets and dangerous ICBMs. We are just dipping our toes into space, and we may not be exactly trustworthy.

And so the intelligent civilizations of the galaxy are keeping us in a sort of “zoo.” They are masking themselves and their signals, making us think that we’re all alone, largely confined to our own solar system and a few nearby stars.

Once we prove ourselves, the hypothesis goes, we’ll be welcomed into the larger galactic community with open arms (or tentacles).

The zoo hypothesis is, honestly, a little far-fetched. It assumes not only the existence of alien civilizations, but also their motives and intentions. But we ultimately do not know if we are alone in the universe. And there’s only one way to find out.

The post What is the Zoo Hypothesis? appeared first on Universe Today.

Researchers developed a fully open-source biomolecular structure prediction model that achieves state-of-the-art performance, at the level of AlpahFold3, in an effort to democratize biomedical research and drug development.

Researchers developed a fully open-source biomolecular structure prediction model that achieves state-of-the-art performance, at the level of AlpahFold3, in an effort to democratize biomedical research and drug development.

String theory remains elusive as a 'provable' phenomenon. But a team of physicists has now taken a significant step forward in validating string theory by using an innovative mathematical method that points to its 'inevitability.'

String theory remains elusive as a 'provable' phenomenon. But a team of physicists has now taken a significant step forward in validating string theory by using an innovative mathematical method that points to its 'inevitability.'

If the experience of watching a FIFA World Cup soccer final is intense, spare a thought for the players, who are competing at an ever increasing intensity, according to a new study.

Engineers have reported a significant advancement in engineering biology and clean energy. A team of researchers has developed an innovative light-driven hybrid nanoreactor that merges natural efficiency with cutting-edge synthetic precision to produce hydrogen -- a clean and sustainable energy source.

New research suggests that the making of string figures, a globally documented practice, may point to shared cultural heritage stretching back millennia. The research offers a new way to investigate the evolution and distribution of cultural phenomena using mathematical methods.

Researchers have demonstrated the high accuracy of their newly developed typhoon observation device that can be dropped from an aircraft into the eye of a typhoon. This kind of device, called a dropsonde, measures storm's atmospheric conditions as it falls from altitude to the ocean surface. The new dropsonde is lightweight and is made mainly of a biodegradable material. It can descend without a parachute unlike conventional dropsondes.

The quantum Hall effect, a fundamental effect in quantum mechanics, not only generates an electric but also a magnetic current. It arises from the motion of electrons on an orbit around the nuclei of atoms. These results can potentially be used to develop new types of inexpensive and energy-efficient devices.

The quantum Hall effect, a fundamental effect in quantum mechanics, not only generates an electric but also a magnetic current. It arises from the motion of electrons on an orbit around the nuclei of atoms. These results can potentially be used to develop new types of inexpensive and energy-efficient devices.

Pile up blocks until the tower collapses. But why does the tower always end up collapsing? Is it possible that it can be built ad infinitum? A new study explores the fascinating and complex dynamics of the stacking of blocks subjected to hazards.

After taking the first images of black holes, the groundbreaking Event Horizon Telescope (EHT) is poised to reveal how black holes launch powerful jets into space. Now, a research team has shown that the EHT will be able to make exciting images of a supermassive black hole and its jets in the galaxy NGC 1052. The measurements, made with interconnected radio telescopes, also confirm strong magnetic fields close to the black hole's edge.

The holidays are in full swing and people are shopping, wrapping and packing to visit loved ones. Along with the extra fees for checked baggage and seat upgrades, some airlines are also considering weight-based pricing. A recent study looked at how people felt about weighing their baggage and themselves to help reduce emissions and found while over half of travelers are not keen about hopping on the scale, some would be open to the idea -- especially if it aligns with their own interests in the environment.

Step into a world so tiny, it defies imagination -- the nanoscale. Picture a single strand of hair, now shrink it a million times. You've arrived. Here, atoms and molecules are the architects of reality, building properties and phenomena that challenge everything we thought we knew -- until now. Researchers have now unlocked a stunning discovery on this invisible frontier: a brand-new type of quasiparticle in all magnetic materials, no matter their strength or temperature. This groundbreaking find flips the script on magnetism, revealing it to be more dynamic than scientists once believed.

New technology could remotely identify various types of plastics, offering a valuable tool for future monitoring and analysis of oceanic plastic pollution. A new hyperspectral Raman imaging lidar system can remotely detect and identify various types of plastics, which could help address the critical issue of plastic pollution in the ocean by providing better tools for monitoring and analysis.