Science

Modeling how cars deform in a crash, how spacecraft responds to extreme environments, or how bridges resist stress could be made thousands of times faster thanks to new artificial intelligence that enables personal computers to solve massive math problems that generally require supercomputers.

Consumers' real-world stop-and-go driving of electric vehicles benefits batteries more than the steady use simulated in almost all laboratory tests of new battery designs, a new study finds.

A pioneering artificial intelligence (AI) powered model able to understand the sequences and structure patterns that make up the genetic 'language' of plants, has been launched by a research collaboration.

Could a decades-long debate about the mysterious movements of stars in Omega Centauri, the largest star cluster in the Milky Way, finally be resolved?

Scientists have developed the first electrically pumped continuous-wave semiconductor laser composed exclusively of elements from the fourth group of the periodic table -- the 'silicon group'. Built from stacked ultrathin layers of silicon germanium-tin and germanium-tin, this new laser is the first of its kind directly grown on a silicon wafer, opening up new possibilities for on-chip integrated photonics.

Photonic space-time crystals are materials that could increase the performance and efficiency of wireless communication or laser technologies. They feature a periodic arrangement of special materials in three dimensions as well as in time, which enables precise control of the properties of light. Scientists have shown how such four-dimensional materials can be used in practical applications.

Photonic space-time crystals are materials that could increase the performance and efficiency of wireless communication or laser technologies. They feature a periodic arrangement of special materials in three dimensions as well as in time, which enables precise control of the properties of light. Scientists have shown how such four-dimensional materials can be used in practical applications.

We tie our shoes, we put on neckties, we wrestle with power cords. Yet despite deep familiarity with knots, most people cannot tell a weak knot from a strong one by looking at them, research finds.

New observations from the James Webb Space Telescope suggest that a new feature in the universe -- not a flaw in telescope measurements -- may be behind the decade-long mystery of why the universe is expanding faster today than it did in its infancy billions of years ago.

Computer memory could one day withstand the blazing temperatures in fusion reactors, jet engines, geothermal wells and sweltering planets using a new solid-state memory device developed by a team of engineers.

Computer memory could one day withstand the blazing temperatures in fusion reactors, jet engines, geothermal wells and sweltering planets using a new solid-state memory device developed by a team of engineers.

Screens for TVs, smartphones or other displays could be made with a new kind of organic LED material. The material maintains sharp color and contrast while replacing the heavy metal with a new hybrid material.

Screens for TVs, smartphones or other displays could be made with a new kind of organic LED material. The material maintains sharp color and contrast while replacing the heavy metal with a new hybrid material.

Astronomers have found a way to spot the smallest, 'decameter,' asteroids within the main asteroid belt. They used their approach to detect more than 100 new asteroids, ranging from the size of a bus to several stadiums wide, which are the smallest asteroids within the main belt detected to date.

Researchers used lab-grown organoids created from tumors of individuals with glioblastoma (GBM) to accurately model a patient's response to CAR T cell therapy in real time. The organoid's response to therapy mirrored the response of the actual tumor in the patient's brain. That is, if the tumor-derived organoid shrunk after treatment, so did the patient's actual tumor.

Researchers have published two studies in which they surveyed readers on their thoughts about AI in journalism. When provided a sample of bylines stating AI was involved in producing news in some way or not at all, readers regularly stated they trusted the credibility of the news less if AI had a role. Even when they didn't understand exactly what AI contributed, they reported less trust and that 'humanness' was an important factor in producing reliable news.

Lots of things out in the Universe can cause a supernova, from the gravitational collapse of a massive star, to the collision of white dwarfs. But most of the supernovae we observe are in other galaxies, too distant for us to see the details of the process. So, instead, we categorize supernovae by observed characteristics such as the light curves of how they brighten and fade and the types of elements identified in their spectra. While this gives us some idea of the underlying cause, there are still things we don’t entirely understand. This is particularly true for one particular kind of supernova known as Type Ia.

You have likely heard of Type Ia supernovae because they are central to our understanding of cosmology. They have an important characteristic of having a uniform maximum brightness. This means we can observe their apparent brightness, compare it to their actual brightness, and calculate their distance. For this reason, they are often referred to as standard candles, and they were the first way we learned that the Universe is not just expanding; it’s accelerating under the influence of dark energy.

From the spectra of these supernovae, we can see that the initial brightness is powered by the radioactive decay of nickel-56, while much of the later brightness comes from the decay of cobalt-56. We also see the presence of ionized silicon near peak brightness, which no other type of supernova has. This tells us that Type Ia supernova are not caused by the core collapse of a star, but rather some kind of thermal runaway effect.

Single progenitor of a Type Ia Supernova. Credit: NASA, ESA and A. Feild (STScI)

The most popular model for Type Ia supernovae is that they are caused by the collapse of a white dwarf. When a white dwarf is part of a close binary with an aging red giant, the white dwarf can capture some of the companion’s outer layer. Over time, the white dwarf captures enough mass that it crosses the Chandresekhar limit, which triggers the supernova. Since the Chandrasekhar limit is always at 1.4 solar masses, this would explain why Type Ia supernovae always have the same maximum brightness.

But as we’ve observed ever more supernovae, we’ve learned that Type Ia supernovae don’t always have the same maximum brightness. There are some that are particularly brighter, with weaker silicon lines in their spectra and stronger iron lines. There are some that are much dimmer than usual, with strong titanium absorption lines. This doesn’t prevent their use as standard candles since we can identify them by the spectra and adjust our brightness calculations accordingly, but it does suggest that the single progenitor model is incomplete.

Illustration of colliding white dwarf stars. Credit: European Southern Observatory

One possibility is that some Type Ia supernovae are caused by white dwarf collisions. Given the calculated number of binary white dwarf systems, collisions can’t account for all supernovae of this type, but stellar collisions are known to occur, and they wouldn’t be bound by the Chandresekhar limit, thus allowing for supernovae that are brighter or dimmer than usual. It’s also possible that some Type Ia supernovae are caused by accretion from a close companion, but the resulting supernova doesn’t destroy the white dwarf, which could explain the dimmer subtypes of these supernovae.

Right now, there are lots of possibilities, and we simply don’t have enough data to pinpoint causes. But the good news is that with new observatories and sky surveys such as Rubin Observatory coming online soon, we will gather a wealth of observational data, particularly from supernovae that occur within our own galaxy. This will provide us with the information we need to finally solve this longstanding astronomical problem.

Reference: Ruiter, Ashley J., and Ivo R. Seitenzahl. “Type Ia supernova progenitors: a contemporary view of a long-standing puzzle.” arXiv preprint arXiv:2412.01766 (2024).

The post Do We Really Know What Becomes a Type Ia Supernova? appeared first on Universe Today.

A spacecraft that can provide the propulsion necessary to reach other planets while also being reproducible, relatively light, and inexpensive would be a great boon to larger missions in the inner solar system. Micocosm, Inc., based in Hawthorne, California, proposed just such a system via a NASA Small Business Innovation Research (SBIR) grant. Its Hummingbird spacecraft would have provided a platform to visit nearby planets and asteroids and a payload to do some basic scouting of them.

Large space missions are expensive, so using a much less expensive spacecraft to collect preliminary data on the mission target could potentially help save money on the larger mission’s final design. That is the role that Hummingbird would play. It is designed essentially as a propulsion system, with slots for radiation-hardened CubeSat components as well as a larger exchangeable payload, such as a telescope.

The key component of the Hummingbird is its propulsion system. It uses a rocket engine that runs on hydrazine fuel. More importantly, it holds a lot of that fuel. A fully assembled system is expected to weigh 25 kg “Dry”—meaning without propellant installed—whereas a fully fueled “Wet” system would weigh an estimated 80 kg. 

Travelling to a Lagrange Point is one of the things Hummingbird could do – Fraser explains why this points in space are important.

That would give Hummingbird plenty of “oomph” – enough to bring its orbital speed up to an estimated 3.5 km/s delta-V, which is required for getting to hard-to-reach objects like some near-Earth asteroids. However, it could also reach other, larger places, like Mars or even Venus, the various Lagrange points, or even Mars’ moons.

When it got there, the prototype of Hummingbird described in a paper presented back in 2013 would take images of its target world using an Exelis telescope. The manufacturer of this telescope has since been bought by Harris Systems, which was then rolled into L3Harris Technologies, the owner of Aerojet Rocketdyne. However, the authors stress that the payload itself was interchangeable and could be tailored to the mission that it was meant to scout.

The Hummingbird bus was also the fuel tank, and it had additional slots for CubeSat components. These components could be used for further data collection or data analysis. However, the paper doesn’t necessarily mention how Hummingbird would handle standard CubeSat operations, like attitude control or communications back to a ground station.

A CubeSat has already made its way to Mars – as described in the JPL video.
Credit – NASA Jet Propulsion Laboratory YouTube Channel

Those could likely have been worked out in future iterations. Additionally, the final design was published before the dramatically reduced cost of getting to orbit, which is now available – the authors don’t even mention a “Falcon” as a potential launch service. A lot has changed in the space industry in the last 11 years. Still, the idea behind Hummingbird, an inexpensive, adaptable platform for preliminary scouting missions to interesting places in the inner solar system, has yet to see its day in the Sun – the project did not appear to receive a Phase II SBIR grant, which could have continued its development. But maybe, someday, it or a similar system will see the light of interplanetary space.

Learn More:
C. Taylor et al – Hummingbird: Versatile Interplanetary Mission Architecture
UT – What Happened to those CubeSats that were Launched with Artemis I?
UT – A CubeSat Mission to Phobos Could Map Staging Bases for a Mars Landing
UT – We Could SCATTER CubeSats Around Uranus To Track How It Changes

Lead Image:
Computer-generated mockup of the Hummingbird spacecraft
Credit – C. Taylor et al.

The post A Cheap Satellite with Large Fuel Tank Could Scout For Interplanetary Missions appeared first on Universe Today.

Many ancient board games have been discovered, but there are no rulebooks so we don't know how to play them. Now AI is bringing these games back to life by working out likely rules

Google has unveiled a new quantum computer called Willow that excels at a benchmarking problem, but it still isn't clear whether these machines can serve a practical purpose