A new effort to map the rumblings in spacetime caused by enormous black hole collisions paints a surprisingly loud and lopsided picture of the universe.
A mysterious object discovered in the main asteroid belt in 2021 was determined to be a main-belt comet by Planetary Science Institute Senior Scientist Henry Hsieh, Scott Sheppard of the Carnegie Institution for Science and Audrey Thirouin of Lowell Observatory.
Main-belt comets are icy objects found in the asteroid belt between Mars and Jupiter—rather than the cold outer solar system where icy bodies are typically expected. They sport comet-like features, like tails extending away from the sun or fuzzy clouds as the sun’s heat vaporizes their ice. They were first discovered in 2006 at the University of Hawaii by Hsieh and his then-doctoral advisor, David Jewitt.
Main-belt comets belong to a larger group of solar system objects known as active asteroids, which look like comets, but have asteroid-like orbits in the warm inner solar system. This larger group includes objects whose clouds and tails are made of ejected dust produced after an impact or as they quickly rotate, rather than just those that eject dust due to vaporized ice. Both main-belt comets and active asteroids in general are still relatively rare, but scientists are discovering them at a growing clip.
Discovered in 1999 in Germany, the Nebra Sky Disc is the oldest known depiction of the cosmos. A recent examination of the Bronze Age artifact revealed the intricate methods used in its creation, which UNESCO described as “one of the most important archaeological finds of the twentieth century.”
The Nebra Sky Disc is a product of the Únětice culture, which originated in the Bronze Age of Central Europe. It reflects a sophisticated ancient understanding of both metalworking and astronomy and was created sometime between 1800 and 1,600 BCE. Clusters of stars, a sun, and a crescent moon are among the celestial bodies depicted by golden inlays covering the blue-green patina of the Nebra Sky Disc. The angle between the solstices is thought to be indicated by two golden arcs that run along the sides of the disc, one of which is now absent. It is thought that a boat is represented by another arc at the composition’s base. Only a few millimeters thick, the disc has a diameter of around 12 inches.
The Nebra Sky Disc is one of the best-investigated archaeological objects. The origin of the raw materials it is made of is well known The disc is made from copper, tin, and gold—materials whose origins have been traced to Cornwall, England. The rich blue-green patina of the disc’s bronze today results from chemical changes over time. Originally, it would have been a deep bronze hue.
The AI race is heating up! In this video, we delve into the competition between Nvidia’s Llama-3.1 and OpenAI’s GPT-4. Discover how these two AI giants are revolutionizing the field of large language models (LLMs) and reshaping AI performance benchmarks. From Nvidia’s groundbreaking Llama-3.1 Nemotron to GPT-4’s advanced video generation capabilities, we analyze their strengths, use cases, and potential to lead the AI revolution.
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Thanks to CRISPR, medical specialists will soon have unprecedented control over how they treat and prevent some of the most challenging genetic disorders and diseases.
CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) is a Nobel Prize-winning gene-editing tool, already widely used by scientists to cut and modify DNA sequences to turn genes on and off or insert new DNA that can correct abnormalities. CRISPR uses an enzyme known as Cas9 to cut and alter DNA.
Engineers at the USC Alfred E. Mann Department of Biomedical Engineering have now developed an update to the tool that will allow CRISPR technology to be even more powerful with the help of focused ultrasound.
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A pair of researchers, one with the Carnegie Institution for Science, the other with California Institute of Technology, has developed a possible solution to the Fermi Paradox. In their paper published in Journal of the Royal Society Interface, Michael Wong and Stuart Bartlett suggest that the reason that no aliens from other planets have visited us is because of superlinear scaling, which, they contend, leads to a singularity. (How do “Predator Civilizations” solve the Fermi Paradox?)
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One of the most powerful assets of the brain is that it can store information as memories, allowing us to learn from our mistakes. However, some memories remain vivid while others become forgotten. Unlike computers, our brains appear to filter which memories are salient enough to store.
Researchers from Tohoku University have discovered that part of the memory selection process depends on the function of astrocytes, a special type of cell that surrounds neurons in the brain. They showed that artificially acidifying the astrocytes did not affect short-term memory but prevented memories from being remembered long-term.
The findings are published in the journal Glia.
Researchers at UC San Diego identify a key pathway leading to neurodegeneration in early stages of ALS, hinting at the potential for short-circuiting the progression of the fatal disease if diagnosed early.
