Uncover reality

For most of us, it seems obvious when we are responsible for an action. If we walk, move our hands, or speak, our brain normally knows that we caused those movements. This ability is known as the sense of agency —the feeling that we are the author of our own actions. But new research shows that this feeling can be surprisingly easy to manipulate. Using immersive virtual reality (VR), researchers demonstrated that people can experience the convincing illusion of walking through a virtual environment while their real body remains seated and almost completely motionless . The study, led by Elena Kokkinara and colleagues , explored how the brain decides whether an action belongs to us and how virtual reality can interfere with that process. How Does the Brain Know an Action Is Ours? When we decide to move, the brain sends motor commands to our muscles. At the same time, it appears to generate an internal prediction of what the movement should feel and look like. Scientists often describe ...

Virtual reality is no longer just a technology for humans. Scientists have now developed a miniature VR headset designed specifically for mice, opening new possibilities for studying how the brain processes vision, movement, learning and fear. Called MouseGoggles , the open-source system was developed by Matthew Isaacson and his team as a compact alternative to traditional virtual-reality setups used in neuroscience. The tiny headset gives head-fixed mice a wide, binocular view of virtual environments while also allowing researchers to track their eye movements and pupil responses. The technology could make animal VR experiments smaller, simpler and easier to reproduce, potentially helping more neuroscience laboratories investigate how the brain responds to complex virtual experiences. Why Do Scientists Use VR With Mice? Understanding how the brain creates behavior is one of the major challenges in neuroscience. Researchers often need to record activity from individual neurons while an...

Future astronauts may not be able to depend on regular shipments from Earth. For missions lasting months or years—especially crewed missions to Mars—astronauts will need to manufacture tools, replacement parts and other components directly in space. One promising technology is photopolymer-based manufacturing , which uses light to turn liquid resin into solid objects. It requires relatively little energy, needs compact equipment and offers precise control over where materials are cured. But researchers have discovered a major problem: the same chemical reaction that hardens the material can generate enough heat to damage the finished product. A team led by Jonathan Ericson has now investigated this problem through experiments on the International Space Station (ISS), parabolic flights and laboratory testing. Their work has produced a predictive thermal model that could help engineers design manufacturing processes that avoid overheating and defects in microgravity. Why Manufacturing i...

Primordial black holes, or PBHs, are one of the most interesting ideas in modern cosmology. Unlike normal black holes, which can form when massive stars collapse, primordial black holes could have formed in the very early universe, long before stars and galaxies existed. A new study by Li and his team explores an important question: Could heavy fields that existed during cosmic inflation make it much easier for primordial black holes to form? The researchers found that these heavy fields can produce a special type of non-Gaussianity in the early universe. This can increase the number of very large density fluctuations and, as a result, greatly increase the production of primordial black holes. How Are Primordial Black Holes Formed? Soon after the Big Bang, the universe was extremely hot and dense. During a period called cosmic inflation , the universe expanded incredibly quickly. At that time, tiny quantum fluctuations existed throughout space. Inflation stretched these tiny fluctuatio...

Black holes are among the most extreme objects in the universe. They have such strong gravity that nothing can escape once it crosses the event horizon. But some black holes can become even more extreme when they carry a very large electric charge. A recent theoretical discussion by Hod and Piran explores an important question: Can nature actually create an extremely charged black hole, or does physics prevent it from happening? The question is connected to one of the important ideas in black-hole thermodynamics, known as the third law of thermodynamics . Earlier studies suggested that forming an extremal black hole could create a problem for this law. Now, quantum physics may offer a possible solution. What Is an Extremal Black Hole? A Reissner–Nordström black hole is a theoretical black hole that has mass and electric charge but does not rotate. Normally, a black hole has to have enough mass compared with its electric charge. If the charge becomes extremely large compared with the m...

For many years, scientists have used a model called ΛCDM to explain how the Universe has changed over time. It describes a Universe containing normal matter, dark matter and a mysterious component called the cosmological constant, Λ . The cosmological constant is usually connected with dark energy , which is thought to be responsible for the accelerating expansion of the Universe. But there is a major problem. Scientists still do not know what dark energy actually is. The amount of vacuum energy predicted by quantum physics is also very different from the amount needed to explain the Universe. At the same time, measurements of the Universe have revealed disagreements between different observations, especially measurements of the expansion rate known as H₀ , or the Hubble constant. Now, a team led by Lee has tested an unusual idea called thermogravity . Instead of using a cosmological constant or traditional dark energy, the theory asks whether the Universe could accelerate because en...

When scientists search for potentially habitable worlds beyond our Solar System, they often look for rocky planets with atmospheres. Earth is the obvious example: its atmosphere helps regulate temperature and allows liquid water to exist on the surface. But rocky planets with atmospheres appear to be surprisingly difficult to find. Now, astronomers have discovered evidence of an atmosphere around an unusual world that is anything but habitable. Located about 154 light-years away in the constellation Pisces , the planet HD 3167 b is a rocky “lava world” so close to its star that it completes an entire orbit in just one Earth day . What makes it especially interesting is that it is reportedly the coolest lava world yet found with evidence of an atmosphere . The discovery, led by University of Chicago scientist Brandon Park Coy , was published in The Astrophysical Journal Letters . Researchers say this strange, extremely hot planet could help answer a much bigger question: How did rocky ...