Matching the neutron stars’ cooling rates to their equation of state could help scientists figure out a quantum theory of gravity.
Why are neutrinos so light?
Did you know that every second more than 100 trillion tiny particles called neutrinos pass through your body without causing any harm? These mysterious particles are produced abundantly throughout the universe in events like nuclear reactions in the sun, radioactive decays in the Earth’s crust, and in high-energy collisions in space. In particular, these subatomic particles play a crucial role in the explosive deaths of stars known as supernovae, where they act as the driving force behind the explosion. Despite their abundance in the universe, they are incredibly difficult to detect directly in experiments since they pass right through any matter and only interact extremely rarely. At the LHC, their existence can only be inferred indirectly by summing up the energy of all other particles produced from the proton collisions and looking for missing energy that has been carried away by the neutrino, which escaped the experiment undetected.
Neutrinos are a type of fundamental particle known as a lepton and they are electrically neutral. They stand out among fundamental particles because of their peculiar characteristics. Not only do they interact exceptionally rarely, but they also possess a minuscule mass, approximately 500,000 times lighter than that of an electron. One possible explanation for the smallness of their mass is given by the “seesaw” mechanism. According to this theory, there exist additional new fundamental particles that are electrically neutral. The mechanism postulates that the masses of these new particles, known as “heavy neutral leptons” (HNLs), are mathematically linked to those of the normal neutrinos, like two sides of a seesaw. The theory also predicts that the HNLs will “mix” with their known cousins, neutrinos. This means that a neutrino, produced in an LHC collision, can change into an HNL, and the HNL can then decay back into known particles that the LHC experiments can detect!
The seesaw explanation for the neutrino mass is particularly attractive and various searches for HNLs have been performed at the LHC and by other experiments in the past (see an example where CMS muon detectors are exploited in such a search). The CMS Collaboration has recently published a new search that makes the assumption that the mixing between the HNLs and neutrinos is very small. In this special case, the HNL can be “long lived” and travel macroscopic distances away from the collision point before decaying. Experiments can then take advantage of the unusual signatures from these “displaced” particle decays when trying to find evidence for the existence of HNLs.
Stephen Wolfram explores simple models of biological organisms as computational systems. A study of progressive development, multiway graphs of all possible paths and the need for narrowing the framework space.
Dr. Ana Diaz Artiles: “When we’re upright, a large part of our fluids are stored in our legs, but in microgravity we get a redistribution of fluids into the upper body.”
What physiological effects can extended periods of microgravity have on the human eye? This is what a recent study published in npj Microgravity hopes to address as a team of researchers investigated how the shifting of fluids under microgravity conditions could lead to eye vessel alterations. This study holds the potential to help space agencies, researchers, and the public better understand the short-and long-term physiological effects of microgravity, specifically with more humans traveling beyond Earth’s gravity on commercial spaceflights.
“When we experience microgravity conditions, we see changes in the cardiovascular system because gravity is not pulling down all these fluids as it typically does on Earth when we are in an upright position,” said Dr. Ana Diaz Artiles, who is an assistant professor in the Department of Aerospace Engineering at Texas A&M University and a co-author on the study. “When we’re upright, a large part of our fluids are stored in our legs, but in microgravity we get a redistribution of fluids into the upper body.”
For the study, the researchers analyzed how lower body negative pressure (LBNP), which involves the transferring of fluids from the upper body to the lower body, could potentially be used to counteract what’s known as Spaceflight Associated Neuro-ocular Syndrome (SANS), which, while still not well understood, often results in physiological changes in the eyes, also called ocular prefusion pressure (OPP). Using 24 participants, 12 male and 12 female, the researchers subjected the participants to treatments inside an LBNP chamber to ascertain the effects on counteracting OPP.
An international team of astronomers has uncovered the formation history of young star clusters, many of which are visible to the naked eye at night.
This remarkable research reveals that most nearby young star clusters belong to only three families, each originating from very massive star-forming regions.
The findings offer new insights into the effects of supernovae on the formation of giant gas structures in galaxies like our Milky Way.
Lakes and seas of liquid methane exist on Saturn’s largest moon, Titan, due to the moon’s bone-chilling cold temperatures at-290 degrees Fahrenheit (−179 degrees Celsius), whereas it can only exist as a gas on Earth. But do these lakes and seas of liquid methane strewn across Titan’s surface remain static, or do they exhibit wave activity like the lakes and seas of liquid water on Earth? This is what a recent study published in Science Advances hopes to address as a team of researchers have investigated coastal shoreline erosion on Titan’s surface resulting from wave activity. This study holds the potential to help researchers better understand the formation and evolution of planetary surfaces throughout the solar system and how well they relate to Earth.
For the study, the researchers used a combination of shoreline analogs on Earth, orbital images obtained by NASA’s now-retired Cassini spacecraft, coastal evolution models, and several mathematical equations to ascertain the processes responsible for shoreline morphology across Titan’s surface. Through this, the researchers were able to construct coastal erosion models depicting how wave activity could be responsible for changes in shoreline morphology at numerous locations across Titan’s surface.
“We can say, based on our results, that if the coastlines of Titan’s seas have eroded, waves are the most likely culprit,” said Dr. Taylor Perron, who is a Cecil and Ida Green Professor of Earth, Atmospheric and Planetary Sciences at the Massachusetts Institute of Technology and a co-author on the study. “If we could stand at the edge of one of Titan’s seas, we might see waves of liquid methane and ethane lapping on the shore and crashing on the coasts during storms. And they would be capable of eroding the material that the coast is made of.”