Lifeboat Foundation

The universe is governed by four known fundamental forces: gravity, electromagnetism, the weak force, and the strong force. The strong force is responsible for dynamics on an extremely small scale, within and between the individual nucleons of atomic nuclei and between the constituents – quarks and gluons – that make up those nucleons. The strong force is described by a theory called Quantum Chromodynamics (QCD). One of the key details of this theory, known as “asymptotic freedom”, is responsible for both the subatomic scale of the strong force and the significant theoretical difficulties that the strong force has presented to physicists over the past 50 years.

Given the complexity of the strong force, experimental physicists have often led the research frontier and made discoveries that theorists are still trying to describe. This pattern is distinct from many other areas of physics, where experimentalists mostly search for and confirm, or exclude, theoretical predictions. One of the QCD areas where experimentalists have led progress is in the description of the collective behavior of systems with many bodies interacting via the strong force. An example of such a system is the quark-gluon plasma (QGP). A few microseconds after the Big Bang, the universe is supposed to have existed in such a state. The way the universe evolved in these brief moments and the structure that subsequently developed over billions of years is studied, in part, through experimental research on collective QCD effects. This briefing describes a recent exciting development in that research. To better understand the results, we begin with a series of analogies.

Imagine you are on a large university campus. You observe student movements in the middle of a busy exam period and find that the number of students entering the library in the morning is related to the number of students leaving in the evening. Perhaps this indicates some conserved quantity, like the number of students at the school. Each student in the library wants enough room to lay out their supplies and textbooks and get comfortable while studying. The library is nearly full and the students are evenly distributed across all the floors and halls of the library to ensure they have ample space. Recognizing and quantifying correlations like these can be useful for studying collective systems. By counting students “here” you can predict how many students are “there”, or by counting students “now” you can predict how many students you will get “later”. In this example, you may have insight into basic temporal and spatial correlations.

Insights from NASA ’s IXPE mission have transformed our understanding of particle acceleration in black holes, using the microquasar SS 433 as a case study to reveal aligned magnetic fields within its jets.

The powerful gravity fields of black holes can devour whole planets’ worth of matter – often so violently that they expel streams of particles traveling near the speed of light in formations known as jets. Scientists understand that these high-speed jets can accelerate these particles, called cosmic rays, but little is definitively known about that process.

Recent findings by researchers using data from NASA’s IXPE (Imaging X-ray Polarimetry Explorer) spacecraft give scientists new clues as to how particle acceleration happens in this extreme environment. The observations came from a “microquasar,” a system comprised of a black hole siphoning off material from a companion star.

The expansion of the universe at some stage of evolution is well described by the Friedmann model. It was derived from general relativity a hundred years ago, but it is still considered one of the most important and relevant cosmological models.

RUDN University astrophysicists have now proven the theoretical possibility of the existence of traversable wormholes in the Friedmann universe. The research is published in the journal Universe.

“A wormhole is a type of highly curved geometry. It resembles a tunnel either between distant regions of the same universe or between different universes. Such structures were first discussed in the framework of solutions to the gravitational field equations a hundred years ago. But the wormholes considered then turned out to be non-traversable even for photons—they could not move from one ‘end of the tunnel’ to the other, not to mention going back,” said Kirill Bronnikov, doctor of physical and mathematical sciences, professor of RUDN University.

It has long been thought that the ingredients for life came together slowly, bit by bit. Now there is evidence it all happened at once in a chemical big bang.

By Michael Marshall

Nobel prizewinner Jim Peebles, who helped create our model of how the universe evolved, discusses dark matter, the value of iconoclastic ideas and the astronomical anomalies to keep your eye on.

By Michael Brooks

Even though black holes swallow anything that comes near them — even light — they are still possible to locate by looking for signs of their effects. Black holes are extremely dense, so they have a lot of mass and a strong gravitational effect that can be observed from light-years away. But the universe is a big place, and researchers are hoping that the public can help them to identify more black holes in the name of scientific exploration.

A project called Black Hole Hunter invites members of the public to search through data collected by NASA’s Transiting Exoplanet Survey Satellite (TESS) to look for signs of a black hole. Using a technique called gravitational microlensing, citizen scientists will look at how the brightness of light from various stars changes over time, looking for indications that a black hole could have passed in front of a star and bent the light coming from it. This should enable the project to identify black holes that would otherwise be invisible.

One of the researchers on the project, Matt Middleton of the University of Southampton, explained in a statement: Black holes are invisible. Their gravitational pull is so strong that not even light can escape, making them incredibly hard to see, even with specialist equipment. But that gravitational pull is also how we can detect them because it’s so strong that it can bend and focus light, acting like a lens that magnifies light from stars. We can detect this magnification and that’s how we know a black hole exists.

If true, this could mark an astronomy breakthrough.

In today’s paper, a unique gravitational wave event is re-examined as the possible origin of an AGN flare. What are the odds?

Over ten years ago, the Dark Energy Survey (DES) began mapping the universe to find evidence that could help us understand the nature of the mysterious phenomenon known as dark energy. I’m one of more than 100 contributing scientists that have helped produce the final DES measurement, which has just been released at the 243rd American Astronomical Society meeting in New Orleans.

Dark energy is estimated to make up nearly 70% of the observable universe, yet we still don’t understand what it is. While its nature remains mysterious, the impact of dark energy is felt on grand scales. Its primary effect is to drive the accelerating expansion of the universe.

The announcement in New Orleans may take us closer to a better understanding of this form of energy. Among other things, it gives us the opportunity to test our observations against an idea called the cosmological constant that was introduced by Albert Einstein in 1917 as a way of counteracting the effects of gravity in his equations to achieve a universe that was neither expanding nor contracting. Einstein later removed it from his calculations.