Physicists have proposed that a mirror universe alongside our own might explain dark matter – and we might be able to see traces of its stars.
Using China’s Five-hundred-meter Aperture Spherical radio Telescope (FAST), astronomers have discovered three new pulsars in an old Galactic globular cluster known as Messier 15. Two of them turned out to be long-period pulsars, while the remaining one spins so rapidly that it was classified as a millisecond pulsar. The finding was reported in a paper published Dec. 11 on the pre-print server arXiv.
Pulsars are highly magnetized, rotating neutron stars emitting a beam of electromagnetic radiation. The most rapidly rotating pulsars, with rotation periods below 30 milliseconds, are known as millisecond pulsars (MSPs). Astronomers assume that they are formed in binary systems when the initially more massive component turns into a neutron star that is then spun up due to accretion of matter from the secondary star.
Located some 35,700 light years away from the Earth, Messier 15 (also known as NGC 7078) is a core-collapsed GC with a radius of about 88 light years and an estimated mass of 560,000 solar masses. It is one of the oldest (about 12 billion years old) and most metal-poor Galactic GCs (with a metallicity of approximately −2.25), and one of the most densely packed GCs in our galaxy.
To construct a Dyson Shell (or Cap), an exceptionally light and very absorptive material would be necessary, because a 20-mile-radius (32 km), 0.4-inch-thick (1 cm) titanium Dyson Shell would have a mass of more than 1,200 Empire State buildings! Alternatively, a Dyson Cap that absorbs radiation that would be fed into a heat engine would have a lower mass, but would also deliver an inferior acceleration.
Furthermore, a gamma-ray laser is currently the only conceivable technology that could be used to make a Schwarzschild Kugelblitz. However, such a laser’s output frequency would need to exceed current technology by more than a billion times. Its pulse duration would have to be a hundred billion times shorter than that of lasers today. The total energy of a single laser pulse would need to be equivalent to the energy the sun puts out in 1/10 of a second.
While it’s true that the technical challenges render it unlikely that a SK will be fueling an interstellar starship anytime soon, it’s imperative that we embrace a wide range of theoretical research. SKs can produce many petawatts of useable radiation; therefore, they hold the potential to be an ideal source of power for interstellar starships. Thus, in time, Schwarzschild Kugelblitzes may merit a position of distinction on the vast technology arc that could one day take us to the stars.
New research suggests that if tiny primordial black holes created during the Big Bang exist, some of them may have been snared by stars and are now forced to eat their way out.
The discovery of stars with their outer layers of hydrogen stripped by companions fills a glaring hole in our understanding of supernovas and binary systems with colliding neutron stars.
The James Webb Space Telescope (JWST) has spotted the oldest black hole ever seen, an ancient monster with the mass of 1.6 million suns lurking 13 billion years in the universe’s past.
The James Webb Space Telescope, whose cameras enable it to look back in time to our universe’s beginnings, spotted the supermassive black hole at the center of the infant galaxy GN-z11 just 440 million years after the universe began.
Dark matter may be more vibrant than previously thought, UC Riverside study reports.
Thought to make up 85% of matter in the universe, dark matter is nonluminous and its nature is not well understood. While normal matter absorbs, reflects, and emits light, dark matter cannot be seen directly, making it harder to detect. A theory called “self-interacting dark matter,” or SIDM, proposes that dark matter particles self-interact through a dark force, strongly colliding with one another close to the center of a galaxy.
In work published in The Astrophysical Journal Letters, a research team led by Hai-Bo Yu, a professor of physics and astronomy at the University of California, Riverside, reports that SIDM simultaneously can explain two astrophysics puzzles in opposite extremes.
Can scientists harness the energy from black holes and turn it into batteries? Here is how this process could work.
A pair of astrophysicists at Tianjin University, in China, has proposed ways that humans in the distant future might use black holes as an energy source. In their paper published in the journal Physical Review D, Zhan-Feng Mai and Run-Qiu Yang outline two possible scenarios in which energy could potentially be harvested from primordial black holes.
As scientists continue to look for ways to meet the energy needs of a growing global population, some have begun to look for options that may not have been considered in the past. In this new effort, the researchers consider the possibility of tapping black holes as a way to power human needs of the future by turning them into batteries.
The first option suggests future astro-engineers could “charge” a primordial black hole (a very small black hole with no spin that formed soon after the Big Bang) by feeding it electrically charged particles until the black hole begins to repel them, signaling it is fully charged, like a battery. Energy could then be collected from the black hole through the use of superradiance, whereby some of the electromagnetic or gravitational waves carrying more energy than was fed in are deflected into the black hole, captured first and converted into a usable energy source.
This whirling Hubble Space Telescope image features a bright spiral galaxy known as MCG-01–24-014, which is located about 275 million light-years from Earth. In addition to being a well-defined spiral galaxy, MCG-01–24-014 has an extremely energetic core, known as an active galactic nucleus (AGN), so it is referred to as an active galaxy.
Even more specifically, it is categorized as a Type-2 Seyfert galaxy. Seyfert galaxies host one of the most common subclasses of AGN, alongside quasars. Whilst the precise categorization of AGNs is nuanced, Seyfert galaxies tend to be relatively nearby ones where the host galaxy remains plainly detectable alongside its central AGN, while quasars are invariably very distant AGNs whose incredible luminosities outshine their host galaxies.
