When Eugene Ho first saw the Apple Watch, it made him think of a jukebox. If the watch piece is the player then the wristband is like a song that can be changed according to taste and mood. Ho is building a band brand, Juuk Design, that acknowledges the watch wearer who likes to change […]
Scientists at MIT have designed a pocket-sized muon detector that can be easily made with common electrical parts, meaning anyone can kit themselves out with legitimately-functional Ghostbusters-esque gear for less than $ 100. The device detects the c…
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High-Energy Cosmic Rays
For decades, astronomers have known that the Earth is consistently struck by high-energy cosmic rays — charged particles that are usually the nuclei of elements — that originate from a source in space outside our solar system. These cosmic rays possess the highest possible energies observed in nature, even higher than what man-made particle accelerators can reproduce, and now, a team of scientists thinks they might have solved the mystery of their origin.
In a study published Science, the researchers, known collectively as the Pierre Auger Collaboration, suggest that these cosmic signals may originate from outside of the Milky Way. Their conclusions were drawn using recordings from the Pierre Auger Observatory in Argentina, the largest cosmic ray observatory currently in existence, and other data.
Although cosmic rays with energy greater than two joules rarely reach Earth, when they do, their interaction with nuclei in the planet’s atmosphere creates a shower of electrons, photons, and muons, making them detectable by researchers. These showers of more than 10 billion particles spread out across diameters measuring several kilometers.
When one of the particles within this shower hits one of the Pierre Auger Observatory’s 1,600 detectors, which are spread out over an area of 3,000 square kilometers (1,158 square miles), researchers can determine its originating direction. In the new research, the Auger collaboration studied the arrival directions of more than 300,000 cosmic particles and discovered that the arrival rates of the cosmic rays vary and aren’t uniformly spread in all directions. The rate is actually higher for certain directions.
According to the team, this anisotropy indicates an extragalactic origin for the cosmic particles, as many are coming from an area where the distribution of galaxies is fairly high. However, because the direction points toward a broad area of the sky, the specific sources remain undetermined.
Our Celestial Origins
We still have much to learn about cosmic rays, and the Pierre Auger Collaboration expects to supplement their findings when upgrades to the Auger Observatory are completed in 2018. Still, this new discovery is worthwhile. Any new knowledge about these particles can help us better understand matter from outside the solar system and, as this research suggests, from outside the Milky Way.
“We are now considerably closer to solving the mystery of where and how these extraordinary particles are created, a question of great interest to astrophysicists,” University of Wuppertal professor Karl-Heinz Kampert, a spokesperson for the Auger collaboration, said in a press release.
Figuring out the mechanisms behind these cosmic rays could help explain how galaxies form and what in their composition accounts for the creation of such high-energy particles. Furthermore, since these cosmic rays are made of particles that are also found on Earth, they could also provide important clues into the fundamental questions about our origins — perhaps even the origins of the universe itself.
The post New Research Suggests Cosmic Rays Hail From Galaxies Beyond the Milky Way appeared first on Futurism.
Earlier this year, I picked up Ruthanna Emrys’ debut novel, Winter Tide, a tale based on the exhaustively canvassed cosmic horror of H.P. Lovecraft. Along with a previous novelette called The Litany of Earth, it subverts Lovecraft’s notorious racism by making his monsters — which were often thinly veiled stand-ins for people of color — sympathetic protagonists. In the 1920s, the US government locks ancient Deep Ones in internment camps, including the series’ protagonist Aphra Marsha. Once Aphra is released after World War II, she goes into hiding — until an FBI agent recruits her to track down a cult.
Next summer, Emrys will release the second novel in her Innsmouth Legacy series: Deep Roots. After coming to terms with helping the US…
The Fermi Paradox
The universe is incomprehensibly vast, with billions of other planets circling billions of other stars. The potential for intelligent life to exist somewhere out there should be enormous.
So, where is everybody?
That’s the Fermi paradox in a nutshell. Daniel Whitmire, a retired astrophysicist who teaches mathematics at the University of Arkansas, once thought the cosmic silence indicated we as a species lagged far behind.
“I taught astronomy for 37 years,” said Whitmire. “I used to tell my students that by statistics, we have to be the dumbest guys in the galaxy. After all we have only been technological for about 100 years while other civilizations could be more technologically advanced than us by millions or billions of years.”
Principle of Mediocrity
Recently, however, he’s changed his mind. By applying a statistical concept called the principle of mediocrity – the idea that in the absence of any evidence to the contrary we should consider ourselves typical, rather than atypical – Whitmire has concluded that instead of lagging behind, our species may be average. That’s not good news.
In a paper published Aug. 3 in the International Journal of Astrobiology, Whitmire argues that if we are typical, it follows that species such as ours go extinct soon after attaining technological knowledge. (The paper is also available on Whitmire’s website.)
The argument is based on two observations: We are the first technological species to evolve on Earth, and we are early in our technological development. (He defines “technological” as a biological species that has developed electronic devices and can significantly alter the planet.)
The first observation seems obvious, but as Whitmire notes in his paper, researchers believe the Earth should be habitable for animal life at least a billion years into the future. Based on how long it took proto-primates to evolve into a technological species, that leaves enough time for it to happen again up to 23 times. On that time scale, there could have been others before us, but there’s nothing in the geologic record to indicate we weren’t the first. “We’d leave a heck of a fingerprint if we disappeared overnight,” Whitmire noted.
By Whitmire’s definition we became “technological” after the industrial revolution and the invention of radio, or roughly 100 years ago. According to the principle of mediocrity, a bell curve of the ages of all extant technological civilizations in the universe would put us in the middle 95 percent. In other words, technological civilizations that last millions of years, or longer, would be highly atypical. Since we are first, other typical technological civilizations should also be first. The principle of mediocrity allows no second acts. The implication is that once species become technological, they flame out and take the biosphere with them.
Whitmire argues that the principle holds for two standard deviations, or in this case about 200 years. But because the distribution of ages on a bell curve skews older (there is no absolute upper limit, but the age can’t be less than zero), he doubles that figure and comes up with 500 years, give or take. The assumption of a bell-shaped curve is not absolutely necessary. Other assumptions give roughly similar results.
There’s always the possibility that we are atypical and our species’ lifespan will fall somewhere in the outlying 5 percent of the bell curve. If that’s the case, we’re back to the nugget of wisdom Whitmire taught his astronomy students for more than three decades.
“If we’re not typical then my initial observation would be correct,” he said. “We would be the dumbest guys in the galaxy by the numbers.”
This article was provided by University of Arkansas. Materials may have been edited for clarity and brevity.
In January of 2016, researchers at the Laser Interferometer Gravitational-Wave Observatory (LIGO) made history when they announced the first-ever detection of gravitational waves. Supported by the National Science Foundation (NSF) and operated by Caltech and MIT, LIGO is dedicated to studying the waves predicted by Einstein’s Theory of General Relativity and caused by black hole mergers.
According to a new study by a team of astronomers from the Center of Cosmology at the University of California Irvine, such mergers are far more common than we thought. After conducting a survey of the cosmos intended to calculate and categorize black holes, the UCI team determined that there could be as many as 100 million black holes in the galaxy, a finding which has significant implications for the study of gravitational waves.
The study which details their findings, titled “Counting Black Holes: The Cosmic Stellar Remnant Population and Implications for LIGO“, recently appeared in the Monthly Notices of the Royal Astronomical Society. Led by Oliver D. Elbert, a postdoc student with the department of Physics and Astronomy at UC Irvine, the team conducted an analysis of gravitational wave signals that have been detected by LIGO.
Their study began roughly a year and a half ago, shortly after LIGO announced the first detection of gravitational waves. These waves were created by the merger of two distant black holes, each of which was equivalent in mass to about 30 Suns. As James Bullock, a professor of physics and astronomy at UC Irvine and a co-author on the paper, explained in a UCI press release:
“Fundamentally, the detection of gravitational waves was a huge deal, as it was a confirmation of a key prediction of Einstein’s general theory of relativity. But then we looked closer at the astrophysics of the actual result, a merger of two 30-solar-mass black holes. That was simply astounding and had us asking, ‘How common are black holes of this size, and how often do they merge?’”
Traditionally, astronomers have been of the opinion that black holes would typically be about the same mass as our Sun. As such, they sought to interpret the multiple gravitational wave detections made by LIGO in terms of what is known about galaxy formation. Beyond this, they also sought to create a framework for predicting future black hole mergers.
From this, they concluded that the Milky Way Galaxy would be home to up to 100 million black holes, 10 millions of which would have an estimated mass of about 30 Solar masses – i.e. similar to those that merged and created the first gravitational waves detected by LIGO in 2016. Meanwhile, dwarf galaxies – like the Draco Dwarf, which orbits at a distance of about 250,000 ly from the center of our galaxy – would host about 100 black holes.
They further determined that today, most low-mass black holes (~10 Solar masses) reside within galaxies of 1 trillion Solar masses (massive galaxies) while massive black holes (~50 Solar masses) reside within galaxies that have about 10 billion Solar masses (i.e. dwarf galaxies). After considering the relationship between galaxy mass and stellar metallicity, they interpreted a galaxy’s black hole count as a function of its stellar mass.
A Common Occurrence?
In addition, they also sought to determine how often black holes occur in pairs, how often they merge and how long this would take. Their analysis indicated that only a tiny fraction of black holes would need to be involved in mergers to accommodate what LIGO observed. It also offered predictions that showed how even larger black holes could be merging within the next decade.
As Manoj Kaplinghat, also a UCI professor of physics and astronomy and the second co-author on the study, explained:
“We show that only 0.1 to 1 percent of the black holes formed have to merge to explain what LIGO saw. Of course, the black holes have to get close enough to merge in a reasonable time, which is an open problem… If the current ideas about stellar evolution are right, then our calculations indicate that mergers of even 50-solar-mass black holes will be detected in a few years.”
In other words, our galaxy could be teeming with black holes, and mergers could be happening in a regular basis (relative to cosmological timescales). As such, we can expect that many more gravity wave detections will be possible in the coming years. This should come as no surprise, seeing as how LIGO has made two additional detections since the winter of 2016.
With many more expected to come, astronomers will have many opportunities to study black holes mergers, not to mention the physics that drive them!
The post Cosmic Census: There Could Be 100 Million Black Holes in Our Galaxy Alone appeared first on Futurism.
Now that they're spotting gravitational waves more often, scientists are expanding their search for cosmic events. Specifically, they're using new computer models to depict the cataclysmic collision that occurs when a black hole joins a neutron star…
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