Buried two kilometres underground in an active ore mine, DEAP-3600 is the most sensitive dark matter detector of its kind. Scientists are hoping to shine a light (so to speak) on one of the deepest mysteries of physics.
Category: physics – Page 413
Evidence that our Sun could release ‘superflares’ 1000x greater than previously recorded
Oh, joy.
What the Sun might look like if it were to produce a superflare. A large flaring coronal loop structure is shown towering over a solar active region. (credit: University of Warwick/Ronald Warmington)
Astrophysicists have discovered a stellar “superflare” on a star observed by NASA’s Kepler space telescope with wave patterns similar to those that have been observed in the Sun’s solar flares. (Superflares are flares that are thousands of times more powerful than those ever recorded on the Sun, and are frequently observed on some stars.)
The scientists found the evidence in the star KIC9655129 in the Milky Way. They suggest there are similarities between the superflare on KIC9655129 and the Sun’s solar flares, so the underlying physics of the flares might be the same.
Event Horizon Telescope reveals magnetic fields at Milky Way’s central black hole
Most people think of black holes as giant vacuum cleaners sucking in everything that gets too close. But the supermassive black holes at the centers of galaxies are more like cosmic engines, converting energy from infalling matter into intense radiation that can outshine the combined light from all surrounding stars. If the black hole is spinning, it can generate strong jets that blast across thousands of light-years and shape entire galaxies. These black hole engines are thought to be powered by magnetic fields. For the first time, astronomers have detected magnetic fields just outside the event horizon of the black hole at the center of our Milky Way galaxy.
“Understanding these magnetic fields is critical. Nobody has been able to resolve magnetic fields near the event horizon until now,” says lead author Michael Johnson of the Harvard-Smithsonian Center for Astrophysics (CfA). The results appear in the Dec. 4th issue of the journal Science.
“These magnetic fields have been predicted to exist, but no one has seen them before. Our data puts decades of theoretical work on solid observational ground,” adds principal investigator Shep Doeleman (CfA/MIT), who is assistant director of MIT’s Haystack Observatory.
How to encrypt a message in the afterglow of the big bang
Physicists have come up with a way to make secret codes based on the cosmic microwave background, the afterglow of the birth of the universe.
Bizarre physics doubted
It will be a replay of the same catastrophic explosion astronomers first saw in November 2014.
Revamped LHC goes heavy metal
Physicists will collide lead ions to replicate and study the embryonic universe.
11/24/15.
New York Times.
Will this European satellite confirm Einstein’s last unproven idea?
The Lisa Pathfinder will test equipment for an orbiting observatory that will peer into the universe’s darkest corners.
New detector perfect for asteroid mining
“The opportunity to be involved in such a project as a graduate student is an amazing opportunity,” said Anna Egner, who is leading the team’s effort to build a mock-up of the spectroscope for an actual payload package. “Having always been enchanted and intrigued by physics and astronomy, working on an instrument that might one day fly into space is awesomely exciting.”
The first commercial missions to nearby asteroids could launch as early as 2020, but it will be decades before asteroid mining begins in earnest. In the meantime, the new spectroscopic technology promises to provide planetary scientists with new details about the chemical composition of the asteroids, comets, moons and minor planets in the solar system: information that is certain to improve our understanding of how the solar system formed. In addition, it could become an important tool in the planetary defense arsenal because it can determine whether objects crossing Earth’s orbit are made from rock or ice.
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Are there More Stars in the Universe than Grains of Sand on Earth?
It may hurt your brain to think about it, but it appears that the answer is possibly to be yes, or at least the numbers are almost in the same ballpark.
Astrophysicists in fact set out to answer this question about a decade ago. It’s a complicated problem to solve, but it’s somewhat easier if you throw in a couple of qualifiers — that we are talking about stars in the observable universe; and grains of sand on the whole planet, not just the seashores.
The researchers started by calculating the luminosity density of a section of the cosmos — this is a calculation of how much light is in that space. They then utilized this calculation to guess the number of stars needed to make that amount of light. This was quite a mathematical challenge!
“You have to suppose that you can have one type of star signify all types of stars,” says astrophysicist Simon Driver, Professor at the International Centre for Radio Astronomy Research in Western Australia and one of the researchers who worked on the question.
“Then let’s suppose, on average, this is a normal mass star that gives out the normal amount of light, so if I know that a part of the universe is producing this amount of light, I can now say how many stars that would associate to.”
Now armed with a guess of the number of stars within a section of the cosmos, the next challenge was to work out the size of the cosmos. Given we know that the cosmos is 13.8 billion years old, we can suppose that we exist in a sphere 13.8 billion light years in volume. But there’s a catch: the universe is possibly immeasurable in size.