What did we do & why is this interesting? Deep technical dive ahead!
We learn about accreting #BlackHoles studying their spectra & short-term (~millisecond) variability, called timing. However, individually, both approaches leave us with a lot of puzzles - so we try to combine them in spectral-timing.
"Nasa has released footage simulating what it's like being sucked into a black hole, a region of space with such strong gravity not even light can escape." #Astronomy#Cosmology#BlackHoles#NASA
It’s now thought that they could illuminate fundamental questions in #physics, settle questions about #Einstein’s theories, & even help explain the #universe.
…In recent yrs, the amt of data that scientists have discovered about black holes has grown exponentially.
In Jan, #astronomers announced that the #JamesWebbSpaceTelescope had observed the oldest black hole yet—one present when the universe was a mere 400M yrs old.…Recently, 2 #SupermassiveBlackHoles, w/a combined mass of 28B suns, were measured & shown to have been rotating tightly around each other, but not colliding, for the past 3B years. And those are just the examples that are easiest for the public to make some sense of.
To me, a #SupermassiveBlackHole sounds sublime; to a #scientist, it can also be a test of wild hypotheses. “#Astrophysics is an exercise in incredible experiments not runnable on Earth,” Avery Broderick, a theoretical physicist at uWaterloo & at the Perimeter Inst, told me. “And #BlackHoles are an ideal laboratory.”
Broderick says that he studies black holes because they are very simple, theoretically & mathematically.
As he explained it, a #BlackHole has a mass, an electrical charge, & an angular momentum (meaning it can spin). “And that’s pretty much it,” he said. “Their behavior is extreme, but the apparatus is something we think we understand.” Another “simple” way to think of a black hole is as an extraordinary amt of mass in a relatively small space. It exerts a gravitational pull so strong that not even light can escape it.
Imagine the mass of Earth condensed to the volume of a marble; imagine a million suns condensed to the volume of a single sun—that’ll give you an idea of a #BlackHole. Some #BlackHoles are formed by stars that have collapsed in on themselves. Other black holes are thought to have been formed by the inward collapse of enormous clouds of gas. (There are other theories, too.)
To look “into” a #BlackHole—from which no photon or wave or ray ever returns—requires considerable #creativity. The interior of a black hole can only be deduced from changes exterior to it. Active #BlackHoles are encircled by intense brightness & billion-degree heat, given off by matter falling toward them—think of the fire of an incoming asteroid—while the black hole itself is unthinkably cold, a tiny fraction of a degree above absolute zero.
It’s in these simple, outlandish objects, Broderick explained,“that 20th-cen #physics breaks down.”…Basically, there’s #Einstein’s theory of general #relativity (which made a tiny but far-reaching correction to #Newton’s concept of #gravity), & there’s #QuantumMechanics. “General relativity is thought of as the theory of the very large & massive, & quantum mechanics is the theory of the very small or very cold,” Broderick said. #BlackHoles are massive(gen relativity), & cold (quantum mechanics).
But, when scientists attempt to use these theories to describe what happens in the interior of a #BlackHole, the implications are, as another astrophysicist put it, “a disaster.” Or, as Broderick put it, the theories “give very different answers.”
#ICYMI: A recent #EHT image reveals strong magnetic fields spiraling from Sagittarius A*, the supermassive black hole at our galaxy’s center. These fields resemble those around the M87 galaxy’s black hole, suggesting commonality among black holes. A hidden jet in Sagittarius A* is also hinted at.
In polarized light, a side-by-side image of supermassive black holes M87* and Sagittarius A* reveals similar magnetic field structures. This suggests universal features governing how black holes feed and launch jets.
What Is Quantum Teleportation?
Teleporting people through space is still science fiction.
But quantum teleportation is dramatically different and entirely real. In this episode, Janna Levin interviews the theoretical physicist John Preskill about teleporting bits and the promise of quantum technology.
@IRAP#Seminar] this Thursday at 11am. Benjamin Crinquant, a young researcher at IRAP, will present the progress we have made in our knowledge of #BlackHoles: from the observations carried out by the #GRAVITY and #EventHorizonTelescope collaborations to the most recent models of the #magnetospheres and #coronae of black holes.