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Unprecedented collision of heavy and light black holes reveal by Gravitational waves

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The gravitational waves from a black-hole merger typically ripple at twice the frequency that the black holes go around each other.

 

LIGO/T. Pyle

Researchers with the world’s gravitational wave detectors said today they had picked up vibrations from a cosmic collision that harmonized with the opening notes of an Elvis Presley hit. The source was the most exotic merger of two black holes detected yet—a pair in which one weighed more than three times as much as the other. Because of the stark mass imbalance, the collision generated gravitational waves at multiple frequencies, in a harmony Elvis fans would recognize. The chord also confirms a prediction of Einstein’s theory of gravity, or general relativity.

Such mismatched mass events could help theorists figure out how pairs of black holes form in the first place. “Anything that seems to be at the edge of our predictions is most interesting,” says Chris Belczynski, a gravitational theorist at the Polish Academy of Sciences in Warsaw, who was not involved in the observation. But the one event is “not quite in the regime where you can tell the different formation [routes] apart.”

Physicists first detected gravitational waves in 2015, when the Laser Interferometer Gravitational-Wave Observatory (LIGO), a pair of detectors in Washington and Louisiana, spotted two black holes spiraling into each other, generating infinitesimal ripples in spacetime. Two years later, the Virgo detector near Pisa, Italy, joined the hunt, and by August 2017, the detectors had bagged a total of 10 black hole mergers.

All involved pairs of black holes with roughly equal masses, says Maya Fishbach, a physicist and LIGO member at the University of Chicago. But on 12 April 2019, the three detectors detected a black hole merger 2.4 billion light-years away in which one weighed 30 solar masses and the other just eight, says Fishbach, who reported on the event at the American Physical Society’s online April meeting. “This is the first event in which we can confidently say the mass-ratio is not one,” she says.

Ordinarily, two spiraling black holes pump out gravitational waves concentrated at a single frequency: double the rate at which they orbit each other. That doubling arises because of the matched masses of the black holes. Every half orbit they return to a position that’s effectively identical to their original one. But if the black holes have distinctly different masses, then general relativity predicts that they should also generate weaker waves at higher frequencies, or overtones.

The next-strongest note sung by the pair should vibrate at three times the orbital frequency, or one and half times the main gravitational-wave frequency. If the main frequency were a C on a piano, the overtone would be the next higher G—a perfect fifth, and the interval of the first two notes in the melody of Elvis Presley’s hit “I Can’t Help Falling in Love with You.” That is what the LIGO and Virgo researchers detected, says Maximiliano Isi, a physicist and LIGO member at the Massachusetts Institute of Technology, who also spoke at the meeting. The overtone rang roughly as loudly as predicted by general relativity, Isi says. “Einstein prevails again.”

Such oddball events might help researchers figure out how the black holes pair in the first place. That’s a puzzle because it’s not obvious how such big black holes can form so close together. Theorists have two general ideas. The pairs could originate from a pair of orbiting massive stars, which each collapse into black holes at the ends of their lives. Alternatively, in so-called dynamical models, the black holes might form completely separately and find each other across space and time, a scenario more likely in globular clusters, the dense clumps of stars found in the outer reaches of galaxies.

Either scenario can probably account for the mismatched black holes in this event, Belczynski says. “If it [the mass ratio] had been 10-to-1 I would have bet on the dynamical models,” he says, as binary star systems generally don’t form with such skewed ratios. Fishbach agrees that the single event isn’t enough to rule out one scenario or the other. But she says that if LIGO and Virgo spot more mismatched events, the statistical distributions could suggest which scenario is more likely.

However, the event could have a more complex origin, says Emanuele Berti, a gravitational wave astronomer at Johns Hopkins University. The fact that the one black hole is so much heavier than the other and appears to be spinning fast suggest that it, too, was the product of a merger. “It looks quiet like the product of a multiple-generation merger,” he says.

More peculiar collisions might be waiting among the dozens of recorded events that researchers have yet to analyze. LIGO and Virgo’s observing run 3, which went from 1 April 2019 until 26 March, picked up 56 new gravitational wave events, more than five times the previous total. LIGO and Virgo researchers had hoped to finish a global analysis of roughly half that data set by now, but the coronavirus pandemic delayed them, says Patrick Brady, a physicist at the University of Wisconsin, Milwaukee, and spokesperson for the LIGO scientific collaboration. Belczynski says he’s anxious to see those results. “I’m just sitting here with my students, my entire group, waiting for this paper.”

Edited by Harry Miller

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SpaceX’s historic NASA astronaut launch debut on track for second attempt – Teslarati

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Rather than making history on May 27th, SpaceX’s highest-profile launch ever – Crew Dragon’s NASA astronaut launch debut – was scrubbed just minutes before liftoff by stormy Florida weather. Unfortunately, conditions appear to be even less favorable on Saturday and Sunday backup windows.

Weather trended well, until it didn’t

The day began with launch fans growing increasingly concerned about a system of low-pressure off of Florida’s northeast coast that strengthened into tropical storm Bertha – the second named storm before the official start of the Atlantic basin hurricane season on June 1st. As the day progressed, Bertha became less of a worry for SpaceX recovery and emergency abort drop zones as it moved further north up the coast eventually making landfall in South Carolina. Then the thunderstorms began firing up.

Hans Koenigsmann, vice president for build and flight reliability at SpaceX, looks at a monitor showing a live feed of a SpaceX Falcon 9 rocket carrying the company’s Crew Dragon spacecraft on the launch pad during the countdown for a launch attempt of NASA’s SpaceX Demo-2 mission. (Credit: NASA/Joel Kowsky)

Going into launch day launch weather officer, Mike McAleenan of the U.S. Space Force’s 45th Weather Squadron predicted a 60% chance of favorable launch weather conditions. That decreased slightly to 50% during the morning’s launch weather briefing. The 50/50 shot of Florida weather cooperating to get the launch off during the one-second long launch window opportunity remained the main concern for the rest of the day.

An ominous thunderstorm rolls over LC-39A ahead of SpaceX’s ultimately scrubbed first attempt to launch the Crew Dragon Demo-2 test flight on Wednesday, May 27th. (Credit: Richard Angle for Teslarati)

During the final thirty minutes of the countdown, many of the weather constraints that were holding up a green-light for launch from cleared up, but one last weather rule remained no-go. McAleenan stated over the internal weather communication loop during NASA’s live broadcast that if the launch window could’ve extended another 10 minutes, the weather would probably cooperate. This wasn’t the case, though. The launch attempt was ultimately aborted just 14 minutes shy of liftoff due to the “field mill” rule not clearing in time. The lightning field mill rule refers to a sophisticated electrical field system that spans the entire area of Kennedy Space Center and the surrounding area of Cape Canaveral responsible for continuously detecting the electrical charge of the atmosphere.

Protecting rockets from producing lightning

Rockets are not permitted to launch through an electrically charged atmosphere because of the possibility of what is called “triggered” lightning – lightning that is actually produced by a rocket bursting through an electrically charged atmosphere. Sending a rocket through an already unstable atmosphere can cause a disturbance, a lightning bolt, to be triggered. This phenomenon has the capability of being potentially dangerous for the rocket and, more importantly in this case, the occupants on board.

A very helpful infographic published by the 45th Weather Squadron regarding the natural and triggered lightning launch rules. (Credit: 45th Weather Squadron)

Demo-2, Round 2

Following a scrubbed first attempt, the 45th Weather Squadron released the L-3 (3 days until launch) forecast for the second attempt to send NASA astronauts Doug Hurley and Bob Behnken to the International Space Station. The prediction looked much like the one going into Wednesday’s attempt. On Thursday morning, May 28th, a new L-2 (2 days until launch) forecast was released showing very little change from the evening before.

SpaceX’s next attempt at a Demo-2 launch will occur on Saturday, May 30th, at 3:22:41pm EDT with another backup attempt scheduled for Sunday, May 31st at 3:00:07pm EDT. The outlook for the weather, however, looks much the same as it did for Wednesday. The 45th Weather Squadron is currently predicting only a 40% chance of favorable launching conditions on both days, and that’s just for the weather directly over LC-39A at the time of launch.

A L-3 weather forcast provided by the U.S. Space Force’s 45th Weather Squadron outlines a 40% chance of acceptable weather conditions at time of launch for SpaceX’s back-up attempt to lauch the first ever crewed mission, Demo-2, on Saturday, May 30th. (Credt: U.S. Space Force – 45th Weather Squadron)

The 45th Weather Squadron does not predict other conditions that can determine a scrub of launch including upper-level atmospheric winds capable of completely sheering apart a rocket at altitude, or weather conditions for booster recovery and the recovery zones needed to rescue the Dragon capsule in the event of an emergency abort scenario. SpaceX has its own team of professionals that work in tandem with the 45th Weather Squadron to monitor the conditions of the recovery and abort zones. SpaceX takes things into consideration like wave height and patterns to determine whether or not conditions are appropriate enough for crews to perform any and all recovery operations that may be needed.

For Saturday’s attempt, the SpaceX Demo-2 will once again face the challenges of precipitation and dangerous lightning producing anvil and cumulus clouds. Expect launch day to look much like it did during the first attempt on Wednesday. SpaceX will need to thread one seriously precise needle to pull off the most historic rocket launch in company history.

Check out Teslarati’s newsletters for prompt updates, on-the-ground perspectives, and unique glimpses of SpaceX’s rocket launch and recovery processes.

SpaceX’s historic NASA astronaut launch debut on track for second attempt




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Tesla's Musk earns $770M in stock options, company confirms – OttawaMatters.com

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DETROIT — Tesla confirmed Thursday that CEO Elon Musk will get the first tranche worth nearly $770 million of a stock-based compensation package triggered by the company meeting several financial metrics.

The electric car and solar panel maker’s board certified that Musk earned the big payout, according to a filing with the U.S. Securities and Exchange Commission. The filing says Musk can buy 1.69 million shares of Tesla stock for $350.02 each, but it wasn’t clear whether he had exercised the stock options. His payout is based on the difference between the option price and Thursday’s closing share price of $805.81.

Musk earned the options as part of an audacious compensation package approved by the board in 2018.

According to the filing, the board certified that Tesla had reached the milestones by hitting $20 billion in total revenue for four previous quarters and a total market value of $100 billion. The company also reached $1.5 billion in adjusted pretax earnings, but that must still be certified by the board, the filing said.

Musk has to hold the stock for a minimum of five years, under the terms of the compensation package.

Musk can afford to wait before cashing in on his latest windfall, given his wealth is estimated at $39 billion by Forbes magazine.

All told, the incentives approved by Tesla’s board in 2018 consist of 20.3 million stock options that will be doled out in 12 different bundles if the company is able to reach progressively more difficult financial goals. It’s one of the biggest corporate pay packages in U.S. history.

In order for Musk to receive all 20.3 million stock options, Tesla will have to generate adjusted annual earnings of $14 billion on annual revenue of $175 billion coupled with a market value of $650 billion. In the past four quarters, Tesla, which is based in Palo Alto, California, has reported adjusted earnings totalling $3.6 billion on revenue totalling $26 billion.

The Associated Press

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Tesla's Musk earns $770M in stock options, company confirms – GuelphToday

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DETROIT — Tesla confirmed Thursday that CEO Elon Musk will get the first tranche worth nearly $770 million of a stock-based compensation package triggered by the company meeting several financial metrics.

The electric car and solar panel maker’s board certified that Musk earned the big payout, according to a filing with the U.S. Securities and Exchange Commission. The filing says Musk can buy 1.69 million shares of Tesla stock for $350.02 each, but it wasn’t clear whether he had exercised the stock options. His payout is based on the difference between the option price and Thursday’s closing share price of $805.81.

Musk earned the options as part of an audacious compensation package approved by the board in 2018.

According to the filing, the board certified that Tesla had reached the milestones by hitting $20 billion in total revenue for four previous quarters and a total market value of $100 billion. The company also reached $1.5 billion in adjusted pretax earnings, but that must still be certified by the board, the filing said.

Musk has to hold the stock for a minimum of five years, under the terms of the compensation package.

Musk can afford to wait before cashing in on his latest windfall, given his wealth is estimated at $39 billion by Forbes magazine.

All told, the incentives approved by Tesla’s board in 2018 consist of 20.3 million stock options that will be doled out in 12 different bundles if the company is able to reach progressively more difficult financial goals. It’s one of the biggest corporate pay packages in U.S. history.

In order for Musk to receive all 20.3 million stock options, Tesla will have to generate adjusted annual earnings of $14 billion on annual revenue of $175 billion coupled with a market value of $650 billion. In the past four quarters, Tesla, which is based in Palo Alto, California, has reported adjusted earnings totalling $3.6 billion on revenue totalling $26 billion.

The Associated Press

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