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How a global network of telescopes may give us first glimpse of a black hole

November 25, 2014 at 8:45 PM EDT
Even though black holes are vital to our understanding of the universe, no one has ever seen one -- yet. To change this, a team of scientists in northern Chile, is using a network of telescopes around the globe to capture an image of a black hole for the first time to prove Einstein’s Theory of General Relativity. Rebecca Jacobson reports.
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GWEN IFILL: Now: an amazing scientific search pushing the limits of what we know about the cosmos, the quest to see a black hole.

The “NewsHour”‘s Rebecca Jacobson went to Chile for this report.

SHEP DOELEMAN, Principal investigator, Event Horizon Telescope: Black holes are some of the most exotic objects in the universe. They come about when matter gravitationally collapses in on itself, and everything becomes pulverized and crushed down into a single point.

REBECCA JACOBSON: MIT astronomer Shep Doeleman is leading an international effort to understand black holes. These exotic objects are fundamental to our understanding of the universe. When stars, dust, and planets cross the event horizon surrounding the black hole, nothing, not even light, can escape. But no one has ever seen one.

Doeleman is trying to change that.

SHEP DOELEMAN: The Event Horizon Telescope project is really about seeing what we have always thought as unseeable.

REBECCA JACOBSON: But to boldly go where no telescope has gone before, scientists have to drive up a 16,500 foot-high mountain. This is the Atacama Large Millimeter, or ALMA, in Northern Chile. ALMA’s 66 antennas form the most powerful radio telescope in the world.

Each antenna weighs 100 tons, and they are so accurate, they can see a golf ball nine miles away. They will form the anchor for the Event Horizon Telescope, a worldwide network of observatories that will capture an image of a black hole for the first time.

ALMA’s antennas sit just 400 feet lower in elevation than Mount Everest’s North Base Camp. Before going up the mountain, we had to undergo rigorous physical testing, because working at this altitude is dangerous.

My blood pressure was a little too high, so we waited a few minutes to see if it would go down.

Ivan Lopez is the safety manager at ALMA.

IVAN LOPEZ, Atacama Large Millimeter/submillimeter Array: If you don’t get to the minimum levels that we have for pressure and oxygen content in your blood, you’re not allowed to go up to the high site.

REBECCA JACOBSON: What could happen to you if you did go to the high site and your blood pressure was too high?

IVAN LOPEZ: You can get a stroke.

REBECCA JACOBSON: And too little blood oxygen can swell the brain and cloud thinking. Oxygen tanks help scientists battle nausea, dizziness and fatigue, but it can still be hard to think straight.

SHEP DOELEMAN: We have what we call summit moments. And what I can tell you is that, once, I spent about five minutes trying to screw in a screw, when, in reality, I was unscrewing it.

REBECCA JACOBSON: And it’s not just the altitude that makes working here difficult. The Atacama is the world’s driest desert. Trucks haul thousands of gallons of water to the observatory every day. Add to that high winds, hot sun, and dangers below ground.

DAVID RABANUS, Atacama Large Millimeter/submillimeter Array: We have actually designed the ALMA antennas to withstand an earthquake of grade nine.

REBECCA JACOBSON: But the tradeoff is worth it. Some say it’s the most beautiful view on Earth of the night sky.

Richard Simon is an astronomer working at ALMA.

RICHARD SIMON, National Radio Astronomy Observatory: The reason ALMA exists is that there is something about astronomy, about learning about our universe and reaching out into it that’s a very human and a very important thing to do.

REBECCA JACOBSON: In 1916, Albert Einstein’s theory of general relativity first predicted the existence of black holes. That was nearly 100 years ago, and that theory has not been disproven. But with no real visuals, it hasn’t been confirmed yet either.

This year, a cloud of space dust is spiraling into the supermassive black hole at the center of our galaxy. If it swallows that dust, as astronomers predict, the event horizon should light up, casting a shadow.

SHEP DOELEMAN: First question is, do black holes exist? And if we see the shadow, that will be the most powerful evidence we have that they do exist. I hope we will see something transformative. I hope we’re going to see something that knocks our socks off, but whatever we see, it’s going to be new and it’s going to raise probably more questions than we have answers to.

REBECCA JACOBSON: It’s a rare opportunity to find out if Einstein was right.

RICHARD SIMON: We think we know the theory of black holes. This is a key test. It’s the — one of the only black holes that we can actually observe and make direct measurements of.

It needs telescopes spread all across the globe to get the maximum separation between telescopes and the maximum resolution, the finest picture possible.

REBECCA JACOBSON: Even ALMA’s powerful antennas can’t do it alone. ALMA will be the anchor for a worldwide network of telescopes. Scientists will link ALMA’s antennas with telescopes in Hawaii, California, Mexico, Arizona, Spain and the South Pole, and then piece together all of the information they collect.

Synching all these telescopes means equipping each with the most precise atomic clock available. That means taking out ALMA’s clock, and replacing it with one that costs a quarter-of-a-million dollars that won’t lose a second in the next hundred million years.

SHEP DOELEMAN: So, right now, we’re in the holiest of holies, the central reference room for all of ALMA. And these are where all the signals that are sent to all the antennas originate. What we have basically done is perform a heart transplant for ALMA.

REBECCA JACOBSON: The Event Horizon project is estimated to cost between $10 million and $20 million over the course of 10 years. But Simon says its mission, and ALMA’s, is worth more.

RICHARD SIMON: There is a deep curiosity that we all have. A hundred years from now, my name and what I have done for this project will probably not be remembered, but what this instrument does and what it means to everyone around the world is something that will be remembered.

REBECCA JACOBSON: The Event Horizon Telescope is slated to begin observations in the spring.

For the “PBS NewsHour,” I’m Rebecca Jacobson in the Atacama Desert in Chile.

 

 

 

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