Spotting black holes

Black holes remain among the more mysterious objects in the universe. Though John Michell and Pierre-Simon LaPlace first posited their existence back in the 18th century, nobody has ever actually seen a black hole. Dr. Sean O’Neill, visiting assistant professor in the Department of Physics at Pacific Lutheran University in Tacoma, attempted to shed some light on these objects that don’t emit any during a talk at this month’s meeting of the Seattle Astronomical Society.

Dr. Steve O’Neill of PLU spoke about black
holes at the December meeting of the Seattle
Astronomical Society. Photo: Greg Scheiderer.

O’Neill’s talk was titled “If We Can’t See Black Holes, How Do We Know They Exist?” His answer to the question boiled down to the notion that scientists have not yet come up with any other plausible explanation for some of the phenomena that they have seen.

The professor noted that traditional methods of observing astronomical objects simply are not practical for viewing black holes.

It would not work to send a spacecraft for a look. O’Neill pointed out that the nearest likely black hole is some 1,300 light years away from Earth. It would take a craft like Voyager about 25 million years to get there, and then, even if it arrived with its power source and transmitter intact, you would still have to wait 1,300 years to receive any messages about its findings.

“Traveling there is a terrible option,” O’Neill understated. “The direct visit option is bad even for things in the outer solar system, let alone things outside of our solar system.”

Imaging is also well nigh impossible, O’Neill said, and not just because a black hole, by definition, does not emit any light. Black holes, though incredibly massive, are also dense and quite small. Today’s telescopes don’t offer adequate resolution for a visual or photographic look; it would take a scope about ten thousand times the size of Hubble to spot the supermassive black hole at the center of the Milky Way.

Other methods offer some hope. O’Neill says we might well be able to spot the gravitational effects of a black hole, especially one circling another or dancing gravitationally with another massive object. In such cases general relativity predicts gravitational waves in space-time, and these might be observed directly. The approach is to use laser interferometry to detect changes in light wavelength. O’Neill says it’s a complicated process from which it is difficult to separate observational noise.

“In practice, there have been no detections of this phenomenon happening yet, even though most people think it probably does happen,” O’Neill said.

O’Neill says gravitational lensing also holds some promise, especially as observing equipment gets better.

“It’s tough to pick out the individual little black holes, though,” he said, noting that the method is used to look at distant, large, massive objects that lens other distant objects.

Though we haven’t yet seen a black hole, there’s plenty of evidence that infers that they exist. O’Neill shared data from observations of stars orbiting the center of our galaxy, seen in the infrared to cut through the dust blocking our direct visual view. Using Newton’s laws on the data from a number of years to reconstruct the orbits of the stars suggests they’re going around something that is about 3.7 million times more massive than our Sun. Whatever it is, we can’t see it because it doesn’t emit any light of its own.

“It’s tough to come up with a good alternative of what this could be,” O’Neill said. “It’s tough to imagine that gravity just goes wrong at this one point, for some reason, at the center of our galaxy.”

“That’s where we get a lot of direct evidence for what we think is the black hole at the center of our own Milky Way,” he concluded.

Looking at other objects leads to similar conclusions. Cygnus X-1 is a huge source of x-rays that is pulling material from a donor star nearby. The material holds a great deal of potential energy because of the high gravity of the system.

“All of that energy has to be converted into some form,” O’Neill explained. “Some of it is certainly kinetic, because stuff will speed up, but some of it is also going to be thermal energy. It will hit other little particles of gas, all of this will heat up to the point that it starts emitting x-rays, and that’s the stuff that we think we can see.”

One of O’Neill’s research interests is computer modeling of the jets of material often spotted shooting out of the centers of galaxies, such as Centaurus A. He shared a number of these simulations, in which material plummets toward a presumed black hole, doesn’t quite fall in, and then shoots away at great velocity. The models can be rotated to simulate views from various angles and compare the results to actual observations. While it’s an active area of research, O’Neill says most scientists are on the same page with their thinking.

“The reigning theoretical model for these jets by far—there’s essentially no viable alternative—is that fundamentally they’re powered by black hole gravity at the source,” he said.

While O’Neill notes that computer simulations like the ones he creates are way cheaper than observing, he expects that actual observations of gravitational waves from merging black holes are not far off. He also thinks that high-resolution x-ray and radio observations will allow us to see the disks of material around black holes within his lifetime.

Asteroid mining: not such a crazy idea

When Bellevue-based Planetary Resources, Inc. first went public in April of 2012 with its plans to mine astroids for water and minerals there were many who reacted with an “Oh, pshaw.” Less than three years later, the successful landing by the ESA Rosetta mission of its probe Philae on the comet 67P/Churyumov–Gerasimenko, out in the far reaches of the solar system, makes it all seem like a more plausible idea.

“I love seeing the success of this mission because it proves that what we are doing is technically feasible today,” said Caitlin O’Keefe, director of marketing for Planetary Resources, on Tuesday during a Science Café talk sponsored by the Pacific Science Center at The Swiss Pub in Tacoma. O’Keefe added that Philae and Rosetta are ten-year-old craft that have spent a decade traversing six billion kilometers of space. Technology has advanced during that time; think about what your cell phone couldn’t do in 2004.

Caitlin O’Keefe, marketing director for Planetary Resources,
spoke about asteroid mining at a Science Café event Tuesday
 in Tacoma. Photo borrowed from Facebook.

O’Keefe and everyone at Planetary Resources understand the skepticism. She quoted company co-founder Peter Diamandis as saying, “The day before something is a breakthrough it is a crazy idea.”

They’re creating the technology today to get themselves to that breakthrough. Advances in spacecraft control, avionics, communication systems, propulsion, and observation will help them identify and then get to resource-rich asteroids.

Unfortunately, one of their first tests of the technology went up in flames. Their Arkyd 3 satellite, which was to try out some of their new systems, blew up with the Antares rocket back in October.

“This was a bummer for our team to watch,” O’Keefe said. “There was a big hooray when it launched, and some not so nice words when it exploded six seconds later.”

But, she added, they’ve been able to shrug it off, in large part because their philosophy is to build a lot of small and relatively inexpensive spacecraft rather than putting all of their space-bound eggs into one billion-dollar basket.

“This is going to be a very important part of the space industry going forward: the ability to accept failure,” she said.

Many of the questions from the patrons of The Swiss during the talk centered around the financial aspects of mining in space. O’Keefe noted that there is a lot of potential. For example, one target astroid is thought to contain some $500 billion worth of platinum, which if mined would be more than has been extracted from Earth to date. While that could be a big payday, their first target is a more common substance: water. Water is good for drinking and protection from radiation, and can be turned into rocket fuel. And O’Keefe pointed out that it’s a lot cheaper to pick up water in space than it is to take it with you. To launch a bottle of water into low-Earth orbit you need about 50 times its mass in rocket fuel, and that pencils out to about $20,000. The savings add up, and it will make long space missions much more fiscally possible; a spacecraft can go all the way from Earth to Pluto on the same amount of fuel it takes just to launch into low-Earth orbit.

Mining may well be easier in the zero gravity of space, too, and the methods for doing it are pretty straightforward.

“Building this technology will be extremely difficult,” O’Keefe admitted. “I’m not downplaying the difficulty of a complicated system, but the theory of how to extract it is pretty well known.”

O’Keefe invited us all to join the asteroid mining effort. You can go to Asteroid Zoo, a venture launched this summer by Planetary Resources and Zooniverse, to help comb through data and identify potentially resource-rich asteroids.

Partial solar eclipse seen in Seattle

The partial solar eclipse of October 23, 2014 was a highly successful skywatching event by Seattle standards. Much of the first half of the eclipse was visible as it dodged clouds around the city. I viewed it from the sidewalk in front of Seattle Astronomy world headquarters in West Seattle.

Few observers held out much hope for seeing the eclipse. The weather forecast had been for rain and clouds for much of the Northwest. In the days leading up to the eclipse area astronomy message boards carried some talk of road trips to sites with better potential for clear skies, such as Yakima or other parts of Eastern Washington, though one seasoned observer wrote, “I have no confidence in finding anywhere drivable that reliably will have clear skies.” Clearly, a man who has been through this before.

Sure enough, we awoke on the morning of the eclipse to heavy rain and solid, dark, gray cloud cover. There seemed scant likelihood we would be seeing the eclipse. But by mid-morning the rain let up, and at about 11:37 a.m. I sent out this tweet and photo:

Blue sky over our world HQ! A chance to see the eclipse yet! http://t.co/9IB3YxBxUx
— Seattle Astronomy (@SeattleAstro) October 23, 2014

The blue sky held for the most part, and though the exact moment that the eclipse began was obscured by a cloud, the sun was out in full glory not long into it.

Just minutes into the partial solar eclipse of Oct. 23, 2014.
Photo: Greg Scheiderer.

It didn’t last long. Not more than 15 minutes later a robust thunderstorm, including lots of hail, blew through the area, obscured the Sun from view and drove us for cover. The storm didn’t last long, but the cloud cover remained for a while. Perhaps 20 minutes to half an hour later, we spotted a patch of blue sky to the west and urged the Sun to steer into it. It did! For the next hour or so the eclipsing Sun played hide and seek with us, dodging under cloud cover and then peeking back out again.

Maximum eclipse happened right about 3 p.m., and about 15 minutes after that one of the neighbor kids who had come over for a look through the Seattle Astronomy telescope and eclipse shades spotted a flash of lightening. A rumbling thunderclap followed a few seconds later, and within a minute or two it was raining and hailing hard. Alas, we’d seen the last of the eclipse for the day. Another blue patch finally arrived right around 5 p.m., old Sol popped into view, but the disk of the new Moon had passed by and the eclipse was over.

The eclipse was especially interesting because of the giant sunspot aimed right at us. You can see it in the photos, which, I admit, aren’t that great. They were made with a little point-and-shoot camera stuck right up to the telescope eyepiece. I don’t claim any real talent for astrophotography, but like to grab a few snapshots, just to show that I was there.

The partial solar eclipse of October 23, 2014, right around the time of
maximum coverage as seen from Seattle. Photo: Greg Scheiderer.

The eclipse put me in mind of the 2012 Venus transit, when bad weather and a desire to see what was a once-in-a-lifetime event convinced me to drive as far as Corning, California for a chance to see the Sun. This time I decided to stay home, and it paid off. While I didn’t see the whole eclipse, I saw enough to enjoy and appreciate this awesome spectacle, and was able to share it with some neighbors too!

I can’t help but laugh at myself because I still audibly gasp most times at the start of these sorts of events. Seeing the solar eclipse or the Venus transit begin just when the scientists said it would just amazes me, and the spectacle itself is so awesome. Even just spotting Saturn again after it has been out of view, or up too early in the morning, tickles my astronomical fancy. The universe is such an amazing place.

I’m happy that Seattle weather gave us a break and let us have a good view of a great celestial show.

Science jargon and the all-there-is

Sometimes when scientists speak nobody has the foggiest idea what they’re talking about. Even other scientists can have trouble decoding the lingo of colleagues from other specialties.

Roberto Trotta thinks that’s a problem. A theoretical astrophysicist with Imperial College in London, Trotta is also passionate about good communication about science. As science communicators ourselves, Seattle Astronomy was excited to hear his recent talk at Town Hall Seattle.

“I’m very much interested in sharing the mysteries and the outstanding questions that cosmology raises with the public at large,” Trotta said. “It’s only fair that we share our ideas and the reasons why we do what we do with the people who are actually funding the work. To me, talking about science in a way that’s understandable and utterly engaging for the public is a very important concept.”

Trotta’s new book, The Edge of the Sky: All You Need to Know About the All-There-Is, uses just the 1,000 most common English words to explain what he does in his day job. That’s a tall order; Trotta had to write about cosmology without using words like telescope, galaxy, Big Bang, universe, and dark energy, none of which made the list.

“This book came out of a little idea that it should be possible to talk about very hard things in a straightforward way that all people can understand,” Trotta said.

It doesn’t always happen that way. Trottoa told the story of Arno Penzias and Robert Wilson working at Bell Labs in New Jersey in 1964. The two were using a new antenna to detect radio waves, but were having trouble eliminating persistent background noise. Eventually they wrote a short paper titled “A Measurement of Excess Antenna Temperature at 4080 MC/S.”

Roberto Trotta talked about his 

book “The Edge of the Sky” 

Sept. 30 at Town Hall Seattle

“What these two gentlemen were trying to say is ‘We picked up the echo from the Big Bang!'” Trotta marveled. They had found the cosmic microwave background and eventually received a Nobel Prize for the work. Trotta gave other examples of scientific papers with language that he called “impenetrable” and “incomprehensible.”

“Jargon is in the way,” he said. “Jargon is one big obstacle in having a dialog with the public.”

Trotta’s first shot at the 1,000-word concept was describing his own job in this simple, straightforward language during a public lecture. It received a positive reaction at that talk, as it did at Town Hall, and so he decided to take the concept further.

“The book began very much as an experiment because I wanted to see how far I could stretch this language,” he explained. “Would it break? Would it become boring? Would it become impossible?” He wondered whether complicated concepts such as dark matter could be explained in such simple terms.

It worked, and early reviews of the book have been positive. Trotta said that writing the book was almost like learning a new language. There were a few hiccups along the way. He first thought of translating “Big Bang” to “Hot Flash.” This turned into “Big Flash” for obvious reasons. Other terms in The Edge of the Sky:

• Universe: The all-there-is
• Galaxy: Star crowd
• Telescope: Big seer
• Dark energy: Dark push
• Earth: Home world

Trotta said that since the book began as a thought experiment he really didn’t have a target readership in mind, but that he hopes it will appeal to readers from young adult on up who want to get a better grip on the sometimes challenging but always fascinating topics of cosmology.

New mystery novel set at Jacobsen Observatory

The University of Washington’s Theodor Jacobsen Observatory is the setting for some of the scenes in a new mystery novel from local author Bernadette Pajer. A celebration of the release of The Edison Effect, the fourth title in Pajer’s series of Professor Bradshaw mysteries, was held recently at the observatory.

Pajer’s protagonist Benjamin Bradshaw is a fictional professor of electrical engineering at the UW and solver of mysteries involving electricity. Seattle needs his expertise; the books are set in the early 1900s, and electricity is still something of a puzzle to people and the police. The tagline for the series is “Seattle in the time of Tesla.”

“It’s a very exciting time period to research,” Pajer says, “not only the city where I was born and raised, all of those details, but the scientific history, where we came from and how quickly.”

A happy coincidence brought Professor Bradshaw to the Jacobsen Observatory. In 2012 Pajer participated in a panel discussion about mysteries at the Taproot Theatre in Seattle, which was performing a stage version of the Dorothy Sayers story Gaudy Night. One of the people who attended the event was George Myers, whose great-great-grandfather was Joseph Taylor, the UW’s first math professor and first director of the observatory. After the discussion Myers emailed a photo of Taylor to Pajer.

Joseph Taylor, the first director of
the UW’s Theodor Jacobsen Observatory,
is a character in Bernadette Pajer’s new
mystery novel The Edison Effect.

“I just knew instantly when I saw that photo that professor Bradshaw knows this guy, and, not only that, they’re friends, so I wove him into The Edison Effect,” Pajer says. She notes that no astronomy happens in the book, but several key scenes occur at the observatory.

Myers and other relatives of Taylor attended the book launch at the observatory, and enjoyed learning a few new things that Pajer’s research turned up about their ancestor. For example, Taylor laid the cornerstone at Denny Hall, which was the first building on the current UW campus, known then as the Administration Building. Its basement is where Professor Bradshaw has his electricity lab. Interestingly, the Jacobsen Observatory was constructed of materials left over from the building of Denny Hall.

“It was fun!” Pajer says of the launch event. “I had the ghost of Bradshaw, and the real ghost of Joseph Taylor that were at the observatory. It was a really cool way that fact and fiction were mingling.”

The character of Bradshaw came to Pajer in part because of her own interest in science. She studied civil engineering at the UW, but dropped out to get married. Twenty years later she went back and earned an interdisciplinary degree in culture, literature, and the arts at UW Bothell.

“It just turned out that I was much better at writing about science than actually doing it,” Pajer says, adding that she finds it fascinating to blend art and science. “I think it makes it more entertaining. Peer science can often be very dry, but when you can present it in an entertaining way, it’s a great way to learn.”

Pajer takes pride in the scientific accuracy of her books. She consults experts during her research and writing, and the volumes have earned the stamp of approval after peer review by the Washington Academy of Sciences. She also works hard to get the historical details of Seattle and the UW right.

The first book in the Professor Bradshaw series was A Spark of Death, published in 2011, followed by Fatal Induction in 2012, Capacity for Murder in 2013, and then The Edison Effect this year. Pajer is just beginning to noodle on her next story, which she thinks may be set in 1907 at the time of the Alaska Yukon Pacific Exposition.

The books are great for lovers of mysteries and science. Check ’em out!