January 22, 2016

Radioactivity is good for you

While most of us tend to think that radioactivity is dangerous, experts say that, like beer, it’s actually good for you in moderation. We learned this while drinking radioactive beer at Bad Jimmy’s Brewing Company in Ballard on Wednesday during the “radioactive edition” of Astronomy on Tap Seattle.

Radioactive beer

UW prof. Rory Barnes makes a point about radioactive beer
during his Astronomy on Tap talk at Bad Jimmy’s Brewing
Company on Wednesday, Jan. 20, 2016. Photo: Greg Scheiderer.
University of Washington astrobiology professor Rory Barnes did the math on the beer. Figuring that a pint is about 90 percent water, carbon is about ten percent of the rest. That works out to 4.5 grams, or about 200 billion carbon-14 atoms. Carbon-14 has a half-life of 5,730 years, which Barnes said means that, in your glass, there’s about one atomic decay every second.

“You are all drinking radioactive beer,” he said. Nobody stopped. I was sipping on a red IPA which was delightful and may have been even a bit more radioactive than the others!

Barnes noted that while we think of Chernobyl or Fukushima when we think about radiation, the process of radioactive decay is pretty important.

Radioactivity is good

“If it weren’t for the radioactivity inside our planet we’d all be dead,” he said. Barnes explained that decay of uranium, thorium, and potassium inside the Earth produces about 50 terawatts of energy, or about 0.1 watt per square meter on the surface. That much energy could run our entire civilization if we could capture it. As it is, it drives geologic processes such as plate tectonics, which helps regulate the amount of carbon dioxide in our atmosphere.

“It’s really important that the planet does a good job of keeping it from building up to too high of a level or dropping down to too low of a level because then our Earth would not be habitable,” Barnes explained. “Without (plate tectonics) the carbon dioxide would either build up and our planet would roast or it would get drawn down and our planet would freeze.”

Earth is in a sweet spot as far as this internal energy goes. Mars generates less than half the energy Earth does and is geologically dead. Jupiter’s moon Io generates a whopping two watts per square meter and is wildly active volcanically. For life, conditions have to be just right.

Radioactivity may lead us to ET

Barnes said that this fact could help guide us to other planets that might be likely to harbor life. The trouble is that in order to determine a planet’s internal energy and radioactivity we would have to look inside a rock that is hundreds of light years away.

“It’s not really obvious how you do that, but that’s what we need to do,” he said. “I’m sorry to say that the answer is that we can’t at this point. This is the limit of our scientific research right now.”

The James Webb Space Telescope will be able to determine the elements in the atmospheres of distant planets. Barnes said it would make sense to use JWST to look at planets that are near where supernovae have occurred, because these stellar explosions spread the heavy elements needed for this sort of planetary energy generation.

Radioactivity and the ages of stars

UW postdoctoral research associate Charli
Sakari explains how the age of a star can
be determined by the presence of radioactive
elements. Photo: Greg Scheiderer.
UW astronomy post-doc Charli Sakari also uses radioactivity in her work. During her Astronomy on Tap talk she explained how she determines the makeup of stars by looking at spectra of the light they emit. Different elements leave a clear signature in the spectrum, absorption lines created when atoms in a star’s atmosphere absorb certain color wavelengths.

“If we measure how dark those lines are we can figure out how much of those elements is present in the atmospheres,” Sakari said.

It is especially informative to look for uranium and thorium.
“Uranium-238 has a half-life of 4.5 billion years, which is about the age of the Sun, whereas thorium-232 has a half life of 14 billion years,” Sakari explained. “These half-lives are long enough that we can use them to date the ages of the oldest stars in the universe.”

The oldest stars have few elements heavier than helium. Younger stars can contain many heavier elements fused in the cores of the generations of stars that preceded them.

Astronomy on Tap Seattle drew a big crowd to Bad Jimmy’s on a rainy Wednesday night. In fact astronomy and beer lovers were packed in so tightly, and were generating considerable warmth, that the staff popped the garage-type doors open to let in a little fresh air. One wag in the crowd speculated that the robust attendance may have been an indicator of the sorry state of network television. We would say that, in eleven months of events Astronomy on Tap, which is organized by astronomy graduate students at the UW, has delivered plenty of good information and tons of fun. The next gathering is scheduled for Feb. 24.

January 14, 2016

Science and art meet in Silent Sky at Taproot Theatre

We love it when science and art meet, and its going to happen this month when Lauren Gunderson’s play Silent Sky, directed by Karen Lund, has its Northwest premiere from Jan. 27 through Feb. 27 at Taproot Theatre in Greenwood.

Silent Sky is the true story of Henrietta Leavitt, the American astronomer who discovered the relationship between the luminosity and the period of Cepheid variable stars. Her work at Harvard College Observatory received little attention during her lifetime, which spanned 1868–1921, but her discovery was the key to our ability to accurately determine the distances to faraway galaxies. Silent Sky plays out against a landscape of fierce sisterly love, early feminism, universe-revealing science, and a time when humans were called “computers.”

Lauren Gunderson
Gunderson is a marvelous playwright who lives in the San Francisco Bay Area. We have seen several of her other plays, including Émilie: La Marquise Du Châtelet Defends Her Life Tonight, the fascinating tale of Émilie Du Châtelet, the 18th-Century French physicist who not only translated Newton’s Principia Mathematica but also made profound contributions in fine-tuning Newtonian mechanics. Émilie usually bested Voltaire, one of her lovers, in battles of wits. We reviewed the 2011 production at ArtsWest in West Seattle and enjoyed it immensely. Silent Sky promises to be entertaining and enlightening as well. The cast includes Hana Lass, an outstanding local actor, in the title role.
Tickets to Silent Sky are available online.

January 13, 2016

State House committee considers curb of light pollution

Rep. Jessyn Farrell
When a bill aimed at curbing light pollution in the State of Washington received a hearing before the House Environment Committee yesterday in Olympia it was the first formal discussion of the topic at the state level in seven years. House Bill 2057 would direct the state Department of Ecology to assess the environmental, economic, and public health effects of light pollution, and to submit the study and policy recommendations for reducing light pollution to the Legislature by next January.

Rep. Jessyn Farrell, D-Seattle, is the prime sponsor of the legislation.

“This is a really important issue,” Farrell said. “There are lots of studies that do show that there is an impact on human health, the natural environment, property values” from light pollution. “The goal here is to study this and see what the current state of that research is.”

Amateur astronomers testify

Farrell said the issue was brought to her by a constituent, David Dorais, who in testimony before the committee described himself as, “a former traffic engineer who knows something about outdoor lighting, especially for street use and safety. As a lifelong amateur astronomer I also know something about how we can do a much better job of illuminating those places throughout the state that need the banishment of the dark.”

L-R: David Dorais, Qiu Min Ji, and David Ingram testified
in favor of HB 2057 at a hearing of the state House
 Environment Committee on Jan. 12, 2016. Photo: Greg Scheiderer.
David Ingram, a volunteer who heads up Dark Skies Northwest, the local chapter of the International Dark-Sky Association, called the night sky a natural resource and a wonderment.

“It has inspired architecture, religion, philosophy, science and technology,” Ingram testified. “I don’t know how our young people are going to be similarly inspired if more than half of them don’t even have a contact with the night sky.”

“It’s of vital importance that we look at the question of what happens to the soul of men and women when they’re removed from contact with the night sky,” Ingram said. He added that he doesn’t want to go back to the dark ages, but believes we have the technology to use light to enhance safety, wayfinding, and commerce efficiently and effectively, without blotting out all of the stars in the process.

Amendments likely

There will probably be some changes to the bill before the committee votes on it. Jessica Archer, who is with the scientific arm of the Department of Ecology, suggested that the departments of Health, Fish and Wildlife, and Commerce be brought in on the study, as Ecology lacks the expertise to weigh in on light pollution’s impact on animals, human health, or property values. Archer also suggested that the scope of the study be more clearly spelled out, which will also help them determine the cost of the effort. Farrell said that she might seek to add potential cost savings to the scope of the study. It’s also possible that the deadline for the study will be pushed out; the due date of January 1, 2017 was set when the bill was first drafted last year.

Farrell noted that HB 2057 takes a far more cautious approach than did fairly comprehensive and directive light pollution legislation that was considered in 2008 and 2009. Mark Johnson, representing the Washington Retail Association, testified that his organization wanted to make sure that any consideration of light pollution didn’t have an adverse impact on safety or business. That’s a reason why Farrell went with a deliberate approach.

“I think we should study this and see if there’s further action that we should take,” she said.

Next steps

The bill must gain the approval of the committee by Feb. 5 if it is to come up for a vote in by the entire House. Our hunch is that the supporters have a good chance to accomplish that. The committee chair, Rep. Joe Fitzgibbon, D-Seattle, is a co-sponsor of the bill. Another member of the committee, Rep. Joan McBride, D-Kirkland, was involved in improving lighting ordinances when she was mayor of that city.

Interested people who were unable to attend Tuesday’s hearing can testify about the bill online. This makes a difference. Write today!

More information:

January 11, 2016

Light pollution study measure to receive hearing before WA legislature

A bill that would direct the Washington State Department of Ecology to recommend ways to reduce light pollution in the state is scheduled to receive a hearing tomorrow before the House Environment Committee. The measure, HB 2057, directs the department to complete a study of the environmental, economic, and public health effects of light pollution, and to submit the study and policy recommendations for reducing light pollution to the Legislature by next January. The hearing is scheduled to begin at 1:30 p.m. Jan. 12 in House Hearing Room B in the John L. O’Brien building on the state capitol campus in Olympia.

Rep. Jessyn Farrell of Seattle is the prime sponsor
of a bill calling for a study of light pollution in Washington.
State Rep. Jessyn Farrell (D-Seattle) is the prime sponsor of the bill. It was introduced in February of last year but never received a hearing. Farrell told us at that time that she feels light pollution is an “important issue,” but that “it’s going to take some time and education to get movement.” She vowed to bring the bill back this session and has made good on that promise.

It’s a good sign that the measure is being heard on the second day of the 60-day session of the Legislature. The timeline is short; the bill will have to be approved by the committee by Feb. 5 to be eligible for further consideration by the full House of Representatives.

It’s also a good sign that the chair of the committee, Rep. Joe Fitzgibbon (D-Seattle), is a  co-sponsor of the bill.

Those unable to attend the hearing in person can comment online using a form on the Legislature’s website. Seattle Astronomy plans to attend the hearing and will keep you posted about the progress of this important legislation.

More information:

January 1, 2016

Our favorite Seattle astronomy events from 2015

Happy New Year from Seattle Astronomy! Yesterday we ran down our top five news stories of the past year. Today, let’s take a look back at our top talks and events from 2015.

Comet Hunter

Renowned comet hunter Don Machholz was the keynote speaker last year at the annual banquet of the Seattle Astronomical Society. Machholz has discovered eleven comets visually, without the aid of CCD cameras and other modern aids, and that’s the record. He does it the old-fashioned way, sitting at the eyepiece for hours at a time and sweeping the sky for something that wasn’t there before.

Machholz told a wonderful tale about his techniques of comet hunting and about the intensely personal reasons that drove him to the quest. It was an informative, touching, and often hilarious presentation filled with images and music.

It’s all relative

Last year was the international year of light and marked the 100th anniversary of the publication of Einstein’s theory of relativity. Jeffrey Bennett toured the country to help us better understand relativity, and stopped in at the April meeting of the Seattle Astronomical Society to give a well-received talk about the concepts of relativity. Bennett is an engaging lecturer and his book, What Is Relativity?: An Intuitive Introduction to Einstein’s Ideas, and Why They Matter, (Columbia University Press, 2014) is a big help, too, that makes a topic that is so mind-bending and daunting to so many truly accessible to a broader audience.

Physics pioneer

Science is mostly about brainpower and creativity, and testing, but there’s some luck involved, too. Case in point: back in 1965 Jim Peebles and colleagues at Princeton were on the hunt for what we now know as the cosmic microwave background, the lasting signature of the Big Bang. Up the road at Bell Telephone Labs, Bob Wilson and Arno Penzias had found the CMB, but didn’t realize what they had! To the latter went the Nobel Prize, but Peebles has been in the forefront of research on the CMB for the past 50 years. We now know a lot about the history of our universe, except for the first fleeting moments that remain a mystery. Peebles talked about that history at a UW lecture in May.

Space tourist

Charles Simonyi shelled out a lot of cash to fly to the International Space Station in a Soyuz capsule with the Russians—speculation is that his tab for two trips, in 2007 and 2009, came to about $60 million. Simonyi gave a talk at the University of Washington in September about the practicalities of space travel, and when it might be possible for those of us with somewhat lesser means.

The answer, sadly, is not that soon, but Simonyi envisions a day when the cost of launching a kilogram of mass into space might be driven down to $100, and that might make the cost of space travel something that more people could consider.
Simonyi’s story was an entertaining one that was as much about the training for his two trips to space as it was about the technical aspects of getting there.

Dark matter and the dinosaurs

Harvard particle physicist and author Lisa Randall has a new hypothesis about what may have killed the dinosaurs on Earth. It’s a surprisingly simple notion, at least once you get past the fact that it depends on a new sort of particle that we haven’t yet detected.

Randall spoke at Town Hall Seattle in November about her ideas and her new book, Dark Matter and the Dinosaurs: The Astounding Interconnectedness of the Universe (Ecco, 2015). The theory in a nutshell: suppose that there’s a type of dark matter that interacts with light. Such dark matter could collapse into a disk, just like our galaxy. As our solar system orbits the galaxy, we periodically go up and down through the galactic plane. Passing through the plane would also move us through this disk of dark matter, which could gravitationally dislodge comets from the Oort Cloud and send them hurtling our way.

It is an interesting idea that Randall says she’ll devote much time to testing in the coming years.