Category Archives: lectures

Meeting the Martians and getting snapshots of far-away planets

It’s possible that some extraterrestrials were at the most recent Astronomy on Tap Seattle gathering, at which we explored the possibility of life on Mars and looked at exciting new techniques for capturing images of exoplanets.

We have met the Martians and they are us—maybe

“Are we all Martian-Americans? We still don’t know,” said Bob Abel, a professor of applied physics at Olympic College and collaborator with the University of Washington’s Large Synoptic Survey Telescope Group. Abel gave a talk titled, “Where Are the Martians?” at Astronomy on Tap Seattle April 26.

Giving a quick geological and topographical history of Mars, Abel said that the Red Planet is just one-half the diameter of Earth, and thus has just one-eighth the volume of Earth, so Mars cooled off pretty quickly.

Mars Mudstones

Curiosity shot this image in Gale Crater on Mars. The mudstones indicate a long history of standing water in that location. Photo: NASA.

“During the early formation of the solar system, it would have cooled to the point where liquid water could exist on its surface before the Earth got to that point,” Abel said, adding that it’s clear that water was once abundant on Mars. The rovers Spirit and Curiosity both landed in craters that used to be lakes, and Opportunity set down on the edge of what scientists think was once a salty sea.

In addition, Abel said that Spirit found opaline silica in Gusev Crater on Mars.

“The place where you find this on Earth is near geysers and hydrothermal vents,” Abel said. You’ll find heat, water, and minerals around these vents. “You’ve got all the stuff for life, and you find the most primitive life clustered around these on Earth.”

Bob Abel

Prof. Bob Abel of Olympic College gave a talk about Mars and Martians at Astronomy on Tap Seattle April 26, 2017. Photo: Greg Scheiderer.

The surface of Mars is awfully barren now, but life could have conceivably existed there in the distant past. Scientists have found meteorites from Mars on Earth, and inside some of those meteorites they’ve found structures that look like nanobacteria. The debate continues over whether these are biological or not.

“It’s still somewhat up in the air, but it’s tantalizing evidence,” Abel said. “The question still remains, did life start earlier on Mars, since it was capable of being inhabited? And by the time Earth was habitable, did meteorites come to Earth and start life on Earth?”

The investigation continues.

As for present-day Mars, while the surface appears devoid of life, we may find something if we dig a little deeper. Abel said that Curiosity detects occasional outbursts of methane on Mars. He pointed out that most methane on Earth is created by biology.

“I’m personally rooting for flatulence, but we don’t know yet what’s causing it,” he laughed. But, through measurements made by many different Mars orbiters, we’ve learned that the planet’s outer core is molten. So beneath the surface there is heat, water, hydrocarbons, and soil: everything life wants. Abel recalled a talk last year by Penelope Boston, head of the NASA Astrobiology Institute.

“She can’t see how life doesn’t exist below the surface of Mars,” Abel said.

Snapshots of exoplanets

Getting photographs of exoplanets—planets orbiting far-away stars—is a relatively new field within astronomy. The first such images were captured just eight years ago or so. Benjamin Gerard said the technology and capabilities within the field are advancing rapidly. Gerard, a doctoral student in physics and astronomy at the University of Victoria in British Columbia, uses the Gemini Planet Imager to trick out pictures of planets near stars that are many light years away. These photos can be useful for figuring out the components of a planet’s atmosphere and whether it has oceans and continents.

Gerard

Doctoral student Benjamin Gerard gave a talk about his work imaging exoplanets at Astronomy on Tap Seattle April 28. Photo: Greg Scheiderer.

Gerard said the main challenges in exoplanet imaging are resolution and contrast. He explained that the key to good resolution is adaptive optics. If you’ve looked through a telescope you have likely had nights when the objects you observe appear to be wiggling around because of atmospheric turbulence. Gemini corrects for this with adaptive optics.

Light from the object hits a deformable mirror as well as a component called a wave-front sensor. The sensor measures the amount of turbulence, sends the information to the mirror’s actuators, which can correct for the aberration.

“The mirror deforms once every millisecond,” Gerard said. “This aberration gets corrected and is constantly re-focused onto the camera. Once it reaches that point this image that is very turbulent suddenly becomes much more stable and we can get much better resolution.”

Gerard said this is a plus for ground-based telescopes.

“With this technique, we can basically take a ten-meter telescope and make it like we were in space,” he said. “With adaptive optics we actually do better than any space telescope in resolution.”

The problem of contrast is apparent to anyone who has visited social media, which is full of bad-contrast photos. Especially common are pics of people posed in front of windows. Often the people appear as silhouettes because the light from the window is way brighter. While exoplanets don’t pose in front of cosmic windows, contrast is a huge problem when it comes to getting the images.

“A planet like Earth is about ten billion times dimmer than it’s host star,” Gerard pointed out. Using a coronagraph helps block out the light of the star and remove its glare from the image. They also use a technique called angular differential imaging to overcome aberrations within the instruments. This is a little bit counter-intuitive to the amateur astrophotographer who typically uses an instrument rotator during long exposures to compensate for the apparent motion of objects caused by the rotation of the Earth.

“For exoplanet imaging this is actually helpful, so we turn off the instrument rotator and the planet appears to rotate with respect to the view of the fixed telescope instrumental aberrations,” Gerard said. “We can distinguish one from the other.” Computer algorithms can later put images made in this way back together to create even greater contrast.

Gerard hopes they’ll be able to do even better in the near future. The Wide Field Infrared Survey Telescope (WFIRST) is scheduled to launch in the mid-2020s. It will have a deformable mirror that should have the capability to image smaller planets like Earth.

“This is many orders of magnitude better than we can do on ground-based telescopes, because on a space telescope you’re much more stable,” Gerard said. “On the Hubble Space Telescope now we can’t reach this sort of contrast because there is no deformable mirror.”

Since Gerard gave the talk NASA announced an independent review of WFIRST that could change its timeline and instrumentation.


The next Astronomy on Tap Seattle gathering is set for May 24 at Peddler Brewing Company.

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Krauss and the greatest story ever told (so far)

We’re living in the best of times and the worst of times according to best-selling author and award-winning theoretical physicist Lawrence Krauss. The best is represented by the Large Hadron Collider (LHC), which has helped reveal the Higgs particle that ties together the standard model of physics. The worst is reflected by the president’s proposed federal budget that could derail physical science research. Krauss spoke about his latest book, The Greatest Story Ever Told—So Far: Why Are We Here? (Atria Books, 2017) last week at Town Hall Seattle. It was an informative and humor-filled lecture.

Lawrence Krauss

Author and physicist Lawrence Krauss spoke April 12, 2017 at Town Hall Seattle. Photo: Greg Scheiderer.

“This is really humanity at its greatest,” said Krauss of the discoveries at the LHC, which represent the work of thousands of scientists from all over the world. Krause’s talk was a walk through the history of discovery in physics, going all the way back to Plato and along the way bumping into Galileo, Newton, Faraday, Maxwell, Einstein, Fermi, Feynman, and more before arriving at quantum mechanics, the standard model, and the Higgs field.

“The real world is so different than the illusion that we see,” Krauss said. “The world of our experience is an illusion, and it’s an amazing story how we, over centuries, have been able to cut through that illusion to see reality underneath.”

We’ll leave the full tour of advances in physics to your reading of the book and, for this article, focus on Krauss’s take on the problems and challenges facing science today. He feels that much of the current mistrust of science stems from a common misconception that tomorrow’s science will make today’s obsolete, and that therefore scientific facts are little more than a subjective fad. Krauss said that is completely wrong.

Truth is eternal

“What is true today—and by true in science we mean what has satisfied the test of experiment today—will always be true,” he said. “Newton’s laws may have been supplanted at the extremes of scale by general relativity or quantum mechanics, but to describe baseballs or cannonballs or even rocket ships, they’re as true today as they were then, and whatever new physics we discover in quantum gravity or whatever, it’s not going to change. At the scale of humans, it’s got to revert to Newton’s laws. A million years from now, whatever we learn in science, if I let a ball go it’s going to fall as described by Newton’s laws.”

Krauss also let us in on what he jokingly referred to as a well-kept secret.

“Scientists are human,” he said. “That means they have prejudices and biases and pigheadedness, and that’s fine. What’s really neat is that science forces them in the right direction, kicking and screaming. The individual scientists are full of nonsense, but the scientific process protects us from that nonsense.”

Searching for a better toaster

Science is almost inextricably tied to technology, and Krauss frets that this causes people to wonder what new discoveries are “good for.”

“People don’t ask that for Mozart concertos or Picasso paintings or Shakespeare plays,” Krauss noted, “but it’s all the same thing. It’s what makes humanity worth living for. The fundamental importance of science, to me, is not the technology, but the fact that it forces us to confront reality and change our picture of our place in the cosmos. That’s what good literature, good music, good art do. That’s what the process of learning and growing as a society is all about.”

End of story?

The “So Far” in the title of the book is a reference to the notion that the story of discovery will continue to get more amazing if we keep asking questions. But Krauss is worried that we may not be able to do so. He noted that the president’s proposed federal budget would cut the Department of Energy—the primary funder of research in the physical sciences—by 20 percent, and eliminate funding for the National Endowment for the Arts, the National Endowment for the Humanities, the Corporation for Public Broadcasting, and the Institute of Museums and Libraries. That would save around $1.82 billion, while Krauss notes that the same budget would provide $2 billion to start building a wall between the United States and Mexico.

“To protect us against these unimaginable horrors, we’re willing to cut these things in our society that are so central,” Krauss observed. “We are in the process of getting rid of what is important for making the nation worth defending.”

“Art, literature, music and science are part of the greatest story ever told, and when we give that up in the name of defense, what are we really killing?” he asked.


More books by Lawrence Krauss:

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Mars astronauts would be “on their own” for medical care

Astronauts on a mission to Mars would essentially be on their own for medical care, according to NASA flight surgeon Dr. David Reyes. With resupply or mission evacuation impossible, and with difficulty in communicating with the ground, astronauts would have to be trained and equipped to provide their own care.

Reyes gave an interesting talk about the history of space medicine last weekend at the Museum of Flight. He noted that being a flight surgeon is the opposite of being a typical doctor.

David Reyes

NASA flight surgeon Dr. David Reyes gave a talk about the history of aerospace medicine April 8, 2017 at the Museum of Flight. Photo: Greg Scheiderer.

“Regular medicine is taking care of sick people in a normal environment,” Reyes said. “Aerospace medicine is taking care of healthy people in an abnormal or unusual environment.” He added that the astronauts are usually super healthy, but the environments they deal with are challenging to say the least.

Much of the job of the flight surgeon is to help determine the medical risks of space travel, to help come up with and test gear to avert those risks, and to help astronauts learn about symptoms of conditions they may encounter.

For example, astronauts in training are put into an altitude chamber, and the air is pumped out of the chamber to simulate the atmosphere at 21,000 feet above sea level. Then they take off their oxygen masks. Reyes said this makes them “goofy” with hypoxia.

“The reason we put them in this chamber is so that they can recognize those symptoms for themselves,” Reyes said. “Everyone has a unique response to low oxygen.” If they’ve experienced it they can recognize it in the event oxygen problems occur in flight.

Mission medical kits

It was fascinating to look at the evolution of medical kits for various missions. In the days of Mercury, the kit was essentially a few bandaids, aspirin, motion sickness pills, and a couple of other remedies. It was not much more than a prudent backpacker would take on a day hike. Mercury missions were short and the astronauts, strapped into a small capsule, didn’t have to do much physical activity.

Mercury Med Kit

A Mercury medical kit. Photo: NASA

With Gemini and Apollo the kits were expanded as the missions became longer and more active, but they still weren’t all that extensive.

“This is like everything you might have in your medicine cabinet at home,” Reyes noted of the kits.

By the time of Skylab each crew received 80 hours of paramedic training. The medical kit was huge and even included a dental kit. The space shuttle went far beyond the home medicine cabinet. The International Space Station has a Crew Medical Officer who is an astronaut with additional medical training. It carries an extensive medical kit with nine different packs. It also employs a Crew Health Care System or CHCS—pronounced “checks”—that is the first robust medical system for space missions.

Given all of that, Reyes pointed out that, “Nothing really serious has happened in space flight.” Astronauts on longer missions suffer bumps and bruises and rashes, and insomnia, but the most serious condition has been a urinary tract infection on one Apollo flight.

Bones and eyes

These days the two problems they’re studying the most are bone mass loss and visual impairment. They’ve known about the bone mass challenge for a while, and it’s why the astronauts spend at least two hours per day exercising. Without it, “We’d send a 40- or 50-year-old astronaut up and they’d come back looking like an 80-year-old after six months in the space station,” Reyes said.

The vision issues only became apparent in the last seven years or so, and Reyes said they’re still researching those. A couple of things happen to some astronauts: fluid buildup in the eye because of zero gravity, and change of eye shape. They’ve developed adjustable eyeglasses should astronauts develop vision problems in flight.

Mars poses challenges

Missions to Mars would provide medical as well as ethical challenges. On all space missions so far, flight surgeons on the ground have been able to offer advice and counsel. For Mars, the long lag for radio signals, up to 22 minutes for transmission, would make conversation difficult, and during the time Mars is on the other side of the Sun from Earth there would be no communication at all.

“When you go to Mars, basically you’re on your own,” Reyes said of the astronauts.

There is debate about how much medical equipment and medicine to take on a Mars mission. Every item launched on a mission represents a tradeoff in mass and cost and whatever might not go along. An even bigger, ethical question involves what happens if an astronaut suffers a serious injury.

“If you have a limited set of supplies, and somebody gets severly injured and will require a lot of care, how much care are you going to give them?” Reyes asked. “If you use up your whole med kit, that puts everybody else at risk. So you have to think, ‘Is there some point that we’re going to withdraw care because we’re jeopardizing the rest of the mission?’”

It’s an on-going area of discussion.

Why be a flight surgeon?

Like many of us who are interested in space and astronomy, Reyes caught the bug from television.

“When I was a kid I watched the Moon landing on TV,” he said. “A black and white TV at my parents’ house.” He thought it was the coolest thing ever.

“I’ve always had an interest in space,” he added. His undergraduate major was in geology, and he studied some planetary science. He then went into the Air Force and medicine. He filled a free month during his residency with an introduction to aerospace medicine course at the University of Texas. He was drawn in by the lectures from real flight surgeons.

“This is what I want to do,” he learned.

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Causing mayhem and mass destruction in the Universe Sandbox

If you’ve ever wondered what would happen if the Sun somehow vanished from the solar system, or wanted to watch planets smash into each other, or thought it would be fun to bombard the Moon with asteroids, you’re in luck! You can do all of those things and more with a computer game called Universe Sandbox2. Dan Dixon, creator of Universe Sandbox2, gave a demonstration of it at this week’s meeting of the Seattle Astronomical Society.

“It is software that allows you to ask fantastical questions about the universe and see plausibly true answers,” Dixon said.

Universe Sandbox2 sells for $25.

The possibilities are vast. The slogan for Universe Sandbox2 is “create & destroy on an unimaginable scale,” and the software delivers. It lets users tinker with an incredible number of variables, from the mass and density of objects to the chemical makeup of their atmospheres. Eliminate all of the carbon dioxide and see what happens! Move the Moon in closer to Earth and watch the chaos. For all of the interesting science questions it can answer, Universe Sandbox2 also appeals to our inner 12-year-old.

“People like to collide things,” Dixon noted, and clearly he is one of those people.

“It’s a physics simulation, so in addition to doing interesting things with orbits, you can also do interesting things with collisions,” he added.

Universe Sandbox screenshot

Screenshot from Universe Sandbox2 of an object colliding with Earth.

Those mash-ups got a lot of oohs and aahs from the attendees at the meeting at the University of Washington. It was fun to see what Earth would do to the ring system if it were placed in orbit around Saturn. (Spoiler alert: Disruptive!) Dixon raced through dozens of scenarios, and that only scratched the surface.

He said the results shown in Universe Sandbox2 are “plausibly” true because they have to make some compromises. They don’t simulate every object or every particle out there because that would take way too much computer oomph.

Plausibly true

“It’s a very simplistic simulation; we’re not doing any pressure waves or dark matter,” Dixon said, “but it still is pretty cool.”

So when Mars smacks into Earth in an attempt to see if a new moon would result, you don’t necessarily have all of the data you would like.

“You really would want to have like a billion pieces,” Dixon said, but “because we’re trying to do this real time on modern-day desktops or laptops, you can’t have as many pieces as you want and get it still to run in real time.”

“We’re undoubtedly wrong in a lot of cases, and there’s a lot of room for improvement in the simulation,” Dixon noted. They’re revamping the way the program handles stellar evolution and are working to improve planetary climate simulations. Part of the challenge is that they’re often simulating events for which there is not yet a scientific answer.

“We’re trying to solve things that are not well-defined or understood,” Dixon said. That’s not to say they’re just making stuff up.

“Being realistic is really important to me,” Dixon said, but they want to let users come up with their own crazy scenarios. “One of the goals of the software is to allow ridiculous premises but then carry that to a realistic conclusion.”

Humble beginnings

In a way, Universe Sandbox2 has been in development for 20 years. When Dixon was in middle school his father downloaded a simple gravity simulator from a BBS list. (Remember those?) It didn’t have many features, but it caught Dixon’s interest.

“I’ve always been fascinated with the motions of gravity,” he said, “and gravity is a really simple formula, too. It’s always fascinating how this really simple formula can do these really beautiful and organic interesting motions.” Later on in middle school Dixon coded his own simulator. He’d tinker with it every once in a while, then became serious about it about ten years ago.

“This was not like the grand ambition. It was a thing I was working on for fun, and now it’s turned into this crazy thing,” Dixon said. “What started as a personal side project is now what myself and eight others do full time.”

“I think if I had a time machine and I went back and showed my younger self what it’s become, I would have been overwhelmed and wouldn’t have started on it,” he laughs.

“This is a passion project that I’m fortunate enough to continue working on.”


View the Universe Sandbox2 teaser below. Purchasing through this link supports not only Universe Sandbox2 but also Seattle Astronomy in our efforts to tell interesting stories.

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Pi Day, Mars Madness, and more this week

Pi Day, Mars Madness, planetarium shows galore, and astro club events fill a busy calendar this week.

Pi Day

Celebrate Pi Day at 5 p.m. Tuesday, March 14 at the Pierce College Science Dome. This free celebration will include hands-on math and science activities, a pi recitation typing contest, and Chaos and Order: A Mathematical Symphony. Please reserve seats in advance for the symphony, which will run at 5 p.m., 6 p.m., and 7 p.m. in the dome. Reservations are not needed for the other activities.

MOF Mars Madness

Phoenix landerMars Madness continues at the Museum of Flight at 2 p.m. Saturday, March 18. This week’s presentation will feature the museum’s Carla Bitter, former education and public outreach manager of NASA’s Phoenix Mars Lander mission, who will give a family friendly, fast paced Mars 101: Know Your Missions presentation, complete with Red Planet prizes. Mars Madness is happening every Saturday in March, and is free with museum admission.

Club meetings

The Olympic Astronomical Society will hold its monthly meeting at 7:30 p.m. Monday, March 13 in room Engineering 117 at Olympic College in Bremerton. A guest speaker will talk about the Moon. Mysteriously, the club website doesn’t list who the speaker will be. Is it a major Moon celebrity?

The Seattle Astronomical Society plans its monthly meeting for 7:30 p.m. on the Ides of March—Wednesday, March 15—in room A102 of the Physics/Astronomy building on the University of Washington campus in Seattle. Guest speaker Dan Dixon, creator of the Universe Sandbox simulation game, will talk about how he and his team of programmers, a planetary scientist, and a climate scientist collaborated to create an app that can model galactic collisions and solar system dynamics.

Planetarium shows

Check out The Secret Lives of Stars, a free show at the Bellevue College Planetarium that will play at 6 p.m. and repeat at 7 p.m. on Saturday, March 18. Reservations are recommended; information about reservations, parking, and location is online.

The Willard Smith Planetarium at the Pacific Science Center offers a variety of programs every day. Check their complete lineup on our calendar page.

Futures file

You can scout out future astronomy events on our calendar. We’ve recently added:

Up in the sky

Jupiter, Spica, and the Moon will form a nice triangle in the evening on Tuesday. The Sky This Week from Astronomy magazine and This Week’s Sky at a Glance from Sky & Telescope offer more observing highlights for the week.

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The expanding universe: discovery, controversies, and hope

We’ve known that there is a universe outside the Milky Way, and that it is expanding, for less than a century.

“Throughout the entire history of the universe, of knowing it’s expanding, there have been a tremendous number of controversies over it, and there’s still one that persists today,” said astrophysicist and author Ethan Siegel. Siegel, author of Beyond the Galaxy: How Humanity Looked Beyond Our Milky Way and Discovered the Entire Universe (World Scientific Publishing, 2015), spoke at last week’s meeting of the Rose City Astronomers in Portland, Oregon.

The controversy actually goes back to before the expansion was observed, to Albert Einstein. His equations describing general relativity suggested that gravity would collapse the universe onto itself, and as he believed the universe was static, he threw in a “cosmological constant” to push back against gravity. Einstein later called that his biggest blunder, though some wanted to let him off the hook for it when dark energy was proposed to do the exact same thing.

“I am here to tell you that this was Einstein’s reasoning and throwing this in there when he did was a super big blunder because the universe isn’t static,” Siegel said. Einstein should have trusted his theory, he said, and taken it to the next step.

The universe is expanding

By the 1920s Edwin Hubble observed a Cepheid variable star in the Andromeda “nebula” that indicated that it was far outside the Milky Way and a galaxy in its own right. Astronomers were also studying redshift as an indication for the speeds at which galaxies were receding from us. Siegel explained that through this, Hubble determined that the universe was expanding at a rate of 600km/sec/Mpc (kilometers per second per megaparsec.) This became the Hubble constant. But it wasn’t so constant.

Siegel noted that, knowing the size and expansion rate of the universe, you can figure its age by running the numbers in reverse and going back to the beginning, to the Big Bang. The resulting calculation determined that the universe was about two billion years old. Geologists at the time had already pegged the age of the Earth as at least four billion years.

“This was a problem for Hubble, because the universe isn’t allowed to be half the age of the Earth,” Siegel noted. “Either this expansion rate is wrong and this age for the universe is wrong, or the age of the Earth is wrong.”

It turns out that Hubble’s main mistake was in figuring that all variable stars are alike. Siegel said Walter Baade came along in the 1940s and discovered that they are not. Finding that most of the Cepheids Hubble had looked at were non-classical, they re-ran the numbers from Hubble’s data.

“As you accumulate more knowledge, as you accumulate a better understanding of what you’re actually loooking at, you can go back and get more useful science out of this data,” Siegel said. This second look doubled the distance to these stars and reduced the value for the Hubble constant to 270km/sec/Mpc. This in turn put the age of the universe at five billion years.

“That’s better,” Siegel noted. “The universe is older than Earth. That’s one problem solved.”

Narrowing it down

Siegel

Dr. Ethan Siegel, creator of the “Starts With a Bang” blog, gave a talk about the age and size of the universe to the Rose City Astronomers February 20. Photo: Greg Scheiderer.

As time went on astronomers developed the “distance ladder” for determining the vast distances in the universe. You first measured the distance to Cepheid variables within the Milky Way, then gauged the distances to other galaxies using Cepheids spotted there. Type 1a supernovae could be spotted really far out. As we learned more about the stars we got a little better at figuring distances.

Things got really interesting in the 1960s, according to Siegel. We discovered that we could determine the ages of stars by measuring their color and brightness. The Hertzsprung–Russell diagram told us that the oldest stars were between 14 billion and 16 billion years old, significantly older than the age of the universe determined by Baade. Astronomer Allan Sandage, who as a graduate student was an assistant to Hubble, came along and said you needed two things to make the universe that old: it had to be low enough in density to make a vast expansion, and the expansion rate had to be low.

Dueling Hubble constants

This, Siegel said, was where the controversy came in. Sandage said the expansion rate would have to be between 50-60km/sec/Mps. Rival astronomer Gérard de Vaucouleurs of France put it at around 100km/sec/Mpc. The race was on to make observations to see which group was right. Amazingly enough, each group’s observations matched up with what they thought the answer would be.

“This just goes to show that you cannot have the same people making the same measurements and trust them,” Siegel said. “This is why you need independent confirmation.”

It turns out Sandage and de Vaucouleurs were both wrong. There’s still no agreement on the right answer, but the disagreements are getting closer together. Sigel said the Hubble Space Telescope’s improvements in measuring the size of the universe return a value of 74±2km/sec/Mpc. The Planck mission’s observations of the cosmic microwave background radiation suggest 67±1km/sec/Mpc.

“There is a fight over the results like there always seems to be, because we are scientists and we cannot agree on anything,” Siegel said. “That is good, because questioning is what keeps us moving forward and what keeps us learning more.”

“The way we’re going to get there is with more and better data,” he added.

Better data

The better data will come from missions such as the European Space Agency’s Gaia, the James Webb Space Telescope, WFIRST, and the Large Synoptic Survey Telescope, which combined might improve our parallax measurements of cosmic distances by a factor of ten. We might also weed out faulty assumptions in the earlier work or get more accurate insights into the balance between matter and dark energy in the universe.

“If we can wait until the next decade, we might see that 74 number come down, we might also see the 67 number come up,” Siegel said. “The point is uncertainties are going to be reduced by more and better data.”

Siegel said that right now it’s pretty much agreed that the universe is about 13.8 billion years old and consists of about 30 percent matter and 70 percent dark energy. But the miniscule pluses or minuses can lead to huge fights.

“When that data comes in at last we will know exactly how fast our universe is expanding, how old it is, and what it all means for both our cosmic origins and our cosmic fate,” Siegel concluded. “That’s pretty good stuff.”


In the podcast linked below Siegel covers much of the topic matter of this article and his talk. His new book, Treknology: The Science of Star Trek from Tricorders to Warp Drive (Voyageur Press, 2017), is scheduled for release in October.

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Search for meaning continues

There is a great menu of interesting talks on this week’s calendar, including three with astronomy themes at a weekend event at Seattle University.

Search for Meaning FestivalSeattle University’s annual Search for Meaning Festival will be held on the university campus all day Saturday, February 25. The festival is a community event dedicated to topics surrounding the human quest for meaning and the characteristics of an ethical and well-lived life. It draws more than 50 authors and artists who will give interactive presentations. Three of these sessions are on astronomy-related topics.

At 9 a.m. Father George Coyne, SJ, former director of the Vatican Observatory and author of Wayfarers in the Cosmos: The Human Quest for Meaning (Crossroad 2002), will discuss the history of the evolution of life in the cosmos. Coyne’s thesis is that this history may lead us to a deeper understanding of what many secular physicists say themselves about the cosmos: that a loving creator stands behind it.

At 10:45 a.m. Margot Lee Shetterly, author of the book Hidden Figures: The American Dream and the Untold Story of the Black Women Mathematicians Who Helped Win the Space Race (William Morrow, 2016), on which the current hit film is based, will give one of the keynote addresses at the festival. Shetterly will talk about race, gender, science, the history of technology, and much else. Reservations for Shetterly’s talk are sold out.

At 12:45 p.m. Marie Benedict, author of The Other Einstein (Sourcebooks Landmark, 2016), will explore the life of Mileva Maric, who was Albert Einstein’s first wife and a physicist herself, and the manner in which personal tragedy inspired Mileva’s possible role in the creation of Einstein’s “miracle year” theories.

Check our post from December previewing the festival, and look at the trailer video below. Tickets to the festival are $12.50 and are available online.

Siegel at Rose City

Author and astrophysicist Ethan Siegel will be the guest speaker at the monthly meeting of the Rose City Astronomers in Portland at 7:30 p.m. Monday, February 20. Siegel will talk about his book Beyond the Galaxy: How Humanity Looked Beyond Our Milky Way and Discovered the Entire Universe (World Scientific Publishing, 2015). He’ll examine the history of the expanding universe and detail, up until the present day, how cutting-edge science looks to determine, once and for all, exactly how the universe has been expanding for the entire history of the cosmos. Siegel is an informative and engaging speaker; check our recap of his talk from last year about gravitational wave astronomy.

AoT Seattle and an app for simulating the universe

AoT FebruaryAstronomy on Tap Seattle’s monthly get-together is set for 7 p.m. Wednesday, February 22 at Peddler Brewing Company in Ballard. Two guest speakers are planned. Dan Dixon, creator of Universe Sandbox² will give an introduction to the app, an accessible space simulator that allows you to ask fantastical what-if questions and see accurate and realistic results in real-time. It merges real-time gravity, climate, collision, and physical interactions to reveal the beauty of our universe and the fragility of our planet. University of Washington professor in astronomy and astrobiology Rory Barnes will talk about “Habitability of Planets in Complicated Systems.” It’s free, except for the beer.

TAS public night

Tacoma Astronomical SocietyThe Tacoma Astronomical Society plans one of its public nights for 7:30 p.m. Saturday, February 25 at the Fort Steilacoom campus of Pierce College. The indoor presentation will be about the zodiac. If the skies are clear they’ll set up the telescopes and take a look at what’s up.

Futures file

You can scout out future astronomy events on our calendar. We’ve recently added several events scheduled at the Museum of Flight, including:

Up in the sky

There will be an annular solar eclipse on Sunday, February 26, but you’ll have to be in South America or Africa to see it. This Week’s Sky at a Glance from Sky & Telescope magazine and The Sky This Week from Astronomy offer more observing highlights for the week.

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