Our favorite books and author talks of 2017

We created Seattle Astronomy because, given our region’s seemingly perpetual cloud cover, there were more opportunities to write about astronomy than to actually observe the night skies. We also read the writing of others, go hear them talk about it, and report back to you! Here are our top five author and book stories of 2017.

1. Treknology

Ethan Siegel’s new book Treknology: The Science of Star Trek from Tricorders to Warp Drive (Voyageur Press, 2017) is a must for any Star Trek fan. As the title suggests, Siegel takes a look at a host of technologies imagined by the various Trek TV series and movies and weighs in on which have already come true, which are on the horizon, and which would still require some discovery. Siegel is reluctant to say something will never happen. Instead, with challenging technologies such as warp drive, he looks at the physics of how it could work and the challenges for bringing that to reality. Siegel isn’t just making this stuff up; he’s a theoretical astrophysicist and writes the blog and produces the podcast Starts With a Bang. Siegel has appeared several times on our pages. Find our article and podcast about Treknology, and our articles about his talks on gravitational waves and the expanding universe given to Rose City Astronomers in Portland, and his talk about dark matter at Astronomy on Tap Seattle.

2. American Eclipse

Former NPR science editor David Baron got the idea to write a book about solar eclipses way back in 1998 when he witnessed his first total solar eclipse from the beach in Aruba. He figured 2017 would be a good year to publish, when interest in the great American eclipse was at its peak. American Eclipse: A Nation’s Epic Race to Catch the Shadow of the Moon and Win the Glory of the World (Liveright, 2017) is the story of the 1878 totality that crossed the American frontier from Montana down through Texas, and it chronicles the efforts of Thomas Edison, Maria Mitchell, and James Craig Watson to view the eclipse. Baron credits the event for sparking a scientific boom in the United States. We just finished the book during a recent train trip and found it to be a marvelous and informative read. Baron spoke at Pacific Science Center in July. Check out our review of his talk.

3. The Greatest Story Ever Told—So Far

Lawrence Krauss is a renowned author and theoretical physicist and cosmologist who packed Town Hall Seattle back in April for a talk about his book The Greatest Story Ever Told—So Far: Why Are We Here? (Atria Books, 2017). We love it when someone can tackle particle physics without causing headaches, and Krauss nailed it with both his talk and the book. Krauss tells not just about the advances in physics over the years, but gives interesting insights about the creative processes that led to the discoveries. As an example, there are at least two cases in which amazing discoveries came when the scientists were sleep deprived because of the recent birth of children! Here’s our review of Krauss’s talk in Seattle. There’s a weak connection between Krauss and Ethan Siegel; one of Krauss’s earlier books is The Physics of Star Trek (Basic Books, 2007).

4. Vacation Guide to the Solar System

Olivia Koski and Jana Grcevich created the “Intergalactic Travel Bureau,” and their book Vacation Guide to the Solar System: Science for the Savvy Space Traveler! (Penguin Books, 2017) is a travel brochure. Packed with information about what to see from Mercury to Pluto, the guide tricks us into learning something in an entertaining and beautifully illustrated format. They spoke at Town Hall Seattle in June. Here our recap.

5. Earth in Human Hands

David Grinspoon himself wonders how an astrobiologist such as himself wound up writing a book about the human impact on Earth. He figures the more we know about how planets work, the better we can be at making changes to the climate that are for the better. In Earth in Human Hands: Shaping Our Planet’s Future (Grand Central Publishing, 2016) Grinspoon notes that we aren’t the first species to radically change the planet’s climate; the humble cyanobacteria killed off just about everything else on Earth once by adding oxygen to the atmosphere. Grinspoon spoke at the Pacific Science Center last January; here’s our recap of his talk.

Purchases made through links on Seattle Astronomy earn us a small commission at no cost to you! This helps us keep the lights on. Thanks!

Treknology looks at Star Trek gizmos

Star Trek first hit the airwaves over a half century ago, and Dr. Ethan Siegel finds it amazing how many of the gizmos, gadgets, and technologies imagined by the various Trek television series have become reality. Siegel, theoretical astrophysicist and science writer, is author of the new book Treknology: The Science of Star Trek from Tricorders to Warp Drive (Voyageur Press, 2017). Treknology is scheduled for release on October 15 and is available for pre-order on Amazon now.

Siegel, a Trek fan since discovering The Next Generation (TNG) as a kid, figures he was just the guy to dig into Star Trek’s technology.

“That intersection of an interest in Star Trek and Sci-fi, of an interest in what it means for humanity, and a knowledge of physics, all of those have come together to make this book possible,” Siegel said.

Treknology devotes a separate chapter to 28 different technologies that were used in the various series.

“These technologies that were so futuristic that they were imagined centuries in the future, some of them don’t appear to be that far off,” Siegel noted. “Some of them are already here and in widespread use. Others that we thought just a few years ago were going to be far-future technologies look like they’re coming to fruition.”

We’ve got that Treknology already

Siegel noted that it was The Original Series (TOS) that came up with the automatic sliding door, now a staple in every airport and supermarket. Your tablet is also cooler than anything Trek came up with.

“What you’ve got in your smart phone is much more impressive that anything that were on those touch-screen pads that Star Trek envisioned,” Siegel said. “Here we are with something that’s smaller, that’s more compact.”

That goes for pretty much all of the computers, he noted.

“We’ve gone way beyond what Star Trek would have envisioned much more quickly than anything that came about in the original series,” Siegel said. At the time of TOS in real life we had room-sized computers that had less computing oomph than today’s pocket calculators. When TNG came around, they figured they had to jazz up the computing and came up with something new and fancy—digital storage.

“Your flash drive is more powerful than a Star Trek isolinear chip,” Siegel noted. “As far as computation goes—ships computer, pads, isolinear chips—we’ve blown away what Star Trek would have envisioned.”

Medical technology

Dr. Ethan Siegel, author of Treknology,
during a lecture in Portland last year.
Photo: Greg Scheiderer.

As an astronomy and physics guy, Siegel said he was especially interested in learning about the medical technologies and biological situations that Star Trek dreamed up. He noted that we may soon be able to use synthehol, a substance with the positive effects of booze without the negative impacts.

“Synthehol is on track pharmacologically to become real,” Siegel said.

We may also be close to helping sightless people see, ala Geordi La Forge—the TNG character played by LeVar Burton—who wore a special visor that allowed him to see the entire electromagnetic spectrum.

“If we can make an implant somewhere in your brain’s visual cortex, and we can wirelessly feed an external signal to that implant,” Siegel said, “this is a potential way to restore sight to the blind,” even if they have no eyes or optic nerves at all. NASA actually tinkered with sight-improving technology in the late 1990s, and called its project JORDY: Joint Optical Reflective DisplaY.

Not there yet

There are other Treknologies that aren’t so close yet. Warp drive is at the top of that list. He says it’s mathematically possible, but it will be tough to make it work in our universe.

“It depends on if you can either have negative gravitational mass or negative energy,” Siegel explained. “If you can, then great, we can build warp drive. If that’s a physical impossibility—and we haven’t discovered anything like that yet—then I don’t know how warp drive can be possible.”

“This is probably one of the most difficult technologies to achieve, but I still don’t want to rule it out and say it’s impossible,” he added. “I want to look at what it would take to make it possible.”

A few other technologies such as subspace communication and transporters would require “extensions” to our current physics to become reality, Siegel said, and we’re a ways from life-like androids and holodecks, too.

Siegel has written widely. His first book was Beyond the Galaxy: How Humanity Looked Beyond Our Milky Way and Discovered the Entire Universe (World Scientific Publishing Co., 2015). He writes the Starts With a Bang blog on Forbes, and produces a podcast of the same name. Siegel can be found under that handle on Twitter and Facebook. He expects to be touring conventions and bookstores around the country in support of Treknology. We look forward to the book’s release next month.

A lighthearted look at the dark universe

Two astronomers recently came independently to the conclusion that the way to figure out the fate of the universe is to build bigger and better telescopes. Prof. Sarah Tuttle of the University of Washington and Dr. Ethan Siegel of the Starts With a Bang blog and podcast both made informative and entertaining presentations about the dark universe at the most recent gathering of Astronomy on Tap Seattle at Peddler Brewing Company in Ballard.

UW astronomy Prof. Sarah Tuttle
spoke at Astronomy on Tap Seattle
May 24, 2017 at Peddler Brewing
in Ballard. (Photo: Greg Scheiderer)

In her talk titled, “Dark Matter, Dark Energy, and Otters,” Tuttle joked that astronomers are “the universal accountants,” and that right now these bean counters are thinking that 68 percent of the universal energy budget consists of dark energy.

“If I were you, I would be concerned, because I both just told you that most of the universal energy budget is dark energy, and we don’t know what it is,” Tuttle said. “Dark matter we can measure and observe, but we don’t know what that is, either.”

There are a lot of theorized particles that could be in the dark-matter mix, but Tuttle said we don’t really understand them yet.

“We are in the process of measuring them and trying to figure out what it could actually be that is dark matter, how it is interacting with everything around it, because it is the dominant form of matter in our universe,” she said. We’re even more in the dark about dark energy.

“We are able to pin down that dark energy exists, that the universe is expanding and accelerating, and we’re not yet quite sure how to explain that,” Tuttle said.

How do we know?

Three experiments have helped reveal dark energy. Observations of the cosmic microwave background and type 1a supernovae have shown us that the universe is expanding. Tuttle is involved with a project called HETDEX—the Hobby Eberly Telescope Dark Energy Experiment—using a 10-meter telescope in West Texas. HETDEX is taking spectra of faint, young galaxies that are Lyman-alpha emitters to try to detect baryon acoustic oscillations. Huh?

“We’re using the clustering of a particular kind of galaxy to measure the distortion of spacetime,” Tuttle explained. She said it’s like throwing a grid of lights over a three-dimensional object—the lights will reveal the shape of the object.

“We use these galaxies to show us the shape of spacetime underneath to expose how dark energy changes with time,” Tuttle said. Other efforts like EBOSS and the South Pole Telescope are working on the same problem.

“We use a lot of different techniques to try to figure out what we’re doing to expose what dark energy is,” Tuttle said. “It turns out it’s going to take more beer and more time before we can answer that question.”

Our fate is in dark energy’s hands

Dr. Ethan Siegel of the Starts with a Bang blog and 

podcast spoke at Astronomy on Tap Seattle May 24. 

(Photo: Greg Scheiderer)

Siegel’s talk was titled “The Fate of the Universe: After 13.8 billion years, where is everything headed?” He noted that it astronomers once saw three possible scenarios for the future of our universe. It could keep on expanding forever, it could eventually collapse back onto itself, or expansion and gravity could balance out just right for a universe that remains about the way it is.

“That’s what we thought for years and years and decades and decades: the fate of the universe is going to be one of these three,” Siegel said. “The whole field of cosmology, which is my field, was the quest to measure what’s it going to be.”

“They’re all wrong,” he said. Dark energy is the wild card. Siegel pointed out that matter dilutes with the expansion of the universe, and radiation gets weaker; it redshifts. Dark energy? We’re not so sure.

“If there’s any type of energy that’s inherent to the fabric of space, then as space grows this energy is just growing,” Siegel explained. “As your universe grows, it’s like you’re just making more and more of this new type of energy if there’s any non-zero energy to space itself.”

A big assumption

Siegel gave a lengthy description of the fate of the universe, from the boiling oceans of Earth to the last black hole standing. It was all based on the assumption that dark energy is constant. But what if it gets stronger over time? Siegel said that would mean that galaxies and solar systems and the Earth would all get torn apart.

“In the fiery final moments, everything, even the atoms that made you up, even the nuclei that made you up, would be ripped apart as well,” he said. “That fate is known as the Big Rip, and it’s possible. I don’t think it’s right, but you can’t be sure unless you measure it.”

Dark energy could get weaker, too, and that could lead to the opposite outcome, a big crunch.

“That’s something we could also measure,” Siegel said. “We haven’t constrained it well enough to know that it won’t rip or that it won’t turn around and crunch again. The way we’re going to find out is through bigger and better telescopes and observatories.”

HETDEX is a big part of that, Siegel noted, and said that the ESA’s Euclid telescope will measure dark energy to better precision than ever before. NASA’s WFIRST (Wide Field Infrared Survey Telescope), scheduled to launch in mid-2020, and the Large Synoptic Survey Telescope, under construction in Chile with hopes of being fully operational by 2022, will also make key contributions to this work.

“If you think that this stuff is fun, I’m telling you it’s going to get even better in the 2020s,” Siegel concluded. Stay tuned.

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 looking 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

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 minuscule 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.

The universe is big, even in small spaces

The universe is pretty vast even in confined spaces. That was the lesson given on opposite ends of the size scale at the most recent Astronomy on Tap Seattle event hosted at Hilliard’s Beer Taproom by University of Washington graduate students in astronomy.

Ethan Kruse

Grad student Ethan Kruse was all set to give a talk that concluded we would never even get out of our solar system because it is way too big. Then a few weeks before the talk Stephen Hawking and friends announced their plan for getting all the way to neighboring star Alpha Centauri in 20 years through a project called Breakthrough Starshot.

“If I’m disagreeing with Stephen Hawking,” Kruse recalled thinking, “I should probably stop for a minute and reevaluate my thesis.”

Kruse remained on point about the mind-boggling scale of the universe. He said that if our Sun was the size of a basketball sitting on the stage of Hilliard’s, Earth would be the size of a sesame seed in the back of the room, 84 feet away, and the orbiting Moon would be the size of a grain of salt. At this scale Jupiter would be a golf ball on the Ballard Bridge and Pluto would be a grain of salt about a kilometer away—about the distance to Bad Jimmy’s Brewing Company, which served as the venue for Astronomy on Tap Seattle for its first year. Alpha Centauri, in this set-up, is some 4,400 miles away—in London or Tokyo.

Kruse pointed out that the fastest spacecraft we have built so far, New Horizons, took a decade to get to Pluto.

“We went from Hilliard’s to Bad Jimmy’s in ten years,” he observed. “Don’t worry guys, we’re going to go to London in 20 years!”

The idea behind Starshot is that a super-light craft with a light sail could be accelerated by lasers to up to 20 percent of the speed of light. Kruse outlined a litany of technological challenges with the concept, including the ability to generate sufficient laser power, creating an adequately reflective material for the sails, being able to accurately aim the lasers at great distances, and shielding the craft from possible collisions with space debris. Still, he concluded, the idea is worth exploring, especially since the same technology could be used to explore the solar system more quickly.

“This is honestly the most realistic thing that anyone has proposed so far for getting to any other star system,” Kruse said.

It will, however, take a great deal of research and development.

“Don’t necessarily count on this before you die,” Kruse concluded. “Space is big.”

Jessica Werk

Professor Jessica Werk, one of the newest hires onto the astronomy faculty at the University of Washington, also used sports equipment to illustrate her talk, “The History of You: The Rather Tumultuous Past of the Atoms in Your Body.” Werk pointed out that atoms are mostly empty space. If the nucleus of an atom were the size of a baseball, the nearest electrons would be a football field away.

After the Big Bang the universe was mostly light atoms: hydrogen and helium and a few others. Where did the carbon and calcium and other heavier stuff we’re made of come from?

“All evidence suggests that these atoms were fused in the cores of very, very massive stars twelve-and-a-half billion years ago,” Werk said. “Since then they have been on an absolutely crazy, long, sometimes violent journey to end up in your body 93 million miles from the Sun on this speck named Earth.”

Those atoms took a somewhat circuitous route to get here.

“Sixty percent of the atoms in your body we at one point outside of the galaxy in the circumgalactic or intergalactic medium,” Werk said. We don’t really know how they got here, but the best theory is that the atoms tend to cool off, and the gas rains back down on the galaxy, collapsing in star formation or becoming part of the debris disk out of which planets form.

There’s some mind-bending scale at the atomic level, too. Werk pointed out that there are 10²³ atoms in a breath of air.

“Each breath-full of air contains more atoms than the number of breath-fulls of air in the entire Earth’s atmosphere,” she said. “What that means is that it is very likely that the last breath of air you just took contained at least one oxygen atom from the first breath of air that you ever took as a human being on planet Earth.”

That reminds us of a recent post by Ethan Siegel on the blog Starts With a Bang, in which he concluded that we all probably share atoms that were once part of King Tut or any other historical figure you might name.

“The matter that makes up your physical body is part of a huge universe that is continually evolving and recycling the material in it into new forms,” Werk concluded.

Gravitational wave discovery ushers in new era in astronomy

“This is beginning a new era in astronomy,” said Ethan Siegel about the publication in February of a paper announcing that scientists had detected gravitational waves. Siegel has taught physics and astronomy at Lewis & Clark College and the University of Portland in Portland, Oregon. He is creator of the science blog Starts With a Bang, and is the author of Beyond the Galaxy: How Humanity Looked Beyond Our Milky Way and Discovered the Entire Universe (World Scientific, 2015). Siegel gave a talk at this month’s meeting of the Rose City Astronomers in Portland about what he calls the discovery of a lifetime.

Ethan Siegel

“This was something, when it was first proposed, that was really taken to be a preposterous consequence of a theory and something that we never really thought we were going to be able to test,” Siegel said. “We have gone in 101 years from pure theory to concrete, direct detection of gravitational waves.”

Einstein’s theory of relativity states that mass and energy bend spacetime, and that’s why objects orbit each other. Relativity explained anomalies in the orbits of planets in our solar system, but Siegel said there is an “extra weird” effect because the orbits decay.

“Another consequence of Einstien’s relativity is that as things spiral in, and it takes a long time to do, but as they do they emit a special type of radiation; they emit radiation that goes through the fabric of space itself,” Siegel said. “This is gravitational radiation.”

It takes way too long for that to happen here in the solar system. For Earth’s orbit to decay completely and merge with the Sun would take 10¹⁵⁰ years, according to Siegel. He said we’ll have to look elsewhere to see the effects happen on human-length time scales.

“You need to find heavy masses; heavier mass in relativity means a stronger effect,” Siegel said. “You need them to have small distances, where small distance is a few kilometers, not a few million miles. And you need them to orbit at fast speeds, where fast is kind of close to the speed of light.”

Luckily these conditions exist. Black holes, neutron stars, and pulsars can do the trick; the gravitational waves detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO) last fall were generated by merging black holes. One of those black holes started out at 36 solar masses and the other at 29. After the merger they weighed in at 62 solar masses. That’s simple arithmetic: 36+29=65; what happened to the other three solar masses? Siegel said, oddly enough, this was a prediction by Einstein as well. It’s the flip side of e=mc².

“When these two black holes merged, three solar masses, about five percent of the total mass, was converted into pure energy,” he said. “That energy is the gravitational radiation and is why we here on Earth were able to detect this huge event of two black holes merging from over a billion light years away.”

Siegel is amazed that we were able to figure the mass, spin rate, merging speed, mass loss and other characteristics of these distant objects.

“We learned all of this information from one 20-millisecond signal that moved two laser arms by less than 10^-18 meters,” he marveled. “What I’d say we have now is a whole new way to discover our universe.”


That way is improving rapidly. The LIGO detectors at Hanford, Washington, and Livingston, Louisiana, are being tweaked to even greater sensitivity. New detectors are planned for Italy, Japan, and India. Siegel said the ultimate would be to build three huge LIGO detectors in space, forming an equilateral triangle in Earth’s orbit and having detector arms hundreds of millions of kilometers long.

“If you do that, you can not only watch things merge with supermassive black holes, you can find mergers of ultramassive black holes,” Siegel said. We might even be able to spot gravitational waves from cosmic inflation within the light of the cosmic microwave background. Siegel said if that happens, it would prove that gravity is a quantum force.

“There’s no way to make these fluctuations unless gravity is inherently a quantum force,” he explained. “The process that makes these fluctuations is a quantum process.”

Siegel said it’s a thrilling time to be involved in astronomy.

“This is the first time we’ve seen something astronomical without using a telescope or light of any type,” he said. “This is the dawn of astronomy beyond light-gathering telescopes.”