Tag Archives: Jeffrey Bennett

International Dark Sky Week April 19-26

International Dark Sky Week is coming around at just the right time. The weeklong (April 19-26) celebration of the night is supported by the International Dark-Sky Association (IDA). It is an opportunity for us all to consider the role of the night and its star-filled sky in each of our lives. This year, IDA is encouraging people around the world to come together online to celebrate the night and engage with authors, creators, scientists, and educators whose works have been vital to the movement to protect the night from light pollution.

“Right now, families around the globe find themselves spending many hours at home together,” notes Ruskin Hartley, IDA’s executive director. “It’s a perfect time to reconnect with the night sky — and International Dark-Sky Week provides a portal for that experience.”

The week includes online presentations by a couple of authors that we have featured in the past on Seattle Astronomy. Paul Bogard wrote one of our favorite books, The End of Night: Searching for Natural Darkness in an Age of Artificial Light (Little, Brown and Company, 2013). Bogard will do a reading from the book Tuesday, April 21. Tyler Nordgren, a professor of physics and an artist, will do a talk about the role of art in conversation on Monday, April 20. Nordgren has created a series of great solar system travel posters and is the author of Sun Moon Earth: The History of Solar Eclipses from Omens of Doom to Einstein and Exoplanets (Basic Books, 2016). Jeffrey Bennett, author of What Is Relativity?: An Intuitive Introduction to Einstein’s Ideas, and Why They Matter (Columbia University Press, 2014), will give a presentation called “I, Humanity” on Sunday, April 19. It is geared toward kids in grades five through seven.

There will be numerous other presentations about various astronomical topics. You can access the full schedule online, but beware that it isn’t particularly user friendly, and specific times for most of the presentations have not yet been set as of this writing.

Further reading:


Please support Seattle Astronomy with a subscription through Patreon.

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

Scheiderer and MachholzRenowned 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

Jeffrey Bennett at the UW's physics/astronomy auditorium. Photo: Greg Scheiderer.

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.

We did a preview interview with Bennett as well.

Physics pioneer

Jim Peebles

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

SimonyiCharles 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

Lisa RandallHarvard 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.

Honorable mention on our list: the lecturers of the Big Bang and Beyond series at the UW, including Andy Connolly, Miguel Morales, Julianne Dalcanton, and Adam Frank; George Musser, who spoke about his book Spooky Action at a Distance: The Phenomenon That Reimagines Space and Time–and What It Means for Black Holes, the Big Bang, and Theories of Everything (Scientific American / Farrar, Straus and Giroux, 2015); and Curiosity rover chief engineer Rob Manning, who gave a talk based on his tome Mars Rover Curiosity: An Inside Account from Curiosity’s Chief Engineer (Smithsonian Books, 2014).

Gifts for the astronomy enthusiast on your list

Many Seattle Astronomy readers seem to be looking for gifts to give to the astro-enthusiasts on their lists this time of year, and often ask us for advice. We have some!

It doesn’t change much from year to year. Check our posts Gifts for the astronomy enthusiast from last year, Picking a gift for the astronomy buff from 2013, and Choosing a gift telescope from 2012. Too busy to scrape around in the past? A few quick tips:

Visit the Seattle Astronomy Store. It’s packed with our favorite gear, books we’ve read from authors we’ve interviewed, cameras, gadgets, and accessories.

Trying to pick a first telescope for someone? The book The Backyard Astronomer’s Guide (Firefly Books, 2008) by Terence Dickinson and Alan Dyer is a great reference, offers fantastic advice about what to consider when choosing a telescope, and makes a great gift in and of itself. It helped me get started, lo those many years ago, and I still use it often. This is the best gift for anyone who is interested in amateur astronomy, but who may not have much idea about how to get started in the hobby.

More books

It’s great to be able to read about astronomy in an area in which rain and clouds are the norm about 11 months of the year. While our store has a big selection, there are a number of good choices that are new in the last year or so, and whose authors have made presentations here in town.

What Is Relativity?: An Intuitive Introduction to Einstein’s Ideas, and Why They Matter (Columbia University Press, 2014) by Jeffrey Bennett is a wonderfully approachable primer on a topic that many people find mind bending, perhaps just because it never gets explained so well. Pick this one up and your gift recipient will be explaining the fabric of spacetime to one and all. Bennett did an interview with us in March and spoke at the April meeting of the Seattle Astronomical Society. He’s been touring the country in support of the book in observance of the 100th anniversary of the Theory of Relativity.

Dark Matter and the Dinosaurs: The Astounding Interconnectedness of the Universe (Ecco, 2015). Harvard astrophysicist Lisa Randall did a talk at Town Hall Seattle in November. Her idea about how dark matter may have done in the large reptiles 65 million years ago is an interesting and relatively simple one. Her research for the next few years will be focused on trying to find evidence that her notion is valid, and that a type of particle of dark matter that reacts to “dark light” may be behind mass extinctions.

Spooky Action at a Distance: The Phenomenon That Reimagines Space and Time–and What It Means for Black Holes, the Big Bang, and Theories of Everything (Scientific American / Farrar, Straus and Giroux, 2015). Author George Musser also talked at Town Hall in November and took a shot at explaining quantum entanglement. He noted that we’re starting to see the hazy outlines of an answer to questions about the how particles in different locations appear to act on each other, but adds that there are still scientists who don’t really believe that non-locality is a real thing.

After Apollo?: Richard Nixon and the American Space Program (Palgrave Studies in the History of Science and Technology) and John F. Kennedy and the Race to the Moon (Both Palgrave Macmillan, 2015 and 2010, respectively). Space historian John Logsdon did two speeches in Seattle this year, one at the meeting of the American Astronomical Society back in January, and the other in June at the Museum of Flight. He insterestingly described the race to the Moon as a one-sided one that we almost lost anyway. A perfect couple of volumes for those interested in the history of space exploration.

The End of Night: Searching for Natural Darkness in an Age of Artificial Light by Paul Bogard. This isn’t a new book, but we absolutely love it for its beautiful writing as well as its important message. Bogard spoke in Seattle two years ago and we’ve been raving about the book ever since.

Emily Lackdawalla of the Planetary Society did a post last year with suggestions for astronomy books for children, and Bennett has also done a number of acclaimed books for children, with links included at the end of our post based on our interview with him.

New experts in town

Cloud Break OpticsIf you’re looking for gear there are new experts in town to help you out. Cloud Break Optics opened earlier this year in Ballard, and it’s the first astronomy shop in town ages that is owned and operated by and for amateur astronomers. Stephanie Anderson and Matt Dahl are the proprietors, they know their stuff, and are more than happy to share. They take online orders, but why not drop by, meet some new friends, see all of those telescopes and eyepieces and gadgets in person, and buy from your local small business.


We are decidedly not astrophotographers, but our friend The Soggy Astronomer is, and he wrote an article earlier this year about good camera choices for this aspect of the hobby. Our post gives a brief summary, and his top picks are included in our store.

Understanding relativity

Jeffrey Bennett thinks we ought to be teaching kids about relativity in grade school because Einstein’s theories explain so much about everything, from why the Sun shines to gravity to how your GPS system knows where you are. His book What Is Relativity?: An Intuitive Introduction to Einstein’s Ideas, and Why They Matter (Columbia University Press, 2014) does a marvelous job of making sense of some of the seemingly strange consequences of relativity.

Jeffrey Bennett

Jeffery Bennett spoke about his book “What is Relativity?” at the meeting of the Seattle Astronomical Society in April. Photo: Greg Scheiderer.

Bennett spoke about relativity at a meeting of the Seattle Astronomical Society in April. He’s on a tour marking the International Year of Light and the centennial of general relativity.

Bennett noted that a key idea of relativity is that it is motion that is relative. He illustrated this by talking about a plane flight between Nairobi and Quito, two cities on Earth’s equator. The plane leaves Nairobi, flies at 1,670 kilometers per hour, which happens to be the Earth’s rotational speed at the equator, and then lands in Quito.

A person standing on Earth would say the plane flew west at 1,670 kilometers per hour. However, a person watching this flight from the Moon would have seen the plane take off, hover while the Earth spun under it, and then land once Quito arrived. That person would peg the plane’s speed at zero. Who is right?

“Einstein’s answer is both are correct,” Bennett said, “and neither one makes sense unless you specify what you’re measuring your motion relative to.”

Absolutes are key in relativity

Bennett explained that the heart of relativity is not what is relative, but the two things that are absolute: the laws of nature and the speed of light. He used an airplane flight to illustrate the latter point as well.

If you’re in a plane going 500 miles an hour, and you throw a ball forward at 10 miles per hour, a person on the ground would see that ball going at 510 miles per hour—the speed of the plane plus the speed of the ball. However, if you shined a flashlight forward, the light would go at the speed of light, not light-plus-500. The motion of the plane does not effect the speed of light.

“It is not effected by motion of either the observer or the source,” Bennett explained. “It’s an experimentally measured fact that the speed of light is the same for everyone, and from this single fact, if you do thought experiments, you can derive all the seemingly strange consequences of relativity.”

Not so fast!

The book is loaded with such thought experiments that help one get a grasp on the concepts. One Bennett talked about at length is the impossibility of exceeding the speed of light. Imagine a spaceship with theoretically unlimited speed. If Bennett, as the pilot, turns on the ship’s headlights, both he and an observer outside the craft would see the light from the headlights moving ahead of the ship at the speed of light.

“If the headlights are going the speed of light then I’m going less than the speed of light,” Bennett explained. “We set no limits, and yet the fact that the speed of light is the same for everyone means I cannot reach it or exceed it.”

“This is not a challenge to be broken technologically,” he continued. “It’s something that simply cannot be done. In fact, the idea that you cannot go faster than the speed of light is so well established that not even science fiction writers try to break it. That’s why they go through wormholes or into hyperspace or make warp drive to bend spacetime, because science fiction writers know you cannot travel through the universe at a speed greater than the speed of light. It simply can’t be done because the speed of light is the same for everyone.”

Bennett explained that the predictions of the effects of relativity have been tested exhaustively, and much of what we see in our everyday lives serves as proof that it works.

“The sun shining is evidence that relativity is correct,” he said. “Every time you turn on a computer or a light our a cell phone you’re testing the theory of relativity and showing that it works. This is an extremely well-established idea.”

Uncommon sense

Bennett speaks about relativity often and finds that many people have a hard time with it because they feel it violates their common sense.

“The good news is it actually doesn’t violate your common sense,” Bennett said. “The bad news is the reason it doesn’t violate your common sense is because when it comes to these ideas, you just don’t have any common sense.”

Why not? Common sense, by definition, derives from everyday experiences.

“These effects of relativity become noticeable when you’re traveling at speeds close to the speed of light. And guess what? You’ve never done that,” Bennett said.


Jeffrey Bennett at the UW's physics/astronomy auditorium. Photo: Greg Scheiderer.

Jeffrey Bennett at the UW’s physics/astronomy auditorium. Photo: Greg Scheiderer.

When it comes to gravity, Newton had the math pretty well figured out, but even he thought the notion of one massive body acting somehow on another had sort of a weird, magical quality. Einstein came along and figured out that gravity is simply curvature of spacetime.

“This is one of the fundamental ideas of general relativity,” Bennett said. “Gravity is no longer a magical force at a distance, it’s just objects following the natural contours of spacetime as they are shaped by masses in the universe.”

Evidence that this is true includes gravitational lensing, gravitational time dilation, black holes, and gravitational waves. The first has been seen, the second measured, and we’ve seen the effects of the third. Bennett said scientists are optimistic they’ll actually detect gravitational waves in experiments this year.

Why relativity matters

Bennett feels that scientific knowledge, understanding of reality, and the inspiring human potential to do great things through science are among the reasons that relativity matters. A fourth reason is highly philosophical.

“In a sense, every action you ever take is a permanent part of spacetime,” he said. “Your life is a series of events, and this means that when you put them all together you are creating your own indelible mark on the universe. Perhaps if everyone understood that, we might all be a little more careful to make sure that the mark we leave is one that we are proud of. This may be a little naive, but I actually believe that if everyone understood the theory of relativity we’d all treat each other a little bit better.”

What Is Relativity? is an outstanding book that dives deeper into these concepts and leaves the reader with a better understanding of relativity.

Bennett talk Wednesday at SAS: general relativity made easy

Dr. Jeffrey Bennett says you don’t have to have the brain of an Einstein to understand general relativity.

“If you want to deal with all the mathematics of it then it is pretty complex,” Bennett says, “but if you want to just understand it on a conceptual level, it’s not that difficult to get a general grasp of it.”

Bennett, the author of of What Is Relativity?: An Intuitive Introduction to Einstein’s Ideas, and Why They Matter (Columbia University Press, 2014), will talk about the book, and relativity, at next week’s meeting of the Seattle Astronomical Society. The meeting, which is free and open to the public, begins at 7:30 p.m. Wednesday, April 15, in room A102 of the Physics/Astronomy Building on the campus of the University of Washington in Seattle. There’s still time to pick up the book, by clicking the link above or the cover to the left, before the talk.

Seattle Astronomy spoke earlier this week with Bennett, an adjunct research associate with the Center for Astrophysics and Space Astronomy at the University of Colorado. He says his Relativity Tour is a bit of an accident of timing. He’d been thinking about writing a book about relativity for several years. When the book came out last year it was just in time for the centennial of Einstein’s breakthrough, and Bennett decided to do his part for the International Year of Light and help the general public understand general relativity and how it makes so many everyday things possible.

Einstein was right

While Einstein proposed general relativity one hundred years ago, Bennett notes that many people still think of it as new physics, and others still strive to prove Einstein was wrong, but Bennett says that’s not going to happen.

“You can’t do that because it has checked out so much; you can’t make the evidence where it does check out go away,” Bennett explains. “In the same way, Einstein didn’t show Newton to be wrong. What you’re really looking for is to see if we can find a place where Einstein’s theory is not yet complete, and we need something else to take us to that next level.”

A good example of such a place is trying to find agreement between general relativity and quantum physics.

“That’s the known hole in our current understanding,” Bennett says. “Even though both work extremely well in the regimes in which they’ve been tested, they don’t quite meet up, and therefore there must be something else that we have not yet figured out that brings them together.”

Relativity for all audiences

Dr. Jeffrey Bennett

Dr. Jeffrey Bennett

Bennett, a recipient of the American Institute of Physics Science Communication Award in 2013, speaks to a wide variety of audiences, from adults down to elementary school kids, and has written children’s books as well as college texts.

“The commonality across all of the work that I do is that it’s all aimed at people who are not really very familiar with science and math, and in some cases, with the older audiences, maybe thinking they’re sort of afraid of these topics,” he says. “I’m always dealing on that introductory level—what science is and why you should care about it. When you’re dealing with it at that level, it’s not really that different to deal with children or with grownups, because either way you’re dealing with the same lack of knowledge and lack of understanding.”

Bennett recommends the talk he will do Wednesday for people from middle school on up, though he says younger kids often understand it as well.

“Come with an open mind,” he urges. “Even if you think this is something that you can’t understand, I think you’ll find you actually can, so I hope people will come in that spirit.”

More reading

General relativity explained

Cool news from the Seattle Astronomical Society, which just announced that the program for its April meeting will be a talk by Dr. Jeffrey Bennett, author of What Is Relativity?: An Intuitive Introduction to Einstein’s Ideas, and Why They Matter (Columbia University Press, 2014).

Bennett has spent much of the last 30 years at the University of Colorado, where he remains an adjunct research associate with the Center for Astrophysics and Space Astronomy. These days he is mainly a writer and he has embarked on a “Relativity Tour” this year, celebrating the centennial of Einstein’s revolutionary ideas. Bennett’s basic premise is that general relativity is not all that difficult to grasp, and his goal is to bring relativity out of the realm of obscure science and help us understand it and the impact it has on our lives.

Oddly enough, it appears that my cats understand relativity. Followers of the Seattle Astronomy Facebook page recently saw the photo below of their demonstration. People trying to help others understand general relativity often ask them to imagine a bowling ball on a bed sheet. In this case Archie and Theodolinda used themselves as the massive objects, and the down comforter represents space-time. The green object in the background may be Neptune.

relativitycatsBennett’s explanation may not be simple enough for cats to understand, but it is advertised as suitable for anyone from middle school on up. Bennett has taught young kids, and in addition to scholarly textbooks and science tomes for adults, he has written a series of children’s books featuring the outer space adventures of Max the dog. To gear up in advance of the talk pick up What Is Relativity? by clicking this link or the photo above. Links to Bennett’s other books are below.

The Seattle Astronomical Society talk will be at 7:30 p.m. Wednesday, April 15 in room A102 in the Physics/Astronomy Building at the University of Washington in Seattle. In addition to SAS, the Relativity Tour is sponsored by Big Kid Science, Columbia University Press, Fiske Planetarium, and Story Time From Space.

More materials

Jeffrey Bennett website

Books by Bennett