LIGO: The Next Generation

As everyone knows, I’m a total surfer dude.  So after all my recent blog posts about the LIGO project (click here, here, or here), I’ve been wondering: could I “hang ten” on a gravitational wave?

There’s still a lot we don’t know about gravitational waves.  LIGO—the Laser Interferometer Gravitational-wave Observatory—is one of the most delicately sensitive scientific instruments ever built.  But as sensitive as LIGO is, it’s still not sensitive enough.  The next generation of gravitational wave detectors promises to do better.

  • Cosmic Explorer: The United States wants to build a bigger LIGO.  Cosmic Explorer will use the same L-shaped interferometer design as LIGO, only ten times bigger.  This will increase the signal amplitude without adding to the amount of background noise the detector picks up, according to the Cosmic Explorer website.  Click here to learn more.
  • Einstein Telescope: Meanwhile the Europeans are planning to build a gravitational wave detector underground.  The Einstein Telescope, as the project is named, will incorporate not one but two laser interferometers, arranged in a triangular pattern.  One of these interferometers will pick up low frequency gravitational waves; the other will pick up waves of higher frequencies.  Click here to learn more.
  • LISA: And lastly, NASA wants to put a gravitational wave detector in space.  The project is called LISA, which stands for Laser Interferometer Space Antenna.  LISA will consist of three small spacecraft beaming lasers at each other, forming a giant equilateral triangle.  Size really does matter when it comes to gravitational wave detectors, and this space laser triangle will be far, far larger than anything we could have built here on the ground.  Click here to learn more.

Some of the questions these next generation gravitational wave detectors could help us answer: How many black holes are there in the universe?  What’s going on inside neutron stars?  What about pulsars or magnetars?  Are there gravitational waves associated with the cosmic microwave background?  Are there gravitational waves associated with dark matter?  Are any gravitational waves coming from unexpected or unknown sources?

So much science will be gained from these projects!  However, I’m not sure if Cosmic Explorer, the Einstein Telescope, or LISA will be able to answer the question I asked at the beginning of this post.  Total bummer!

Disclaimer: I’m not really a surfer dude.  Actually, I’m terrified of the ocean and I’ve never even learned how to swim.

Sciency Words: Kilonova

Sciency Words: (proper noun) a special series here on Planet Pailly focusing on the definitions and etymologies of science or science-related terms.  Today’s Sciency Word is:


In a recent presentation at Princeton University, Dr. Beverly Berger—an astrophysicist from LIGO—used a very interesting term.  Imagine a pair of neutron stars orbiting each other, spiraling closer and closer together, until suddenly “they go splat!” as Dr. Berger enthusiastically described it.

The more official-sounding term for this is kilonova, Dr. Berger then explained.  The term kilonova originates from this 2010 paper, which predicted that the merger of either two neutron stars or a neutron star and a black hole would produce a very bright flash of light.

The authors of that paper calculated that, at peek luminosity, this flash of light would be approximately a thousand times brighter than a nova explosion—hence “kilonova.”  (In case you’re wondering, a kilonova is still not as bright as a supernova—a supernova is “as much as 100 times brighter than a kilonova” according to this article from NASA.)

Of course the LIGO project is designed to detect gravitational waves, not bright flashes of light.  But as you can see in the highly technical diagram below, a kilonova is accompanied by subtle ripples in the fabric of space-time—gravitational waves, in other words.

In August of 2017, the LIGO project detected exactly the kinds of ripples that would indicate two neutron stars had “gone splat.”  As this article from the LIGO website explains, alerts were “sent out to the astronomical community, sparking a follow-up campaign that resulted in many detections of the fading light from the event, located near the galaxy NGC 4993.”

One thing I’m still not clear about: what happens after a kilonova?  It seems the scientists at LIGO are wondering about that too.  According to that same article from the LIGO website, the 2017 kilonova produced either the largest neutron star that we’ve ever observed OR the smallest black hole.  “Both possibilities are tantalizing and fascinating,” the article says, “but our data simply isn’t good enough to tell us one way or the other.”

Fortunately there are a few projects in development that might help us understand kilonovae—and similar cosmic cataclysms—a little bit better.  We’ll take a look at some of those upcoming projects in Monday’s post.

#IWSG: Stop Acting Like a Little Kid

Welcome to the Insecure Writer’s Support Group!  If you’re a writer, and if you feel in any way insecure about your writing life, click here to learn more about this awesome group!

All in all, last month was a good month for me.  I had a meeting with my editor that I thought went well.  I attended a physics seminar in Princeton, an experience which really fueled my creativity as a science fiction writer.  Oh, and I wrote an article that I’m really proud of for Fiction Can Be Fun (click here to read it!)

But no matter how well things are going for me, there’s always somebody who wants to drag me down.  This time, I’ve been told that I need to stop acting like a little kid.  I’m too old to keep chasing these childish writing dreams.

Except I didn’t find this particular insult to be particularly insulting.  Rather, my thought was: Little kid?  Oh, you have no idea how right you are!  Allow me to give you a tour of my personal “writing zone.”

A few years back, I moved to a new house.  In that process, I ended up getting rid of my writing desk.  I don’t like desks.  Sitting at a desk is such a grownup thing to do, and I didn’t want to do it anymore.  Instead, I bought a thick, heavy blanket, laid it out on the floor, and called that my new writing zone.  It’s a comfy and cozy environment for writing.

As you can see in the highly technical diagram above, I keep several things in my writing zone:

  • A dictionary, specifically the New American Heritage Dictionary, which happens to be my favorite dictionary.
  • Two thesauruses, because if I can’t find the right word in one of them, there’s still a chance I might find it in the other.
  • Two notebooks, one for first drafts and another for rewrites.
  • My computer, so I can stream music.
  • Coffee mug full of pens.  Why?  I think that’s self-explanatory.

So whenever I write, I don’t sit at a desk.  I don’t even own a desk.  Not anymore!  Instead, I lie down on my belly, feet kicked up in the air—just like a little kid.

Oh, and you may have noticed in that highly technical diagram one other thing I keep in my writing zone: a picture of my B.I.F.F.  That’s a picture of my muse.  She’s not just my imaginary friend—she’s my best imaginary friend forever, or my B.I.F.F.

So if you want to insult me, don’t tell me my writing dreams are childish.  Don’t tell me I’m acting like a little kid.  That’s not an insult to me.  That’s a point of pride.

P.S.: Shoot, I always forget to promo this….  If you’d like to help support what I’m doing here on Planet Pailly, click here to “buy me a coffee.”  I don’t actually drink coffee, but your money will help me keep my coffee mug full of pens.

That Time the Galaxy Ripped Itself Apart

Do you remember that time back in 1969 when the entire galaxy ripped itself apart?  No?  Me neither.

Last week, I had the opportunity to attend a physics seminar at Princeton University.  The presenter was Dr. Beverly Berger of LIGO.  She was there to tell us all about the discovery of gravitational waves.

Part of Dr. Berger’s presentation was historical.  There were attempts to detect gravitational waves before the LIGO experiment.  The first such attempt was conducted by Joseph Weber of the University of Maryland.  Weber’s idea was that gravitational waves would cause solid objects to expand and contract ever so slightly.  This expansion and contraction would produce friction and thus heat.

In principle, this change in temperature could be measured.  So Weber constructed a giant metal cylinder to serve as a gravitational wave detector (click here to see a picture of it).  And in 1969, Weber detected his first gravitational wave!  Or at least he thought he did. There was a tiny pulse in his data which, as Dr. Berger described it in her presentation, indicated that gravitational waves were emanating from the center of our galaxy!

Except no one was able to confirm Weber’s findings, and the discovery was widely discredited as a result.  But of course we now know, thanks to LIGO, that gravitational waves do exist.  We also know (or at least we strongly suspect) that there is a supermassive black hole in the center of our galaxy, right where Weber’s gravitational waves supposedly came from.

Given all that we now know, I think it’s fair to ask if Joseph Weber might have detected gravitational waves after all.  Someone in the auditorium did, in fact, ask that question.  But no, it’s absolutely impossible.  Weber’s instruments simply weren’t sensitive enough.

According to Dr. Berger, the only way Weber’s gravitational wave detector would have detected gravitational waves is if the entire galaxy had suddenly ripped itself apart.  Obviously that didn’t happen. The galaxy is still here. [citation needed]

P.S.: I’ve had the pleasure of meeting Dr. Beverly Berger several times now.  It’s sort of a friend of a friend situation.  Anyway, Dr. Berger has very kindly introduced me to a new scientific term.  I’ll have that for you in Friday’s episode of Sciency Words!

Your Life: Now with More Sci-Fi

The nice people over at Fiction Can Be Fun invited me to write a special blog post for them.
Has life got you down? Try turning your problems into science fiction! It won’t make your problems go away. Trust me, it won’t. But you might get a really cool Sci-Fi story out of it!

Fiction Can Be Fun

As it says on the front page, whilst Debs and I write the majority of the content on this blog ourselves, we’re also delighted to post contributions from others.  The periodic fifth Sunday in the month frequently causes consternation as we try and figure out what we’re going to be putting in that slot.  This time around, that fifth Sunday has coincided with our third birthday (time flies…), and we wanted something extra special.  This month we kicked off with a prompt we came up with in honour of James Pailly.  James runs the Planet Pailly blog, which is completely awesome, and well worth your time (once you’ve finished up here of course).  James has been a great friend to this blog, and he has very kindly written this article for us. I feel very privileged that we get to post it here.

–    David

They say we’re all…

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Sciency Words: Gravity Waves vs. Gravitational Waves

A few years back, I made a bit of a fool of myself in front of a professional physicist from LIGO.  You see, I kind of have a reputation, both online and in real life.  I’m the Sciency Words guy.  I’m the guy who knows stuff about scientific terminology.

So it’s pretty embarrassing when I get my scientific terms mixed up!  For today’s episode of Sciency Words, I’d like to share with you the two terms I got confused about so that the next time you meet a physicist from LIGO, you won’t make my mistake.


Gravity waves have to do with fluid dynamics: the movement of liquids and gases.  As an example, imagine an air mass being blown up and over a mountain range. Once over the mountains, that air mass will start to fall downwards again due to the force of gravity.

But of course air masses don’t sink straight down like lead weights.  Air has a lot of buoyancy, so that air mass will bob up and down for a while until it settles into a stable equilibrium.  This bobbing up and down motion will produce ripples in the atmosphere, and those ripples are called gravity waves.

Gravity waves have been observed both in Earth’s atmosphere and Earth’s oceans.  They’ve been observed on other planets as well.  Basically any time part of a liquid or gaseous medium is forced upwards, you can expect gravity to pull it back down again, producing gravity waves.


Gravitational waves have to do with Einstein’s theory of general relativity.  As an example, imagine two black holes spinning rapidly around each other. Even if you’re watching this from a safe distance, you might notice the combined gravitational attraction of those black holes grows stronger and weaker in a regular, oscillating pattern.

Well, actually you probably won’t notice that.  Even in the most extreme circumstances, those oscillations in gravity are barely detectable.  But they do happen.  The LIGO Project confirmed that in 2015 (the news wasn’t announced until 2016).

French theoretical physicist Henri Poincaré gets credit for coining the term gravitational waves (ondes gravifiques in French).  He first wrote about them in 1905, around the same time Einstein was formulating his theory of special relativity.  I’m not sure who coined the term gravity wave, but English mathematician George Biddle Airy was the first to mathematically describe gravity waves in 1841.

My mistake was asking a physicist who studies gravitational waves for LIGO a question about gravity waves in the atmosphere of Titan.  I mean, it’s an understandable mistake, getting these two terms confused—unless you’ve been introduced as an expert on scientific terminology!!!  Then it’s super embarrassing!!!

P.S.: As it so happens, I got the chance to meet up with that same LIGO physicist once again this week.  She was giving a presentation at Princeton University.  Don’t worry.  I didn’t embarrass myself too much this time.  I’ll tell you more in Monday’s post!

The Carbon Chauvinist

Professor Kessler had precious little patience for this new generation of young people.  They were obsessed with their implants, obsessed with their ridiculous bio-augmentations. Those projector lenses were constantly shining in their eyes, and those little audio dots were always clipped to their ears.  Who knew what they were actually looking at at any given moment?  Who knew what they were actually listening to?  Even in class, you could never be sure.

“Eh-hmm…” Kessler grumbled, standing in front of his blackboard.  Kessler had refused—adamantly refused—to let them install holographics in his classroom.

“Hmm… eh-hmmm…” Kessler tried again. Finally, the last two students stopped talking and took their seats.  But Kessler knew they’d probably keep pinging each other over Lin-Q or Alphazed or whatever the latest fad communications service happened to be.

Kessler turned, picking up a piece of chalk, and started writing on the board: Earth, Corillistrad, Delte Majoris…

“This is Galactic Political History 101,” Kessler said, continuing to write planet names on the blackboard.  “As some of you must surely be aware, there are billions upon billions of planets out there.  The galaxy is unimaginably vast.  And yet at the same time, you will find that the galaxy is also quite small.  Yes, quite small indeed.”

Kessler finished writing—there were only fourteen planets on his list—and turned his attention back to the room full of students.

“Write these names down.  Memorize them.  These are the only planets with oxygen atmospheres.  These are the only planets where complex, intelligent life can exist.  The entirety of galactic civilization lives on or near one of these fourteen planets, and thus out of the many billions of worlds in the cosmos, only these fourteen planets are of any real importance.”

To Professor Kessler’s surprise, a hand went up.

“Hmm… yes?  Yes, what’s your question, young man?”

“What about chlorine?”

“Yes… what about it?”

The young man laughed awkwardly. “Well, I mean, there are planets with chlorine atmospheres too, aren’t there?  And there’s life on those planets, and a lot of important stuff must be happening there, right?  With the chlorine breathers, I mean.  Wouldn’t that be part of galactic political history too?”

Kessler grimaced a smile.  “Quite.  Well, wouldn’t that make things interesting!  There certainly are some… things on those chlorine worlds.  Very strange things.  The result of a peculiar form of inorganic chemistry, or so I’m told.  But are those things truly alive?  Does inorganic life truly qualify as life?  Well, if you ask me…” Kessler chuckled “… I don’t think it does.”

There was an audible gasp from the whole class.

“Is it okay for him to say that?” someone whispered nervously.

Kessler shook his head and turned back to his blackboard.  Young people. There must be some discussion thread going around—something on Nova-Net or Techu-Techu or one of the other activist platforms.  This whole generation of young people gobbled up that sort of nonsense about alternative forms of life.

Fourteen planets.  There were only fourteen planets in the whole galaxy that were worth talking about, and that was the lesson plan Professor Kessler intended to stick to.

Sciency Words: Entomopters

Sciency Words: (proper noun) a special series here on Planet Pailly focusing on the definitions and etymologies of science or science-related terms.  Today’s Sciency Word is:


It is aerodynamically impossible for insects to fly, or so French entomologist Antoine Magnan famously claimed in 1934.  And it’s true.  If aerodynamics means the scientific principles governing the flight of airplanes, then you will have a very hard time explaining how insects fly using aerodynamics alone.

Do you know what else is aerodynamically impossible, or at least aerodynamically very, very difficult?  Flying on Mars.  The atmosphere is too thin for fixed-wing aircraft.  But perhaps where traditional aerodynamics fails, insect aerodynamics might succeed!

At least that was the thought behind the entomopter, a project proposed by Robert Michelson and colleagues at the Georgia Tech Research Institute back in the early 2000’s.  The term entomopter comes from two Greek words—entoma, meaning insect, and pteron, meaning wing.  So an entomopter is a flying machine that mimics the “aerodynamically impossibly” flight of insects.

As Michelson explains in this article:

Aerodynamic analyses of [insect] flight consistently revealed that their wings must produce 2-3 times more lift than conventional wings, and in some cases up to 6-7 times.  The extra load-lifting capacity this would offer Entomopters is highly significant, and indicates that a novel design based on flapping insect flight would outperform a more traditional aerodynamic approach.

The prototype entomopter built by Michelson and his research team was modeled after the hawk moth (scientific name Manduca sexta).  With a ten-centimeter wingspan, the hawk moth is an unusually large insect, which makes it easier to observe and study the movements of its wings. And I have to admit in this concept video from NASA, there is something distinctly moth-y about the way the entomopter flies.

I first learned about the entomopter while researching last week’s post on NASA’s NIAC program.  The entomopter was one of those so-crazy-it-might-work proposals that won grant money through NIAC.

You may have heard about the Mars Helicopter Scout (a.k.a. Marscopter), which will be accompanying NASA’s next Mars rover.  You may have also heard about Dragonfly, the robotic quadcopter that NASA plans to send to Titan sometime in the 2030’s. Neither of these spacecraft qualify as entomopters, and I’m really not sure how much thanks either Marscopter or Dragonfly owe to the entomopter project.  But I strongly suspect there is some sort of connection there.

Today’s Blog Post is 100% Chemical Free!

A few years back, I was on a wine tour in New Jersey.  It was a delightful adventure!  At one point, however, a very lovely vineyard owner told our tour group: “We don’t put any chemicals on our plants.”

I had to bite my tongue.  What I really, really, really wanted to say was: “Oh?  Not even H2O?”

Whenever I’m told something is “chemical free,” I am legitimately unsure what that means.  I know chemical free is supposed to mean free of artificial chemicals, or free of dangerous chemicals, or something to that effect.  But which chemicals do you consider dangerous? Which chemicals do you consider artificial?

Let me put it to you this way.  If you’re saying you don’t put any chemicals on your plants, then you obviously don’t consider water to be a chemical.  What about fertilizers?  Fertilizers are packed with sulfates and phosphates and nitrates.  I guess those don’t count as chemicals either.  So just how many chemicals do not count as chemicals?

Labeling a product “chemical free” creates a vague space in which some chemicals are chemicals and some aren’t.  I feel like there’s enough vaguery there that all sorts of things could be called chemical free.  Now I’m sure that that New Jersey vineyard owner had no nefarious intentions; but I’m equally sure that someone, somewhere—perhaps someone on the top floor of a skyscraper—is chuckling over how gullible the consumers of “chemical free” products can be.

Sciency Words: NIAC

Sciency Words: (proper noun) a special series here on Planet Pailly focusing on the definitions and etymologies of science or science-related terms.  Today’s Sciency Word is:


Every once in a while, you’ll hear that NASA is working on some crazy Sci-Fi technology.  Space elevators, warp drive… stuff like that.  How seriously should you take this?  Well, I’m not sure, but NASA does have this special program called NIAC.

When NIAC was first created in 1998, the acronym stood for “NASA Institute for Advanced Concepts.”  The program was canceled for budgetary reasons in 2007, but then it was revived in 2011.  The acronym now stands for “NASA Innovative Advanced Concepts.”

As explained in a recent article from Scientific American, “The program functions as NASA’a venture capital arm, in that it supports technologies that might pan out, big-time.”  Basically, if you have a proposal for some highly speculative new space technology—something that sounds a little bit crazy, but not too crazy—NASA might give you grant money for your research.

NIAC funding has gone toward space elevators and robotic space bees.  A mission to Proxima Centauri using tiny “chip” sized space probes?  That got NIAC funding.  The almost magical sounding Mach effect thruster—a propulsion system that uses zero propellant?  That got NIAC funding.

Some of these ideas have been ridiculed by the scientific community and in the popular press.  And I have to agree: this stuff really does sound crazy.  But remember, The New York Times once ridiculed Robert Goddard for his crazy idea that rockets could get us to the Moon.  The New York Times was really harsh in their criticism.

But as we now know, Goddard was right, and The New York Times famously published an apology in 1969, just days before Apollo 11 landed on the Moon.

Most NIAC-funded projects probably won’t work out; but imagine what would happen if a few of them did!  So the next time you hear that NASA is working on some crazy sounding Sci-Fi tech, that probably just means somebody won a NIAC grant. I’m still not sure how seriously you or I should take these NIAC-funded projects, but maybe it’s okay to take them just a little bit seriously.