Doing the (Gravity) Wave

All the different kinds of waves we currently know about – radio, microwave, visible light, X-rays and so forth – are caused by one and only one process: electrons in atoms giving varying amounts of energy to particles of light called photons. These photons are merely vehicles that carry the energy FROM atoms undergoing various electrical and magnetic reactions TO our Walkman, our popcorn, our digital camera, our X-ray film. Thus the electromagnetic energy transfer process is carried out THROUGH space (FROM an antenna TO a radio), but it does not physically ALTER the space between the origin and destination points.

Gravity waves are fundamentally different. To begin with, they are not caused by atoms gaining and losing electromagnetic energy. Gravity waves are caused instead by the mere motion of atoms in space, just like waves in a pond are caused by the mere motion of a pebble thrown into the water. Just like a ripple in water, gravity waves cause a ripple in space.

A ripple in space: such a thing is hard to imagine, to say the least. For now, imagine it like this. Say you had a bathroom sponge sitting on a set of bathroom scales. The sponge represents Our Universe, so it’s made not of plastic foam, but made instead of quantum spacetime foam (QSF). (How does QSF differ from polyurethane, you ask? Check these SciSCoop pages in the middle of the 22nd Century and we’ll get back to you). This sponge even has some flecks of mold in it; that’s extraterrestrial life – including us. Somehow a lit match gets dropped on this sponge, it catches fire, and it burns with a bright flame. You can see electromagnetic energy in the form of visible light from the flames. In a very crude way, this is the story of the Big Bang. When we take pictures of the Cosmic Microwave Background with NASA satellites like COBE and WMAP, we’re sort of taking electromagnetic snapshot pictures of the burning QSF sponge in which we live.


But while our QSF sponge is electromagnetically burning its way into a cold ash, the bathroom scale on which it sits has not registered any change at all! Let’s change that right now by dropping a steel ball bearing on the top of our sponge. BAM! The impact squishes our sponge momentarily and the bathroom scales jerk for a moment as they register a spike of weight. A camera can’t capture the internal squish of the sponge – that’s not its job – but the bathroom scales DOES. And that pulse of squishiness in the foam is for our purposes a gravity wave.


Nobody has yet discovered a gravity wave, but we’re trying. Our latest attempt is with some new billion-dollar bathroom scales we’ve built in Louisiana and Washington called the
Laser Interferometer Gravitational Wave Observatory, which so far hasn’t seen a thing – but then, it just recently got turned on this year and is still undergoing fine-tuning.


Sinking that kind of money into bathroom scales just isn’t done unless there is a belief that some pretty heavy ball bearings are getting dropped on the spacetime foam in which we live. And indeed they are, in the form of double stars. Most solar systems have two suns revolving around each other – ours would be that way if the planet Jupiter were a little bigger and had ignited into the star it could have been. In their old age, a few double star systems become special super-dense stars called neutron stars that spiral in to collide with each other eventually. This spiraling dance of binary neutron stars in itself is believed to create gravity waves that are possibly too weak to be measured directly with LIGO – but just thinking about them has been good for a Nobel Prize anyway. When the two neutron stars finally collide, tho, they create a black hole. THAT collision is one heck of a big steel ball bearing dropped smack dab in the middle of the spacetime foam in which we live – one that LIGO is designed to “see.”


So how long do we have to wait before LIGO registers one of these star crashes? At last, dear reader, we’re at the “current news” paragraph of this story. Last week it was announced the wait may not be as long as we’d thought. The discovery of a new dual neutron star system was announced, and this one is scheduled for impact in a mere 85 million years!!! While LIGO won’t be tuning in on THAT impending gravity wave, the study published in Nature suggests that binary neutron stars may be much more common than we had thought in the universe as a whole – and that means the gravity wave from one could be rippling through our solar system on its way to LIGO measurement sooner than we think.


Newton had it easy in Quicksilver and in real life when he teased out the secrets of electromagnetic waves. He only needed a glass prism, and he had a steady source of sunlight every day. Today’s scientists need LIGO and have to wait for an as-yet undertermined amount of time for a gravity wave from outer space to slither through the Louisiana swamps. But hey, you’ve got to start somewhere in the trek for godlike mastery of an entirely new wave spectrum…

11 thoughts on “Doing the (Gravity) Wave”

  1. I actually read the book a few weeks back. It was interesting, but I found it a little disappointing – mainly because it’s so immense a book and it doesn’t come to a real conclusion. Yeah, ok, we’ve gotten used to that with Harry Potter – but at least J.K. Rowling wraps up each book quite nicely…

    Also, the book has a lot of subtle and not-so-subtle references to the world of his Cryptonomicon – not least that Bishop Wilkins who features prominently in the first part of Quicksilver was the author of the original Cryptonomicon. And the family names Waterhouse and Shaftoe will be familiar, as also the mysterious island nation of Qwghlm.

    In many ways Stephenson’s book reminded me very much of some other historical fiction I’ve read recently, in particular Wayne Johnston’s Navigator of New York, and his earlier Colony of Unrequited Dreams (which happens to be about Newfoundland, where Wayne and I grew up, and which also bears a passing resemblance to Qwghlm itself). I don’t know if Johnston pioneered this stylistic approach of attaching a completely fictional character to a real historical one, but Stephenson extends it to great effect with Waterhouse and the others, attached to Newton, Wilkins, Leibniz, royalty of all sorts, and dozens of other characters from the 17’th century. It’s certainly an interesting read…

    Funnily enough, with my parents visiting recently, we dug out an old book of nursery rhymes, which included one about Bobby Shaftoe – which makes me wonder how many other cultural references I’ve missed in his books. Ah well.

    I did have to go look up when MIT was actually founded (about 150 years after the book suggests for the laying of the corner-log of the “Massachusetts Bay Colony Institute of the Technologickal Arts”). Lots of cute stuff like that in there…

  2. You’ve got to be kidding. My last comment was about the Hammy Hamster TV show for kids and the one before that was about cannibalism and genocide. There ain’t nothin’ off topic at SciScoop.

  3. Hey, my newspaper editor thinks you’d make a better book critic than those he pays to write what you said :o)

  4. …see our military enemies in the dark with infrared waves…

    I always assumed it was this way. But my friend who flies helicoptors in the Army National Guard tells me it is not so. They dont use equipment that actually senses infrared in his unit. The night vision stuff that the great majority of the army uses is actually seeing standard, visible wavelength photons. It is simply a photo-multiplication device — one photon hits the sensor, many hundreds (thousands?) are sent to the pilots eye.

    I just thought that was an interesting tidbit.

  5. …the Army does indeed use BOTH infrared systems and visible photomultiplier tubes (so-called “starlight scopes“) to see in the dark. An example of a military infrared vision system like the one I was talking about is FLIR or “forward-looking infra-red”.

  6. Hey, I’d write reviews for free books :-) Though my wife might object – we have half a dozen big bookshelves in the house, all overflowing with most shelves two books deep…

  7. Uh, nevermind.  Don’t answer that.

    Unless they’re syndicated, I’m fairly sure the other book reviewers are all local.. but, hey, I’ll ask!  And yes, you do get a free book because the review pay is lousy.  Poor wife and all the books.  But there IS something grand about owning books– especially hardbacks.

    Of course, I’ve also suggested that our fearless administrator write BRs for the local paper. After all, he IS a local.   I remember reading somewhere recently, “You can lead a spacesuited horse to frozen lunar water, but you can’t make him melt it and all that.”

  8. …is that there’s only seven people who read them. An article I write here on SciScoop gets read by high hundreds to low thousands of people. I think I stay with our hard-won readership here!!! Besides, just about the only books I really read anymore are pulp fictions that I can rip through really fast like Richard Marchinko’s stuff – I’ll read the Rogue Warrior’s latest immediately upon publication even if it IS retreaded from the last one, I love that guy. I’m currently bogged down on Quicksilver and I STILL haven’t gotten around to the latest Harry Potter in the floor by my bedside…

  9. … perfectly logical rationalization.  I was thinking time constraints more than readership, RJ.   But really, in this high tech theme park right here in AL, you’d probably pull at least 12-15 TIMES readers.

  10. After one of my GN reviews, the cartoonist offered to send me the next volume for free. As it happened in that case, I already owned vol 2, so I politely declined. I also seem to remember Drog saying Robert Sawyer’s publicist kept sending him new (hardback!) books from the publicist’s other authors for a while after the interview. So you might just try writing a review and posting it here and seeing what happens.

    The trouble with that being (from the perspective of us Sci-Scoop readers) that if you have only a given amount of time for writing submissions, your time is better spent on the kinds of things you’ve been submitting. Writing engaging and insightful articles about space science is a rarer talent than writing engaging and insightful book reviews. Of course, if you could do both (hint hint) …

Comments are closed.