A seam in the multiverse

Strange things happen at my house. Mostly computer stuff: the sound on my desktop refuses to mute when I ask — no, demand — it; printers mysteriously chat with each other in the dead of night and print out seemingly — only seemingly — incomprehensible reports on their meetings; my ebook, charged to within a nanometer of its battery’s capacity, is dead in the morning despite having been turned off, then charges up perfectly and is fine. It’s possible the ebook is an invited non-voting observer in the printer meetings, but it doesn’t seem to attend them all.

Well, ok, I thought, maybe Julian Assange is using my stuff to communicate with Putin, or something. There are oddly slow periods on the internet, and recently my router went on strike and I had to bring in a scab, which is working fine, but some of my other electronics are behaving strangely since the switch. I am willing to admit I can’t fully control my cyber-paramours. But this morning, the insurrection spread to something not even attached to the internet: my coffeepot.

My habit is to freshly grind some coffee at night before I go to bed, and get everything ready so that when I wake, all I have to do is poke a button, and Bob’s your uncle. Don’t laugh, I actually have an Uncle Bob, although he died at the age of five back in nineteen ought something or other. Anyway, this morning I smugly poked the button, ate my breakfast, and went to pour myself a delicious cuppa.

All I got was hot water.

Damn, I thought, I forgot to put in the coffee! It’s happened before, though rarely. So I opened the top, and, what the hell, there sat the filter, and in it was the proper amount of ground coffee, dry, as they say, as a bone. This is where String Theory, multiverses, and what-not come in. The design of the coffeepot is such that the heated water literally has nowhere else to go but through the coffee and into the pot, unless it clogs completely, in which case it would erupt all over the counter. Which it did not do.

You may have read a piece I posted recently about Shakespearean monkeys, in which I pointed out that, according to the theory of probability, there was no reason they couldn’t crank out, say, Henry V the minute they sat down rather than eons later. Similarly, if we are but one universe in a bubbly lather of multiverse, and if these bubbles, each containing it’s own set of physical laws, are bound to encroach on each other eventually, why not now, and why not at my house?

On the other hand, is it possible I inadvertently put the carafe, still full of water, in its place without first pouring the water in the reservoir?

Nah!

Oh, Mr. Einstein, you’re such a kidder!

So, here’s the deal:  my cousin Bert, who lives on the planet Schnipplefarq, and I have devised an experiment.  We have carefully synchronized our watches to Cosmic Mean Time.  I will leave Earth at a prearranged time in my spaceship, which travels at exactly one half the speed of light, making a bee-line for Bert’s house, where he will wait with his notebook to write down the results.  In my spaceship, I will have two items: a red laser pointer, and a high tech bean shooter capable of shooting a bean, also at exactly one half the speed of light.  At a pre-determined time, I will simultaneously point the laser at Bert’s house and press the button, and launch a bean, also at his house.

Since the speed of light is constant, according to Mr. Einstein, and the speed of the bean is relative to the speed of my spaceship, they should arrive at the same time.  Bert will have long since given up, of course, forgetting that our carefully synchronized watches will be way off, since time for me and my watch will pass more slowly than for him and his.

What should happen is that my red pointer light will arrive on time, but magically blue.  Bert, by that time, having decided that I’m hopelessly forgetful, will have put away his notebook and gone back into the house for a quick shot and a nap.  So he won’t notice when the bean also arrives at the same time, having increased to infinite mass due to travelling at the speed of light.  Which is just as well, since Bert, his shot glass, his comfy chair, and his planet will be annihilated by the collision.

Now, you might think what I find bothersome about all this is that time slows down for me, or that a bean could acquire infinite mass just by going real, real fast, but no.  Oh, it’s true that while I’m zipping along relative to Bert, he’s also zipping along relative to me, and why wouldn’t our time distortions cancel out, or that infinite mass would by definition have to include everything else out there, but that’s not it. It’s the concept of speed.

See, we happen to live on a planet that is way, way larger than we are, which gives us the illusion that it’s stationary, so when we think of speed, it’s relative to the great blob of  stuff under our feet.  If we go six mph, we mean six miles of earth has passed beneath us during an hour.  But the earth itself is not standing still.  It’s rotating at about 1,036 mph, and orbiting the sun at about 67,000 mph.  As if that’s not enough, the sun is moving through the galaxy at about 447,400 mph, and the galaxy is moving … well, you get the point.  You are really moving many, many thousands of miles per hour.  Plus six.

All of this speed, of course is relative to something else, us to the earth, the earth to the sun, and so on.  This means that it could be said that when we are moving six mph, the earth is moving that same speed relative to us.  Put another way, two cars, each going 30 mph relative to the earth, might be going anywhere from 0-60 relative to each other.

So what is the speed of light relative to?  According to Mr. E, nothing!  Or rather, itself.

Okay, let’s see.  If I wanted to measure the speed of light, I could count the number of some units of it that pass by during some time interval, like counting power poles from a train to figure out how fast it’s going.  That might be waves, but that’s dependent on frequency, and you get tautological pretty quick doing that.  Or it could be particles, but counting photons is worse than trying to figure the number of water molecules passing in a stream.  You’re left with bursts of light.  So you do that and get a good number.  Then Cousin Bert (still alive for the nonce) does the same thing, with the same bursts, while zooming past you at cosmic speeds.  And gets the same number.

What?  I don’t even know what speed means in that context.

Don’t even ask what would happen if I got the velocity upgrade for the pea shooter.

The mountains and the sea, Part 2

Ah, GPS!  What would we do without it?  Those satellites tell us exactly where we are. That’s what they do, isn’t it?

Well, not exactly.  In fact, the only thing a GPS satellite does is tell you what time it is up there.  For that to tell you where you are, two things are required: two perfectly synchronized clocks, one in the satellite and one in the receiver, and a way to tell exactly how long the signal from above takes to get to you.  The clocks in the satellites are atomic clocks; they’re be accurate for many millennia.  The clocks here are quartz clocks, like your fancy wristwatch; they’re cheaper and you can easily reset them if they get off, something you can’t do to the satellite clocks.  The satellites just send out regularly timed strings of pseudo-random numbers.  The necessary calculations to figure out where we are all done down here.  The receivers generate the same, and then compare the signals to get the lag.  Since we know the speed of light, which is the same as radio waves, calculating the precise distance is easy peasy.

A little sidebar of interest: you know those equations Einstein came up with you thought were only good for bombs and nuclear reactors?  Without them, GPS wouldn’t work worth a damn.  You see, the satellites orbit at about 12,000 miles, far enough for them to be moving significantly faster that anything on the surface of the earth.  So fast, in fact, that time actually slows down for them relative to the earth.  If you don’t take that into account, you’ll end up thinking you’re in the middle of the ocean somewhere.

Cool.  There are enough satellites (27) so that you can get at least 3 or 4 from anywhere on the planet, and can thus pinpoint your location by trilateration.  But there are issues.  The military, which originally developed GPS, also wanted to know the elevations as well as horizontal location.

Remember sea level?  Our lumpy egg of a planet drove us to turn that into an abstract surface, where all points on it had the same gravitational potential.  An easy way to think of that is to think of a surface where an object weighs exactly the same, no matter where it is (yes, if you want to lose weight, just climb a mountain).  This surface is called the geoid, and is less lumpy than earth as a whole, but lumpy all the same.  GPS gives you the actual surface of the earth, but you have to adjust that to sea level to get a useful elevation.  Shouldn’t be a problem, right?

Wrong.  Since the geoid is irregular, there’s no easy way to model it for the computers to work with.  The best we could do was a smoothish egg, kinda-sorta where we thought sea level was, but often significantly different.  What to do?  It turns out that traditional ways of measuring elevation, with spirit levels, was very, very good at arriving at the geoid.

Years ago, I worked as a land surveyor when the military was just developing GPS.  The Defense Department sent out memos to surveyors everywhere, requesting us to set up our receivers at known elevation points every chance we got, and report the official elevation along with the what the GPS receiver thought the elevation was.  It wasn’t too long before an accurate model of the geoid was available.

Now you know what that little flat box does when you tell it to go to Grandma’s house, by the mountains or the sea.

The mountains and the sea, Part 1

Rummaging through my closet, I came upon my old professor hat.  Thought I’d put it on, and write a bit about sea level.

If you’re a hiker, you’re familiar with those USGS topo sheets showing, among other things, terrain relief.  You probably also know those numbers you see on the elevation lines are all measurements of the vertical distance to sea level.  Even if you’re not into hiking, you might know the elevation of some mountain, or the highest point in your state, or the levee down by the river; same thing for them, measured above sea level.

You probably also know that the sea level is rising.  What does that do to all those numbers?

Well, nothing, actually.

It might seem that the level of the sea used to be constant, and any change is pretty recent, but there have always been fluctuations, both on a local and a global scale.

Think about something as seemingly simple as determining sea level at any given point on a shoreline.  Do you measure it during high tide or low?  Full moon or new?  What about those little ripples  of waves lapping the shore; is your measurement going to be taken at the maximum encroachment or the minimum?

Okay, fine, you say, measure all those points and use the average.  That, in fact, was originally what was done, which is why the official elevation was always given as distance above mean sea level.  Unfortunately, that doesn’t fix things.  Because, you see, you have to ask yourself, mean sea level exactly where?  The solution was to take means at various points, and average those, and so on.

What developed was a convention in which a statistical mean was taken as sea level, which didn’t correspond to actual sea level anywhere in particular.  At this point, sea level was already an abstraction, but some respect was still given to the original concept, and means were kept as close as possible to actual sea levels.  But it turned out that if you used a global mean, the numbers were too far off.  In the end, we got elevations taken with respect to various regional reference points, or datums, around the world: the North American datum, the European datum, and so on.

Confused?  How can sea level differ so much around the world?

First of all, the earth is not a sphere; it’s more like a lumpy egg.  As a result, early suggestions to use the center of the earth as a reference were useless.  Furthermore, water is not even level with respect to local elevations.  Lake Huron, for example, is 5 centimeters higher at the south end than at the north end.  This is partly due to the direction of water flow, but also in the difference in composition of what’s under it.  The iron-rich substrates in the north are denser, and therefore exert a greater gravitational pull.  These effects are compounded globally.

The result is the so-called equipotential system of sea level.  Rather than using the physical measurement of the distance from a point above another point, mean sea level is now defined as an imaginary surface on which every point measures the same gravitational pull.  The only concession to the actual level of the sea is in the name.

Of course, that used to be a very hard thing to measure.  Thank goodness for GPS satellites.

(to be continued)

Time and the swelling tide

I was just out walking in the town I live in.  An unseasonably nice day, warm and breezy, like the best days of early fall.  Then it hit me: my generation may very well be the last to experience habitable climates on most of Earth.

It is almost certainly too late to adopt enough changes to avoid disaster.  As for our social preoccupations, they are vexing, for sure, but not nearly on an order of magnitude comparable to environmental issues.  No matter how our current crises play out, how sordid or how sublime our responses to the xenophobia raging across the planet, it will all take its place in history, alongside all the ages, dark, golden, or forgotten.

If there still is history.  If the effluent we keep pumping into the air leaves us with a future, let alone history.

In a way, it’s a self-correcting problem.  Either we correct our course, which seems increasingly unlikely, or we render our planet inhospitable.  In either case, our cultures will change, and our sheer numbers will decrease, in the former case by intelligent design, in the latter by brute force.  The earth will return to its inanthropic cycles, none the worse for wear, to whatever state counts as normal.

We are far too young a species to grasp what that is.  Earth has passed through phases as diverse as completely covered with ice, an atmosphere poisonous to virtually any life, and desiccation more severe and universal than anything since we crawled out from our ancestral apes into the brave new world.  Through most of it, life had yet to occur, much less evolve, and even when it had, it clung tenuously to existence.  At least five times since it’s emergence, life has been almost wiped out.  Even our own species was squeezed through a fine and narrow filter some 60,000 years ago, when genetics point to a breeding population of Homo sapiens of less than 2,000.  Some scholars speculate that it was during this period that our evolving intelligence was given a swift kick to accelerate it, in response to the demographic crisis.

Given how that is turning out, I’m not very optimistic.  I hope I’m wrong.

C

I don’t get it. C, that is. The speed of light.

I get that it’s supposed to be constant, and I get that the idea enables us to have GPS and all kinds of other wonderments, and I don’t even wonder why, since the universe gets to have any rules it wants, as far as I’m concerned. I just don’t get what it means that the speed of light is constant. Not light itself, mind you, but its speed. An attribute trumps the thing it’s attached to.

When you’re talking about speed, the first question that pops up is, relative to what? With light, it doesn’t matter, it’s the same regardless of what it’s measured against. If I’m standing still, and you’re moving, we will still get the same reading on our cosmic radar guns. As if that weren’t enough boggle for one topic, yours would arrive a little bluer or redder than mine, because, of course, the frequency, which I would have thought had some relation to speed, is not constant.

What exactly was Einstein on about when he was talking about the speed of light? Clearly, velocity, almost by definition, is what relates time to space, so I get why it should have a central place in a theory that regards space-time as a continuum. But velocity is an attribute, dammit! It has no existence outside of the thing it is a characteristic of. How can it possibly be the root phenomenon of reality as we know it?

Then again, I still don’t understand airline pricing, so maybe such things are just beyond my grasp.

Wilderness revisited

It’s a crazy world.  The other day, I decided to go for a walk; it was the first gorgeous day after a period of rain, and utterly irresistible.  I ended up at the city library, one of those Carnegie structures so ubiquitous in small and medium towns across America, a millionaire’s atonement for ravaging society, back when such people even cared.  This particular one sits in a little park with a bandstand and a monument to a parents’ grief for their soldier son, killed in action.  It has the added virtue of offering coffee from one of those Keurig pod machines for fifty cents.  Pretty good coffee, too, and you get entertained by the myriad characters that hang around such places.

It was, as I said, a beautiful day, so I took my coffee outside, to sit by the fountain donated by another benefactor to the glory of his family.  It was windy, so it was just as well the fountain was off.

Just as I settled in, I heard an animal running somewhere behind me, a large dog, I thought.  As it passed in front of me, though, I was startled to see a young deer bounding headlong toward the midday traffic.  It’s not a huge town, but the streets along the park run to four lanes, and I worried that the deer wouldn’t make it without getting pancaked against a cement truck.  No problem.  In a flash, it cleared six lanes, including a side street, and disappeared into an adjacent church parking lot.

Now, those with a mystical bent might see an omen of some kind here.  Me, I just reflected on the fact that our town, these days essentially just a suburb of St. Louis, has grown very rapidly, outstripping its sleepy county seat days, and leaving nearby wildlife precious little room for, well, wild life.  Ironically, as habitat shrinks, so does the taste for hunting among the minions of the town, now pretty much gentrified and unused to killing their own food.  Canada geese, which used to pass here twice a year during migration, now stay year round in the many ponds dug for all the wilderness-sounding suburbs (Iron Mountain Lake, Notting Hills Forest, etc.).  People complain about the scat, but eating the birds is illegal, so they thrive.  As do wild turkeys, of all things, frightening toddlers in their own yards.

This is happening all over the country, as demographic studies continue to show the increasing urbanization of America.  At least we don’t have bears where I live; that would, indeed, be a portentous omen.

I suppose the upshot is that wherever you might find omens, there is usually a practical element involved as well.  I’m reminded of a student I had while doing archaeology on the island of Ithaka, in Greece.  It was, of course, the home of Odysseus, and we were at the foot of Mount Aetos.  My student, who was supposed to be paying attention to a prism pole he was holding, looked up and cried, “Hey, what kind of bird is that?”

I looked where he was pointing, to his left.  “It’s an eagle,” I said, “and it’s to your left.  According to Homer, that’s a bad omen.”

“Oh,” he said, and turned around until it was on his right.