Why dont we use sundials anymore

In the garden of Tudor Place, the house museum in Georgetown, an 18th-century sundial is framed by a saying that begins: "With warning hand I mark time's rapid flight."

Except, it doesn't. Or not with any useful precision.As anyone who has purchased or admired sundials knows, they look great but are lousy timekeepers. In theory, the shadow cast by the upright marker is supposed to fall on a horizontal dial divided into hours. As the sun crosses the sky, the shadow moves around the face to the appropriate marked hour. But don't set your watch by it.

"They are garden decorations," said Dave Kreiner, a sundial maker in Cedarburg, Wis. "They have nothing to do with telling time." Kreiner, who owns a company called Accurate Sundials, is among a cadre of sundial experts who, separately, are trying to restore the sundial as the precise celestial instrument it once was.

The problem: Sundials must be tailor-made for their location, and generic antique reproductions are not. Instead, they are built typically to show time at a latitude of 40 degrees, roughly the midline of the United States between Philadelphia in the east and Northern California in the west.

This may not matter to people drawn to the garden to escape the clock, who find a sundial merely a gracious ornament and are charmed by the notion of tracking the loose passage of the day as told by the sun. The same plume of fountain grass ignited by the morning sun forms dark blades with dazzling edges toward twilight. That connection to the natural world is much of the value in gardening.

But the sundial's laxity does matter to others, especially because it can be fixed. "Everyone is fascinated when they see a sundial actually working," said Frederick W. Sawyer III, president of the North American Sundial Society. "In the home garden, it would be nice for people to set them up so they actually work."

You can make a mass-produced sundial a little more accurate by correcting its orientation north, and even tilting the pedestal it is on, but for one of far more accuracy you will need to get a better dial.

First, the angle of the sundial's slanting shadow maker, which is called a gnomon, has to match the latitude it is in. The angles between the hour marks must also be arranged for one's latitiude.

Also, the noon mark on the dial must be oriented to true north.

Even then, the sundial will not precisely match the clock. Every day, the sun reaches its high point in the sky, the moment known as the meridian: Hence the designation of a.m. (ante meridiem) and p.m. (post meridiem). The meridian occurs at a different moment within a single state, or even a single ZIP code.

Time zones were invented in the 19th century to bring uniformity in an industrial age, and each of the world's 24 time zones has one fixed average meridian. In the Eastern Standard Time zone, it is at longitude 75 degrees west, just to the east of the Delmarva Peninsula. Hence we now exist in two temporal worlds: sun time and clock time.

"Our mentality changed at the beginning of the 20th century," said Sawyer. "It's another way of noticing how we are being removed from nature."

Kreiner seeks to correct sundial accuracy with gnomons and dials customized to specific locations.

Look at his Web site, www.accuratesundials.com, and you will see how dials and gnomons differ by state. Models in aluminum, copper, brass and granite range in price from $259 to $599.

They are made either to record standard time or daylightsaving time; he recommends the latter because most people are in the garden in summer. You cannot simply rotate a sundial pedestal to put your sundial forward or back.

Even a sundial built for your garden does not account for another variable of solar time: The sun does not keep a precise 24-hour day. Sometimes it is early, sometimes late, by a few seconds or minutes depending on the time of year. This is related to the Earth's tilted axis and its elliptical orbit around the sun. For sundial scholars, this produces something called the equation of time, and it means that even an accurate sundial will gain 16 minutes in the weeks leading to Halloween and lose almost 15 minutes by Valentine's Day.

It is a variation of little consequence either to the sun, the Earth or, for most of human history, the people upon it. Even when we tried hard to measure time with such things as primitive sundials and, later, clocks, solar time remained something to be regarded and followed. When you bought a wind-up clock in the 19th century, you got a little sundial to place on your windowsill so that each solar noon, you could correct the errant mechanical timepiece, said Sawyer.

Now, though, as we strive for ever greater precision, it is solar time that is faulted for its inaccuracy. Indeed, we care not for solar noon anymore, but set our clocks by an atomic chronometer in Boulder, Colo., that measures time by aiming lasers at a fountain of cesium atoms and getting them to glow back. Its owner, the National Institute of Standards and Technology, says it is accurate to within a second every 20 million years. It is the godclock, bestowing truth and purpose on all other timepieces.

But just as clocks can be improved, so can sundials. Sawyer, a retired actuary in Glastonbury, Conn., has devised a sundial within a sundial: Its inner scale measures sun time, the outer one clock time.

The sundial at Tudor Place, a mansion built by the Peter family, was retrieved from the Peter's ancestral home in Scotland in the early 20th century. It forms the centerpiece of the boxwood knot garden. Robert Kellogg, a physicist from Rockville, Md., and registrar of the sundial society, said members of the society calculated that the hour markings were geared to around 48 degrees north, nowhere in the British Isles but close to Augsburg, Germany. "Of course," he said, "it would never tell time" correctly in Scotland or Georgetown.

This does not diminish its delight as the decorative heart of a formal but serene and relaxed pleasure garden.

Sun time may be fast and loose, but as an inscription on a sundial at the historic Hampton estate in Towson, Md., points out, it is still "more sacred than gold."

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You read that right: sundials. According to an article in The Telegraph, sundials are at risk of dying out.

This will come as shocking news, no doubt, to anyone that thought sundials had already died out, which is everyone.

Nic Brunetti, the author of the article and most bored journalist currently employed on the planet, spoke to Dr. Frank King of Cambridge about the rapidly diminishing … industry, I guess? … of sundials. Let’s take a journey.

Frankly (ha), that seems like more than we need. Sundials are not important in any sense of the word.

I’m not a scientist, but I’m pretty sure that Dr. King is overstating the complexity of a sundial just a tad. Not only do sundials (invented in ~1500 BC) predate trigonometry by a good 1200 years, according to Wikipedia, but I’m 99% sure I made a sundial in elementary school by putting a pencil through a paper plate.

How was I able to do that? Because sundials are not that complicated. Here’s a rough guideline for how to make a sundial:

Put a stick in the ground
Draw a line due north from that stick. If you don’t know which way north is, use a compass (a far more modern invention than the sundial)
Write a “12” next to that line
Wait an hour, then write a “1” next to that line
Etcetera.

That’s most of it. The ancients didn’t have compasses, so they had to wait until the sun was at its highest, which they did by marking the shadows cast by the sun until they figured out which shadow was shortest, at which point they called that whatever the ancient Egyptian word for “noon” was.

This has nothing to do with telling time, but how would you know?

Then, of course, the ancients would have noticed that their sundial markings from the summer didn’t line up in the winter when the sun is lower and days are shorter, so they would have drawn all these complicated curves to explain the variations of the seasons.

You’ll notice that this is unreadable, not just because it’s too complicated but because it’s cloudy.

Does that sound mind-bogglingly tedious? That’s because it was. You see, once ancient peoples figured out how to farm, they could delegate food production to a few people instead of everyone, giving the intellectual elite enough free time to stare at a fucking stick all day for months on end.

Keep in mind that the Egyptians, who invented the sundial, didn’t even need it. They had already invented hourglasses and similar devices called “water clocks,” in which you put a bowl with a hole in it into a basin of water. The bowl fills up and when it sinks, an hour (or whatever) has passed.

Which brings me back to the supposedly rigorous mathematics required to build sundials. Sundials aren’t complicated, they aren’t necessary, they’ve literally never been necessary, and also, is Dr. King aware that we still teach math?

I took algebra, trigonometry, and geometry in school. So did millions of other people. All that math is still out there in the banks of human knowledge. If all memory of sundials suddenly vanished from human history tomorrow, and then someone thought “let’s make a way to tell time from a stick,” we could definitely figure it out.

YOU DON’T SAY. “Hey kids! Check this out! It tells time, but not when it’s cloudy or in the night time. And it’s only accurate to about 10 minutes. And you can’t move it or it won’t work any more. Sure, other clocks can tell you the phases of the moon, the day of the week, and give you more precise readings than “two-ish,” but can they be constructed by a cave person? THEY CANNOT.”

But Dr. King isn’t going to sit back and let sundials be lost to the annals of history like the trebuchet or the Archimedes screw or the astrolabe (all of which are much more recent inventions and yet, still, obsolete because obviously). Why? Because sundials are still super important, guys.

…what?

WHAT?

Listen, I’m not a trained mental gymnast, but I’ve been a keen spectator of the sport for years. I’ve watched people contort their minds into the most stupendous shapes for the sake of an argument, so I’m usually pretty good at connecting the dots between two points in an argument.

Dr. King has stumped me. I cannot, for all my experience, figure out how he thinks that “the mathematical insight is akin to the one used for GPS technology.” First of all, instrument-aided navigation didn’t start to show up in human history until the 1200s —roughly 2500 years after sundials were invented. If they were somehow useful for navigation, you’d think the Egyptians would have figured that out earlier.

Secondly, GPS uses timed electromagnetic signals from satellites to base stations on Earth. That signal needs to be precise to a few nanoseconds. It’s so sensitive, in fact, that general relativity has to be taken into account — clocks run slower nearer to the earth than farther away, and that difference matters.

Ignore the technological barriers of getting a satellite into space — just the very idea of satellite-based navigation requires levels of math that weren’t even conceived until the 20th century.

Which brings me to my last point. Dr. King says there are fewer than 100 sundial experts in the world, right? He also says that in their “heyday,” there were upwards of 600, which is also a small number. So if we’re running out of sundial experts, how the fuck are all these GPS satellites and self-driving cars doing so well? Could it be that the hundreds of people in the Air Force’s 2nd and 19th Space Operations Squadrons, the ones responsible for keeping GPS satellites in the air — and the thousands of people that had to develop the system and get the satellites in the air — also know some math?

And that’s not to mention the thousands of people and billions of dollars being poured into self-driving cars by companies like Tesla, Uber, and Google. How many sundials have the collective employees and investors of those built? I don’t like to speculate, but it’s zero.

Sorry, Dr. King. Sundials are dying, and you know what? That’s probably fine.