Times of Day

Why did humans need fixed times of the day, like "noon" and "midnight"? 

I was wondering about these terms and writing a post for my origins blog, and came across additional information beyond etymologies that I'll post here.

There are several answers to why humans needed fixed times of the day. We love to organize things, and communal life included religious rituals, markets, work schedules, and meetings, and those needed a shared system of timekeeping. 

Times of day allowed long-distance coordination as societies expanded and trade increased, people needed consistent points of reference—even if the Sun wasn’t visible.

Things like contracts, taxes, leases, transportation, and recordkeeping all require clear definitions of when one day ends and another begins. 

These official - and eventually precise - times of day enabled scientific and navigational progress since astronomy, calendars, and navigation at sea relied heavily on precise solar measurements—especially noon.

fixed times of day like noon and midnight to organize life around the natural rhythms of light, darkness, and the movement of the Sun. These terms didn’t appear all at once—they evolved over thousands of years as people developed more precise ways to measure time. 

Noon originally meant the moment when the Sun reached its highest point in the sky. This is now called "solar noon." This was a natural reference point for early societies: The Sun’s highest point was a dependable daily marker. It divided the daylight into “before” and “after.” Farmers, travelers, priests, and traders could all use it to coordinate activities. 

In ancient civilizations — Egypt, Mesopotamia, Greece, and Rome — solar noon was the anchor for their earliest "clocks" (like sundials). Even when mechanical clocks arrived in the Middle Ages, they were adjusted every so often to match the actual solar noon. 

 The word shifted over time: In medieval Latin and Old English, nona meant the ninth hour after sunrise (about 3 p.m.). Over centuries, the prayer schedules of monks shifted, and by the 14th–15th century, English speakers were using noon to mean 12:00.

Midnight is the natural opposite of noon, and after noon was defined as the midpoint of the daylight period; it made sense to divide the entire 24-hour cycle into two halves. Midnight became the point exactly opposite solar noon. A convenient boundary between one day and the next, and it was a reference point for the start of calendars, laws, and later, timetables. 

Before mechanical clocks, people didn’t think much about precise (hours and minutes), and night was divided into “watches,” or segments, mainly for keeping guard. Mechanical clocks (1300s onward) made a precise 12:00 a.m. possible. When time zones were standardized in the 19th century for railroads, midnight officially became the start of the civil day.

Time in Three Dimensions

This is way beyond my high school and college science, but I find this kind of theorheticaal physics fascinating. Physicist Gunther Kletetschka proposes a radical shift in how we understand reality. The universe may have not one, but three dimensions of time. This 3D time framework could help solve one of physics’ biggest problems — reconciling quantum mechanics with general relativity.

I was taught in school to think of time as a single river that always flows in one direction. Kletetschka offers a very different idea. What if time actually has three separate directions, much like the three directions of space? In his view, each “axis” of time operates at a different scale — one for the tiny quantum world, one for everyday life, and one for the vast structure of the universe.

By splitting time this way, his math can connect phenomena that usually don’t fit well together — from the strange behavior of particles to the way the universe expands — all without breaking the familiar idea of cause and effect.

One reason this theory is gaining attention is that it doesn’t just sound interesting; it matches real numbers. It correctly reproduces the known masses of particles such as electrons and muons, and even offers predictions for things we haven’t measured precisely yet, like the masses of neutrinos and the exact speed of certain gravitational waves. Those predictions mean scientists can actually test the theory in the future.

Kletetschka also flips our usual picture of space-time. Instead of imagining space and time woven together as equals, he suggests that time is the fundamental “canvas,” and space forms on top of it — more like the paint than the canvas. If this idea holds up, it could lead to an entirely new way of understanding the universe and how everything in it fits together.

Don't get to far off course. Having three directions of time doesn’t mean time travel or rewinding the past. Instead, it means that different processes can unfold along different time paths, allowing for multiple outcomes without violating the flow of cause and effect.

What makes the proposal especially intriguing is its goal: unifying the two major pillars of modern physics. Quantum mechanics explains the very small, while general relativity explains the very large — and the two theories don’t naturally agree with each other. By rebuilding the foundation around three-dimensional time, Kletetschka hopes to create a model that works smoothly for both.

Unlike many past theoretical attempts that stayed theoretical, this theory points directly to experiments that could confirm or reject it. That makes it a serious candidate in the ongoing quest for a single, unified understanding of how reality works. If the theory is eventually proven correct, it would mean that matter, energy, and even the forces of nature are all expressions of how three-dimensional time bends and flows. It could spark a major shift in how we imagine the cosmos and our place within it.

"...results have not yet been accepted by the broader scientific community. The theory is still in the early stages of scrutiny..."

And what does this have to do with consciousness? 

 

Always a good idea to be a bit skeptical of new theories...

Gunther Kletetschka, "Three-Dimensional Time: A Mathematical Framework for Fundamental Physics", Reports in Advances of Physical Sciences Link DOI: 10.1142/S2424942425500045

When Black Holes Collide

That is not a headline I would think we would not want to see, but astronomers have detected the largest merger of two black holes to date via measuring gravitational waves. The collision produced a single black hole roughly 225 times the mass of the Sun.

A post at caltech.edu says that the signal, designated GW231123, was detected during the fourth observing run of the LVK network on November 23, 2023. I didn't feel a thing back then - or since.

These points in space, whose gravitational pull is so strong that nothing escapes (including light), form when very large stars run out of fuel in their cores. The object collapses in on itself, shrouding the core in an incredibly warped region of spacetime. That's why they are sometimes theorized to be a way to travel through time. At least, in science fiction tales, the idea of a wormhole works.

Being a time travel fan, I like this hypothetical structure that connects disparate points in spacetime. One way to visualize it is as a tunnel with two ends at separate points in spacetime (i.e., different locations, different points in time, or both). 

A wormhole visualized as a two-dimensional surface.
Route (a) is the shortest path through normal space between points 1 and 2.
Route (b) is a shorter path through a wormhole. 
Image: MikeRun, CC BY-SA 4.0, Link

Wormholes are based on a special solution of the Einstein field equations. It's not helpful to me but, more precisely, they are a transcendental bijection of the spacetime continuum, an asymptotic projection of the Calabi–Yau manifold manifesting itself in anti-de Sitter space.

The existence of black holes was first theorized by Einstein in 1916, predicted by his theory of general relativity. The theory posited that what we experience as gravity is actually the effect of mass curving space and time—in the case of black holes, it's curved to the point where light is effectively "stuck" inside.

The event horizon is the term for the boundary of a black hole beyond which light can't escape.

Black holes are probably fairly common on a universe level. Scientists estimate there are 40 quintillion (1 quintillion equals 1 billion billion) black holes in the universe, none of which can be seen directly. Instead, their effect on nearby objects reveals their presence, indicating properties like size and spin. The pull of black holes can cause nearby matter to superheat, emitting X-rays detected on Earth. This is how the presence of Cygnus X-1, the first confirmed black hole, was detected in 1964.

The first-ever "image" of a black hole was published in 2019 by the Event Horizon Telescope, capturing the light bent around the object. The black hole is located 50 million light-years away in the M87 galaxy.

When the Sun and Clock Agree

One of my daily web stops is EarthSky which reminded me that this is the time of year that for a few days clock time and sun time agree. As someone who has a sundial in the garden since childhood, I do pay attention to that shadowy movement.

When the midday sun climbs highest today, if you have a sundial, it will read 12 noon and your local clock will also read 12 noon.

I have always had a sundial in my garden. It keeps me in touch with the movement of the Sun during the day and during the seasons.

Of course that pesky daylight savings time game we play might make your clock say 1 pm today when the sundial says noon. It's all so confusing.

Your local clock time is standard clock time, as long as you live on the meridian that governs your time zone. Denver and Philadelphia, for example, are on the meridian for their respective time zones. East of the time zone line, then your local time runs ahead of standard time and west of the time zone line, local time lags behind standard time.

The sundial and clock agree four times a year: on or near April 15, June 15, September 1 and December 25.

My simple sundial shows a shadow from its style onto a surface marked with lines indicating the hours of the day. The style is the time-telling edge of the gnomon, the straight edge. As the sun moves across the sky, the shadow-edge aligns with hour-lines.

There are plenty of sundials available to you at a wide variety of prices and complexities.

Sundials that directly measure the sun’s hour/angle must have that edge parallel to the axis of the Earth’s rotation to tell the correct time throughout the year. My simple one needs some adjustments during the year and I do play with time and move it to match my clock time every once and awhile.

Isaac Newton had a pretty interesting variation on the sundial. He used a small mirror placed on the sill of a south-facing window. The mirror would cast a single spot of light on the ceiling and, depending on the geographical latitude and time of year, the light-spot on the ceiling was pretty accurate to the marking he made.

I think it's a good idea to pay attention to the cycles in our lives, both natural and man-made. They are very much a part of us, whether we pass attention to them or not.

I would not mind having a Copernicus Armillary (above) in my home, though I suspect my wife would not think it appropriate to our decor - and might not appreciate me paying $3000 for it. It is an astronomical instrument that would have been found in libraries and laboratories of the past. I did find some online for less than a hundred dollars so maybe...

More on sundials at Weekends in Paradelle 

Into The Dark Flow

Centaurus

First dark matter and dark energy. Now, we find parts of our universe moving at very high speeds and in a uniform direction that can't be explained by any of the known gravitational forces in the observable universe. Astronomers are calling the phenomenon "dark flow."

Dark flow is the name given to the motion of galaxy clusters with respect to the cosmic microwave background radiation which should be randomly distributed in all directions. But it is not - a three year study concluded in 2008 that there was a common motion of at least 600 km/s toward a 20-degree patch of sky between the constellations of Centaurus and Vela.

This dark flow must be outside the "observable universe."

The "observable" universe doesn't actually mean as far as we can see with a powerful telescope. There's a fundamental limit to how much of the universe we could ever observe, no matter how big the telescope.

If the universe formed about 13.7 billion years ago, and light started traveling toward us immediately after the Big Bang, the farthest it could ever get is 13.7 billion light-years in distance. So, if there are parts of the universe that are farther away, we can't see farther than light could travel over the entire age of the universe.

One theory is that the motion results from the influence of no-longer-visible regions of the universe prior to inflation. (Telescopes cannot see events earlier than about 380,000 years after the Big Bang, when the universe became transparent.)

Another theory is that it is the gravitational influences of other universes.

Vela is a constellation of the southen sky (in the illustration it is at left center) and the word is Latin for the sails of a ship. It was originally part of a larger constellation, the ship Argo Navis. The larger constellation (shown here) was later divided into three parts, the others being Carina and Puppis.

Time Machines

When I was in second grade, I saw the film The Time Machine at a drive-in theater. It was directed by George Pal, starred Rod Taylor, and was released in 1960. It was scary. It was cool. It had "primitive" special effects by today's standards. But I loved it.

Eventually, it sent me to the library to get the novel by H.G. Wells. Twenty years later, I taught that book to a bunch of like-minded seventh graders that I had lured into reading its very 19th century pages with very 21st century imaginings about traveling through time.

Then, the summer after fourth grade, I tried to build a time machine in my own basement. I had a "lab" in a old coal bin that was full of chemistry sets, rockets, rocks, any tool I could find, model car kits and salvaged electronic components.

I had no idea where to start or what to do, but I just went at it. (Years later, I would jealously watch ET do the same kind of thing successfully.) I have never lost my fascination for time travel.

Last May, artist Paul St George exhibited an outdoor interactive video installation linking London and New York City in a faux "telectroscope."

Unfortunately, I only found out about it after it was over.

Of course, it wasn't any more real than the ones from earlier centuries - but it "worked."

It had a fictional "back story" that said that the device worked by using a transatlantic tunnel started by the artist's fictional great-grandfather, Alexander Stanhope St. George. People looking in one end in NYC could see and hear those at the other end in London.

telectroscope photo via my Flickr friend urbanshoregirl

I like the term "distant seeing" that was attached to the invention and has remained.

The installation art actually used a visual high speed broadband link between London and New York City that did allow people to see across the ocean.

You can't really call any of these "television systems" or "time machines." And the term telectroscope was replaced by the term "television." But, looking back at the original 1870s imaginings, it sounds like they were describing television or the Internet - or some merging of the two that is in progress right now.




Go Deeper

• Paul St. George's Telectroscope Project
• http://en.wikipedia.org/wiki/Telectroscope
• The Telectroscope Project Blog
• BBC News video of the Telectroscope Project
• Telectroscope Video from New York City