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It is now a month until the total solar eclipse of 2017 (on August 21) when the Moon will completely block the sun. This rare event will be visible across the United States, though there is an actual line it will travel across the U.S.

Have you already seen a total solar eclipse? Probably not. Though some have occurred in the past 100 years, if you lived in the U.S. they were either not visible or only in a few locations. The last one was in 1991.  There are many kinds of eclipses – total , partial, annular etc.  I have written here about other solar and lunar eclipses. To witness a total solar eclipse means to see your piece of the world in darkness during daytime and feel the temperature dramatically drop.

The media is calling this the Great American Total Solar Eclipse (which sounds like a ride at an amusement park) but it will darken skies all the way from Oregon to South Carolina. The path of totality is about 70 miles (113 kilometers) wide. Don’t plan on driving along the path to follow the eclipse. It will move at about 1500 mph.

You may have seen stories in the media about the event and about towns that are planning celebrations  –  and booking accommodations, selling t-shirts, eye protection etc.  If you are in the path of totality, then you will need eye protection, and any viewers should use protection.

A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partially obscuring the image of the Sun for a viewer on Earth. A total solar eclipse occurs when the Moon’s apparent diameter is larger than the Sun, blocking all direct sunlight, turning day into darkness.

Totality always occurs in a narrow path across the surface of the Earth for that portion of the planet in daylight.

In my neighborhood, there will not be totality but it will be 73% blocked. It will begin at 1:22 pm, peak at 2:44 pm and end at 4 pm.

Imagine the fear and confusion any eclipse must have created to the ancients. A total solar eclipse would be the most frightening of all eclipse.

John Fiske wrote back in 1872 in his book Myth and Myth-Makers that:

…the myth of Hercules and Cacus, the fundamental idea is the victory of the solar god over the robber who steals the light. Now whether the robber carries off the light in the evening when Indra has gone to sleep, or boldly rears his black form against the sky during the daytime, causing darkness to spread over the earth, would make little difference to the framers of the myth. To a chicken a solar eclipse is the same thing as nightfall, and he goes to roost accordingly. Why, then, should the primitive thinker have made a distinction between the darkening of the sky caused by black clouds and that caused by the rotation of the earth? He had no more conception of the scientific explanation of these phenomena than the chicken has of the scientific explanation of an eclipse. For him it was enough to know that the solar radiance was stolen, in the one case as in the other, and to suspect that the same demon was to blame for both robberies…

The Summer Solstice for 2017 in the Northern Hemisphere happened here at 12:24 AM EDT today, Wednesday, June 21.  Did you miss it?

I was still awake, but I didn’t feel anything odd. Due to those manmade time zones, it happened yesterday Tuesday, June 20, at 9:24 PM on the other coast. And it is only the Summer Solstice in the Northern Hemisphere. It is the Winter Solstice in the Southern Hemisphere.

In any case, the Sun reached its northernmost point from the equator.

Solstice is from the Latin solstitium, from sol (sun) and stitium (to stop). It did seem to earlier observers that the Sun appeared to stop at this time and then again to announce the winter solstitium.

In ancient Egypt, this solstice marked the start of the new year. They watched for the rising of the star Sirius which occurs around this time and it coincided with the annual flooding of the Nile River.

The halfway point between the spring equinox and the summer solstice was on May 1. That day is known as May Day or Beltane and it marked the beginning of summer for the ancient Celts. It was a day for dance and song to celebrate that the sown fields were starting to sprout.

This is the day with the most hours of sunlight during the whole year – even if it is rainy and cloudy where you are reading this. Here in Paradelle, dawn broke today at 3:18 A.M., the Sun rose at 5:25 A.M. and it won’t set until 8:32 P.M. giving us 15:06 hours of sunlight.

If we were on Mercury, which has practically no tilt relative to the plane of its orbit, we wouldn’t experience any true seasons. Bummer. If we were on Uranus, which is tilted by almost 98 degrees, the seasons would last 21 years. Also a bummer.

If I lived in Sweden, it would be traditional to celebrate this day by eating the first strawberries of the season. Since we just passed the Strawberry Full Moon, and since strawberries never go out of season in Paradelle in this age of supply chain eternal summer, I’ll have some strawberries myself today.

 

One of my daily web stops is EarthSky which reminded me that this is one of the few times of the year that 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 only 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 markings 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.

Copernicus Armillary

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. But I did find some online for less than a hundred dollars so maybe…

This post first appeared on One-Page Schoolhouse

Whether it feels or looks like spring or like winter outside your home today, spring is officially here. It slipped under my pillow while I was still asleep this morning at 6:28 am ET here in the Northern Hemisphere.

Our ancestors my not have understood what was happening to our planet from a celestial viewpoint, but they were more careful observers of the world around them and definitely marked today as something significant. Ancient observers built devices, buildings and places like Stonehenge to measure and mark changes in the Sun’s movements. Of course, that was what they thought was happening – that the Sun was moving closer or further from Earth. They may have been wrong on that part, but they were able to mark that today was midway between the sun’s lowest path across the sky in winter and highest path across the sky in summer.

Though we visualize an equinox as occurring on the imaginary dome of Earth’s sky, it is a very real point on Earth’s orbit that is halfway between the two extremes of the sun’s path in your sky. “Your sky” because though the equinox occurs at the same time for all of us. The seasons are based on whether you are in the Northern or Southern Hemisphere.

One thing you can observe easily at each equinox (no Stonehenge required) is that the sun rises due east and sets due west from where you live. An equinox happens when the ecliptic – or sun’s path – intersects the celestial equator, that imaginary line above Earth’s equator.

Go outside around sunset and sunrise and notice the location of the sun on the horizon with respect to local landmarks. You can then use those landmarks to find those cardinal directions in the months ahead and observe how the sunrise and sunset points move southward or northward. I showed my young sons this many years ago by crudely tracking the sunrise moving from window to window during the year from the vantage point of our East-facing family room. It was a pretty interesting lesson in science.

Today the sun is on the celestial equator. It may be springlike outside or it may still seem like winter, but the new season has arrived.

 

 

sun500nc

The year just started but just a moment ago (22:49 Universal Time, 5:49 p.m. EST) Earth reached its closest point to the Sun for this year. We are at Earth’s perihelion (Greek peri “near” + helios “sun”).

Nothing extraordinary about this. Earth is closest to the sun every year in early January. This is isn’t why we moved into winter in the Northern Hemisphere. That is from the tilt of the planet, not the distance. In fact, we will be farthest away from the sun in early July, during our summer.

How much closer? About 3 million miles (5 million kilometers) closer. Big numbers but relatively not a big change in distance. Still, it wouldn’t be a bad idea to acknowledge the big star’s presence today. It’s already dark here in Paradelle, but the Sun is out there keeping us alive even on these wintry and cloudy days. Thanks, Helios!

A paper by a team of astronomers has folks talking about aliens – even though the paper never really discusses aliens. I find it intriguing, but, for me, the real thought experiment is something I will conclude with here.

These astronomers found an odd star that behaves in a way that is difficult to explain. The star is boringly called KIC 8462852. (Astronomers need to work on their naming conventions. “Death Star” would have been much better.) NASA’s Kepler mission has found this and many other stars. The brightness of this star dips, as do many stars. There is a slight dimming when a star has planets that orbit it and pass directly in front of the star as seen from Earth or the telescope. That is called a transit. The brightness dips about one percent or less. It is a way that exoplanets have been found. The dip will be periodic, repeating every few days, weeks, or months, depending on the size of the planet’s orbit.

KIC 8462852 is bigger, hotter and brighter than our Sun, but too faint to see with the naked eye. The dips in the light from it are not periodic but arbitrary and sometimes drop by 15 or 22 percent.

That’s not from a planet. Even a big Jupiter-sized one would only knock out that 1 percent of the starlight. But whatever it is, it’s big – maybe half the size of the star. I remember from elementary science class that you could fit more than a thousand Earths inside the Sun. Very big something out there.

The scientists probably suspected the furor and buzz this would get in the press and included obvious causes that can be eliminated. It’s not a flaw in the telescope, or debris from a planetary collision or a series of comets orbiting the star.

aliensWhat explanations remain?

Physicist Freeman Dyson popularized the Dyson Sphere (not a fancy rolling ball vacuum cleaner) which speculated that we (or some aliens) might build thousands of gigantic solar panels and put them in orbit around their Sun to power the planet. This could expand until you had a gigantic sphere that completely enclosed the star.

It sounds like something from sci-fi (and it was in an episode of Star Trek: The Next Generation). This sphere would be dark in visible light but emit a lot of infrared light.

Have we observed an advanced alien civilization building a huge solar collectors?

An article published in The Atlantic by Wright and Boyajian is what has Internet-popularized this topic.

This is the dream of those who use radio telescopes to look for signals from out there and SETI (Search for Extraterrestrial Intelligence) and all the alien watchers and those who hope to make contact. (Yeah, watch the movie or read the book by that name.)

Here’s my big takeaway. The light we are seeing is 1500 light years away. If they were building 1500 years ago, I suspect that they are done by now. And if they are watching us, they are seeing us in about 505 A.D. We certainly look like a bunch of dopes who could easily be conquered, on a nice planet with water and resources. Do we really want to find them or have them find us?

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All around I fear that Jonathan's (and most modern) satire is lost in a world that is itself a satire. The corporation side. All fall down The chenille is blooming its odd flowers again. It's August in NJ.

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