Saturday, August 29, 2015

First Flower

Intact specimen of
the fossil montsechia
Photo by
Bernard Gomez
Paleobotanists have identified an extremely early aquatic flowering plant montsechia vidalii in its fossilized form.

The 125 to 130 million-year-old fossil provides a record of one of earliest known flowering plants on Earth ― a mythical first flower present during the age of dinosaurs.
"A 'first flower' is technically a myth, like the 'first human,'"
David Dilcher, Paleobotanist
Montsechia has the rudimentary characteristics of a flowering plant, also known as an angiosperm.
"Montsechia possesses no obvious ‘flower parts,’ such as petals or nectar-producing structures for attracting insects, and lived out its entire life cycle under water. The fruit contains a single seed which is borne upside down."
David Dilcher
Montsechia produced seeds within a carpal, the female reproductive organ of a flower. Carpals are a component of the gynoecium which is the term that describes the parts of a flowing plant that develop into the fruit and seeds. Gynoecium is a composite word from the Greek words gyne, meaning woman, and oikous, meaning house.
"There’s still much to be discovered about how a few early species of seed-bearing plants eventually gave rise to the enormous, and beautiful, variety of flowers that now populate nearly every environment on Earth."
David Dilcher


Saturday, August 22, 2015

The Perseids

The Perseids are meteor showers observed in mid-August. Meteors or shooting stars are cosmic debris entering Earth's atmosphere at high velocity leaving a trail of burning gases observable in the night sky.
There was a star riding through clouds one night, & I said to the star, 'Consume me'.
Virginia Woolf, The Waves
Perseid meteor shower.
NASA/Bill Ingalls, Aug. 13, 2015

The Perseids are named after the constellation Perseus which is the area in space where the Perseid meteor shower emanates from, also called the Radiant. The word Perseids is derived from the Greek Perseides (Περσείδες) referring to those born of Perseus. In Greek mythology, Perseus is the son of the Zeus (god of the sky).

The Perseids occur as Earth's orbit intersects a band of debris left behind by comet Swift-Tuttle.

Sand-sized debris shed from the comet collides with Earth's atmosphere at speeds on the order of 130,000 miles an hour. The swift decrease in velocity, some 130,000 miles per hour of kinetic energy, transfers to the air molecules on impact causing the molecules to lose electrons.

The particles vaporize in streaks of light. The glowing streak is ionized air.
My dad took me out to see a meteor shower when I was a little kid, and it was scary for me because he woke me up in the middle of the night. My heart was beating; I didn't know what he wanted to do. He wouldn't tell me, and he put me in the car and we went off, and I saw all these people lying on blankets, looking up at the sky.
Steven Spielberg


Saturday, August 15, 2015

Faces Near and Far

Near side of the Moon
With tidally induced synchronicity, the Moon exposes the same face to observers on Earth. The face we see is called the Near Side. The Far Side is never visible to observers on Earth.

The Man in the Moon

The Near Side of the sunlit full moon is observable from earth every 29.5 days. The full moon reveals dark areas (lunar maria) corresponding to basaltic plains and lighter areas corresponding to highlands.

Over the ages humans have recognized pareidolic visages of human faces, heads or bodies. The familiar face of the moon has evoked various Man in the Moon mythologies. Illustrations in western art often depict a simple smiling face in the full moon or a caricatured human profile in the crescent moon.

Synchronous Rotations

The Moon exposes the same face on Earth because of a phenomenon interchangeably called tidal locking, gravitational locking, or captured rotation.

Tidal forces on Earth have slowed the rotation of the Moon so that Earth and the Moon have synchronous rotations. Specifically the Moon makes a full rotation about its axis in about the same time it orbits Earth (depicted below on the left).

Rotating Moon orbiting Earth
Not to scale
Moon with no rotation orbiting Earth
Not to scale

If the Moon had no rotation (depicted above on the right), it would expose its near and far sides to observers on Earth while orbiting Earth.

The Soviet satellite Luna 3 showed us the first image of the far side of the Moon in 1959. The far side has been recorded by various spacecraft over the years including most recently by the DSCOVR spacecraft. The DSCOVR image below shows the far side of the Moon as it orbits over the Pacific Ocean near the North American continent.

Far side of the Moon crossing between DSCOVR spacecraft and Earth on 16 July 2015

“The moon is a loyal companion.
It never leaves. It’s always there, watching, steadfast, knowing us in our light and dark moments, changing forever just as we do. Every day it’s a different version of itself. Sometimes weak and wan, sometimes strong and full of light. The moon understands what it means to be human.
Uncertain. Alone. Cratered by imperfections.”

Tahereh Mafi, Shatter Me


Saturday, August 8, 2015

True Yellow

Humans distinguish blue, green, yellow, and red as unique hues. Unique hues are psychologically primary — we perceive them as pure rather then a blend of colors.

In higher and lower latitudes, seasons are associated with a dominant color palette: greens during the growing season; reds, yellows, and oranges during harvest; and shades of gray when the snow flies.

Olive Trees with yellow sky and sun
by Vincent van Gogh
Saint-Rémy, November 1889

Seasons also seem to affect our perception of color. Psychologists at the University of York have published research indicating humans see yellow differently in the January (winter in the UK), than in June (summer in the UK).
"In York you typically have grey, dull winters and then in summer you have greenery everywhere. Our vision compensates for those changes and that, surprisingly, changes what we think ‘yellow’ looks like."
Lauren Welbourne, University of York, Department of Psychology
Yellow is unusual among the unique hues because most people, despite differences in retinal physiology, age, and culture, tend to agree on true or unique yellow. Subjects in the UK exposed to chromatically adjusted artificial light were asked when the light reached true yellow. Significant differences in the recognition of true yellow occurred depending on whether it was winter or summer.
"What we are finding is that between seasons our vision adapts to changes in environment."
Lauren Welbourne
Painters have long appreciated the changes in the quality of light over the course of a day or across seasons. It seems our minds adjust our perception of color to re-balance or compensate for some of those variations.
Some painters transform the sun into a yellow spot, others transform a yellow spot into the sun.
Pablo Picasso


Saturday, August 1, 2015

Lunation Calendar

There's usually one fully sunlit moon per month. Yesterday a second full moon appeared before July ceded our days to August.

Full Moons of July 2015

An occasional extra full moon is a function of the astronomical regularity of lunation and the papally decreed Gregorian Calendar introduced by Pope Gregory XIII in 1582.
Lunation - One lunar cycle with average duration of 29.53 days.
Our word moon comes from the Old English word mona.
"Even the word month is likely derived from the word moon and an Indo-European word, mê, which means to measure."
Howard Markel
By measuring diurnality from the dark new moon to the sunlit full moon, our ancestors developed monthly calendars. Religious rituals like the Christian Easter were dutifully computed and observed around predictable lunar cycles. The Islamic calendar is purely lunar. The Christian Gregorian calendar is quasi-lunar.

Widely adopted, the Gregorian calendar has 12 months in a year. By comparison there are 12.37 lunations per year.
365.24 days/year ÷ 29.53 days/lunation = 12.37 lunations/year
The Gregorian calendar has exactly 12 months in a year, so an accumulation of .37 lunations occurs each Gregorian year. The accumulations of fractional lunations beyond the counting number 12, accounts for the occasional extra moon in a year.

An extra moon, whether considered over the time frame of a year, or over a season, or over a month, is colloquially called a blue moon to signify its rarity.
The blue moon isn't really an extra moon or blue in color, rather it follows as a side effect from a human construct of time - the Gregorian calendar.

Moon and Antelao
Image: Marcella Giulia

“Her antiquity in preceding and surviving succeeding tellurian generations: her nocturnal predominance: her satellitic dependence: her luminary reflection: her constancy under all her phases, rising and setting by her appointed times, waxing and waning: the forced invariability of her aspect: her indeterminate response to inaffirmative interrogation: her potency over effluent and refluent waters: her power to enamour, to mortify, to invest with beauty, to render insane, to incite to and aid delinquency: the tranquil inscrutability of her visage: the terribility of her isolated dominant resplendent propinquity: her omens of tempest and of calm: the stimulation of her light, her motion and her presence: the admonition of her craters, her arid seas, her silence: her splendour, when visible: her attraction, when invisible.”
James Joyce, Ulysses