Dark as the Night

What is day and night but just your experience while located on the surface of our planet.  Twenty four hours is the measure of the time it takes the Earth to rotate once on its axis give or take some seconds.  In one full rotation of the Earth you will be bathed in the light from our sun directly or through clouds and the rest of the time you will be in the dark.  But is the night really dark?  Not exactly.  Step into a closet with a tightly closing door and turn off the light.  What do you see?  Nothing.  Without any light you can see nothing, not even your hand right in front of your face.  That is truly dark.

There are many reasons for the night to not be dark.  Even after you eliminating, fires, volcanoes or your porch light you will not have a truly dark experience.  If the moon happens to be above the horizon you will be again be bathed in the light from our sun reflected off of the moon.  Moonlight can be bright enough to see objects and your surroundings with no problem, though colors are reduced to drab shades of grey.  You can see your shadow and moonlight prevents most clear nights from being dark.  Take the moon away.  Would you then have a dark night?  As dark as the closet?  Actually no, quite far from it.   Turning out the lights and picking a moonless night ends the immediate glare but as your eyes become accustom to the dark, previously unnoticed sources of illumination become apparent.  Lights from a nearby town or city light up the sky, especially if there are clouds passing over the light source.  Light from cities reflect off clouds, moisture and dust in the atmosphere and can provide illumination nearly as bright as the moon.  This sky light can be bright enough to overwhelm the light from all but the brightest stars.

Get away from the cities, towns, airports shopping malls and highways and you will leave the sky reflected light behind and again presumably set the stage for a true dark night.  However, even after you have escaped from civilization and are out on a clear moonless night, especially in the summer, you will realize this is still no dark closet.  The sky can still be veiled with a hazy diffuse light.  This is called air glow.  The molecules of air in the thin upper atmosphere of the Earth, after a day of bombardment from the ultraviolet portion of sunlight, will absorb this radiation and in doing so loose some electrons to become ionized.  This is not a stable condition and as the night proceeds these gases calm down, recapture their lost electrons and in the process emit feeble light.  This sky glow can also overwhelm the light of dim stars and provide enough ground illumination to see clearly by.   A more energetic version of this light show is the Aura Borealis or Northern Lights.  Eruptions in localized areas of the sun's surface, called flares spew clouds of high energy particles and radiation that escape the sun's gravity.  A continuously flow of much lower energy level particles also occurs called the solar wind.  This energetic material is captured in the Earth's magnetic field as it travels away from the sun and is guided to the poles where it streams down into the upper atmosphere and collides with the Oxygen, Nitrogen and other molecules of which the air is composed.  This bombardment provides a much more sudden and violent shock to the air molecules than the ultraviolet bath of the noon day sun, particularly when a flare on the sun directs this material at the earth.  These shocked air molecules also lose electrons but more more of them and when the gas calms down recapture of the lost cloud of negative electrons provides a more significant burst of light.  The Aura are mostly green but can also be blue, yellow and red.  A sky charged with high energy particles will emit light nearly as bright or brighter than a full moon.

So eventually you find yourself in the middle of a desert in the southwest, hundreds of miles from civilization's lights and south of all but the highest energy and least frequent low latitude aural displays.  You are there preferably there in the middle of the winter when the sun's light is indirect enough to do little energizing of the atmosphere.  Now you expect a dark night right?  Well not so quick.  When the dust settles you look around and still see the ground, your hand in front of your face and very likely your shadow.  This is because all light has not been eliminated.  What remains is the light from the hundreds of thousands of points of light in the sky high above and the irregular milky white band of diffuse light that stretches from horizon to horizon all of which make up our Milky Way galaxy.  The light from the suns in our galaxy are shining brightly through trillions of miles of space to light our dark night. The sum of all these candles in the dark is a light that you can walk by and see nearby surroundings.  A "bright, starlit night" is exactly that, bright, and this brightness is due solely to the star light shining down from all directions above.

But this is a dark sky isn't it?  Even though it is covered by tiny points of light, none amounting to more than a twinkling point.  Even the planets Mercury, Venus, Mars, Jupiter and Saturn, though they outshine the stars, still do not exhibit more than the point source of light unless you observe them through the magnification of binoculars or a telescope.  This is our dark night.  But what if it wasn't like this.

What if we lived on a planet orbiting a star that was not isolated like our sun but a member of a group of suns all born from the same nebula of gas an dust.  If we lived on a planet where our sun was a member of a cluster such as this one that I photographed through my telescope, the only dark we would know would be what we could find in a closet, closed room or cave under ground.  On our planet orbiting a cluster sun, there would be hundreds or thousands of suns in our sky all farther away than our sun but close enough to have a visible disk.  Some might be reddish or yellow, bluish or orange.  Many shining brightly enough to be painful to look at directly and all shining their light down continuously from all directions in the sky.  Sources of light to fill the sky much brighter than a full moon all the time.  The only variance during the rotation of the planet would be when the sun that we orbit is above the horizon to join the many other smaller suns.
 

  No day and night but only bright and brighter. On a world orbiting a cluster sun the inhabitants would not know what night was, dark yes, but closet dark, not outside walking around in the dark.  Outside dark would not exist and the term "night"  would have no meaning or at least not the same as we give it.

It's About Time

I've been reading some books on the subject of time. All eventually discuss whether time exists separate from space and matter or if it exists at all.

The theory that time is some tangible thing seems wrong. Sand you can see running down in an hour glass but time is more like and adjective than a noun. To answer the questing; What is time? is in trouble immediately. It would be as difficult to answer the question; "What is fast?"

I would suggest that time in the colloquial sense is a measure of gaps between events such as sun rise and sun set and it implies that between those events something was happening. That something was time. Time was moving along or evolving or flowing between these discrete events or the events were embedded in the flow of time. But the gaps between perceived events are not time and in fact gaps between events are not really gaps.

If you peel back the layers of the physical world and look at ever smaller or ever larger scales, you realize there is always something going on and the gap we thought existed between events, for which we devised clocks to measure, are in fact full of activity and other events. I proposed that there are no discrete events. In actuality there is a continuum of activity, most of which falls beyond our ability to sense. Possibly as a result of our insensitivity to this micro and macroscopic sea of activity, we have created devices that section the gaps we perceive between observed events into increments of change and we call this keeping time. A clock is such a device with a visible display depicting changes that are regular and repeatable. The discreteness of its motion though is an illusion. A spring may provide mechanical energy or the chemical reaction of a battery may power a motor that causes a mechanical arm to pivot about a central pin pointing to numerals equally spaced around a circle. Long before the hand sweeps to the next tic mark on the clock face, there is a crowd of gears or clouds of electrons behind the scenes turning away or racing through circuitry, piling up pressure to move the hand. The hand then helps us section the day and night into apparently discrete intervals. What we are measuring, such as day and night are also just an artifact of our viewpoint. Night an day are just our side of the planet rotating in and out of the its own shade as it continuously spins on its axis in the light of our sun. This occurs as we continuously revolve about the sun and the sun orbits the center of the galaxy which is drifting closer or farther from the other members of our local group of galaxies all of which are linked to the fabric of an expanding universe. Nothing is discrete or still and there is no such thing as empty.

Nothing ever stops or is at rest and nothing is as exact or discrete as it appears to our limited senses. A resting "solid" object that appears motionless, is actually expanding and contracting with temperature differences across it's surface on a microscopic scale. If we look closer, the entire structure of the object is vibrating at the atomic level and electrons wander about the interior and exterior as electric and magnetic fields continuously pass through the object. Nothing is still.

Nothing is empty. Even a vacuum is not empty. If you go into deep space far from out sun, if you can see only one star you can be assured that energy from that star is continuously passing through every cubic inch of space in your vicinity. Even in the cold vast space between galaxies the vacuum is full of energy. Energy in the form of light, magnetic fields, electric fields and gravitational fields permeates all of the universe. At scales far below that of the scale of galaxies we have so called empty space again between and within the atoms that make up our bodies and all we see. On the scale of an atom there is vast, apparently empty space between the nuclei of atoms and the cloud of orbiting electrons. However, as we look at ever smaller scales we see that this apparent empty space again is not empty but a seething foam of virtual particles representing the energy that is locked into very the structure of the universe. There is no such thing as empty.

Thus all events we perceive actually are embedded in a continuum of mater and energy in motion. Events we perceive have developed to the point of our observation through a continuous sequence of events and will dissipate in a similar manner at dimensions or in forms beyond our capability to observe. If we could perceive all activity we would understand that existence is just a continuum of events, overlapping preceding and following unending.

The universe is full of continuous change. In a sense the universe was set in motion and will remain in motion unless there is a source of external influence. We perceive only a tiny fraction of the activity of the universe. Keeping time is our way to fill the gaps created by our limited perception. If we "saw" everything we would need no clocks, watches, sundials or calendars. We would know what has happened, what is happening and could extrapolate what will happen.

Time is just the human attempt to catalogue events we experience.