Posted by: T. Boyd | October 10, 2009

Relativity for Relatives

I asked my wife, “Do you want to hear more about Einstein’s theory of
relativity?”  She answered, “Not at the moment.  Why
don’t you tell Mei Mei about it.”  Said I, “Well, she doesn’t
really fit the clever title of this article.” “Sure she does.
She’s a member of the family, you know.” “But Shih Tzus are not known
for their complex thoughts,” I protested.   My wife
replied, “However, she will give you her full attention.”

“All right; listen up, Mei Mei,”  I announced to my loyal dog
as she chewed on one of her dozen chews currently in
circulation.  She lifted her head and looked at me, expecting
a kibble for her effort.

I began the story:  Once upon a time, actually in the late
1800’s, several scientists decided to detect for certain the ethereal
substance that supposedly filled the universe in which the waves of
light traveled.   Since all waves are vibrations of
something, then, they reasoned, light waves had to be traveling through
some medium.  This substance was called “aether”.

Since this must be true, the scientists speculated, then as the earth
whizzes through the aether on its trip around the sun, they should be
able to see an effect on the speed of light caused by that motion.

Two scientists, Michelson and Morley, set up a very sensitive apparatus
in 1887 that would detect even the slightest change in this speed by
using the interaction of two beams of light, one beam parallel to the
direction of the earth’s motion in space, and the other beam at right
angles to the first beam.

Mei Mei’s eyes were beginning to wander, so I added some zooming
motions with my arms and made swishing noises of the earth’s path in
the aether around the sun that would have made my grandson proud.

Michelson and his partner saw absolutely no change in speed.
Maybe the aether was moving at the same speed as the earth.
They waited 6 months later to repeat the experiment, when the earth’s
direction would be reversed in its solar orbit.  Again, no
change.  This was very puzzling,  for it seemed to
indicate that the speed of light was a constant which did not vary with
Earth’s movement.

In stepped the theoretical physicists, including Einstein.
They hypothesized that experimenters in a laboratory which was
traveling at constant speed in a straight line would always measure the
speed of light to be 186,000 miles/second no matter how fast the lab
was moving, and that aether did not exist.

Mei Mei kindly licked my face and went over to take a nap.  I
exclaimed, “Mei Mei, don’t you want to know what the consequences of
such a radical theory would be?”  No response.

Next week I will tell why this discovery requires rulers to get shorter
and clocks to slow down if they are traveling in a fast moving
laboratory.

The true light, which enlightens everyone, was coming into
the world (John 1:10)


Read more at BrightMysteries.net, or TinyURL.com/BrtMys, and you can write Boyd at BrightMysteries@verizon.net.


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Posted in Here's Thinking, Published in Caroline Progress, Relativity

Posted by: T. Boyd | October 10, 2009

The Search for Ceres, Juno and Uranus

He reveals deep and hidden things; he knows what is in the darkness, and the light dwells with him (Daniel 2:22)

Some astronomers, including yours truly, plan to see Juno, one of the brighter asteroids, and the planet Uranus this fall as both are presently in good position for observing.

In the 1980’s while teaching at Randolph-Macon College (RMC), some of my students used the college’s observatory to search for the largest asteroid, Ceres, also classified as a dwarf planet. We knew from the Naval Ephemeris and Nautical Almanac where it was supposed to be located among the stars.

We took careful photographs of that part of the sky using a Schmidt Camera, 8 inches in diameter and about 2 feet long, which was mounted on the side of the main 12 inch diameter telescope.  This allowed us to use the telescope to aim and guide the camera.

In total darkness, we cut the 35mm. film into individual frames.  Then we inserted one piece of film at a time into a magnetic film holder, and placed it into the camera through a small door in the camera’s side.  After the camera was closed, we could turn on our flashlights to help us position the telescope and to take notes on our procedures.

After we aimed the main telescope, we extinguished the lights and, being careful to cause no movement or vibration of the apparatus, we uncovered the lens of the camera for a few seconds to capture the star and asteroid light onto the film.

We then repeated these steps several times, using varying amounts of time to give us a range of exposures.  The first part of the search was finished.

Back in the science building we developed the pieces of film and mounted them in slide holders.  We projected the film negatives with a slide projector upon a screen, and compared the image with sky charts of the same part of the sky.

We searched for what seemed like hours, knowing that once we found the matching pattern in the charts, we could then look for an extra dot on the negatives that would indicate the asteroid.  RMC had a wonderful set of photographic charts of the sky done by the Palomar giant telescope in California which we used for comparison.

After almost giving up in frustration, someone in the group noticed the pattern looked familiar, but was reversed left and right.  We flipped the slide and quickly found the matching area on the charts, and then…Eureka!  We found an extra point of light on the screen right where the almanac predicted.  We had found the asteroid, Ceres!

It was a very exciting moment for the students and teacher alike.  We felt we had joined the ranks of those long ago scientists who found things hidden in the skies.

Also found at TinyURL.com/BrtMys,  To join Boyd in trying to see Juno and Uranus through a telescope, write him at BrightMysteries@verizon.net.


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Posted in Here's looking, Published in Caroline Progress

Posted by: T. Boyd | September 21, 2009

Relativity and Einstein’s Clocks

He has made everything beautiful in its time. Also, he has put eternity into man’s heart. (Ecclesiastes 3:11)

It is time for another lively discussion with my bride about physics and astronomy.

She declares, “I read today that the atomic clock in Denver gains time over its sister clock in Europe.  And that gravity is responsible.   See, I told you no one really knows what time it really is!”

“Oh, that’s right,” I reply.  “Before we got married every clock in your house was set to different times, all fast, so you could get somewhere early or at least not too late, right?”

“Yes, it worked very well, and then I married you, and I have been late ever since,”  she answered.  “You went around the house and set every clock and watch so that they read the exact time to the nearest second.  It was crazy!”

I patiently added, “But I left your wrist watch alone, so you could have your own standard time. Anyway,  do you know why gravity affects a clock?”

“No,”  she replied cautiously, not sure she wanted to endure one of my long-winded expositions.  “But, go ahead.”

“Well,  Einstein said to think of a rocket ship that is accelerating in gravity-free space with the same acceleration that earth’s gravity would cause a body to fall.  All experiments would give the same result on the moving rocket or on a rocket at rest on the earth.”

I took a sip of my tea and continued, “Now, suppose that you are on the rocket ship that is accelerating, lying on the floor looking ‘upward’ toward the ceiling.  If there were a clock on the ceiling, sending a flash of light every second toward the floor, the flashes of light would be seen by you as arriving at a faster rate than one each second.  This is because you are accelerating upward.  To you, the ceiling clock would be running faster than one on the floor.”

“Wait a minute (no pun intended),” she interrupted.  “The clock would also be accelerating, would it not?  And so the effect should cancel.”

“No, ” I argued, “the propagation of light is independent of the motion of the source (the clock).  So the blips of light would arrive somewhat bunched together in time.”

“Now, because of the equivalence between an accelerating rocket ship, and one resting with the equivalent gravity on the earth, a clock on the ceiling of the rocket ship, would be running faster than one on the floor by the same amount in both situations,” I continued.

I concluded, triumphantly, “Therefore, because Denver, the mile-high city, is further away from the center of the earth than the city in Europe where the other clock is, the signals from the higher altitude clock will be received at a rate slightly faster than the one at the lower altitude!”

Unruffled by my logic, she smiles, “Precisely.  So, in other words, no one really knows what time it is.”

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Posted in Here's Thinking, Published in Caroline Progress, Relativity

Posted by: T. Boyd | August 24, 2009

Number of Galaxies and Stars

Here is an expanded version of the first part of the last blog entitled:  Galaxy Zoo … This one was just submitted to the Caroline Progress.

I finally jumped in. I found out about the GalaxyZoo.org web site some time ago, but had never participated till last Saturday. I did the 20 minute tutorial with hands-on practice, and then enjoyed classifying about 10 galaxies in my first session.  It is easy and requires no prior knowledge.

The Galaxy Zoo site has a huge deposit of deep sky photographs taken by the 8 foot diameter telescope at Apache Point Observatory, New Mexico. The photographs are posted on the site.  Volunteers examine pictures one by one and answer a series of questions about the appearance of each galaxy.  Then the project scientists analyze the answers statistically to classify each galaxy.

The creators of the site expected a few thousand volunteers, but they had a huge response, with some 70,000 galaxies being classified every hour  on the first day of the announcement.  The number of volunteers is now more than 150,000.  One of them, a Dutch teacher, Ms. Hanny Van Arkel, 25, discovered a one-of-a-kind sight now appropriately called Hanny’s Voorwerp’ (Dutch for object).  It is a large bright greenish-blue “blob”, still awaiting classification, located near a huge galaxy.  Vast opportunities await us!

On Sunday I gave a short talk during the worship time about the amazing number of galaxies, each containing a huge of number of stars, all created for God’s glory and for our enjoyment.  Yesterday, I read on the NASA web that there are about 350 billion galaxies in our universe.

Since the Milky Way Galaxy, where we live, is an average size galaxy with an estimated 200 billion stars, then the number of stars in the universe is about 70 billion-trillion stars!

I have no feel for such large numbers.  I have a hard time trying to get a feel for the size of a trillion dollars, a term frequently used to describe the U.S. budget.  So lets try to think how big just one trillion is.

Last week on the radio, I heard a man tell a tale about a trillion dollars ($1,000,000,000,000) that gave me a better grasp on the magnitude of that number.  Here is a paraphrase of what he said.

“Suppose you are very, very wealthy and older than Methuselah, and you are making payments on your mansion on a non-interest loan of one trillion dollars.  Your house payment is 1 million dollars a day ($1,000,000/day)!”

The story continues.  “You bought the house on the day that Christ was born 2000 years ago [like I said, you are very old], and started paying back the loan at that time – a million bucks a day.  Then, how much of the loan have you paid off?  Answer: about 70%.  ‘When’. you ask, ‘will my last payment be?’  Answer: in the year 2750.  Only 741 years to go.”

So that’s one trillion.  The number of stars in the universe, by comparison,  is about 70 billion times that.    It is an understatement to say that the universe that God made and maintains “by the word of His power [Heb 1:3]” is mind-boggling.  He is awesome.

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Posted in Here's looking, Published in Caroline Progress

Posted by: T. Boyd | August 21, 2009

Galaxy Zoo and Watching Moons of Jupiter

Hanny's Voorwerp

Blue-green object found by Hanny Van Arkel

He delivers and rescues;
He works signs and wonders
in heaven and on earth, (Daniel 6:27 ESV)

I finally jumped in. I found out about the Galaxy Zoo web site some time ago, but never participated till today. I did the 20 minute tutorial with hands-on practice, and then enjoyed classifying about 10 galaxies in my first session.

This site has a huge deposit of deep sky photographs taken by the 2.5-meter telescope at Apache Point Observatory, New Mexico. The photographs were posted on the site and they asked for volunteers to go through the pictures one by one and answer a series of questions about how the galaxy appears to them. Then the project scientists analyze the answers statistically to classify each galaxy.

The creators of the site expected a few thousand volunteers, but they had a huge response, with some 70000 galaxies being classified every hour within one day of the announcement. Last summer one of the volunteers, a Dutch teacher, Ms. Hanny Van Arkel, 25, discovered a one-of-a-kind sight now appropriately called Hanny’s Voorwerp’ (object). It is still awaiting identification. It is a large bright greenish-blue “blob” near a huge galaxy.

You can join in on the fun for free at GalaxyZoo.org and contribute to a worthwhile project.

The other heavenly sight which I hope to be able to see (the August skies in Caroline County, VA, permitting) is to watch the activity of Jupiter’s moons. Every 6 years, we have a period of time when the plane of the orbits of the moons going around Jupiter is edge-on with Earth bound observers. And we are in that period now and for the next three or four months.

During that time, the moons will periodically eclipse one another, blocking the sunlight illuminating a moon. These are called eclipses just as when our Earth blocks the sunlight reaching our moon. Also the other periodic class of events is occultations when one moon blocks our view of one of the other moons. A table of times that these can be seen in North America is given by SkyAndTelescope.Com.

I will watch the weather prediction to try to see as many of these that I can. If I could rig up a light meter (photometer) to my telescope, I could contribute to the compilation of data that helps the team of astronomers to learn more about each moon. But even if I can’t do that, it will be a fun effort. I enjoy just seeing the moons anyway, and to see these eclipses and occultations will be very exciting to me.

Some of the upcoming better events of these Jupiter events are (times in EDT):

Aug. 31, 10:04 p.m. – an 81% occultation

Sep. 15, 10:12 p.m. – an 86% eclipse

Sep. 23, 12:41 a.m. – a 96% eclipse

If you would like to join me in these viewings, you can write me at BrightMysteries@verizon.net

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Posted in Here's looking

Posted by: T. Boyd | August 11, 2009

On, Comets! On Showers!… Dash Away All!

The title is a little corny, but it’s appropriate for the dogs days of August. Each year we celebrate our older son’s birthday on August 11. For years we went out on that night to observe one of the most reliable meteor showers of the year, the Perseid Meteor Shower.

Great Comet of 1882 - Used by permission of WikiPedia

Great Comet of 1882 - Used by permission of WikiPedia

This light show of “shooting stars” is the dust left behind by the comet Swift-Tuttle first named after two astronomers that “discovered” it in 1862. It returned 130 years later in 1992, and is now thought to be the same
comet seen in 69 BC and AD 188 by the Chinese.

I will write more details about comets and meteors later when there will be another major meteor shower this fall and the readers can prepare to see it. Right now I will relate my wife’s version of our summer experiences. She writes:

“In the late night of Aug. 11 we customarily marked the occasion by lying on the ground counting meteors. Previous to going out we would darken the house to get our night vision going. Dad put out a blanket on the ground and summoned us.

“No flashlights were permitted, and getting into position in the dark was challenging. It took a few minutes for meteors to become more important than elbows and blanket share, but when we settled in, the event was memorable. Some of us took our pillows. It was always hot, often damp, and usually buggy.

“Our dog Penny licked our faces and was generally delighted that we were at last seeing the appeal of the outdoors after dark. Each of us wanted to see the most meteors, and we called out and pointed, all the while keeping track of our own personal total.

“We seemed to do best when we simply relaxed and didn’t try to focus too much on any particular area of the sky. Every once in a while, there would be a really spectacular one that seemed to streak across the whole sky. These brought oooh’s and wow’s and a sense that we were sharing something very special indeed.

“The boys and I usually lasted about 30-45 minutes before the bug repellent gave out completely, and the fans inside the house became irresistible. But Dad stayed out for usually another hour. His description at breakfast the next morning was a bit like a fisherman’s description of the one that got away.”

Her story makes me want to try again this year. So on Tuesday and Wednesday, weather permitting, I will probably take my truck out to a treeless site and try to count the meteors as I lie in the bed of the truck. I’ll report my score next week . [Author notes: both nights were cloudy and rainy, so I saw nothing.  But several friends in other states saw them.]

More about our Father’s glorious creation, about comets and meteor showers, can be found at BrightMysteries.net, or TinyURL.com/BrtMys, and you can write Boyd at BrightMysteries@verizon.net.

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Posted in Here's looking, Published in Caroline Progress

Posted by: T. Boyd | July 29, 2009

Orbiting the Moon

He never sleeps, He never slumbers
(Ps. 123:4, paraphrase & Take 6 song)

Recently, we celebrated the 40th anniversary of the space mission,
Apollo 11, during which two of the astronauts landed on the Moon -
a goal set by President John Kennedy in 1961, and accomplished in
July 1969, an amazing achievement in just 8 years.

To me, however, the most heroic part of the Apollo program was the
rescue of the Apollo 13 crew after a near-fatal explosion occurred
on the Service Module that supplied oxygen and electricity to the
whole spacecraft. The 3-man crew moved to the Moon Landing Module
(the LM) to be used as a lifeboat.

The Mission Control crew in Houston scrambled to figure out how to
get the 3-man crew back to Earth safely. To get the ship onto the
“free-return-to-Earth” trajectory, they would have to correct the
course that had already been set for the landing on the Moon.
Unfortunately, the LM had limited instruments to set up for a “burn”
of the maneuvering jets to do the correction.

Maneuvering in space is weird. For example, if you were orbiting
Earth in the space shuttle and you wanted to dock with the space
station ahead of you, you cannot just speed up toward the target.
You actually have to drop into a lower orbit by “slowing down” and
let the orbital dynamics carry you ahead of the target, and then
you go back to the target’s orbit by “speeding up”.

Mission Control devised a way by using an alignment telescope on
board the LM to check to see if the spacecraft’s jets were pointed
in the correct direction. At 73:46 hours into the mission, loud
cheer erupted inside the LM as well as in Houston that the chosen
navigation star (our Sun) was exactly where it should appear in the
telescope .

The Mission Control Flight Director, G. Griffin, recalled his
exhilaration at that time: “My God, that’s the last hurdle – if we
can do that, I know we can make it.” (quote from here near the end)
After they swung around the Moon, they fired the jet for 5 minutes making it possible to make it back to Earth with a splash- down time of 142:54 hours.

If you have watched the movie, “Apollo 13″, you know that there was
much more going on during the 6 day mission. They managed to rig
up filters with tape and plastic to remove carbon dioxide. They had
to severely restrict water intake to have enough to last till
splashdown. And they had to turn off the heat to save electricity,
making it hard to sleep at the freezing temperature of the LM.

People all over the world were watching and praying. Tears of joy
were shed and many prayers of thanksgiving went up from all over
the Earth at the moment they were safely home. God “who watches
over you will not slumber. Indeed, He … never slumbers nor sleeps.”
(Ps. 121:3-4)

This article published in the Caroline Progress, 2009. Also “blogged” at BrightMysteries.net.

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Posted in Here's looking, Published in Caroline Progress

Posted by: T. Boyd | July 14, 2009

Protons, Neutrons, and Such

He is the radiance of the glory of God and the exact imprint of his nature, and he upholds the universe by the word of his power. (Hebrews 1:3 ESV)

I was thrilled as a young graduate school student to get to work with a nuclear accelerator in a project to build a neutron detector. Unlike charged particles, such as protons and electrons, neutrons easily pass through the stainless steel walls of the vacuum chamber into the surrounding area. So the detector was placed on a stand about 6 feet away from the collision chamber. Thus only neutrons and gamma rays could reach the detector from the collisions

One big problem is that the detector was flooded with many more gamma rays than neutrons. But the flash of light produced by a neutron is slightly different from a gamma ray. Also gamma rays travel at the speed of light (since they are just high energy bundles of energy, or photons, like light, while neutrons cannot travel at that speed since they have mass.

The neutrons would travel the 6 feet in about 100 billionth’s of a second, much longer than gamma rays which would travel that distance in a mere 6 billionth’s of a second. The electronics, even in 1966 when I did this work, could use the time difference as well as the characteristics of the light flashes to filter out the gamma rays.

Neutrons are very strange. They cannot exist very long outside of a nucleus. They decay into protons and electrons in about 10 minutes in free space (actually that is their half-life – more about that sometime). And even though they have no charge, they will not stay with another neutron unless a proton is present. And, conversely, protons will not stay together unless neutrons are present.

Going further, we can see that nuclei are themselves strange. The number of protons and neutrons that a particular nucleus (an isotope) contains determines its stability, but not in a very logical manner. For example, stable hydrogen, which always has one proton, can have zero or one neutron, but two neutrons will make it unstable.

Helium, with two protons, is stable with one or two neutrons, but not three. As a person tries to predict the stability of an isotope as more protons and neutrons are added, he or she quickly finds great difficulty in doing so.

For instance, Beryllium with four protons, is stable with five or six neutrons, but not with only four neutrons. The pattern of nearby isotopes would seem to say that this nucleus ought to be stable with four of each.

For example, here is a list of stable (happy) and unstable (unhappy) arrangements:

Number of Number of   Stability        Name of Atom
protons   neutrons
   1         0       very stable        Hydrogen
   1         1       barely stable      Deuterium
   1         2       unstable           Tritium
`  2         0       very unstable      ---
   2         1       quite stable       Helium 3
   2         2       very stable        Helium 4
   3         2       unstable           Lithium 5
   3         3       stable             Lithium 6
   3         4       stable             Lithium 7
   4         3       unstable           Beryllium 7
   4         4       very unstable !!   Beryllium 8
   4         5       stable             Beryllium 9
   4         6       stable             Beryllium 10

The reason that Beryllium 8 is a surprise is because, being an even-even nucleus, it should be more stable than its siblings. For example a nearby isotope, Carbon 12, is very stable and prevalent on the earth, and it has 6 protons and 6 neutrons. And why should Tritium be more stable than Helium 3, with the latter having the protons repelling each other so strongly?

The atom is made up of a positively charged nucleus and the negatively charged electrons surrounding the nucleus. The force of attraction between unlike charges, called the electrostatic force, is well known and can be described by a simple algebraic expression.

What force keeps the nucleus together? This is called the strong nuclear force. There has never been a simple explanation found for this mysterious force. It requires advanced mathematics to give even an approximation of it. And the “weak” nuclear force is stranger still, requiring Einstein’s relativistic theory to even start understanding it. It is the force that causes the instabilities found in nuclei.

In all, there are 4 known fundamental forces: gravity, electromagnetic, the strong nuclear force, and the weak nuclear force. The first two have been adequately explained by laws that were discovered years ago by scientists, most notable of which were Isaac Newton (1643 – 1727), and James Maxwell (1831-1879).

The universe is held together by these various forces, that, like the material of the universe, were created out of nothing. In Hebrews 1, the scripture says “He … holds all things together by the word of His power.” The inventor of the world knows how He did it. Someday we will know, but maybe not till we see Him face to face.


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Posted in Atomic/Nuclear Physics, Published in Caroline Progress, Relativity

Posted by: T. Boyd | July 7, 2009

Holograms

And we all, with unveiled face, beholding [or reflecting] the glory of the Lord,  are being transformed into the same image from one degree of glory to another. (2 Cor. 3:18 ESV)

Holograms are now used in many products, mostly as a security measure to help prevent forgery of credit cards or even of some currency.  When I examined my credit cards last evening,  one popular card showed a silvery image of a white dove in flight with wings outstretched.  By examining it under a small light source, I could see that it was a 3-D image of the dove, and by tilting the card slightly from side to side it even appeared to flap its wings a little bit.

The first holograms required laser light in the production and in the viewing of them (since then viewing in ordinary light has been made possible). About thirty-five years ago, several of my students tried making some.  It was a very exacting process, and we were not successful with our limited apparatus.

I have seen some very remarkable holographic displays in museums.  One such circular hologram depicted the head of a young lady, and as you walked around the film, you could see her whole head from every angle just as if she were in the center of the circle of film.  Her eyes even appeared to follow you as you moved.

The first experience of seeing this was breathtaking for me. When you looked over the edge of the holographic film, you saw nothing but empty space in the center of the circle. When the  light used to illuminate the hologram was turned off, the image disappeared.

Suppose the film were to be cut up into a bunch of small 1″ squares, for example, and handed out to the people looking on.  If you were there, as you looked through your piece of the film, you would see the lady’s entire head in 3-D from a particular angle.  For example you might see the head from her right side.  Another person might see the back of her head.

By swapping around the squares with each other, you would be able to see the image from every angle and acquire a complete picture of how the lady really looked. In like manner, every person on earth has been given a particular unique view of our creator, and as we share with each other about what we have seen and heard of him, we learn more and more about his glorious self, the unlimited treasure of our maker.

You can read more about the details at BrightMysteries.net and at TinyURL.com/BrtMys.  You can e-mail Boyd at BrightMysteries@verizon.net .

By the way, as usual, this article, written by me,  is copyrighted by the Caroline Progress, Bowling Green, VA,and so it should not be published without their permission.  It is posted here with their permission.

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Posted in Here's looking, Published in Caroline Progress

Posted by: T. Boyd | June 25, 2009

Pure Light and True Light

“The true light, which enlightens everyone…”

What is pure light? Or maybe the first question ought to be, what is light? Light is simply an electric-magnetic wave just like the waves of radio, TV, and x-rays except its wavelength is in the visible range. The wavelength of FM radio and the TV channels 2 through 13 (at least before the switch to digital TV) is in the range of 3 feet to 18 feet.

The wavelength for light is in the range of 15 to 30 millionths of an inch, very small indeed. X-rays have wavelengths that are much smaller still. Our human eyes can only detect the waves in the visible range. Our skin can detect the warmth of infra-red light (wavelengths longer than visible light) and can burn from ultra-violet light (wavelengths shorter than the visible ones).

What is pure light? The definition I have in mind is light that has only one wavelength. Most light that we see is made up of many different wavelengths. Sun light is a continuous mixture from the deepest blues to the brightest reds and all colors in between as a prism or a rainbow can show.

But a laser, for example, produces a very narrow range of wavelengths, or a single wavelength as far as our discussion is concerned. And like a pod (school) of dolphins swimming along in synchronization, all the waves produced by the laser are in lock-step with each other which keeps the light from spreading out very much. It is very useful light for medical and scientific uses because it can be focused so well.

What about true light? More of the quote above is: In him was life, and the life was the light of men. The light shines in the darkness, and the darkness has not overcome it… The true light, which enlightens everyone, was coming into the world (John 1:4-10 ESV).

Pure laser light is used in Lasik surgery, for example, to reshape the cornea of the eye to correct vision problems. And there are types of lasers used to remove unwanted tattoos.

Another use of pure light is to measure accurately the distance to the moon within one inch. This light is bounced back by reflectors left there in the late 1960’s and 1970’s at certain locations on the moon.

So just as pure light can be used in surgery to heal problems, and in astronomy to add accuracy to our measurements, the true light can be used to shine in the darkness of our world to reveal things that need revealing and to bring healing to our souls.

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Posted in Here's looking, Published in Caroline Progress

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