StarWatch: Moravian College Astronomy

MARCH 2022

MARCH STAR MAP | MOON PHASE CALENDAR | STARWATCH INDEX | NIGHT SKY NOTEBOOK

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1333 MARCH 6, 2022: An Explosion of Daylight: Welcome to March and to the explosion of light that is currently underway as the mid-northern latitudes transition from the long shadows of winter to the shorter shadows of spring. That doesn’t mean that we are immune from the possibilities of a winter blast, but any snow that does accumulate will melt more rapidly because the sun is racing higher into the sky each day, and its energy is becoming more intense. Remember the recent ice storm of February 24-25? Once the sun returned on the 25th, the ice was gone in a few hours, and the roads rapidly dried. Had that same storm occurred in early January with the temperature just a few degrees lower, chances are that many of us would have been sitting at home without power. • You can prove how the sun’s energy is on the rise for yourself. Take a flashlight, either the old type with an incandescent lamp, or the newer ones that illuminate with an LED source. Hold the flashlight vertically above a tabletop and observe the area of light falling on its surface. That circle of light represents the greatest amount of insolation (solar energy received) that can be collected by Earth’s surface from the sun. The zone which sees the sun directly overhead each year occurs between the Tropic of Cancer (north) and the Tropic of Capricorn (south) with the equator centered in the middle. These two tropic lines represent the limits of where the sun can be found at the zenith. Lower the angle at which the light is striking the table, but keep the light source at the same distance from the table’s surface, and you will observe the beam widening and also dimming because of the greater area that the light has expanded. This is the winter scenario for mid-latitudes. • It’s not difficult to comprehend why conditions must get cooler in winter and warmer in the summer, but there is obviously more that is occurring. As the sun moves northward, not only does its altitude in the sky get higher, but its rising and setting positions are also moving northward too, creating a longer path across the sky that the sun must follow, lengthening the time that Sol is above the horizon. Both of these circumstances add to the amount of energy that is being received by Earth’s surface. If we take the date of this article, March 6, and go to April 3, with the midpoint occurring at the time of the vernal equinox on March 20, the amount of time that the sun will be above the horizon will increase by one hour and 15 minutes. However, it will also appear as if this explosion of daylight has been mostly shifted to the end of the day when all of us are awake. That is because on March 13 the clocks will spring ahead by one hour, causing the sun to set a full hour later than on the previous day. Keep in mind that the sun will also rise an hour later in the morning. Happy, almost spring. I can’t wait. Ad Astra!

1334

MARCH 13, 2022: The Seven Warning Signs of Spring

It is a matter of taste with regards to the time of the year you are most attuned. My wife is an ardent fall and winter person. She doesn’t like the bugs or the heat of the warmer months. Obviously, since opposites attract, I’m definitely a spring and summer kind of a guy. I thought it might be fun to write this column from my wife’s perspective as she contemplates the dreaded season of spring that that is just about to start. Here are seven dire warning signs that spring is about to pounce. • (1) Higher sun, (2) longer days, (3) more northerly rising and setting locations of the sun: These three warning signs must always go together. Since the Earth’s axis of rotation is tilted by 23.5 degrees to the perpendicular of its orbital plane, the sun oscillates north and south of the Earth’s equator by just that much, 23.5 degrees, during the time period of one year. The sun favors the Northern Hemisphere from the vernal to the autumnal equinoxes. Currently, Sol is climbing higher in the sky each day. The vernal equinox marks the day of its greatest vertical movement. Its radiation is striking the Northern Hemisphere more directly, causing an increase in energy absorption, with more energy being taken in by the Northern Hemisphere during the daylight hours than is being released at night; so we are gradually feeling the grip of winter loosen. In addition, as the sun moves northward, its path across the sky increases in length, and the days become longer. My wife started noticing this unwanted change about six weeks ago, but the lengthening days and higher sun started happening right after the winter solstice on December 21 of last year. In addition, as the sun moves northward, its rising and setting positions also move northward too. • Shining into our living room window, (4) the smiley moon was noticed by her just this past week. During the spring, the moon’s orbital path which differs by only five degrees from the sun’s annual trek through the heavens is tilted at its steepest angle, about 70 degrees, to the western horizon. After a new moon, the thin waxing crescent rockets skyward at this steep angle, its horned feature appearing very much like the smile of a jack-o-lantern without any teeth. You have to add the eyes, but it’s a sure sign that spring is just around the corner and waiting to give my wife a migraine. Catch the next smiley moon during the early days of April. (5) Hello, Big Dipper; goodbye, Orion: Not a true constellation, but recognized by Americans as one of the standard bearers of the nighttime sky, the seven stars of the Dipper can function as a seasonal timepiece when it is observed right after dark. If you make the annual path of the Dipper into a clock, it travels counterclockwise around the North Star as the seasons advance. At the time of the summer solstice, it is at the 11, autumnal equinox, 9; winter solstice, 5; and by the dreaded vernal equinox, it is at the 3. Another way of explaining this is to say that the Big Dipper currently stands handle down, cup up in the northeast right after dark. Likewise, Orion the Mighty Hunter of the winter sky with its three belt stars in a straight line is rapidly sinking face down into the west. • (6) Cooler colors during the day: Because the sun is low in the wintertime, the longer path that its light must traverse when it enters the atmosphere allows the air molecules to filter out more of the shorter wavelengths of light, the blues and greens, allowing more yellows, oranges, and reds to pass through the air. This creates a warmer hue to land and cityscapes. During springtime the midday sunlight is becoming harsher and less reddened because the sun is higher in the sky, its light more concentrated as it passes through less atmosphere before its energy reaches the Earth’s surface. • The final “bad boy” that heralds springtime is (7) the setting of the clocks ahead by one hour. “Spring ahead, fall behind” is how the old saying goes. If you are reading this StarWatch on the day of its publication, March 13, then you should already have done that a few hours ago. If you have not sprung ahead, then you are definitely behind. Spring is here in just one week even though there is snow on the ground right now. Sorry about that, honey. Ad Astra!

1335 MARCH 20, 2022: Strange Universe: The universe can be a sobering place. Our part during its 13.8 billion-year history has been brief at best, and only in the past century have we begun to understand its complexities and comprehend how strange a place it truly is. During the last 100 years, we have been grappling with how we can unite the four forces of nature into a single elegant mathematical equation. In the quantum (small) world, the forces that govern the atom, the strong and weak nuclear forces and the electromagnetic force, have been unified into a single mathematical concept. The holdout is gravity. • In the world of the small, the strong nuclear force governs the core of an atom. Almost everyone knows from playing with magnets that like charges repel, but when protons containing a repelling positive charge get very close to one another, the strong nuclear force trumps the force of repulsion, attracting the protons to each other. Why don’t they simply careen together and become inseparable? • It is the neutrons in the nucleus of the atom that keep the protons at the correct distances so that cannot happen. Likewise, neutrons and protons contain even smaller entities, two different types of quarks which have fractional charges: a proton with a positive charge of one has two up quarks (+2/3 charge per up quark) and one down quark (-1/3 charge). In concert they equal a charge of positive one. The neutron with no charge, has two down quarks (-1/3 charge per down quark) and one up quark (+2/3 charge) that equals a charge of zero. What is so fascinating about quarks is that the farther away they move from each other, the stronger the attractive force between them becomes making them virtually inseparable. • The weak nuclear force governs how radioactive elements decay or break apart into less complex atomic constituents while the electromagnetic force governs how elements interact (bond) with each other, in other words, creating the chemistry of this universe. • So what governs the interactions of massive objects in the cosmos? The answer is gravity, but it is not so much of an attractive force as it is a warping of space (length, width, and height) and time. High mass objects distort the fabric of space much like a heavy object would deform an elastic sheet. Objects in space maintain orbits at specific distances along this curvature based upon their velocities. The beat of time also varies, drumming slower near more massive bodies. Time also moves at a slower pace the faster objects travel. • Gravity can also be simulated by acceleration as witnessed by anyone who has ever ridden in an elevator in a skyscraper. When the elevator accelerates up or down, you feel your weight increase (up) or decrease (down) as the illusion of more or less gravity takes place during the acceleration process. Einstein put gravity in its place with his theories of special and general relativity in 1905 and 1915. • And here is the rub. The mathematics of the quantum universe has yet to be unified with the mathematics of general relativity to form a comprehensive theory of everything. Quantum physics and general relativity are like stop and go, oil and vinegar. They don’t mix; at least no one has found the correct caldron (formula) where they could combine to form a wonderful stew that explains everything! • How can astronomers describe the origin of the universe that began with a volume much smaller than an atom, fully a part of the quantum world, but with all of the “ingredients” that would eventually evolve into the universe that we observe today, filled with hundreds of billions of massive galaxies? We will never know the answer to that question unless we can unify the big and the small. • It is a strange universe indeed, and one that we still do not fully understand. Ad Astra!

1336 MARCH 27, 2022: The God Equation: One of the great discoveries that has eluded physicists in the 21st century is the unification of all four forces of nature. See last week’s StarWatch for additional insights. On the atomic scale the strong nuclear force provides the “glue” which keeps protons stable in the nucleus of atoms, the weak nuclear force governs how radioactive elements and their isotopes decay into less complex constituents, and the electromagnetic force governs the interactions of atoms and molecules in chemical reactions. Although the quantum world has been unified mathematically, there is no single equation which can combine quantum mechanics with general relativity (gravity), the weakest of all of the four forces, but the one that extends across the entire universe. Why is unification so important? • If the universe burst forth from a primordial atom (quantum theory), then how could it have evolved into the universe that we observe today, containing hundreds of billions of massive galaxies (general relativity)? How can astronomers explain the mechanics of a black hole, a gravitational well that can “suck” humongous quantities of matter into a singularity, if we cannot discover how the quantum world and gravity are interconnected? • If this topic piques your interest, may I suggest Michio Kaku’s book, The God Equation: The Quest for a Theory of Everything, Doubleday, 2021. Last week’s StarWatch and the text that you are reading now were inspired by his thoughts. • Kaku believes that the answer may lie in String Theory, the belief that we live in a 10 or 11-dimensional universe, but that we are only cognizant of the properties of space (length, width, and height) and time. The other dimensions are hidden from our view because of their incredibly small size. Brian Greene, another well-known string theorist, once compared the size of a string to a tree in the volume of the solar system. • Strings are vibrating strands of energy that are made to oscillate in certain ways because of these hidden dimensions. An example might be the strings “hiding” inside the quarks contained within the protons and neutrons of atoms. These specific string vibrations give the quarks their properties, which in turn, give the protons and neutrons their attributes that we observe in everyday objects. Therefore, matter ultimately composed of energy strands becomes another illusion just like gravity. The chair that supports you as you read this column is made from energy masquerading as matter. • This has not been the first book that I have read about descriptive string theory, but it has certainly been the best. Michio Kaku eloquently, and perhaps more importantly, humbly details its pros and cons. As an example, it unites the four forces of nature in this universe, but it also predicts an infinite number of solutions to an infinite number of possible universes. If you’ve ever wondered where the multiverse came from, well, it’s string theory. As you might have already guessed, the concept of strings is purely mathematical, and its biggest drawback is that there are no experiments at the present moment that can test the validity of the theory. This means that string theory is safe, not a good attribute when dealing with scientific questions. Still with all of these drawbacks, Kaku confesses that string theory may lead nowhere, but at the same time, it may be the solution to everything. So he and perhaps 100 other individuals around the world continue the quest for The God Equation. More in two weeks… Ad Astra!