Is there life in our Milky Way galaxy? If that answer is, “Yes”, is there some way of making an educated guess about how many civilizations might, currently, populate our galaxy?
It’s not the cold, empty belief system you might think…
2018 Dale Alan Bryant
In that, it is not possible to have a palpable, ‘sensory’ relationship with God, God can be found, or revealed, in the physical universe where He has left his mark(s), using the scientific tool of Astronomy.
Science has always, and can always only be described as a ‘tool’; a self-correcting tool, which, by observation and comparison of our surroundings allows us to make sense of our world. It doesn’t set out to try and do this for us; that’s our part. But when we can’t make sense of the results, we don’t discard them as useless, or undesirable. We just realize – we don’t understand. Like a camera in its indifference, it only describes what is, or is not. There is nothing outside of that to either like or dislike. Rather, that decision is up to us and, whether or not we do, the Scientific Method will give us an unbiased answer. As with common sense, we’ll either like what it tells us, or we won’t. But that’s our problem; science has already done its job.
When I bought my house, I found myself in the happy position of, its ‘keeper’; it’s maintainer. From someone else’s perspective, it might have seemed that I was wrapped up in the material thing called, “house”. But in fact, I was actually involved in a deep appreciation and gratitude for having been blessed with such a possession. Acquiring a house, vehicles, a steady job, etc., were absolute necessities for maintaining another blessing – my kids. That I actually ‘had’ any of these things was sometimes beyond my comprehension – and also, much of the time, beyond my ability to feel anything along the lines of having ‘deserved’ them, or feeling confident that I could hold onto them for any length of time – but, never beyond a keen sense of gratitude and appreciation for having them. I knew their worth, and I intended to maintain their ‘value’ in that sense. But, they were a means to an end. That I should inevitably enjoy the beauty in those things, e.g., the beauty in their inherent functionality, or their efficiency at the same time, was, I suppose, intrinsic to my appreciation for them; and I intended to do my job to preserve them. I guess that all of those things are part of living a tolerable, or, at best, good life. But, serendipitously, you sometimes find good things – especially when you’re looking for something else…
That’s how it is in my relationship with God. Along the way (by scientific discovery – and understanding that, it is usually better to travel, than to arrive), you find that there is more to the idea of the ‘destination’, than the destination itself. There is the beauty and the intelligence of design and of function. There is a cerebral satisfaction in the – sometimes unexpected – demonstration of the physical interrelationships of things, which for me, typically, translates to reason. I could not, or at least, would not want to dismiss these things as mere ‘novelties’, or ‘curiosities’, or ‘pastimes’; they are not. In the same way that an artist may be understood, on some level, through his paintings or music, these methodologies can lead to an understanding of, and a close-ness, to, God. And I think that it’s unfortunate that they seem to go un-appreciated or under-appreciated, or misinterpreted entirely and dismissed as irrelevant or unimportant by so many; I cannot believe that God has endowed us with an intellect, and with evolutionary, biologically-acquired, perfectly adapted given senses – only to wastefully forego their use or their significance.
In a testimonial in the Bible, (Mark 12:30), it states: “Thou shalt love the Lord, thy God, with all thy heart, and with all thy soul, and with all thy mind, and with all thy strength.” In another, (Psalm 19:1), it says: “The heavens declare the glory of God, and the sky, above, proclaims His handiwork.” I am so grateful for the inclination to do these things, one through the other, by the exploration of, and the literal exposure to, His Creation, and by an attempt to understand it. Along with prayer, meditation, and reflection/contemplation: I cannot imagine any better way, to – honestly, and to the best of one’s ability – pursue a relationship with ‘God’.
For myself – Science is neither a ‘golden image’, nor is it a ‘false god’ any more than, and in fact, far less so, than even a Church, or a Crucifix are for many people. Like any tool – it is a means to an end. The ‘Scientific’ Path to God
How fast do you (or something else!) fall?
The statement: “An object in free-fall accelerates at a velocity of 32ft/sec2” (thirty-two feet per second per second, or, 32 ft per second, squared) – is one of the most confusing ideas in physics for the lay-person, myself included. This seems to be, mainly, because people confuse acceleration with speed, and speed with velocity, and because they’re not taking atmospheric drag, resistance, or buoyancy into account…oh, and one more thing; they do what I do – they over-think it!
The idea here, applies to objects that are in free-fall: a condition where, the only physical influence on a given body, is gravitation (in a vacuum**, e.g., the vacuum of space). This, actually intrinsically simple problem, has gotten the best of me more times than I care to admit. (And, this could, very well, be one of them!)
Nevertheless – it will help to remember, that: Velocity, is the rate at which an object changes its position in space. It is a vector quantity (it has two components: speed and direction). Here we will be, primarily, concerned only with speed. And we’ll take it step by step; it’ll be fun you’ll see!. Well then, here goes…
If we want to determine the distance that an accelerating object – say, a brick, dropped from a bridge – has fallen, after a time, given in seconds (easiest to do in whole seconds), then: after one second, the object has fallen a distance of 16.1ft. Now, you might think that, after two seconds the brick will, obviously, have fallen twice that distance – 32.2ft – since twice the amount of time has elapsed since the first second. But, due to the acceleration of gravity, which accelerates objects in a gravitational field at a rate of 32ft per second per second (known as the Gravitational Constant, or, 32.2ft/sec2) – this is a continuously accelerating brick; it is constantly gaining speed, at that rate, with the passage of time.
So, we have a falling brick. And, we have a bridge. But, for the purposes of this demonstration, we are going to need one more thing: a perfect – or, near-perfect – vacuum. Why? Because we will need to dispose of air. The presence of air will introduce atmospheric resistance in the form of friction, buoyancy, and drag. We don’t want to deal with those things, just yet. So, for the time being, we will have a falling brick, and a tall bridge, in an air-free environment.
Now, in our quirky little environment, we’ve got a falling brick, which is speeding up as it goes along, falling under our prescribed conditions, so that, after two seconds, it has fallen 64.4ft; after 3 seconds, it has fallen 144.9ft; after 4 seconds, 257.6ft, and so on. All objects, regardless of mass or weight, fall at this same rate in a vacuum, as demonstrated by Galileo Galilei’s famous experiment, where he dropped two iron balls of different weights (atmospheric drag is negligible here because of the ball’s relatively small size). Galileo’s demonstration was done, purportedly, from the top of the 186-ft, now leaning, tower, in the city of Pisa, Italy, around the year 1590. Whether he actually performed the experiment is moot (and, actually, still unknown); it has been tested – and re-tested, ad infinitum, ever since.
So, you can determine an object’s speed, in miles per hour, for any given interval during its fall (again, let’s do it in whole seconds), simply by multiplying by the number of seconds, squared, by 60 [to get feet, per minute], then, by 60 again [to get feet, per hour], then dividing that number by the number of feet in a mile (5,280), to get miles, per hour.
O.K., now – if we want to know how fast our brick is falling after the first four seconds of its fall (why, we might want to know this, is just so much whimsy – however): we simply write this expression:
.5 x 32.2 (ft.) x 4sq. (16.1 sec) x 60 (ft. per min) x 60 (ft. per hr) / 5,280 (feet in a mile) = 175.6 mph – or:
Now – wasn’t that fun?!!
Because the brick’s acceleration is constant as it approaches the ground, after 6 seconds it will be falling, according to our, slightly lengthy calculator, at a speed of 579.6mph! If we had done this experiment at normal atmospheric pressure (about 14.7 lbs, per square inch), our speedy little brick would have been slowed to a near-crawl – to around 122mph (terminal velocity) because of adjustments for drag and buoyancy, due to air resistance. And so, for obvious reasons (because, it would be a real pain in the *ss to try and figure out), we’ve left it, literally, out of the equation. But, since this is reality, and we’re stuck with it (apparently, to some degree), I will state here, that, our brick, under the influence of an atmosphere, will reach terminal velocity (the fastest speed, that, friction, from an increasingly thickening atmosphere, will allow) after only a few seconds, depending on how its shape, angularity, etc., respond to interaction with the air; I know – complicated and boring, right?!
But – wait! – there’s hope!…because, this rule also applies to objects in orbit as well. Let’s take the International Space Station, for example. The ISS is, as far as physics is concerned, a massive object, in vacuum, and in free-fall around the Earth and, which, has two motions working on it at the same time: a downward pull from gravity, towards Earth’s center, and a lateral, or, “sideways” motion where, it resists its gravity-induced fall toward the ground.
Now, the ISS is falling “around” the Earth, as the curvature of its surface causes the ground to “fall” away from the ISS, at the same rate that the ISS is falling toward Earth’s center, thus giving the spacecraft a combined orbital velocity of, approximately 17,000mph! The altitude of the ISS, and other bodies high above Earth’s surface, can be adjusted and maintained by properly timed thrust-maneuvers, using Newton’s 3rd law of motion which states, in effect, that, any action produces an equal but opposite re-action. The necessary thrust to maintain its orbital altitude, either, from it – or from any of its attached spacecraft – can be induced by using a built-in reaction control system (RCS package, or, retro-rocket package). Thus, an orbiting spacecraft’s pitch, roll, and yaw can be maintained – indefinitely.
Indeed, this situation applies to the moon, in its monthly orbit around the Earth, and to the Earth, and other planets, around the sun. But – there is an insidious, almost unbelievable situation going on here, that describes the attraction of all massive objects to all other massive objects and, in fact, to all matter in the universe…but, that’s for another essay; we both need a break here!
(Whew!…sometimes – I wish, Galileo had kept his BALLS home that day!)
(** Space is a near-perfect vacuum; the average cubic-inch of space contains only around 10 hydrogen atoms and a stray photon or two).
Why, is there ‘air’? – I guess Bill Cosby asked it best (or, at least, funniest), in the title of one of his 1960’s stand-up comedy albums. When my older brother received that album, I was 6 – I wondered why, myself. So, now I ask – does it really do US any good?
It seems that answer is, ‘yes!’ – and a resounding, ‘no’, as well; depending on ‘what’ you are…
©Mar 2014 Dale Alan Bryant
Comic, Bill Cosby, once posed a question in the title of one of his early, classic albums of stand-up comedy – “Why is there air?”
Let’s start with another, more fundamental question: “What is air?” In the Earth’s case, air, is its atmosphere – a blanket of various gases, approximately 250 miles deep, surrounding its outer crust. Air can be any gas, or combination, thereof. Our atmosphere is mostly nitrogen, carbon dioxide and argon – but it also contains a highly, “questionable” component – oxygen, at 21%. Most planetary atmospheres contain very little, if any of the troubling stuff; initially, Earth’s atmosphere contained none. Our oxygen (O) is, mainly, a by-product of living organisms, like bacteria and plant life. Those organisms convert the ambient CO2 (carbon dioxide) in the atmosphere into oxygen, which higher forms of life, eventually, became adapted to.
The Great Oxygenation Event, as it is known occurred sometime during the Pre-Cambrian period of the Paleozoic era, some 542 million years ago preceding the Cambrian Explosion [of life]. During this period, bacteria began to spread, worldwide, which in turn began producing an abundance of oxygen, which, in turn, generated more plant life. Oxygen combines easily with other elements, e.g., iron, hydrogen, etc. The early release of oxygen had bonded with those elements and was released into the still, nearly oxygen-free atmosphere, as free oxygen. Only single-celled bacteria existed before this time, which had no need of the nasty stuff! Nevertheless, as more complex multi-cellular life forms arose, they began to adapt to the increasing oxygen levels generated by the bacteria and vegetation. The present level of oxygen in our atmosphere is, as mentioned, 21%; but, it actually got as high as 35% during the reign of the dinosaurs by the beginning of the Mesozoic era. By this time, living organisms had begun to utilize oxygen so efficiently, and it was so abundant, that, a general trend toward increasing size of multi-cellular organisms took place – fossilized spiders have been found measuring more than 2 ft. across! (Egads!…)
Earlier, I had inferred that oxygen was a bit of a problem. Well, fond of the stuff, as you and I may be, this is true. Oxygen is not an inert gas; it is highly reactive, corrosive and poisonous to some organisms – more so, in Earth’s earliest days. Oxygen reacts with nearly everything that it comes into contact with, and, it is highly flammable. It is, at bottom, almost entirely, responsible for the corrosion, rust and decay, that takes place on our planet. We’re all too familiar with what oxygen, combined with moisture, can do; together, they wreak havoc on our possessions containing even the smallest amounts of iron, in particular, our automobiles. Air, also holds moisture and heat. Together, moisture conspires with heat to support the micro-organisms which cause disease and decay.
As a rule, an atmosphere, especially one containing oxygen, is not a good thing for whatever it comes into contact with, nor is it even the ‘norm’ in the universe (the near-vacuum of space is the norm; an average cubic-inch of space contains only around 10 hydrogen atoms and a stray photon or two).
Now, back to, “Why?” there is air. Most of our solar system’s planets and moons have some type of atmosphere, with varying compositions, densities and thicknesses. As the early Earth was beginning to cool, gases trapped within its rocky mantle and outer crust began to escape through cracks and vents (this process is called out-gassing), to uniformly surround the planet.
Additionally, some components of our atmosphere were delivered, via comet and asteroid impacts. Due in part to our atmosphere, conditions here on Earth, are just right, for the continual re-shaping of its surface, from rain and wind (including hurricanes and tornadoes), along with geological processes. Only in space can the destructive forces of an atmosphere be avoided entirely. Space, is cold, dry and still; nothing, can ever rot, burn, or erode there without the introduction of an oxidizer – even food will remain, eternally “fresh” there. Moreover, our old, metallic, robot explorers, like Pioneers 10 & 11, and the Voyager spacecraft, launched in the 1970’s, are in pristine condition – as bright and shiny as the day they were built. Too bad they didn’t think about that back in 1957 – they could’ve put a ‘57 Chevy, right off the assembly line, into orbit, and today it’d be in factory-new condition! (And, of course, mine!!)
Earth’s moon has no atmosphere, making conditions on its surface nearly the same as they are in space. Instruments left on the surface by the Apollo astronauts are in new condition, and some are still in working order, some 45 years later. And because there is no wind or rain, the boot-prints left by the astronauts in the lunar dust are as fresh and crisp today, as the day they were imprinted there – and will remain so, for millions of years to come – as long as we leave them alone. Only, the extremely slow accumulation of meteoritic dust on the lunar surface, coming from space, will dull their outlines slightly after many millennia.
On Earth – and, perhaps, only on Earth – we have atmospheric conditions that are, both, conducive to, and detrimental to living things. But, oxygen fuels our campfires – and our spacecraft; liquid oxygen (LOX) has been used in our rockets all the way back to the German V-2, but the combustion of the combined fossil fuels has lead to an excess of carbon in the atmosphere, the effects, of which, have yet to be realized. Currently, other astrobiologists, using data from the Kepler Space Telescope are focusing on searching for exoplanets possessing atmospheres with at least some oxygen content, that might support some form of life, and, that lie within a certain distance from their host suns, called ‘habitable’, or ‘Goldilocks Zones”. This seems a reasonable expectation, since, most of the only forms of life that we know- Earth life – utilize those conditions. The breadth of the Goldilocks Zone in our own solar system, runs from Venus, out to about Mars; Earth is about in the middle.
Nevertheless, with life being as adaptable as we have seen it to be, filling niches, from the deepest super-hot oceanic vents, to as deep as a mile into the Antarctic ice sheet, we may need to modify our current models of what gives habitable zones their, ‘habitability’.
Earth has been struck – more than once, in its geologic history – by very large asteroids.
Is it all over? What are the chances we’ll ever be hit again?
2017 Dale Alan Bryant
The threat of an asteroid impacting our planet, has existed since its formation, some 3.8 – 4.0 billion years ago (Gya). Materials left over from the coalescence of the Sun and planets, ultimately, accreted into the comets and the asteroids of the Asteroid belt, that we’re familiar with today.
Approximately 3.8 Gya, during the period known as the Late Heavy Bombardment (LHB) of Solar system development, the Earth, and the other rocky (terrestrial) planets had formed, by the accretion of most of their present-day masses. Material that was left over was widely distributed throughout the inner Solar system, and, by gravitational attraction, eventually impacted the surfaces of those terrestrial bodies, which include: Mercury, Venus, Earth, Mars, Earth’s moon, and the moons of Mars. These celestial bodies soon became saturated with impact craters, but, due to erosion by atmospheric dynamics, e.g., wind and rain, most of the evidence for these impacts has been erased on Earth, and on Venus. But, by the lack of substantial atmospheres, Mercury, Earth’s moon, Luna, and Mars’ moons, Phobos, and Deimos, respectively, retain the evidence of those 3.4 billion-year old impacts. There are still a few good examples of ancient asteroidal impacts remaining, here on Earth, e.g., Meteor (Barringer) Crater in Arizona, and a few other ancient and weathered craters scattered around the globe; but, in general, the evidence is difficult to detect visually.
An asteroid, in whole, or in part, is called a ‘meteor’ when it is traveling through the atmosphere and producing a visible vapor-trail (more appropriately, vapor- train): it is the train itself that we call a meteor – the term does not refer to the actual object that produces the train; that, is called a meteoroid: a particle, typically only the size of a grain of sand. The vapor train may appear as a long trail of whit-ish smoke, about the width and length of an airliner contrail (condensation trail) , and, usually having a bright, circular or oblong, ‘head’. But in reality, it is a ‘corridor’ of super-heated, ionized air created by the meteoroid’s swift passage through the upper atmosphere. Meteors typically enter the atmosphere at an altitude of 60-70 miles, at speeds well above 70,000mph! Some of these dense, iron and/or rocky objects may explode during their atmospheric descent, like the one that caused the Chelyabinsk air-burst that occurred in February of 2013, over Chelyabinsk, Russia. That air-burst was caused by an asteroid, the size of a five-story apartment building; that object exploded 15-miles above the heads of the townspeople of Chelyabinsk – fragments, of which, have been recovered over the years (of the meteor — not the townspeople). An asteroidal body can be the remnant material left in the wake of a comet, or rogue members of the asteroid belt.
Well – so far, so good…
However, and, though it is rare, some of these chunks of rocky-iron space debris, can survive intact, long enough to make it to the ground, depending the object’s size, composition, air-speed, and its angle of entry into the atmosphere. It was an asteroid impact that caused the extiction of the dinosaurs, in a mass-extinction that wiped out many of the, then-existing, forms of life on Earth. There have been five such mass-extinctions in Earth’s history; in particular, the Permian Extinction – an event, which, wiped out more than 95% of all living things on the planet, including marine life.
There are millions of asteroids and comets remaining in the Solar System today, that are in orbit around the sun, most of them confined to the asteroid belt that lies between the orbits of Mars, and Jupiter. But, due to the complexities of Solar System dynamics, occasionally, the orbit of an asteroid changes dramatically, in accordance with Newton’s 3rd Law of Motion, producing a shift in its trajectory. These changes can cause an asteroid’s orbit to wander, and, perhaps, coincide with Earth’s orbit at some point (and it only takes, that one point!). If both bodies, happen to end up, in the wrong place, at the wrong time – a collision occurs. At certain times, annually, we find ourselves, in, what’s called, an asteroid field, when the Earth is surrounded by hundreds of members of a dense ‘pack’ of asteroids. Smaller individuals, are called meteoroids. The entire months of April and October are two of these times. Some asteroid trajectories are known, and predictable; others are not. The Chelyabinsk asteroid, was one of the one’s that wasn’t; in fact, no one – not even astronomers, or their instruments – saw it coming.
The odds of being killed by a meteor or asteroid strike, in your lifetime, are extremely low, indeed – around 1 in 1,600,000. But if that makes you feel any better – consider this: you are 200 times MORE likely to be struck by an asteroid than you are to win a Powerball lottery!
Ahh, but there’s good news…
If an asteroid’s trajectory is known, and closely monitored, and, with enough advanced warning, a collision can be avoided by having the asteroid, harmlessly, deflected away, with robotic spacecraft intervention. We are, now, for the first time ever, in a position, technologically, to deal with this problem. The element of randomness in the equation tells us that there is no time to waste; a catastrophic asteroid-impact event may be entirely predictable –IF– the potential impactor can be detected in time, and then, deflected away onto a harmless trajectory. No one would argue whether or not this is a goal worth pursuing – right now. Our children – and every generation, following them – will be eternally grateful to us; there can be no doubt.
But, there are some prerequisites to accomplishing this goal: We need a ‘dedicated’ system of equipment, such as optical and radio telescopes, radar and warning systems, and, robotic, reactionary spacecraft. These instruments would be devoted, exclusively, to monitoring and encountering these potential threats, known to astronomers, as NEO’s, or, Near-Earth Objects. There are several ways for a spacecraft to approach and influence an orbiting body; all of them are, almost, ridiculously simple, and effective. One, is to physically, ‘nudge’ the offending body off course. There are a variety of ways of accomplishing that. One way, is to transfer momentum from the spacecraft – or, from an impactor body, launched from it – to the asteroid. A spacecraft carrying some given body/mass as its payload, would launch (“fire”) that mass, as a projectile, to the asteroid’s surface and, thereby, imparting the projectile’s inertia onto the asteroid and changing its trajectory (this demonstrates, Newton’s 2nd Law of Motion). The projectile itself, could be, simply, some amount of water, stored in a container aboard the spacecraft. Or, possibly, the projectile could be a low-energy explosive. Another way, would be to, literally, ‘spray-paint’ one side of the asteroid’s surface. A layer of light-colored, reflective paint could be used to gradually move the asteroid out of harm’s way, by employing photons from sunlight, known as the solar wind. Pressure from these photons on the painted side of the asteroid, would cause it to move, very slightly, but enough to put it onto a different trajectory. Pretty clever, that Newton!
Another way, using another of his laws of gravitation, would be to ‘park’ a spacecraft containing some given mass at such a position nearby the NEO, that it would ‘tractor’** the asteroid off of its current course, and, over time, move it onto a harmless trajectory.
The world’s major space agencies, e.g., NASA (the National Aeronautics and Space Administration) and the ESA (the European Space Agency), are in dire need of funding to build, occupy, and maintain the anticipated, needed equipment. The realization of such an arrangement would allow an ongoing – 24/7/365 – program, that continuously monitors, thousands, if not hundreds of thousands, of NEO’s, their trajectories, other relevent characteristics, and their threat-potential to Earth – and its inhabitants. If an NEO’s trajectory is predicted to become an impact threat at some future time, dedicated, robotic spacecraft equipped with an array of systems suitable for the task, can be launched to the asteroid and, with a choice of several methods, render the NEO – harmless.
(**This is the idea behind, Star Trek’s, ‘tractor-beam’: ‘pulling’, some massive object into the vicinity of the starship, “Enterprise”)
Ever wonder, just, what the heck, this is supposed to mean, anyway?!
May 2012 by Dale Bryant
Folks – this is a lot easier than you think – and I’m going to demonstrate that for you, right now, before you can say “Lorentz Transformation” – 5 times fast…
The expression “E=mc2”, is an algebraic equation, first used in one of four papers by Albert Einstein, known as the ‘Annus Mirabalis’ papers (from the Latin, ‘annus mīrābilis’, or, “miracle year”). It was published in the ‘Annalen der Physik’ scientific journal, in 1905. These four articles contributed substantially to the foundation of modern physics and changed accepted, conventional views on space, time, mass and energy. His, “General Theory of Relativity”, was published in 1915). And here’s what he was talking about….
If, either, (rest) energy, or, (total) mass disappears from a system, it is always found that both have simply moved to another place, where they are measurable as an increase in, both, energy and in mass which corresponds to the loss in the first system. This means that neither matter (mass), nor energy can be created, or destroyed; however, one can be ‘converted’ to the other. Think of them as being the same, fundamental ‘quantity’ of some thing (any thing). Einstein showed that, matter, was in fact a form of stored-up energy. His intent was to show that matter and energy are different states of the same thing (though, fundamentally, different; for now, think of ice, water, and steam as being different states of the same quantity. It’s not quite the same, but it’s easy enough to imagine for our purposes here).
Please excuse any unit substitutions I might use here, throughout; I use them for familiarity purposes only; the basic premise and magnitudes remain unchanged.
That being said, the conversion of matter to energy takes place at the atomic level, with proton and neutron particles and involves tremendous amounts of heat transfer. In a mass of a nuclearly unstable element, like Uranium-235, a neutron is fired at a U-235 atomic nucleus, causing its components to ‘split’ and, thereby, releasing all of its binding energy (the ‘binding’ nuclear forces (the Strong Nuclear Force, and the Weak Nuclear Force) which hold the components of an atomic nucleus, i.e., protons and neutrons together), which, in the process, affects the next, neighboring atom, causing a chain-reaction, violent ‘ripping’ apart of the entire mass, resulting in a nuclear explosion. ( The energy released in this process is unimaginable, so try not to think about it!)
‘E’, stands for energy in the form of an erg, or joule unit. Now, ergs and joules aren’t units that are too familiar to many of us so, though not entirely accurate (but, enough for our purposes), let’s substitute ‘watts’ for joules, instead. We can all easily imagine what the energy output, in the form of visible light, from a 100-watt light bulb looks like, and we’ll save that for just a minute. Next, is the arithmetical operator ‘=’, meaning “is equal to”, so that we can, ultimately, turn this seemingly vague equation into a clear sentence in everyday English. Next, is the letter, ‘m’ (‘m’ and ‘c’ are traditionally used in lower case). ‘m’ stands for mass, measured in ounces.
Now, let’s say that we had a penny, made of Uranium-235, rather than of zinc. If we had a particle accelerator handy, we could ‘split’ a U-235 atom, by bombarding it with, say, a neutron. A U.S. penny, weighs just under 1/10th of an ounce (yes, I checked). In the equation, ‘E=mc2’, ‘m’ is going to represent that 1/10 ounce, so, we will multiply that by the next letter, ‘c’, which stands for the velocity of light, in feet (I’m converting it from meters) per second. Now comes the superscripted, numeral 2, meaning “squared”, or c times itself, or c x c — so we are multiplying, m x (c x c).
O.K. – you had to figure something like this was coming – the point where things get messy and, unfortunately, that’s going to be here in the value of c, which is going to be: 983 million feet, per second. Sorry about that.
Alright – let’s take a deep breath – because, neither one of us really wants to know that 983 million feet squared, is 967 quadrillion feet; nor is there really a more palatable way to put it, even if we had used miles, instead – which, just happens to be: 183 trillion…sorry, again. But, all this vagueness and vastness is where all the excitement is; because – here is the whole thing in a nutshell (and, in English, as promised!):
Let’s say we set out to convert the mass of our U-235 penny into energy, say, on the island of Nantucket. The total energy, “E” (in watts), of that conversion, would be calculated as “m” (the mass of the penny), multiplied by ‘c’ (the speed of light, times itself) – initiating, through nuclear fission brought about by the bombardment of a subatomic particle (neutron) into the nucleus of an atom of Uranium 235. In the process – the extracted energy would generate an explosion, so intense that probably some part of the little island’s beaches – and some small portion of its landmass – would remain intact. But that’s it; the rest of the island – would be floating, above, where it used to be – as fractured grains of sand and water vapor; radioactive grains of sand and water vapor, at that. As for those 100w light-bulbs? It doesn’t really matter at this point. It’s a lot of watts – if you were to glance at all that light – you’d be blinded, permanently. All from a tiny penny.
As for the conversion of energy into matter, it happens all the time in the interiors of exploding stars known as supernovae. Under the intense pressure and heat in their cores, elementary particles are ripped apart and reassembled into other elementary particles, and so on. Ultimately, this is where the heavy metals we’re familiar with here on Earth are made; iron, gold, platinum, etc. But that’s a story for another time.
The first, and, to date, most terrible proof of the conversion of mass to energy came in two grapefruit-sized masses, weighing eight pounds each, of the highly unstable metals, Plutonium-239 and Uranium-235 (both, isotopes, a kind of by-product of those elements, proper). These were used as catalysts for the atomic bombs that were detonated, 8 miles above the cities of Hiroshima and Nagasaki – and, sadly, their citizens, in Japan, in 1945. 8lbs, per city.
Our above equation, “E=mc2”, for the conversion of mass to energy and vice-versa, is only one aspect of the Theory of Relativity, but I chose it as a starting point for its dramatic potential and, therefore, “sink-in-ability”. Other aspects of Relativity, include the restrictions of travel beyond the speed of light; length contraction of massive objects; time-dilation (the slowing down of time, as speed/velocity increases); gravitational lenses; infinite mass – and quite a bit more… And, though Einstein showed us how an atomic nucleus could be tapped for its energy, he was a pacifist, who abhorred violence; it was society, that felt it necessary to use the equation’s more vicious implications against itself.
“E=mc2”; use it – don’t abuse it!
Could Earth suffer another collision with an asteroid?
The question is not, “if”; the question is, “when”…