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Bringing the Universe to Your Classroom!

Saturday, April 7, 2018

Look - Up in the Sky: It's a Bird! It's a Plane!

... Well, yes, it probably is.

As an astronomer, with an interest in astro-biology and, therefore, in the possibility that life exists elsewhere in our universe - invariably, almost daily - someone will ask me something like: "Do you believe in aliens and UFOs?" My answer is, generally, something like: "I *ABSOLUTELY* believe that, "they", are out there. They're just not, here."  But they don't like that answer, and at that point, the conversation usually turns to questioning the current state of my sanity: "How can you possibly believe in life in the universe - but NOT in UFOs?" Well, there are some really good reasons for this; and, here is my answer:

"Tweet" "Tweet" "Tweet"!

THE SHORT STORY:

1) Universal Constants There is no 'getting around' such things as universal constants: they are constants because they are, by nature, unchangeable; nothing can alter them. They obey inherent, long-proven, immutable laws of physics that are the same - everywhere in the universe. (How we know this, is another, very long story - so forget it.)  But, what this means, is that, no, intelligent, alien life-forms (or, 'Extraterrestrial Biological Entities', if you prefer), could build a vessel for space travel that could 'out-maneuver', or, 'get around', say, the speed of light, for one. They would be subject to the same distances and travel times that we would be subject to. Even if they were from some planet in the nearest star/planetary system, which is the Proxima Centauri system - and even if they could travel at the speed of light - it would take their spacecraft 4.2 years to arrive here at Earth - the same length of time that it takes light to travel that very same distance. 

So, let us take a look at light for just a minute: 'Light', is a mass-less, neutrally-charged radiation from a particle called a photon. Photons are propagated through the vacuum of space in waves, at a constant speed, or, velocity. That velocity never varies, and we can use it to measure the distance to any celestial object by calculating the time it takes to travel from one place to another. The way we can measure these distances is by knowing the speed of light itself, which has been determined, and confirmed, countless times, to be exactly: 186,282.3976 mi/sec. Therefore: light from the moon takes 1.3 seconds to arrive at our eyes, here on Earth. Light from the sun takes 8.5 minutes. From the nearest star, Proxima Centauri, to our Solar System, the travel time for light is 4.2 years.  From those travel times we can define the distance that light travels, in, say, one year's time - 5,874,601,670,000 miles. This is where we get the term light-year (LY) from. So, one light-year (LY) = 5,874,601,670,000 miles. The term is used as a measure of distance, rather than of time, for obvious reasons. And, as if that weren't bad enough - the next closest star hosting a known planetary system, is Fomalhaut. Fomalhaut ('foam*a*low'), is 25 LY's away. This means that our brave little aliens - in their very special (and, very impossible) light-speed-traveling spacecraft - would take 25 years to get here! After Fomalhaut, comes Pollux, at a distance of 34 LY's, and then, Algieba, at 126 LY's, way out there in interstellar space. There are many, many more stars beyond 126 light-years, this is true, but: nothing in the universe can travel at the speed of light, except light; that speed limit is reserved - for EMS radiations, only.**

The reasons for this are far too involved to get into in this limited space, so, as I had implied, earlier - I won't. You'll have to take my word for it. Violation of these restrictions (where the violation would exist, hypothetically, only), would bring on all kinds of impossible, even, laughable consequences; for example: infinite length-contraction and infinite mass, to name just two. Length-contraction, and mass increase, are two, verified relativistic effects from General Relativity. They are very real - and, they are problematic to mess with - so we're staying away from them. In short, anyone else out there is limited to the same physical restrictions, as ourselves.

The top speed that any of our manned-spacecraft has ever achieved, is about 26,000 mph - that's, one hour, to travel 26,000 miles. That's pretty darned fast, right? Nevertheless, in one hour light will travel 670,000,000 (670 million) miles. So, let's cut our 'little alien friends' some slack, and say that they have built a spacecraft that can travel 100 times the speed of our own. That will give them, a top speed of - 2,600,000 mph! Now, I've calculated it all out, so, I'll skip all the math here, but it's going to take those guys - 11,151 years to get to Earth - from the very closest star!  And if they're from Fomalhaut, it'll take them - only, 44,604 years - to get here!  And if they intended on going back home - they'll need an additional 44,604 years for the return trip! (Are you seeing the collective problem here?) Not a good position to be in, for interstellar space-farers, to say he least.

Next item up for attack:

2) The unreliability of 'eyewitness' UFO reports Most people don't spend much time, on any given night, staring up at the sky. They might notice the moon and stars, an occasional meteor, or, falling star - but that's about it. But, astronomers, typically, spend many hours on any, given, clear night peering intently into the sky. Not only are they in, direct, visual contact - night after night, year after year - but, they also have highly sensitive instruments, trained on various sectors of the celestial sphere.

I have never known any astronomer to file a UFO report - or, even, having had a sighting. Why should this be, when, so many others have?! The answer is not that astronomers are involved in some kind of UFO/conspiracy cover-up (if they were - I would have spilled the beans a long time ago). No; there is no need to be. You can't conspire about something that, you understand, does not exist. Moreover, unlike so many others, when it comes to strange-looking objects in the night sky, the astronomer has seen it all. She/He understands the many kinds of objects that the night sky has to offer, which, the typical layperson, couldn't identify if their lives' depended on it.  I really don't mean to sound so harsh, but, that's a harsh truth - and I've heard all kinds of stories, misrepresentations, and misinterpretations. The  problem that we astronomers have with this, is, that so many people think they can.

There are many, many celestial phenomena that the average layperson has never or, possibly, will never experience, such as, bolide or fireball meteors - especially the rare, larger asteroid fragments. Back in April of 1966, a large, iron asteroid fragment, had entered the atmosphere, at a shallow enough angle that its long flight through the thickened air slowed it considerably. Anyone not familiar with such sight could easily have mistaken it for a burning aircraft. The 15ft.-diameter chunk of space-iron, which, emitted, glowing green and yellow at its leading edge, or, 'head', took about 45 seconds to cross the sky, from horizon to horizon, moving parallel to the thickened column of air hugging the Earth's surface at such a low angle. The object left a trail of glowing, orange fragments, along its path - coupled with a wide corridor of white smoke, which I could trace all the way back to its point of origin (exclusive to my position). Measurements taken from Harvard College Observatory of the flight-path of the object, determined that it was 160 miles, due West, of my position on Cape Cod, and 60 miles in altitude, when it entered the atmosphere moving northwards, over New Jersey.  Then the rough, melting, mass of rock and iron, 'skipped' back out of the atmosphere, somewhere over Ontario, Canada. Sightings of asteroid passages of this magnitude are very rare; typically, a once-in-a-lifetime event. I was very fortunate to have seen two of them, as well as, the following, aging Earth satellite. 

In late July of 1979, I was spending the afternoon at Quissett Harbor, when I was treated to a replay of the 1966 asteroid flight. Low over the treeline, at the northwest horizon, there appeared a brilliant, blue-white object about the size of the full moon moving towards the southwest at an elevation of about 40 degrees. The object produced a long, white train of smoke behind it, which I was able to trace back to its point of origin. The object moved slowly across the sky at about the same velocity as that of the '66 fireball. I later learned that it was a large' chunk' of the Skylab, orbiting space station, which had suffered orbital decay that afternoon and plummeted through the atmosphere, at a moderately low angle, and ended up - in pieces - in the Australian Outback.  And there's more confusion in the sky: planetary groupings, conjunctions, opposition's, some of which, even include the moon; comets, asteroids, satellite panel, and, antennae flares, the International Space Station, and, even, 'stationary meteors' (I've witnessed exactly one case of the latter). 

My point, is, that these, admittedly, spectacular events are very, very rare and could confuse anybody that didn't have a background in astronomy, and meteorology - and that includes pilots.  Aircraft pilots have it particularly tough when it comes to identifying objects in the sky that they aren't familiar with. One of the reasons for this is lack of depth-of-field, or, an inability to determine an unfamiliar object's size, distance, and proximity, for want of a familiar reference point, or, a familiar object to compare with. This is because 'binocular vision', or, the 3-D, or, 'stereo' aspect of an object, beyond about 50 feet, is lost. This is the distance at which camera lenses become, 'fixed', at infinity. The 3-D effect is lost at that point and the brain's ability to judge an object's relative distance, relative velocity, or, even its dimensions, is lost, unless the object is one that the viewer can recognize, and therefore, it's dimensions recalled to memory. Even then, relative distance and relative velocity are judged - not by vision, per se - but by the observer's familiarity with the object. 

Aside from those celestial and meteorological surprises, and at least as important, is the subject of visual phenomena. For example, small, star-like points of light when seen in the sky, against a dark background, can produce, physical, visual phenomena like the one that I experienced, one night, in younger days, while watching the stars at the beach with my brother... Standing, facing the southern horizon and opposite our positions on the beach, we noticed a 'star' that was moving very slowly along the horizon and toward our right. After several minutes, it became apparent that the 'star' had a second component to its motion; it was moving toward us as well. After about another minute, it grew much brighter, and larger, and then -- began to sway, slightly -- back and forth, like a pendulum! We both saw this. At the same time. And at that point, I said to my brother, "Are you seeing what I am?!"  He answered, "You mean, it's wobbling!?"  Yes, that's what we saw all right. Meanwhile, there was no sound, whatsoever. Knowing that this was an impossible feat, for any conventional aircraft, and, that it broke, probably several of Newton's Laws of Motion, I then, yelled to my brother - of all things - "let's ditch into the dune grass - fast!"  Immediately after those, "out-to-lunch" words of wisdom, left my big mouth - we both heard the tell-tale, unmistakable - "thwup, thwup, thwup, thwup, thwup, thwap, thwap, thwap, thwap" - of approaching, doppler-compressed helicopter rotor blades....and then, we went home. And we didn't mention it, to anyone - ever again.

This common, but typically unrecognized, visual 'mirage' is called the 'pendulum effect'. It's just one of many possible anomalies of the human, eye-brain interface. There are others (some, you wouldn't believe!), like a  type of image 'flicker' that can cause a seizure in certain, affected persons. And there are others, even some that you have, likely, unwittingly experienced, at one time or another. For more enlightenment, see: http://onlinelibrary.wiley.com/doi/10.1113/jphysiol.1977.sp011686/full

On any given day, there are around 200 reports of UFO's, around the globe. And there are also  those who have a tendency toward 'conspiracy theory' out there, as well. Current television, 'documentary'-style programming which focuses on ancient alien visitation, and the like, are presented in serial form. They are able to continue on, and on, and on - only because they have nothing of import to present. Speculation is, seemingly, blissfully infinite. An important point once made by the late, Carl Sagan, very simply, states: "Extraordinary claims require extraordinary evidence"; and that - is the missing component in the data from those who make such claims as, possessing 'proof', of flying, extraterrestrially-piloted, vehicles/crafts, etc., over the skies of Earth. The 'proof' - in any form - of visitation by beings from other worlds, simply, doesn't exist. And, not to burst anyone's bubble - but, here's a little quote of my own: "In Science, you go with what you've got - not, with what you'd like to have".

So, I feel that I'm safe in saying, that, our skies are not full of the alien spacecraft, and their pilots, that most witnesses of 'UFO's' believe there to be. If and when that situation ever changes - and it is, hypothetically, entirely possible - it'll be a different story. But for the moment, the reigning consensus on whether or not we're being visited by beings from other worlds, by those who know best (the Astronomers), is, a big, fat "No".  **(This applies to all forms of radiation in the Electromagnetic Spectrum, including: radio waves, microwaves, infrared light, visible light, ultraviolet light, x-ray, and gamma ray radiations; all, are forms of light.)

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