©02 The Media Desk
http://themediadesk.com
No, not cosmetology, make-up and its uses. Cosmology.
Most of the Desk's readers that went to public schools before say, 1985 would know it as Astronomy. Those that are postdoctoral fellows at MIT might want to call it Astrometrics or something equally heady, and throw a bunch of mind numbing equations at you as well. The Desk will stick with Cosmology.
What it is is the study of the heavens in a journalistic way.
True journalism (NOT what the Desk does) involves the answering of the five (or six) questions represented by 'Who, What, When, Where, Why' and maybe 'How'. Astronomy was simply looking at the stars and planets and taking a picture once in awhile. Astrology was trying to decipher any affects they had on us. Cosmology is a little bit of this and a little bit of that, and a pinch of some other subjects that only make sense to people that stay up all night watching Space Opera Theater and can do the Vulcan Salute without dislocating their fingers.
Who: Cosmologists try to answer every question except the 'Who' part of it, they leave that one for people like the Desk. A select few invoke God when all other explanations of the 'Uncaused First Cause' fail. But only then.
What: If you listen to the pros they can't even agree on the definition of a 'Star'. Does it require nuclear fusion, if so, is it H-1 or will H-2 suffice (these terms may or may not be explained later). How about heavier elements, say, fusing Hydrogen into Lithium or something. Yet once you are past that, there is a surprising amount of agreement on some things. And open warfare about other things. True enough, nobody has actually SEEN a Black Hole (you could not actually SEE a Black Hole even if you were standing on it.) but most of those that make their living doing this kind of thing agree they must exist. Past that, you're back into "fightin' words".
When: Here's another point to argue about. According to some research papers, the universe itself is about 13 billion years old. Yet there are those that claim some stars (quasars see below) may be in the 15 billion year old class. Can the universe be younger than its oldest residents? Then there is data that some pulsars are lying about their age like Hollywood Actresses. It could be that universal expansion hasn't been constant throughout history. Some red shifted light (Doppler Effect- light from object moving away is of longer wavelength than from stationary object) of galaxies moving away from us may be influenced by the gravitational pull of our own galaxy. And so on. So exactly how old is the universe? Who knows?
Where: Yes even that is a question. For many years the Earth was the center of the entire universe. Then it wasn't. Then it was again. Is it? Probably not. But you'll never prove it through observation. You look that way and you see for how many billions of light years. You look the other way, and guess what. Same numbers. Look up. Ditto. Everything seems to be moving away from us at basically the same rate (except objects further away are moving faster, and speeding up!). OK. So if we're not the center of reality, then what is? The Pros use analogies of raisin bread and balloons with dots on them, but it works out the same. If there is no meaningful center to the Universe, what does it matter if we think there is and we are it?
Why: The questions don't get any easier do they? Why did the Big Bang happen? Well. So we can ask the question is as good an answer as you're going to get. If it hadn't happened, or if Creation hadn't happened, either works just as well here. We wouldn't be worried about it now would we?
And now... HOW:
... and does so without Wild Turkey.
OK, IF you went to a Public School before 1985. Forget everything you learned in Science Class.
The Desk remembers a science book it had in Junior High in the mid-seventies (during the Moon Landings!) that talked about a 'land bridge' between Africa and South America. Continental Drift was still brand new and the teachers clung to their 'steady state' theory with a death grip. The dinosaurs had died out gradually. World Wide Cataclysmic Events were the stuff of B-movies. Nobody had heard of the Iridium Anomaly at the Cretaceous-Tertiary
Boundary that all but sealed the deal on something Earth-Shattering happening sixty-odd million years ago.
Then all of the sudden, in the mid-seventies, things changed.
Dramatically.
The Earth HAD changed. And changed fantastically. Several times.
Some went from looking down, to looking up.
"If our little lump of rock had changed, how about the sky?"
Confirmation of supernovas through telescopic observation and backed up by ancient Chinese and other manuscripts made it abundantly clear that stars come and go. And do so on a somewhat regular basis.
And then came the Hubble Space Telescope and other orbiting toys.
With the heavens now open for inspection our proudest boast that our Sun was special fell to the floor like a cookie jar with a hungry toddler in the house. While our precious star is brighter than ninety-five percent of the other stars in the galaxy, those dim sisters outnumber our type of star and those brighter are rather rare even though we see them more often. Eighty percent of stars in the Milky Way are red dwarfs, dimly glowing relatively cool bodies of which even nearby ones are not even visible to the naked eye. G-type stars, like our sun, are a minority, four percent of the Galaxy.
And now that you mention it. Our Galaxy, while good sized, isn't so special either.
Hubble, in just a couple of photographs, discovered more galaxies than had been discovered in the previous millennia. Six Thousand of them in the 1995 shot of the 'Tadpole Galaxy' alone.
A few are bigger, many are smaller. Most are in clusters, some in super-clusters, others are alone. And all of them have millions, aye, even thousands of millions (billions) of stars.
Then they discovered planets. And then they didn't... Well maybe they did after all.
That's the way it went. Some of those of the Astrometrics camp thought they had done the right math based on the 'proper motion' of stars (movement of a star in relation to other stars as they all orbit the center of the Galaxy together) to 'prove' there were planets orbiting the star.
OK... quickly. As the Moon orbits the Earth it exerts a 'tug' on the Earth. Causing tides. It also causes the Earth's orbit around the Sun to wobble a bit. OK. Still here? So too does a planet tug on its star. Obviously something the size of Jupiter (300 times as massive as the Earth) tugs on its star more than we do. And if such a giant planet was a bit closer to its star, it would tug more. And there you have it.By measuring the observable differences in the star's path, and making some basic assumptions on the star's mass and predicted orbit, you could work out, with a very fancy calculator, how massive the planet orbiting it is.
And the stars they are orbiting are everything from one of those all too common red dwarfs to a few of the dimmer Main Sequence stars. For one very simple reason. Because the star isn't blindingly bright, like our sun, planets, orbiting dust clouds and companion Brown Dwarfs are relatively easy to spot.
Which is easier to see from the highway driving past? A Giant Redwood Tree in the New Jersey Pine Barrens, or a New Jersey Pine in a Redwood Forest?
If a G type star like our sun some fifty light years or so away had a swarm of planets around it, a couple of which sported a civilization more or less like ours... and a bunch of asteroids, comets, orbiting satellites pumping out their version of MTV all day and all night...
... we would never know it.
The star is too bright. The planets and their associated moons and rings couldn't reflect enough light or heat to overcome the solar radiation. The civilization's radio emissions couldn't cut through the interference from the star.
For those reasons, we are not even looking for ourselves out there. Not yet anyway. We are just learning how to recognize planetary systems that we could live in. As a science, this one is still riding with its training wheels on its bike.
But things are looking better for other aspects of our getting to know the neighborhood.
Not Exploring it. But, well, window shopping.
The Closest stars are in the five to ten Light Year Range.
OK, that's fairly close right?
Well, compared to say, our nearest sizable galactic neighbor, M31 (Andromeda) which is 2.9 million light years way, yeah, Alpha Centauri, at 4.3 really is next door. It only takes the light of the star just over four years to get here. Not bad.
Except the Light Year is a measure of the distance LIGHT travels in one year. Moving along at 186,000 Miles per SECOND a Light Year is equal to 5,850,000,000,000 MILES. Almost six trillion miles. Six Million Million.
So four point three light years comes up to roughly 25.8 Trillion Miles.
But can't we get there?
In short No.
Nothing we currently have can get to even half of light speed. The Space Shuttle in Orbit is booking along at 18,000 miles per hour. It would need over thirty five YEARS to go just ONE Light Year's worth of distance. At that rate, it would simply Never make it to Alpha Centauri.
Even using the Maximum Application of Current Technology and Theory (and costs be danged)... Using Nuclear Fission (and maybe even Fusion) as a propulsion system... And throwing everything we have at the problem, the best we could do Right Now would be MAYBE reaching something on the order of three-quarters the speed of light. Which works out to just over Four Trillion Miles a Year. Which would make it six and a half years to get to Alpha Centauri. Anything much faster than that, and you run into problems described by Mr. Einstein where a body moving at speeds approaching the speed of light increases its mass due to the energy load it is carrying. So the next step faster may require an equal amount of energy used to reach that speed from a standing start in the first place. So there you sit, for over six years. Let's run out and sign up.
Six and a Half Years in something the size of the Space Shuttle. With enough air, food, water, fuel, and diversion to last the crew for Six and a Half Years. It would be towing several Freight Cars of Supplies. Which would need more fuel to push. Which would require more storage. And Etc. And that's just to get there, we haven't even thought about coming back.
So- Possible? Yes.
Actually DO-ABLE? No.
And don't even mention Warp Drive- Faster than Light Travel.
While some physicists say that it IS possible... Theoretically. Right now, given today's technology, and equally important, today's energy production facilities, it simply cannot be done.
Today.
That doesn't mean that Tomorrow it won't be invented. And sometime in the Future we won't be warping off to Sirius, 8.6 light years away, for the weekend and wonder what all the fuss was about.
Dark Stars.
No, not Black Holes. Not even really a close relative. Some call them Brown Dwarfs. Are they stars or are they planets? Doesn't really matter.
In some respects, Jupiter is one. It radiates more heat than it receives from the Sun. It is actually warm. Some say this is due to nuclear reactions in its core, others claim it is due to the gravitational reactions in the core continuing to collapse from its formation and compaction of matter on the atomic level is releasing energy, but is not actually Fusion. Whichever. Bottom line, in some respects it is as much a star as some say Brown Dwarfs (which, by the way are not brown at all, but a very dark red leaning toward black) are.
Main Sequence Stars, the Sun and its cousins, and some of those off the Sequence which are on their way out, we'll talk about them later, are using gravity to drive nuclear fusion which produces their light and heat. The heat stokes the nuclear fire, causing more fusion, and so on. For stars like our Sun, this process lasts something on the order of five to eight billion years. Some stars are far too hot and, if you can believe it, form, burn, cook themselves, and die in just a few million years. Others glow steadily for billions of years until one day, boom. Supernova.
Other stars run as hot and cold as a temperamental old cookstove. And these are fascinating as well.
Variable Stars range from pulsars (which are a special type of star but a 'star' nonetheless) that confound to Cepheid Variables that are almost comforting in their cycles. Most of the stars turn out to be double stars, a bright star orbiting a dimmer companion, or two. Others are still something of a mystery. Seems singular stars, like ours (so far) are rather unusual.
One theory of Pulsars is that they used to be regular main sequence stars that met a nasty fate, shedding most of their bulk in a nova explosion, and are now small dense masses of stellar core a dozen miles in diameter or so that is rotating at some ungodly rate. Some of the slowest pulsars spin a few times a minute, flashing like ye olde basic coastal lighthouse, others, some with masses twice that of our sun or more, are turning in space dozens, even hundreds or more, times per second. If you were standing on the surface of the north pole of the pulsar in the Crab Nebula, the stars in the sky would be lines, solid circles around you as you spun in place once every three hundredths of a second, .03 of one second.
How much is three hundredths of a second? You can't blink that fast.
According to people that study this kind of thing an average blink runs .15 to .3 of a second. The Pulsar rotates at .03 of a second. Which means if you blinked, you'd miss something like five rotations.Other variables seem to turn their own thermostats up and down on a more or less regular basis. Some scientists say they are entering their death throes and gravity is battling outward radiation pressure and it is just a matter of time before one or the other wins and the star as we know it ceases to exist. Either it collapses into a Black Dwarf and becomes essentially a great lump of coal slowly cooling in space, or it blows up in a spectacular show and ends up... well, something else. It just depends on the mass it starts with. Other experts say variable stars are just another variation on an infinite range of stars and they are behaving as they were meant to, and have been, since they formed however many years ago and will go on for however many more, and there's not a whole lot we can do about it either way.
Speaking of Unreal....
You were wondering about Black Holes.
OK. We'll go there.
Well, actually we won't GO there. But we'll talk about them.
First out of the can. Black holes have NOT been directly observed. Not even by the Hubble. By definition, a Black Hole is essentially that. Whatever caused them to come into being, they are now holes in space from which neither matter nor light can escape. (Although recently some have proposed that some exotic critters like Hawking Radiation can make a break for it.)
We have seen what may be Accretion disk around what may be a Black Hole (the disk is a cloud of dust and debris that is being drawn into the gravity well of the Black Hole. Think soap bubbles swirling around the whirlpool as your kitchen sink drains). Such as in the constellation Cygnus. These have been directly observed. Now whether they are actual proof of the existence of a Black Hole or not, well, that remains to be seen. But it might not be a good idea to bet against it at this point.
Neutron Stars are wanna be Black Holes that just don't have the moxy for it. Tiny, cold, darkening, slowly spinning hulks with enormous mass for their size. Maybe at one time they were a pulsar, maybe they used to be a regular star that skipped the Black Dwarf phase. However they got that way, all they are now is a navigational hazard to any starships passing through the area. And the only way we can detect them is by the effect of their gravity on whatever is in the area.
Some of the braver theorists go further to surmise that Black Holes may be essential to the creation of galaxies and stars and planets, and thereby life itself, in the Universe.
In the Stellar Furnace, all elements up to Iron can be accounted for. Nuclear Fusion releases energy as you combine, well, Hydrogen-1 Atoms (Hydrogen-2 is Deuterium, ye olde basic Hydrogen, one proton, one electron, plus a neutron, it fuses at a lower temperature in the star and makes other stuff) to make Helium. Helium becomes Carbon, and so on. Once all the Carbon and other lighter elements end up as Iron, you're done Releasing Energy. It now TAKES energy to overcome electron resistance and other factors to create a heavier element. So the star that has cooked up all its Hydrogen and Helium is now a giant magnet in space. Our Black Dwarf or something similar.
But if the star has enough mass, and does the Nova Dance, and becomes a Black Hole or even a little less and ends up a Neutron Star... all bets are off. Gravity pulls in everything in the neighborhood, including bits of neighboring stars if close enough. Planets, dust, even the occasional space probe launched to exam them. The atoms are packed so tightly it is conceivable to think of the core of a Black Hole or Neutron Star as nothing more than a Single Atom. The only difference is mass.
Our brave Stellar Theorists suggest there is a Critical Mass phase where the pressures of heat, radiation, rotation, and maybe even its own overwhelming gravity, cause the Black Hole to Explode in something akin to the original Big Bang. Spewing untold tons of matter back into the universe in the form of great plumes of heavy elements and compounds. Uranium, Gold, Lead, and all the rest, formed in the bowels of a Black Hole.
But is a Black Hole Dark Matter?
Well. Yes and no. Yes in the sense that Dark Matter is basically everything in the Universe that does not light up. No in the sense that at one time Black Holes were probably stars.
Planets are Dark Matter. Interstellar Dust Clouds are too. So are Neutrinos (one of those things that cannot be seen, cannot be directly measured, and so far the Government cannot tax, but may make up a good piece of the mass of the Universe). Everything that has Mass, exerts Gravity on everything else in the Universe. Your coffee cup is pulling on the Earth just as assuredly as St. Peter's Cathedral is. In fact, St. Peter's is pulling on your coffee cup, and it on the Cathedral. However. The Planet has more pull than both of them. So they fall toward the planet when dropped much more noticeably than the planet's 'fall' toward them. If you go to test this by dropping St. Peter's and measuring the Earth's reaction, let Fox News know so they can tape it. In your experiment, the Earth would react to the falling cup and cathedral on an order of magnitude which would reflect the difference in mass between the coffee cup and the church. Yet unless you had instruments far more sensitive than anything currently in use, you wouldn't be able to tell. Even if you dropped K-2 from the International Space Station, the planet would barely notice as far as gravitational deviation goes.
But the affect is cumulative. The more mass you have, even in different bodies, the more gravity you have. If you put your coffee cup in St. Peter's you have added to its mass, and thusly to its gravity. Now put the building on K-2, and you have even more. Take the Earth and its Moon together, and you have more yet. So it goes with Dark Matter. And for that matter (pun intended) stars as well, but we're talking things that don't glow in the dark here. The vast, nearly endless, tracts of dust and gas in the galaxy may not seem very massive. Especially since we can see stars shining through them. But if you have a dustcloud scores of light years long, that's a lot of dust. You've emptied vacuum cleaner bags, dust in quantity has mass. Even if individual interstellar dust particles may be smaller than your average grain of beach sand and most of the gas is Hydrogen, that is still a lot of Cumulative Mass.
And it has Gravity.
Remember that.
Back a little earlier we mentioned that the Universe is Expanding.
OK. So?
We won't get into what it is expanding into. Nobody knows. If Chicago wants to expand, they buy up a few soybean fields, pave them, build a pizza joint and some apartments, and the City has expanded. But there aren't any bean fields around the edge of the Universe for it to expand into. Supposedly, it is expanding into NOTHING. OK, before we all get a headache. Let's continue.
Since The Beginning, whatever that beginning was, the Universe has been expanding. For some Thirteen to Eighteen Thousand Million Years, it has been expanding.
Will it continue to expand into the Nothing beyond forever and ever and on and on? Until its galaxies are an eternity apart, their stars slowly cooling as the combined gravity of the galactic clusters allows more and more of their matter to escape until the last ones burn out and the universe slowly goes dark and cold. Lifeless. Forever expanding into nothing.
Will it reach a state of equilibrium, like a soap bubble, extending itself until its rotation generated centrifugal force equals its combined gravity and thus remain static. More or less unchanging.
Or will its outward expansion be overcome by its combined gravity. Slowing the expansion until it stops, then everything will begin to fall in on itself in a fiery antithesis to the Big Bang, the Big Crunch. Which may well result in another Bang, creating the Universe all over again.
Well. All three are possible.
And all three have their proponents. And all three have some data to back them up.
It all depends on a single number. Represented by the Greek Letter Omega. The Critical Mass here is the whole number 'one'. If the Universe's density, Omega, is less than one, it does not have enough mass (gravity) to halt the expansion, and will go on flying apart forever. If Omega is exactly one, then it will reach that equilibrium, and, sometime just this side of forever run out of fuel and go cold. If Omega is more than one, the expansion stops and reverses and 'Crunch'.
There is NOT enough mass in all the Stars, Un-Stars, Black Holes, Brown Dwarfs, and Pulsars to equal a Universal Mass of even close to one.
The key is in that Dark Matter we talked about before. Dust. Gas. Rocks. Even Neutrinos. Some observations suggest the Milky Way is swimming in a cloud of dust several times larger than it is. Such clouds have been observed around other galaxies, such as M-51, the Whirlpool Galaxy, and M-32 Andromeda. That galaxy's shroud of dust and gas is easily twice the size of the galaxy proper itself.
Some people think Chicago makes up most of Illinois. Even after our soybean field cum pizza joint expansion, the State of Illinois is still many orders of magnitude larger than Chicago. Nevermind what Mayor Daley said back in his day, there is more to the Land of Lincoln than the City of Big Shoulders.
So it seems to be with Galaxies. Yes the part that we see, stars, glowing clouds giving birth to bright blue young stars, Black Holes swallowing entire solar systems, is spectacular. But the part we can't readily see may be two or three times more massive than the galaxy we can see.
If our solar system is Seat 13 row 9 Section D at Wrigley Field
and the Milky Way is the City of Chicago, it may very well be that the rest of the State of Illinois is the Dark Matter Cloud surrounding us. We just can't see it from our seat.
Now the question. Is the Dark Matter in and around the Milky Way, and the Whirlpool, and Andromeda, and the rest of the Galaxies in the Universe enough Mass, enough Gravity, to add up to more than an Omega of One and thereby Close the Universe? To Stop the Expansion and ultimately result in the entire thing, including our seat at Wrigley, being recycled into a New Universe?
The answer?
We don't know. Maybe. If Neutrinos and other odd little particles actually have Mass. And they seem to, maybe.
Maybe.
Hang around another Ten Billion Years and see.
Back in the Good Old Days. Everybody knew Jupiter had the most moons of every planet in the Solar System.
Well. Now, you have to check to see which one it is this month. Right now. Saturn has over 30. Just how many more may turn up around either, who knows. Uranus may actually have more moons than the King of Planets, Jupiter.
Back in the Good Old Days, the nineteen thirties no less, everybody knew Pluto was it for the Solar System. There was something special, almost holy, about the number nine.
Well. If Pluto were discovered today it would not be called a Planet. For one, it is smaller than Earth's Moon. Also, Pluto's own moon is almost as big as the 'Planet' itself. Charon makes Pluto actually a double planet if it's anything at all. Then its orbit takes it inside Uranus for part of its year, and it is tilted far out of line with the rest of the planets.
Is Pluto, whatever it really is, It for the Solar System?
Hardly. There is considerable interest in probing beyond to the Kuiper Belt and the Oort Cloud and other regions of space Out There for everything from Planet X to a companion Brown Dwarf of the Sun.
Is it likely they will find another member of our Solar System or a special friend of the Sun?
Well, from the Sumerians, or even before, to just after the American Revolution, there were Six Planets. Mercury, Venus, Mars, Jupiter and Saturn. Earth itself wasn't recognized as a Planet until, well, embarrassingly late in history, but we won't talk about that. Six. That was it.
Then a gentleman looking for something else noticed a small greenish speck that shouldn't be there. Uranus. 1781. Seven Planets.
Seven really is a Holy Number. To those that preach such things, Seven Planets made the Solar System Perfect.
Until the 1840's when Astronomers working out the path of Uranus noticed something quirky, did some math, and predicted, then found Eight. Neptune. And later, Pluto.
At one time it was Heresy to believe the Earth was Round. If you sailed too far, you'd fall off. It was also the Center of the Universe. And while you're at it, it had always been as it is today.
Then it was taught, OK, even Preached, that Planetary Orbits were perfectly round. And well... OK... most of them almost are. Almost. But none of them are perfect circles around the Sun.
The Earth came into existance on October 23rd 4004 BC. At Nine AM.
It was a Friday too...
Nevermind that on that date some civilizations had already been around for a thousand years making Green Tea.
We KNEW it to be true.
Inconvienient facts Must be Ignored.
We KNOW it to be True.
Land Bridges. Flat Earth. Six Planets.
Ecosystems MUST have Sunlight as their ultimate source of energy. You cannot have plants and animals existing around thermal vents on the Ocean Floor two miles below where Sunlight Has Ever Reached.... hhmmm...
Imagine... Just Imagine... what you will KNOW tomorrow.
Pass the Green Tea.
selah
[NOTE: There is no way the Desk can credit the books, papers, websites, and TV documentaries it has read, and viewed, and used, over the years. Suffice it to say the everything cited is either readily available, public domain, or put out by a Government Agency. ] If you are interested... below are a few links to sources for more information.Thank you.
[WEBMASTER NOTE: The Desk is NOT a Physicist, nor does it play one on TV. But it does find the whole thing, to coin a phrase- FASCINATING
Thank you.][FURTHER NOTE: The Desk would like to thank a Day Job co-worker for advice and proofreading for this article. She is not only a knowledgeable star-gazer and amateur Cosmologist and is much better informed about these things than the Desk, she also happens to be a perfectly charming and stunningly beautiful young woman. Thank you- Ma'am.
Dr. Leftover ]
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