Red Giants & White Dwarfs: Our Lovely, Lovely Universe
Red giants and white dwarfs: Some of the most fascinating things in the known universe.
Stars shine by burning hydrogen in thermonuclear reactions
So a very strange thing happens when the core depletes its hydrogen ration.
It contracts, under gravity, drawing more fissionable material into the centre
And the new reactions push against the star’s shell, inflating it like a balloon.
But as it grows, the star also gets cooler and cooler, eventually turning red.
Ergo, it becomes a ‘red giant’ glowing sinisterly in space, like the Devil’s own eye.
Now, if the star wasn’t very big to begin with, then once the nuclear fuel is gone
Then the writing’s on the wall – the poor star will collapse into a white ball.
Although not big, the ball will be super dense and will now be called a ‘white dwarf’.
Nova and Supernova explosions: The fireworks displays of the gods.
The life of the white dwarf, formerly known as a star, is not over yet.
The white dwarf’s gravity can easily attract matter from a nearby planet.
Since the dwarf was once the core of a star, its gotta be pretty hot,
So the new matter is ignited right on the sphere’s surface and ‘Kaboom!’
You have this huge, huge flash of light called a nova.
And if the amount of matter was big enough, you get a Supernova.
By the way, there’s this massive star called Eta Carinae
And in the near future, she’s going give us a spectacular supernova!
Asteroid Impact and ‘Interacting’ Galaxies: The universe’s biggest traffic accidents.
You see, everything in space is moving and often very, very fast
And, believe it or not, there’s not enough space in space for everything
So every second of every day, something collides with something else.
Particles collide, planets collide and even entire galaxies collide!
(Hey, I wouldn’t make this up you know - I’m honest as Abe Lincoln).
We very much suspect that an asteroid collision wiped out the dinosaurs
And there are galaxies still dazed after accidentally bumping into each other;
They very shamefully stagger around like drunken sailors!
Chaos a.k.a Brownian Motion.
There are no traffic rules in the visible universe
And if it’s true that our destinies are controlled by the stars
Then it’s little wonder that our lives are so chaotic!
I remember when I was about knee high to a grasshopper,
My mum would tell me to make my bed after my nap at lunch hour
And uncountable little motes would rise whenever I flapped the blankets.
They were most visible when they got caught in the sun’s diagonal bars
And if you observed closely, you’d notice that they had no direction in particular.
At that time I didn’t know that the chaos was caused by invisible collisions
And just marveled at what I’d created – my own little universe!
Mars and Venus: Two of the planets in our solar system.
I can remember what the teacher was wearing in my first science lesson.
Okay, I tell a lie – I don’t remember what he wore for fashion
But I do remember what I learnt and it had to do with the solar system.
What we have are eight major planets, and lots of other stuff, orbiting a sun
That will one day grow into a red giant and probably collapse into a white dwarf.
Planet Earth, meanwhile, is ruled by men and women – the same species but so different
That it’s as if one gender came from Venus and the other from Mars
And they met on Earth whereupon they have been trying to coexist ever since.
Albert Einstein & Isaac Newton: Two of our best-known scientists.
Einstein gave us the theory of relativity and let us know that E=MC2
Cambridge University’s Isaac Newton gave us the laws of motion.
He put the ‘acceleration due to gravity’ at ten metres per second
Which means that if, for example, you were to fall from a passenger plane
Then you would hit the ground at a speed of about…er…hold on,
this is Physics 101 – where’s that damn calculator? –
Calculators are like cops – where are they when you need one?
Anyway, the point about acceleration is, ‘Don’t fall off a building or a plane!’
Carbon and Hydrogen: Some of the chemicals of life.
And on the sixth day, God took some carbon and hydrogen,
Added a dash of oxygen, a pinch of phosphorus and a modicum of nitrogen
And carefully mixed it all up before placing it in a pre-heated oven.
And when the first man finally emerged, naked and alone,
He looked up at the celestial beings in their dazzling white robes
And said: ‘All right, who’s the comedian who stole my clothes?’
Our Beautiful Spaceship Earth.
Three doors down from the Sun – actually, our nearest star –
Is our humble abode, Mother Earth. Among the planets, she’s not the biggest
But she is the fairest of them all! One thousand miles per hour is her rotational velocity
And as if that wasn’t enough, she still orbits the sun at 67 times that!
You can tell that the Earth is speeding because each month a different constellation floats by:
Aquarius, Pisces, Aries, Taurus, Gemini, Cancer…
Don’t look now, but I think the Earth is a giant spaceship!
We spend billions of dollars trying to reach the nearby moons and planets
While in actual fact, we take a free ride around the sun each year!
The Universe and You.
The universe is really, really big – I’m taking phenomenal.
It’s so big that no matter what technology we use, we can only see a tiny fraction of it
And, more’s the pity, it contains some things that we can’t see at all.
There’s dark matter, anti-matter, anti-particles, cosmic radiation;
There are quarks, neutrinos, black holes, worm holes, extra dimensions;
There might be parallel universes, shadow universes, etcetera.
And should our universe once collide with its anti-universe,
Then we will all disappear in the Mother of All Light Flashes.
In a universe so vast it seems that we hardly count but we actually benefit
From the existence of some very distant objects.
The precise distance of the Earth from the Sun and planets is crucial
And giants like Jupiter can gravitationally disrupt the trajectories
Of speeding asteroids that might otherwise crash into us.
It is likely, very likely, that when you’re staring at the universe,
The universe is, at that precise moment, staring at you!
Copyright © 2007 Alex N Nderitu
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