Monthly Archives: September 2010

Universal truth: it’s big and getting bigger – Analysis Alex Klein

Found this article in the Times… and thought I’d share it the only way I can as it was behind Mr Murdoch’s paywall. Besides… in the grand scheme of things according to this article.. copyright infringement does not really matter one iota.

The Universe is extraordinarily ancient. Scientists estimate that the Big Bang – the spontaneous, explosive creation of all space, time and energy – occurred 13.75 billion years ago.

To put that in perspective, imagine if the Universe’s lifetime up until now were the length of a 90-minute football match. The Earth wouldn’t have emerged until 60 minutes in. Life develops about seven minutes later. The dinosaurs would have gone extinct just 26 seconds ago. All human history? Squeezed into the last eight-hundredths of a second, quicker than the blink of an eye, let alone the final whistle.

The Universe is as big as it is old. While scientists suspect that it could be infinite in volume, the portion that we can see measures more than 92 billion light years in diameter: that is, light, the fastest thing in the universe, would take 92 billion years to cross it.

By contrast, a beam of light could circle the globe seven and a half times in a single second.

It is not just the size of the Universe that boggles the mind. Our very own galaxy, the Milky Way – one of 100 billion others – is more than 100,000 light years in diameter and filled with around 400 billion stars. The closest one to us – other than the Sun – is Proxima Centauri: 4.2 light years away. Even if you hitched a ride on the fastest man-made object, the Helios 2 probe, it would take you 41,152 years to get there.

When you gaze at the stars, you are actually seeing a snapshot of what they looked like eons ago. Starlight has to travel for thousands, millions, or billions of years before reaching your eyeballs.

Even light from our Sun takes more than eight and a half minutes to get here. (If the Sun were to disappear, we wouldn’t know for eight and a half minutes.)

If the sheer size of the cosmos seems overwhelming, consider this: it’s getting bigger. The Universe itself – the very fabric of space – is expanding at an extraordinary rate and getting faster.

The accelerating expansion of the Universe is one of science’s great mysteries.

Scientists theorise that it is driven by an enigmatic “dark energy” which permeates all space and whose nature has never been discovered. That’s not the only puzzle. Gravitational models show that most of the matter in the Universe must be completely undetectable. Since we have no idea what or where it is, scientists call this mystery mass “Dark Matter.” Without it, gravity wouldn’t pull matter together nearly as powerfully, and galaxies, planets, and stars would float away from each other into nothingness.

As space expands, the Universe will slowly cool to absolute zero and all matter and energy will be diluted and dispersed. Although, for the world’s end, Robert Frost would “hold with those who favour fire”, it seems that “ice” will win the day.

Albert Einstein showed that all mass bends the space and time in which it sits, from your pencil to Alpha Centauri. A black hole was his worst nightmare. It forms when a large, dying star collapses in on itself during a supernova: an explosion powerful and bright enough to outshine an entire galaxy.

At the centre of the doomed star, highly concentrated matter, heavier than a thousand Suns, bends spacetime so violently that it creates a singularity: a point of infinite density and heat that, like the precursor to the Big Bang, is incomprehensible to modern physics (Einstein tried and failed to find a unified theory that could describe it). The rift in spacetime sucks down anything near it. Because not even light can escape, nobody knows what happens inside.

At the centre of our galaxy and many others, the Hubble Telescope has revealed a massive thermonuclear forge, fiery with energy and emitting intense radiation, birthing millions of new stars. The culprit? A hungry, supermassive black hole.

Discs of matter and gas accrete and circle rapidly around it, swirling in the intense gravity. Through the friction, scorching heat is released and gas compressed, creating new stars. The accretion discs of black holes are the most efficient and luminous engines in the Universe.

Ninety-eight per cent of the matter in the Universe is hydrogen and helium, the two main fissile gases that comprise stars. So where do all the rocks, air, trees, ducks and people come from? The answer lies in the supernova.

During massive star explosions, huge surges of energy and heat produced by nuclear reactions allow a process called fusion to take place. Lighter elements are violently squeezed and fuse into heavier ones: the entire periodic table. This means that you, your computer screen, your car and the whole planet are literally made of stardust, cast off in the dying throes of an exploding red giant.

Given that the Universe contains about nine billion trillion stars, many of them much like our own, scientists doubt that life is unique to one, average planet. The astronomer Frank Drake calculated that our galaxy alone should contain millions of other civilisations. In 1984, a Martian meteorite found in Antarctica shocked the world with possible traces of fossilised alien microbes.

And beyond bacteria, the “Wow! Signal”, detected in Ohio in 1977, showed signs of possible extraterrestrial, intelligent origin. But Dr Stephen Hawking has warned us not to talk to aliens, as an advanced civilisation might view us the way we see animals, not hesitating to raid and destroy our planet.

Planets have different personalities. While satellites looking for life focus on rocky, Earth-like ones orbiting in a star’s “goldilocks zone” – not too hot, not too cold, where liquid water can exist – most planets are like Saturn and Jupiter: gas giants.

Saturn is a dazzling planet that enchanted Galileo, with its paper-thin icy rings, 500 mile-per-second winds, and many mysterious moons – one of which, Enceladus, could support life. But if you could find a big enough bathtub, Saturn would float in it. The planet is less dense than water.

Considering the vastness of the cosmic ocean, humankind has barely gotten its feet wet. Yet, incredibly, the Voyager 1 probe, launched in 1977 and still operating, is nearly 8.7 billion miles away, far past Pluto, and leaving the Solar System behind.

On board, it carries two golden phonograph records engraved with images and sounds of life on Earth, time capsules for alien discovery.

Although the Apollo 13 lunar mission was a failure from which the American astronauts barely escaped alive, by bravely sling-shotting around the Moon, the men earned a record that has remained unbroken since 1970. They travelled farther away from anyone, everyone and everything than anyone has ever been.

By Alex Klein

Now don’t that just put my overdue EON bill and the middle east conflict into perspective?

Posted via email from Bear Faced’s Posterous