Tuesday, December 21, 2010

The Nature of Existence

Hey guys! I haven't posted for a long time since I'm kinda busy with other stuff. Anyway, as I was searching for something to watch today, I came across this documentary called "The Nature of Existence". I thought that this was kinda interesting so I'm sharing it here. Haven't seen it myself so I'll be watching this after I make this post. I hope you enjoy this.

Saturday, December 4, 2010

Is the Universe Infinite?

Explore the biggest question of all.. Since ancient times, we've looked into the night skies and wondered: How far do the stars stretch out into space? And what's beyond them?

In modern times, we built giant telescopes that have allowed us to cast our gaze deep into the universe. Astronomers have been able to look back to near the time of its birth. They've reconstructed the course of cosmic history in astonishing detail.

From intensive computer modeling, and myriad close observations, they've uncovered important clues to its ongoing evolution. Many now conclude that what we can see, the stars and galaxies that stretch out to the limits of our vision, represent only a small fraction of all there is.

Does the universe go on forever? Where do we fit within it? And how would the great thinkers have wrapped their brains around the far-out ideas on today's cutting edge?

For those who find infinity hard to grasp, even troubling, you're not alone. It's a concept that has long tormented even the best minds.

Over two thousand years ago, the Greek mathematician Pythagoras and his followers saw numerical relationships as the key to understanding the world around them.

But in their investigation of geometric shapes, they discovered that some important ratios could not be expressed in simple numbers.

Take the circumference of a circle to its diameter, called Pi.

Computer scientists recently calculated Pi to 5 trillion digits, confirming what the Greeks learned: there are no repeating patterns and no ending in sight.

The discovery of the so-called irrational numbers like Pi was so disturbing, legend has it, that one member of the Pythagorian cult, Hippassus, was drowned at sea for divulging their existence.

A century later, the philosopher Zeno brought infinity into the open with a series of paradoxes: situations that are true, but strongly counter-intuitive.

In this modern update of one of Zeno's paradoxes, say you have arrived at an intersection. But you are only allowed to cross the street in increments of half the distance to the other side. So to cross this finite distance, you must take an infinite number of steps.

In math today, it's a given that you can subdivide any length an infinite number of times, or find an infinity of points along a line.

What made the idea of infinity so troubling to the Greeks is that it clashed with their goal of using numbers to explain the workings of the real world.

To the philosopher Aristotle, a century after Zeno, infinity evoked the formless chaos from which the world was thought to have emerged: a primordial state with no natural laws or limits, devoid of all form and content.

But if the universe is finite, what would happen if a warrior traveled to the edge and tossed a spear? Where would it go?

It would not fly off on an infinite journey, Aristotle said. Rather, it would join the motion of the stars in a crystalline sphere that encircled the Earth. To preserve the idea of a limited universe, Aristotle would craft an historic distinction.

On the one hand, Aristotle pointed to the irrational numbers such as Pi. Each new calculation results in an additional digit, but the final, final number in the string can never be specified. So Aristotle called it "potentially" infinite.

Then there's the "actually infinite," like the total number of points or subdivisions along a line. It's literally uncountable. Aristotle reserved the status of "actually infinite" for the so-called "prime mover" that created the world and is beyond our capacity to understand. This became the basis for what's called the Cosmological, or First Cause, argument for the existence of God.

Monday, November 29, 2010

Quantum Suicide and Immortality, Schrödinger's Cat and the Weird World of Quantum Mechanics

This is a very long article but I promise that it's worth the read if you find Physics fascinating.

How Quantum Suicide Works
by Josh Clark

Introduction to How Quantum Suicide Works
A man sits down before a gun, which is pointed at his head. This is no ordinary gun; i­t's rigged to a machine that measures the spin of a quantum particle. Each time the trigger is pulled, the spin of the quantum particle -- or quark -- is measured. Depending on the measurement, the gun will either fire, or it won't. If the quantum particle is measured as spinning in a clockwise motion, the gun will fire. If the quark is spinning counterclockwise, the gun won't go off. There'll only be a click.

Nervously, the man takes a breath and pulls the trigger. The gun clicks. He pulls the trigger again. Click. And again: click. The man will continue to pull the trigger again and again with the same result: The gun won't fire. Although it's functioning properly and loaded with bullets, no matter how many times he pulls the trigger, the gun will never fire. He'll continue this process for eternity, becoming immortal.

Go back in time to the beginning of the experiment. The man pulls the trigger for the very first time, and the quark is now measured as spinning clockwise. The gun fires. The man is dead.

But, wait. The man already pulled the trigger the first time -- and an infinite amount of times following that -- and we already know the gun didn't fire. How can the man be dead? The man is unaware, but he's both alive and dead. Each time he pulls the trigger, the universe is split in two. It will continue to split, again and again, each time the trigger is pulled.­

This thought experiment is called quantum suicide. It was first posed by then-Princeton University theorist Max Tegmark in 1997 (now on faculty at MIT). A thought experiment is an experiment that takes place only in the mind. The quantum level is the smallest level of matter we've detected so far in the universe. Matter at this level is infinitesimal, and it's virtually impossible for scientists to research it in a practical manner using traditional methods of scientific inquiry.­

Saturday, November 27, 2010

Dark Future of the Sun

Our Sun has served Earth well for almost five billion years. It's bathed us with heat and energy. But like humans, our home star is mortal. In five billion years, it will stop nurturing its planetary offspring.

The Sun

Taken by Hinode's Solar Optical Telescope on January 12, 2007, this image of the Sun reveals the filamentary nature of the plasma connecting regions of different magnetic polarity.

The aging star will bloat out beyond the orbit of our planet incinerating all living things--including humans if we're still around.

Life-cycle of the Sun

Hate E-mails with Richard Dawkins

Thought this one was really funny! lol