ISMED Newsletters

» Return to News Gram Archive Main Menu

News Gram™ November 2005

November 2005 ~ Volume 12, No. 4

When it comes to how the world came into being, it’s good to know a lot of physics, astronomy, mathematics and even philosophy. More than anything, though, you’d better have a really rich imagination, one that knows no limits. Add to this preparation the requirement that you won’t ever really know which theory is right or wrong, since verifying your idea of how the world stepped out of its egg can’t be confirmed. The reward for divining a path through this maze of problems is the process itself. It’s great fun if you like puzzles. Here are a few ideas that led to the emergence of what is now known as the Big Bang Theory.

In 1927, a Belgian priest, Georges Lemaître, suggested that the universe got its start with a gargantuan explosion. Lemaître, who received his Ph.D. from MIT in the same year, proposed that the galaxies were moving away from one another in all directions. The universe, he claimed, was expanding. Lemaître’s problem was that he had no evidence to support his theory. It took a few years before Edwin Hubble, working at Mount Wilson observatory in California, offered Lemaître’s idea without ever having heard of him. Unlike Lemaître, Hubble had evidence to support his position and the idea of a cataclysmic beginning to the universe was launched. He determined that the velocity of a galaxy was directly proportional to its distance from us. A galaxy twice as far from us is also traveling twice as fast. Combined with the red shift, a change in the spectrogram of a galaxy, the idea of a sudden blow up at the  beginning of everything received added support.

In 1964, two researchers, Arno Penzias and Robert Wilson discovered background microwave radiation that the Big Bang Theory predicts. For this work they received the Nobel prize. More recently, NASAs COBE satellite detected cosmic microwaves from the furthest reaches of the universe, indicating that there was a remarkable homogeneity of matter in the earliest moments of the universe’s existence.

In the succeeding moments, billions of times shorter than a single second, there came into existence madly rushing particles of matter and anti-matter. As the two different kinds of particles collided, they destroyed one another, leaving energy in their wake. As this process progressed, more matter survived than anti-matter, which is fortunate for us since we are not made out of anti-matter. Billions of moments before the end of the first second, the universe continued to expand and other particles began to form. These particles, known as baryons, were created at about 10-33 seconds after the big bang and included photons, neutrinos and quarks. The infant universe began to cool and more complex particles such as protons and neutrons came into being. Soon came leptons, which included elections, neutrinos and photons that would begin the process of forming elements like hydrogen, helium, lithium and more.

When did all this begin? Put down your calendar. Astronomers and physicists estimate that the age of the universe is between 10 and 20 billion years. It’s the calculation that’s really interesting. Here’s how it works. Astrophysicists can determine the distance of a particular galaxy as well as its velocity. If you divide the distance by the velocity you get time. Here’s what the numbers look like:

4.6 x 1026 cm/1 x 109 cm/sec = 4.6 x 1017 sec

It turns out that 4.6 x 1017 sec equals approximately 15 billion years. It doesn’t matter which galaxy you use. Just plug in the numbers for that bunch of stars and you wind up with the same age for the universe. In other words, about 15 thousand billion years ago there was a huge explosion that brought into existence the world as we experience it today.

The Big Bang Theory has a number of detractors who offer a variety of arguments. One theorist asserts that the spectroscopic changes that make up the red shift are caused by another process than the one supporting the Big Bang. Another argues that the age of some objects in the universe is older than the theoretical age of the universe itself. There is a theory that our galaxy, the Milky Way, has only undergone 45 to 60 rotations, which is not enough time for it to have assumed its spiral shape. It would have had to spin around on its axis many more times in order to develop the geometric eccentricity of a spiral structure. Also, there have been identified chains of galaxies in the universe that would have required hundreds of billions of years to develop.

So don’t relax too much about the origin of the universe. There is still plenty of mystery to keep you up at night. And if you get really excited about how the world came into being, get a small telescope, wait for a clear night and point it up at the sky. Look at the Great Nebula in Andromeda and just imagine the trillions of miles, the billions of worlds and the magnificence of creation. All from a moment before time began.

•   •   •

» Return to News Gram Archive Main Menu