How Would You Graph It?

Our friend Steve is fascinated with what happened before the Big Bang, the theorized birth of the universe that occurred some 13.7 billion years ago. He is always asking me, “What’s before the Big Bang?” His question is partly motivated by sheer interest, but also because he runs a company that sells planetarium systems that allow users to model 3D data sets on their planetarium domes. You can load any data set onto the system and fly through it. So, of course, we loaded the COBE and WMAP data, which depict the last flickers of the Big Bang as seen at 2.73 degrees Kelvin. Now, if you fly out through that data set, you can theoretically be OUTSIDE the last flickers of the Big Bang. So, while you can’t do that in real life, the exercise does hold a certain fascination.

Physicist Martin Bojowald at Penn State University has been thinking about the same question, too, but from a physicist’s standpoint. His answer is that there may well have been another universe that collapsed, and through that action, gave birth to our own universe. He has developed a mathematical model that details the properties of a quantum state (that is, the state of a particle described by its position and momentum expressed in quantum numbers) as it travels through what he calls the “Big Bounce.” This bounce replaces the Big Bang as the event that began our universe. What’s more, if this quantum state can be studied, scientists could glean something about the earlier universe, although we’d never know if we are correct about what it tells us.

Now, that probably sounds pretty handwavy, but it’s not to a physicist, one of those legions of scientists who work to understand the atomic structure of everything that exists. To understand this (and you can read more about his work here), you have to know about the quantum state. And quantum phsyics, which is a term that gets thrown around whenever somebody wants to point out the geekiest thing you could think of to study.

Quantum physics is a way of explaining the physical behavior of the small particles that make up atoms: electrons, protons and neutrons. You can’t exactly observe these babies in real time, but you can figure out what states they can be in and use mathematical models to map those states. That’s more or less what Dr. Bojowald and his colleagues are doing. But, they’re taking things one step further by using something called “Loop Quantum Gravity,” the quantum theory that does to spacetime what quantum physics does to particles. That is, it tries to look at spacetime in discrete units and describe those units, in particular, the high energies present at the beginning of space and time.

The researchers are using this theory to trace the universe back through time. They are finding that the universe at its beginning point had a minimum volume that was not zero. It had a maximum energy that was not infinite. Then they applied the mathematical equations of their theory to make a model of the universe, and take it as far back as they could. What they found was that the model produces valid mathematical results past the point of the classical Big Bang–that is, it seems to describe conditions BEFORE the the birth of this current universe. So, theoretically now, the scientists have a way of looking through a quantum physics window into the time before the Big Bounce.

This may all sound quite technical, and it is. But, since we can’t know for sure what happened before the creation of THIS universe, models (based on solid observational evidence) are our best bet at figuring out what happened ‘way back then. And, it doesn’t exactly answer Steve’s question. In fact, it raises more!