Rewriting Laws of the Universe

When we look out at the night sky across vast, cosmic distances using our most sensitive and advanced telescopes, we look back in time. Einstein taught us that light has a finite speed; therefore, it takes light longer to travel to us the further one looks.

Thanks to this, cosmologists have been able to see light dating back to about 14 billion years ago. This light reveals something spectacular and mysterious – the Universe is filled with a sea of energy, waves of tangled electrons and photons in the form of a hot fluid, known as a plasma. We call this plasma the Cosmic Microwave Background (CMB).

We cosmologists have precise theoretical and observational evidence that this plasma underwent gravitational collapse with the aid of an invisible form of matter, called dark matter, forming the first stars and eventually forming the organised superstructure that inhabits the current Universe.

However, a mystery still lurked: the properties of this sea of energy seem to originate from what Einstein called “spooky action-at-a-distance” - objects communicating with each other at instantaneous speeds across ridiculously large distances. This is known as the horizon problem.

In 1981, my colleague, Alan Guth of MIT, proposed an elegant solution to this problem. The idea was to introduce a new player called the inflation field that filled the Universe, and whose energy caused space to expand extremely rapidly. The repulsion that arises due to gravitational effects caused by inflation neatly solves the horizon problem – it makes those regions that we thought to be spookily interacting subject to the weird, but well-confirmed, laws of quantum physics.

The theory of cosmic inflation also provided us with a physical mechanism that answers a question that had long troubled cosmologists: how did the seeds of structure originate in a seemingly featureless primordial Universe over 14 billion years ago?  READ MORE...

The Big Band IS NOT the Beginning

The Big Bang teaches us that our expanding, cooling universe used to be younger, denser, and hotter in the past...

However, extrapolating all the way back to a singularity leads to predictions that disagree with what we observe...

Instead, cosmic inflation preceded and set up the Big Bang, changing our cosmic origin story forever...

Where did all this come from? In every direction we care to observe, we find stars, galaxies, clouds of gas and dust, tenuous plasmas, and radiation spanning the gamut of wavelengths: from radio to infrared to visible light to gamma rays. No matter where or how we look at the universe, it’s full of matter and energy absolutely everywhere and at all times. 

And yet, it’s only natural to assume that it all came from somewhere. If you want to know the answer to the biggest question of all — the question of our cosmic origins — you have to pose the question to the universe itself, and listen to what it tells you.

Today, the universe as we see it is expanding, rarifying (getting less dense), and cooling. Although it’s tempting to simply extrapolate forward in time, when things will be even larger, less dense, and cooler, the laws of physics allow us to extrapolate backward just as easily. 

Long ago, the universe was smaller, denser, and hotter. How far back can we take this extrapolation? Mathematically, it’s tempting to go as far as possible: all the way back to infinitesimal sizes and infinite densities and temperatures, or what we know as a singularity. 

This idea, of a singular beginning to space, time, and the universe, was long known as the Big Bang.

But physically, when we looked closely enough, we found that the universe told a different story. Here’s how we know the Big Bang isn’t the beginning of the universe anymore.  READ MORE...

Parallel Universes

Our universe is unimaginably big. Hundreds of billions, if not trillions, of galaxies spin through space, each containing billions or trillions of stars. Some researchers studying models of the universe speculate that the universe's diameter could be 7 billion light-years across. Others think it could be infinite.

But is it all that's out there? Science fiction loves the idea of a parallel universe, and the thought that we might be living just one of an infinite number of possible lives. Multiverses aren't reserved for "Star Trek," "Spiderman" and "Doctor Who," though. Real scientific theory explores, and in some cases supports, the case for universes outside, parallel to, or distant from but mirroring our own.

Multiverses and parallel worlds are often argued in the context of other major scientific concepts like the Big Bang, string theory and quantum mechanics.

Around 13.7 billion years ago, everything we know of was an infinitesimal singularity. Then, according to the Big Bang theory, it burst into action, inflating faster than the speed of light in all directions for a tiny fraction of a second. Before 10^-32 seconds had passed, the universe had exploded outward to 10^26 times its original size in a process called cosmic inflation. 

And that's all before the actual expansion of matter that we usually think of as the Big Bang itself, which was a consequence of all this inflation: As the inflation slowed, a flood of matter and radiation appeared, creating the classic Big Bang fireball, and began to form the atoms, molecules, stars and galaxies that populate the vastness of space that surrounds us.  TO READ MORE, CLICK HERE,,,