Stephen Hawking’s final paper was published this week. Like his last book, The Grand Design, it is about how the universe began. In 1979, he became the seventeenth Lucasian Professor of Mathematics at Cambridge University. His modest aim was to understand the universe, the whole thing, from beginning to end. He missed his mark by […]

# Tag Archives: Einstein

# Mind over math: We need to change the worldview of physicists.

It all began so easily. Physics uses math so it was natural for physicists to look for math that is convenient. This led physics down a dead-end street. Fixing it could lead to a huge opportunity. The beginning goes back to the 1600s. Having revolutionized what would soon be called physics, Isaac Newton fell into […]

# With a new way to measure space we may learn why it is expanding.

These are exciting times. Every few months astronomy surprises us with insights into ancient secrets. New telescopes are scanning galaxies throughout the visible universe. Most galaxies are mind-bogglingly far away. Exactly how far has long been a fundamental issue. But we just got a whole new way to measure it. Today the universe is much […]

# What are the quanta in quantum gravity? A hundred years ago Einstein said “space”. So where are we now?

Quantum gravity is all the rage in physics these days. There are books about it but none say what quantum gravity is. And none report real progress. We should be upset about this. Really! Quantum gravity tries to reconcile our two immensely successful—but mutually inconsistent—theories about the world: quantum theory and relativity. A quantum theory […]

# Albert Einstein showed that space has shape. Let’s take a look at this esoteric concept.

We now know that, far from being nothing, space is a something. Indeed space is a much more substantial something than the average density of all the matter that we see in the universe. We also know that space has shape as Albert Einstein showed. But what is the shape of space? How are we […]

# Until recently our cosmic neighborhood was growing faster than the speed of light. Now it’s run into a roadblock.

“From a physical point of view everything that is outside our neighborhood is pure extrapolation.” – Willem de Sitter (1932) Physics is coming up against two fundamental limits: It can never observe the biggest and the smallest things that it needs to study. Some seem satisfied this is the end of our search for ultimate […]

# An amazing birthday present: a universe that allows time travel and helps us understand our existence

In 1949 Austrian-American logician Kurt Gödel gave a friend a strange birthday present: a rotating universe. Gödel is widely regarded as the world’s greatest logician. Albert Einstein, the greatest physicist, was his best friend. For years they walked home from the Princeton Institute for Advanced Study almost every day. The present—for Einstein’s 70th birthday—dealt with […]

# What is Planck-scale physics and why does it matter?

The Planck-scale physics story begins long ago. In 1901 German physicist Max Planck publishes an explanation for strange properties of radiant heat. He says its energy is quantized. In other words, it radiates in distinct little bits. He sees this as a mathematical convenience and doesn’t really believe it. His math requires a constant he […]

# Genius, Einstein and much ado about nothing: Let’s fix the fallacy of empty space

We think of space as empty. It’s not. Quite aside from stray hydrogen atoms and fleeting quantum particles in the vacuum, space is substantial. It has mass. Indeed Planck-satellite measurements now show space is three times denser than the average of the universe’s matter. Yet like the rest of us most physicists still treat space […]