Quantum theory is probabilistic by nature. Because of fuzzy effects of quantum indeterminacy, the equations of quantum mechanics can’t tell us exactly what an object is doing, but only what the likely outcome will be when we interact with it. This probability is determined by the Born rule (named after physicist Max Born). The rule has various forms, but in the most common approach it means that squaring the wavefunction of an object yields the probability of a particular outcome. The Born rule works extraordinarily well, making quantum theory the most accurate scientific theory we have, but it is also an assumption. It’s a postulate of quantum theory rather than being derived formally from the model. So what if it’s wrong. Read More

## Emergence Of Gravity

As dark matter continues to vex astronomers, new solutions to the dark matter question are proposed. Most focus on pinning down the form of dark matter, while others propose modifying gravity to account for the effect. But a third proposal is simply to remove gravity from the equation. What if the effects of gravity aren’t due to some fundamental force, but are rather an emergent effect due to other fundamental interactions? A new paper proposes just that, and if correct it could also explain the effects of dark matter.Read More

## Close Enough

A black hole is an object that has gravitationally collapsed under its own weight. It could be formed from the the remains of a dead star, a dense central region of a galaxy, or perhaps even a small fluctuation in the early dense moments of the cosmos. Regardless of the cause, the trick is to compress a large enough mass into a small enough volume. In other words, if the density of matter is high enough, it will collapse into a black hole.Read More

## Order Of Magnitude

Suppose you picked up a single grain of sand and held it at arms length. The sand grain would cover just a tiny patch of sky. Now imagine you found the darkest patch of night sky you could find and looked long and hard at an area no bigger than that single grain of sand. In 2004 the Hubble space telescope did just that, observing a tiny patch of dark sky for a total of 55 hours. The image it produced is known as the Hubble Ultra Deep Field. It found more than 10,000 galaxies that were present when the Universe was just 400 – 800 million years old. Read More

## Quantum Teleportation Across The Dark Web

Quantum teleportation brings to mind Star Trek’s transporter, where crew members are disassembled in one location to be reassembled in another. Real quantum teleportation is a much more subtle effect where information is transferred between entangled quantum states. It’s a quantum trick that could give us the ultimate in secure communication. While quantum teleportation experiments have been performed countless times in the lab, doing it in the real world has proved a bit more challenging. But a recent experiment using a dark fibre portion of the internet has brought quantum teleportation one step closer to real world applications. Read More

## The Nine Billion Names Of God

Quantum theory is strange and counterintuitive, but it’s very precise. Lots of analogies and broad concepts are presented in popular science trying to give an accurate description of quantum behavior, but if you really want to understand how quantum theory (or any other theory) works, you need to look at the mathematical details. It’s only the mathematics that shows us what’s truly going on. Read More

## The Power Of Balance

Suppose I were to pick two numbers. I won’t tell you what those numbers are, other than to call them A and B. If I asked you what there sum is, A + B, you couldn’t tell me the answer without knowing A and B, but you could tell me one important thing: the answer will be a number. That might seem trivially obvious, but it actually says something important about numbers. Any two numbers when added together will give you a number. That’s because numbers under addition form what is known as a group. Read More

## A World Of Pure Imagination

In science, physical quantities are represented by numbers. A block has a mass of 42 kilograms, a car moves at 25 meters per second, or a star is 142 light years away. In mathematics these are known as real numbers. One of the basic properties of real numbers is that any real number multiplied by itself is a positive number. For example, 3 x 3 is 9, and (-4) x (-4) is 16. But imagine a number where its product is actually negative. For example, what if some number i works so that i x i is -1. Such a number is known as an imaginary number. The term imaginary number often gives the impression that these numbers are merely mathematical abstractions, but when it comes to the physical universe, imaginary numbers are quite real. Read More

## Slings And Arrows

Newton’s laws are a story of arrows. Not physical arrows (although that’s sometimes the case) but a kind of mathematical arrow known as a vector. Read More