Imagine a toy city, seen from afar. Now imagine that some of the buildings have Lego-shaped castellations, others have Lego-shaped holes in the walls, and there are a few loose Lego bricks lying around. All this evidence leads us to guess that the whole toy city is made up of Lego bricks. When we get up close, we see that our guess is correct. By a similar blend of evidence and theorizing, John Dalton, around 1800, came up with the Atomic Theory
Millions of people will soon travel to a narrow strip in America to witness a rare event: a total solar eclipse. On 21 August, many will look up to the sky to witness this phenomenon – will you be one of them? In the following shortened excerpt from Totality: The Great American Eclipses of 2017 and 2024, learn what types of eyewear you should be using to watch the Sun disappear
Space missions like the Rosetta space probe built by the European Space Agency, that recently reached and studied the comet 67P/Churyumov-Gerasimenko, address the profound question of how life came to Earth by quantifying the composition of comets in the Solar System. Comets are made of the pristine material from which planets were formed. By exploring the composition of comets, we can thus access the pristine composition of the building blocks of planets.
Anyone who has experienced the diamond ring effect that heralds the start of a total solar eclipse will tell you that it is the most beautiful natural phenomenon that they have ever seen.
The unreasonable popularity of pseudosciences such as ESP or astrology often stems from personal experience. We’ve all had that “Ralph” phone call or some other happening that seems well beyond the range of normal probability, at least according to what we consider to be common sense. But how accurately does common sense forecast probabilities and how much of it is fuzzy math? As we will see, fuzzy math holds its own.
How do you capture the spectacle of a total eclipse with a camera? Photographing an eclipse isn’t difficult. It doesn’t take fancy or expensive equipment. You can take a snapshot of an eclipse with a simple camera (even a smartphone) if you can hold the camera steady or place it on a tripod. The first step in eclipse photography is to decide what kind of pictures you want.
Quantum mechanics allows some mind-bending effects. A recent paper shows us how to make an image of the silhouette of a cat using a set of photons that had never interacted with the cat object. The photons that had actually interacted with the cutout, and carried information about it, had even been discarded. The explanation depends on the ideas of quantum superposition and interference; the trick is in transferring quantum information from one set of photons to another.
On 25 September 2015 scientists at the LIGO experiment detected something that no human had ever seen before: a gravitational wave. This wave was emitted by two black holes that lived and died more than a billion years ago. Each of the black holes was around thirty times as massive as our own sun, and when they merged they gave out so much energy that they temporarily outshone every star in the observable Universe put together.
Voltaire is known today for Candide, a short novel published in 1779. The young hero Candide travels the world in a tale littered with rape, murder, pestilence, enslavement, and natural catastrophe. Amidst this apocalyptic nightmare, Candide’s tutor Dr Pangloss maintains a philosophical detachment, arguing against all evidence to the contrary that we live in the best of all possible worlds.
The planet Mars shares its orbit with a few small asteroids called “Trojans”. Recently, an international team of astronomers have found that most of these objects share a common composition and are likely the remains of a mini-planet that was destroyed by a collision long ago. Trojan asteroids move in orbits with the same average distance from the Sun as a planet, trapped within gravitational “safe havens” 60 degrees in front of and behind the planet.
Oxford lists several definitions of belief, but here is a paraphrase of their meanings: something one accepts as true or real; a firmly held opinion; a religious conviction; trust, faith, or confidence in something or someone. How do truths believed by individuals or groups compare with scientific truths? On the face of it, scientific observations and experiments are backed by physical evidence, repeated in many settings, by many independent observers around the world.
Some say everything is made of atoms, but this is far from true. Light, radio, and other radiations aren’t made of atoms. Protons, neutrons, and electrons aren’t made of atoms, although atoms are made of them. Most importantly, 95% of the universe’s energy comes in the form of dark matter and dark energy, and these aren’t made of atoms. The central message of our most fundamental physical theory, namely quantum physics, is that everything is made of quantized fields.
It’s been 116 years since Max Planck introduced the quantum idea, yet experts still disagree about quantum fundamentals. My previous post on the wave-particle duality problem, argued the universe is made of fields, not particles, and that photons, electrons, and other quanta are extended bundles of field energy that often act in particle-like ways.
Can magicians (illusionists) really levitate themselves and others or bend spoons using only the power of their mind? No. Emphatically no. But they surely make it seem as if they can. Enjoy being fooled? Then you’ll love watching really good magic shows that allow people the opportunity to suspend their disbelief momentarily. But don’t let this suspension become permanent.
A few ancient Greek philosophers seriously considered this question and concluded that everything is made of tiny particles moving in empty space. The key 17th-century scientist Isaac Newton agreed, but a century later, Thomas Young’s experiments convinced him and others that light, at least, was a wave, and Michael Faraday and James Maxwell showed that light and other radiations such as infrared and radio are waves in a universal “electromagnetic field.”
In September 2015, the UK Met Office and Met Éireann (the Irish meteorological service) announced a project to give names to potentially damaging storms. The basis for naming any particular storm was the expectation that there would be major impacts on conditions over the British Isles and, in particular, of very high winds. The first storm, Abigail, brought high winds to northern Scotland and the Outer Hebrides.