Author Archives: Attention to the Unseen

The human mind as the preeminent scientific instrument

Walter Isaacson writes: This month marks the 100th anniversary of the General Theory of Relativity, the most beautiful theory in the history of science, and in its honor we should take a moment to celebrate the visualized “thought experiments” that were the navigation lights guiding Albert Einstein to his brilliant creation. Einstein relished what he called Gedankenexperimente, ideas that he twirled around in his head rather than in a lab. That’s what teachers call daydreaming, but if you’re Einstein you get to call them Gedankenexperimente.

As these thought experiments remind us, creativity is based on imagination. If we hope to inspire kids to love science, we need to do more than drill them in math and memorized formulas. We should stimulate their minds’ eyes as well. Even let them daydream.

Einstein’s first great thought experiment came when he was about 16. He had run away from his school in Germany, which he hated because it emphasized rote learning rather than visual imagination, and enrolled in a Swiss village school based on the educational philosophy of Johann Heinrich Pestalozzi, who believed in encouraging students to visualize concepts. While there, Einstein tried to picture what it would be like to travel so fast that you caught up with a light beam. If he rode alongside it, he later wrote, “I should observe such a beam of light as an electromagnetic field at rest.” In other words, the wave would seem stationary. But this was not possible according to Maxwell’s equations, which describe the motion and oscillation of electromagnetic fields.

The conflict between his thought experiment and Maxwell’s equations caused Einstein “psychic tension,” he later recalled, and he wandered around nervously, his palms sweating. Some of us can recall what made our palms sweaty as teenagers, and those thoughts didn’t involve Maxwell’s equations. But that’s because we were probably performing less elevated thought experiments. [Continue reading…]

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Will quantum mechanics swallow relativity?

Corey S Powell writes: It is the biggest of problems, it is the smallest of problems.

At present physicists have two separate rulebooks explaining how nature works. There is general relativity, which beautifully accounts for gravity and all of the things it dominates: orbiting planets, colliding galaxies, the dynamics of the expanding universe as a whole. That’s big. Then there is quantum mechanics, which handles the other three forces — electromagnetism and the two nuclear forces. Quantum theory is extremely adept at describing what happens when a uranium atom decays, or when individual particles of light hit a solar cell. That’s small.

Now for the problem: Relativity and quantum mechanics are fundamentally different theories that have different formulations. It is not just a matter of scientific terminology; it is a clash of genuinely incompatible descriptions of reality.

The conflict between the two halves of physics has been brewing for more than a century — sparked by a pair of 1905 papers by Einstein, one outlining relativity and the other introducing the quantum — but recently it has entered an intriguing, unpredictable new phase. Two notable physicists have staked out extreme positions in their camps, conducting experiments that could finally settle which approach is paramount. [Continue reading…]

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How did complex creatures evolve from simple single-celled organisms?

Emily Singer writes: In September 2014, Christa Schleper embarked on an unusual hunting expedition in Slovenia. Instead of seeking the standard quarry of deer or wild boar, Schleper was in search of Lokiarchaeota, or Loki, a newly discovered group of organisms first identified near deep-sea vents off the coast of Norway. The simple, single-celled creatures have captured scientists’ interest because they are unlike any other organism known to science. They belong to an ancient group of creatures known as archaea, but they seem to share some features with more complex life-forms, including us.

Though little is known about Loki, scientists hope that it will help to resolve one of biology’s biggest mysteries: how life transformed from simple single-celled organisms to the menagerie of complex life known as eukaryotes — a category that includes everything from yeast to azaleas to elephants. “Next to the origins of life, there’s probably no bigger mystery in the history of life,” said John Archibald, an evolutionary biologist at Dalhousie University in Nova Scotia.

The jump from single cells to complex creatures is so puzzling because it represents an enormous evolutionary gulf. “How do you make a eukaryote, that’s a big question,” said Schleper, a microbiologist at the University of Vienna in Austria. “It’s a huge transition.”

Though single-celled organisms blanket the Earth and are capable of impressive biochemistry — some can eat nuclear waste, for example — their structure and shape remain simple. Cells from animals, plants and fungi, which make up the eukaryotes, are much more sophisticated. They possess a suite of features lacking in their simpler brethren: a nucleus that houses DNA; an energy-producing device known as the mitochondrion; and molecular architecture, known as the cytoskeleton, that controls cell shape and movement.

Most biologists agree that at some point around two billion years ago, one featureless cell swallowed another, and the two began to work together as one. But the details of this process — whether this symbiosis jump-started an evolutionary process, or whether it happened midway along the path to eukaryotes — continue to drive huge disputes in the field. [Continue reading…]

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The theory of parallel universes is not just maths – it is science that can be tested

By Eugene Lim, King’s College London

The existence of parallel universes may seem like something cooked up by science fiction writers, with little relevance to modern theoretical physics. But the idea that we live in a “multiverse” made up of an infinite number of parallel universes has long been considered a scientific possibility – although it is still a matter of vigorous debate among physicists. The race is now on to find a way to test the theory, including searching the sky for signs of collisions with other universes.

It is important to keep in mind that the multiverse view is not actually a theory, it is rather a consequence of our current understanding of theoretical physics. This distinction is crucial. We have not waved our hands and said: “Let there be a multiverse”. Instead the idea that the universe is perhaps one of infinitely many is derived from current theories like quantum mechanics and string theory.

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Science is a dynamic, ongoing reconfiguration of knowledge and must be free to change

David P Barash writes: Coming from a scientist, this sounds smug, but here it is: science is one of humanity’s most noble and successful endeavours, and our best way to learn how the world works. We know more than ever about our own bodies, the biosphere, the planet and even the cosmos. We take pictures of Pluto, unravel quantum mechanics, synthesise complex chemicals and can peer into (as well as manipulate) the workings of DNA, not to mention our brains and, increasingly, even our diseases.

Sometimes science’s very success causes trouble, it’s true. Nuclear weapons – perhaps the most immediate threat to life on Earth – were a triumph for science. Then there are the paradoxical downsides of modern medicine, notably overpopulation, plus the environmental destruction that science has unwittingly promoted. But these are not the cause of the crisis faced by science today. Today science faces a crisis of legitimacy which is entirely centred on rampant public distrust and disavowal.

A survey by the Pew Research Center in Washington, DC, conducted with the American Association for the Advancement of Science, reported that in 2015 a mere 33 per cent of the American public accepted evolution. A standard line from – mostly Republican – politicians when asked about climate change is ‘I’m not a scientist’… as though that absolved them from looking at the facts. Vaccines have been among medical science’s most notable achievements (essentially eradicating smallpox and nearly eliminating polio, among other infectious scourges) but the anti-vaccination movement has stalled comparable progress against measles and pertussis.

How can this be? Why must we scientists struggle to defend and promote our greatest achievements? There are many possible factors at work. In some cases, science conflicts with religious belief, particularly among fundamentalists – every year I find it necessary to give my undergraduate students a ‘talk’ in which I am frank that evolutionary science is likely to challenge any literalist religious beliefs they might have. In the political sphere, there is a conflict between scientific facts and short-term economic prospects (climate‑change deniers tend to be not merely scientifically illiterate, but funded by CO2-emitting corporations). Anti-vaxxers are propelled by the lingering effect of a single discredited research report that continues to resonate with people predisposed to ‘alternative medicine’ and stubborn opposition to establishment wisdom. [Continue reading…]

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Competition in Cambrian seas 542 million years ago helped cause an explosion in animal diversity

Brooke Borel writes: Battles fought 542 million years before today helped fuel a blast that brought humans and most animals into existence. The great Cambrian Explosion was a period of unprecedented one-upmanship. Beastly claws crushed through thin skin, and soft-bodied creatures evolved shells shaped like scythes, sickles, and shields.

For about a billion years prior, the cells and genes that would later create animals were evolving in microscopic organisms who inhabited the oceans of Earth. These essential molecular changes may only be inferred today because they’re not preserved in fossils. The earliest traces of animals, about 580 million years old, appear soft, with no sign of claws, teeth, limbs, or brains. Then, within 54 million years (a relative blink but still, 270 times the duration of humans’ existence thus far), most of the main animal groups around today originated. This rapid rate of increase in animal architectures has never since been repeated.

A simple species count does not do justice to the power of the Cambrian Explosion. Species have continuously formed over time. A new type of moth may have antennae that are furrier than its sisters; a new species of dinosaur may be distinguished by clawed wings and vicious front fangs. But a new phylum — a major branch on the tree of life, the upper-level ranking that separates an insect from a pterodactyl — is rarely born.

Most of today’s 30 to 40 animal phyla originated in the Cambrian, and have persisted through time with hundreds of variations on a theme. [Continue reading…]

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