Thinking about emergence

Paul Humphreys writes:

If you construct a Lego model of the University of London’s Senate House – the building that inspired the Ministry of Truth in George Orwell’s novel Nineteen Eighty-Four – the Lego blocks themselves remain unchanged. Take apart the structure, reassemble the blocks in the shape of the Great Pyramid of Giza or the Eiffel Tower, and the shape, weight and colour of the blocks stay the same.

This approach, applied to the world at large, is known as atomism. It holds that everything in nature is made up of tiny, immutable parts. What we perceive as change and flux are just cogs turning in the machine of the Universe – a huge but ultimately comprehensible mechanism that is governed by universal laws and composed of smaller units. Trying to identify these units has been the focus of science and technology for centuries. Lab experiments pick out the constituents of systems and processes; factories assemble goods from parts composed of even smaller parts; and the Standard Model tells us about the fundamental entities of modern physics.

But when phenomena don’t conform to this compositional model, we find them hard to understand. Take something as simple as a smiling baby: it is difficult, perhaps impossible, to explain a baby’s beaming smile by looking at the behaviour of the constituent atoms of the child in question, let alone in terms of its subatomic particles such as gluons, neutrinos and electrons. It would be better to resort to developmental psychology, or even a narrative account (‘The father smiled at the baby, and the baby smiled back’). Perhaps a kind of fundamental transformation has occurred, producing some new feature or object that can’t be reduced to its parts.

The notion of emergence can help us to see what’s going on here. While atomism is all about burrowing down to basic building blocks, emergence looks upward and outward, to ask whether strange new phenomena might pop out when things get sufficiently large or complex. [Continue reading…]

Anthropocene vs Meghalayan: Why geologists are fighting over whether humans are a force of nature

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Many scientists believe it is impossible to ignore the human impact on the planet when defining the geological age we live in today.
Shutterstock

By Mark Maslin, UCL and Simon Lewis, UCL

The Earth discovered it was living in a new slice of time called the Meghalayan Age in July 2018. But the announcement by the International Union of Geological Sciences (IUGS) confused and angered scientists all around the world.

In the 21st century, it claimed, we are still officially living in the Holocene Epoch, the warm period that began 11,700 years ago after the last ice age. But not only that: within the Holocene, we are also living in this new age – the Meghalayan – and it began 4,250 years ago.

Over the past decade, more and more scientists have agreed that human impact on Earth is so significant that we have entered a completely new geological phase, called the Anthropocene, including a group convened to agree a formal definition. The world of science was expecting an official announcement acknowledging this Anthropocene Epoch, not the unheard-of Meghalayan Age. It was so unexpected it turned up zero hits on Google when first reported. So what’s going on?

[Read more…]

Geoffrey West: What is complexity in the cosmos?

 

Steven Weinberg: Is mathematics invented or discovered?

 

Roger Penrose: Is mathematics invented or discovered?

 

Stephen Wolfram: Is mathematics invented or discovered?

 

Science and the Loss of Confidence Project

Dalmeet Singh Chawla writes:

In September 2016, the psychologist Dana Carney came forward with a confession: She no longer believed the findings of a high-profile study she co-authored in 2010 to be true. The study was about “power-posing” — a theory suggesting that powerful stances can psychologically and physiologically help one when under high-pressure situations. Carney’s co-author, Amy Cuddy, a psychologist at Harvard University, had earned much fame from power poses, and her 2012 TED talk on the topic is the second most watched talk of all time.

Carney, now based at the University of California, Berkeley, had, however, changed her mind. “I do not believe that ‘power pose’ effects are real,” she wrote on her website in 2016. The reason, she added, was that “since early 2015 the evidence has been mounting suggesting there is unlikely any embodied effect of nonverbal expansiveness.” Other researchers, it turned out, could not replicate the power pose results, and withering scrutiny of the Carney and Cuddy study by fellow scientists mounted.

Carney’s assertions and Cuddy’s responses were widely covered in the media. (Earlier this year, Forbes reported that Cuddy had successfully refuted criticism of the power-posing study.) And despite her own eventual refutation of the findings, Carney did not believe the original paper warranted a full retraction, because it “was conducted in good faith based on phenomena thought to be true at the time,” she told the research integrity blog Retraction Watch. [Continue reading…]

What are the limits of manipulating nature?

In Scientific American, Neil Savage writes:

Matt Trusheim flips a switch in the darkened laboratory, and an intense green laser illuminates a tiny diamond locked in place beneath a microscope objective. On a computer screen an image appears, a fuzzy green cloud studded with brighter green dots. The glowing dots are color centers in the diamond—tiny defects where two carbon atoms have been replaced by a single atom of tin, shifting the light passing through from one shade of green to another.

Later, that diamond will be chilled to the temperature of liquid helium. By controlling the crystal structure of the diamond on an atom-by-atom level, bringing it to within a few degrees of absolute zero and applying a magnetic field, researchers at the Quantum Photonics Laboratory run by physicist Dirk Englund at the Massachusetts Institute of Technology think they can select the quantum-mechanical properties of photons and electrons with such precision that they can transmit unbreakable secret codes.

Trusheim, a postdoctoral researcher in the lab, is one of many scientists trying to figure out just which atoms embedded in which crystals under what conditions will give them that kind of control. Indeed, scientists around the world are tackling the hard problem of controlling nature at the level of atoms and below, down to electrons or even fractions of electrons. Their aim is to find the knobs that control the fundamental properties of matter and energy and turn those knobs to customize matter and energy, creating ultrapowerful quantum computers or superconductors that work at room temperature.

These scientists face two main challenges. On a technical level, the work is extremely difficult. Some crystals, for instance, must be made to 99.99999999 percent purity in vacuum chambers emptier than space. The more fundamental challenge is that the quantum effects these researchers want to harness—for example, the ability of a particle to be in two states at once, à la Schrödinger’s cat—happen at the level of individual electrons. Up here in the macro world, the magic goes away. Researchers manipulating matter at the smallest scales, therefore, are trying to coax nature into behaving in ways that strain at the limits imposed by fundamental physics. The degree to which they succeed will help determine our scientific understanding and technological capacity in the decades to come. [Continue reading…]

The next big discovery in astronomy? Scientists probably found it years ago – but they don’t know it yet

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An artist’s illustration of a black hole “eating” a star.
NASA/JPL-Caltech

By Eileen Meyer, University of Maryland, Baltimore County

Earlier this year, astronomers stumbled upon a fascinating finding: Thousands of black holes likely exist near the center of our galaxy.

The X-ray images that enabled this discovery weren’t from some state-of-the-art new telescope. Nor were they even recently taken – some of the data was collected nearly 20 years ago.

No, the researchers discovered the black holes by digging through old, long-archived data.

Discoveries like this will only become more common, as the era of “big data” changes how science is done. Astronomers are gathering an exponentially greater amount of data every day – so much that it will take years to uncover all the hidden signals buried in the archives.

The evolution of astronomy

Sixty years ago, the typical astronomer worked largely alone or in a small team. They likely had access to a respectably large ground-based optical telescope at their home institution.

Their observations were largely confined to optical wavelengths – more or less what the eye can see. That meant they missed signals from a host of astrophysical sources, which can emit non-visible radiation from very low-frequency radio all the way up to high-energy gamma rays. For the most part, if you wanted to do astronomy, you had to be an academic or eccentric rich person with access to a good telescope.

Old data was stored in the form of photographic plates or published catalogs. But accessing archives from other observatories could be difficult – and it was virtually impossible for amateur astronomers.

Today, there are observatories that cover the entire electromagnetic spectrum. No longer operated by single institutions, these state-of-the-art observatories are usually launched by space agencies and are often joint efforts involving many countries.

With the coming of the digital age, almost all data are publicly available shortly after they are obtained. This makes astronomy very democratic – anyone who wants to can reanalyze almost any data set that makes the news. (You too can look at the Chandra data that led to the discovery of thousands of black holes!)

[Read more…]

The Dreamtime, science and narratives of Indigenous Australia

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Lake Mungo and the surrounding Willandra Lakes of NSW were established around 150,000 years ago.
from www.shutterstock.com

David Lambert, Griffith University

This article is an extract from an essay Owning the science: the power of partnerships in First Things First, the 60th edition of Griffith Review.

We’re publishing it as part of our occasional series Zoom Out, where authors explore key ideas in science and technology in the broader context of society and humanity.


Scientific and Indigenous knowledge systems have often been in conflict. In my view, too much is made of these conflicts; they have a lot in common.

For example, Indigenous knowledge typically takes the form of a narrative, usually a spoken story about how the world came to be. In a similar way, evolutionary theories, which aim to explain why particular characters are adapted to certain functions, also take the form of narratives. Both narratives are mostly focused on “origins”.




Read more:
Friday essay: when did Australia’s human history begin?


From a strictly genetic perspective, progress on origins research in Australia has been particularly slow. Early ancient DNA studies were focused on remains from permafrost conditions in Antarctica and cool temperate environments such as northern Europe, including Greenland.

But Australia is very different. Here, human remains are very old, and many are recovered from very hot environments.

While ancient DNA studies have played an important role in informing understanding of the evolution of our species worldwide, little is known about the levels of ancient genomic variation in Australia’s First Peoples – although some progress has been made in recent years. This includes the landmark recovery of genomic sequences from both contemporary and ancient Aboriginal Australian remains.

[Read more…]