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The TRAPPIST-1 system of exoplanets, approximately 40 light-years away
Exoplanets galore
As of the present date (August 2019), more than 4000 exoplanets have been discovered orbiting other stars, and by the time you read this even more will have been logged. Several hundred exoplanets were announced in a July 2019 paper (although these await independent confirmation). All of this is a remarkable advance, given that the first confirmed exoplanet discovery did not occur until 1992.
Most of the discoveries mentioned above are planets that are either too large or too close to their sun to possess liquid water, much
Continue reading How many habitable exoplanets are there, really?
A large cluster galaxy in the center acts as a gravitational lens, splitting the light from a more distant supernova into four yellow images (arrows)
The standard model of physics has reigned supreme since the 1970s, successfully describing experimental physical reality in a vast array of experimental tests. Among other things, the standard model predicted the existence of a particle, now known as the Higgs boson, underlying the phenomenon of mass. This particle was experimentally discovered in 2012, nearly 50 years after it was first predicted.
Yet physicists have known for many years that the standard model cannot be the
Continue reading How fast is the universe expanding? New results deepen the controversy
Introduction
In an advance that may presage a dramatic new era of pharmaceuticals and medicine, DeepMind (a subsidiary of Alphabet, Google’s parent company) recently applied their machine learning software to the challenging problem of protein folding, with remarkable success. In the wake of this success, DeepMind and other private companies are racing to further extend these capabilities and apply them to real-world biology and medicine.
The protein folding problem
Protein folding is the name for the physical process in which a protein chain, defined by a linear sequence of amino acids, assumes its equilibrium 3-dimensional structure, a process that in
Continue reading Protein folding via machine learning may spawn medical advances
Homo Deus
In his new book Homo Deus, Israeli scholar Yuval Noah Harari has published one of the most thoughtful and far-reaching analyses of humanity’s present and future. Building on his earlier Sapiens, Harari argues that although humanity has made enormous progress across in the past few centuries, the future of our society, and even of our species, is uncertain.
Harari begins with a reprise of human history, from prehistoric times to the present. He then observes that although religious beliefs are much more nuanced and sophisticated than in the past, human society still relies heavily on the narratives
Continue reading Homo Deus: A brief history of tomorrow
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Introduction
Four mathematicians, Michael Griffin of Brigham Young University, Ken Ono of Emory University (now at University of Virginia), Larry Rolen of Vanderbilt University and Don Zagier of the Max Planck Institute, have proven a significant result that is thought to be on the roadmap to a proof of the most celebrated of unsolved mathematical conjecture, namely the Riemann hypothesis. First, here is some background:
The Riemann hypothesis
The Riemann hypothesis was first posed by the German mathematician Georg Friedrich Bernhard Riemann in 1859, in a paper where he observed that questions regarding
Continue reading Mathematicians prove result tied to the Riemann hypothesis
A colony of the new Syn61 bacteria; credit: BBC
Creating life
In a remarkable development with far-reaching consequences, researchers at the Cambridge Laboratory of Molecular Biology have used a computer program to rewrite the DNA of the well-known bacteria Escherichia coli (more commonly known as “E. coli”) to produce a functioning, reproducing species that is far more complex than any previous similar synthetic biology effort.
Venter’s 2010 project
This effort has its roots in a project spearheaded by J. Craig Venter, the well-known maverick biomedical researcher known for the “shotgun” approach to genome sequencing pioneered by his team at
Continue reading Computational tools help create new living organism
Optimal stacking of oranges.
The sphere-packing problem
The Kepler conjecture is the assertion that the simple scheme of stacking oranges typically seen in a supermarket has the highest possible average density, namely pi/(3 sqrt(2)) = 0.740480489…, for any possible arrangement, regular or irregular. It is named after 17th-century astronomer Johannes Kepler, who first proposed that planets orbited in elliptical paths around the sun.
Hales’ proof of the Kepler conjecture
In the early 1990s, Thomas Hales, following an approach first suggested by Laszlo Fejes Toth in 1953, determined that the maximum density of all possible arrangements could be obtained
Continue reading Researchers use “magic functions” to prove sphere-packing results
Introduction
Right off, it may not sound like pi, climate change denial and young-Earth creationism have much in common. In fact, there is an important connection. Here is some background.
Computing pi
Pi = 3.1415926535…, namely the ratio between the circumference of a circle and its diameter, has fascinated not only mathematicians and scientists but the public at large for centuries. Archimedes (c.287–212 BCE) was the first to present a scheme for calculating pi as a limit of perimeters of inscribed and circumscribed polygons, as illustrated briefly in the graphic to the right (see this Math Scholar blog for details).
Continue reading Pi, climate change denial and creationism
AI’s rocky start
The modern field of artificial intelligence (AI) began in 1950 with Alan Turing’s landmark paper Computing machinery and intelligence, which outlined the principles of AI and proposed a test, now known as the Turing test, for establishing whether AI had been achieved. Although early researchers were confident that AI systems would soon be a reality, inflated promises and expectations led to the “AI Winter” in the 1970s, a phenomenon that sadly was repeated again, in the late 1980s and early 1990s, when a second wave of AI systems also disappointed.
A breakthrough of sorts came in the
Continue reading Google AI system proves over 1200 mathematical theorems
Credit: Wikimedia
The reproducibility crisis in science
Recent public reports have underscored a crisis of reproducibility in numerous fields of science. Here are just a few of recent cases that have attracted widespread publicity:
In 2012, Amgen researchers reported that they were able to reproduce fewer than 10 of 53 cancer studies. In 2013, in the wake of numerous recent instances of highly touted pharmaceutical products failing or disappointing when fielded, researchers in the field began promoting the All Trials movement, which would require participating firms and researchers to post the results of all trials, successful or not. In
Continue reading P-hacking and scientific reproducibility
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