Month: October 2017

SI Updates

The updated constants include
the Boltzmann constant (which relates temperature to energy), and
the Planck constant (which can relate mass to electromagnetic energy),
the charge of the electron and
the Avogadro constant (the quantity that defines one mole of a substance).

“There are no dramatic changes. The Boltzmann constant is very consistent with earlier values. The temperature experts requested 8 digits for the constant and the last digit happened to be 0”.

The Planck constant has shifted downward by 15 parts per billion from its earlier value, due to new data collected since 2014. The Planck constant was determined by 2 experimental techniques, known as the Kibble balance and the Avogadro method. All of the measurements that were used for determining the new Planck value met previously agreed-upon international guidelines for levels of accuracy and consistency with one another.

The Planck constant can be used to define the kilogram, and using a fundamental constant for defining mass will solve many problems. Mass must be measured over a very large scale, from an atom to a pharmaceutical to a skyscraper. “At the low end, you currently use 1 type of physics to determine mass; at the high end, you use another type of physics”.

But the Planck constant will provide a consistent way for defining mass across all of these scales, with whatever laboratory method is used to measure mass.

The volt will change as well, since the Planck constant will also help to define it in the revised SI. A volt based purely on the fundamental constants will be very slightly smaller, ~100 parts per billion, than the current scientific realization of the volt, established in 1990. The top-level metrology labs will have to recalibrate their high-precision voltage measurements.

Antimatter cubesat

Antimatter is the most energy dense material in the universe. Positron dynamics core innovations is the ability to generate intense beams of cold positrons using an array of moderators. They use a radioisotope as a source of positrons. They react the gamma particles to get a charged ion which they direct with magnetic fields for propulsion. Rocket engines based on this would have exhaust at 10% of the speed of light.

Darkness

Darkness is either really good, or really bad. fascinating. lower light levels are both due to better technology and tragedy.

At their core, night lights are a generally human phenomenon. As such, they are tempting proxies for things like standard of living and economic activity. An illuminated place, sufficient to be detected by an orbiting satellite, represents the substantial influence we have on pushing back the darkness of the nighttime sky.

Chinese Dominance

China publicly announced that it is now in a ‘cold economic war’ with the US for the future of the world. China was so confident of its eventual victory, it clearly articulated the centerpiece of their effort to accomplish it: 1 belt 1 road. Unfortunately, due to a self-inflicted wound (Trump is merely a symptom), the US couldn’t be in a worse position to counter this effort. Decades of blind adherence to economic and social neoliberalism has shattered US cohesion along all 3 vectors: moral, mental, and physical. The result has been intractable economic stagnation, social turmoil, and political chaos. Even worse is on the horizon: the US is careening towards identity authoritarianism. In time, the US may be able to regain stability. Regardless, it’s unlikely the US will find a way through this crisis fast enough to mount a successful conventional counter to China’s challenge. So, what is to be done under the assumption the US will eventually recover, but not soon enough for conventional efforts?

Learning by reproducing

Students taking Stanford’s Advanced Topics in Networking class have to select a networking research paper and reproduce a result from it as part of a 3-week pair project. At the end of the process, they publish their findings on the course’s public Reproducing Network Research blog. It’s well worth having a look around the blog: the students manage to achieve a lot in only 3 weeks! In the last 5 years, 200 students have reproduced results from 40 papers.

In ‘Learning networking by reproducing research results’ the authors explain how this reproduction project came to be part of the course, what happens when students try to reproduce research, and the many benefits the students get from the experience. It’s a wonderful and inspiring idea that I’m sure could be applied more broadly too.

Mass Extinction Overrated?

After decades of researching the impact that humans are having on animal and plant species around the world, Chris Thomas has a simple message: Cheer up. Yes, we’ve wiped out woolly mammoths and ground sloths, and are finishing off black rhinos and Siberian tigers, but the doom is not all gloom. Myriad species, thanks in large part to humans who inadvertently transport them around the world, have blossomed in new regions, mated with like species and formed new hybrids that have themselves gone forth and prospered. We’re talking mammals, birds, trees, insects, microbes—all your flora and fauna. “Virtually all countries and islands in the world have experienced substantial increases in the numbers of species that can be found in and on them,” writes Thomas in his new book, Inheritors of the Earth: How Nature Is Thriving in an Age of Extinction.

The Second World Wars

The subtitle is How the First Global Conflict Was Fought and Won, and the author is Victor Davis Hanson. I loved this book, even though before I started I felt I didn’t want to read yet another tract on WWII. Most of the focus is on the logistics and management side:

By 1944, the US Navy was larger than the combined fleets of all the other major powers.

At the start of the War, the United States accounted for 60% of world oil output.

The US soldier was treated for psychiatric disorders at a rate 10x that of German troops. The average hospital stay for an American soldier was 117 days and 36% were not returned to the front. Supplies for a typical American soldier exceeded 36 kg per day.

The German army killed ~1.5 GIs for every German soldier lost.

The highest American fatality rate was in the Pacific, at 4%, still a remarkably low rate for the war as a whole. America did so well because of high gdp and remarkably efficient supply lines and equipment and air and naval support.

Kids? Just say no

Just as those wanting a companion animal should adopt an unwanted dog or cat rather than breed new animals, so those who want to rear a child should adopt rather than procreate. Of course, there are not enough unwanted children to satisfy all those who would like to parent, and there would be even fewer if more of those producing the unwanted children were to take anti-natalism to heart. However, so long as there are unwanted children, their existence is a further reason against others breeding.

Rearing children, whether one’s biological offspring or adopted, can bring satisfaction. If the number of unwanted children were to ever come to zero, anti-natalism would entail the deprivation of this benefit to those who accept the moral prohibition on creating children. That does not mean that we should reject anti-natalism. The reward of becoming a parent does not outweigh the serious harm procreation will cause to others.