Teaching AI to “Do No Harm”

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Is There an Artificial Intelligence in the House?

For SIAM News:

Medical care routinely involves life-or-death decisions, the allocation of expensive or rare resources, and ongoing management of real people’s health. Mistakes can be costly or even deadly, and healthcare professionals—as human beings themselves—are prone to the same biases and bigotries as the general population.

For this reason, medical centers in many countries are beginning to incorporate artificial intelligence (AI) into their practices. After all, computers in the abstract are not subject to the same foibles as humanity. In practice, however, medical AI perpetuates many of the same biases that are present in the system, particularly in terms of disparities in diagnosis and treatment (see Figure 1).

“Everyone knows that biased data can lead to biased output,” Ravi Parikh, an oncologist at the University of Pennsylvania, said. “The issue in healthcare is that the decision points are such high stakes. When you talk about AI, you’re talking about how to deploy resources that could reduce morbidity, keep patients out of the hospital, and save someone’s life. That’s why bias in healthcare AI is arguably one of the most important and consequential aspects of AI.”

[ read the rest at SIAM News ]

Bicycles, networks, and biological homeostasis

The linked article is for SIAM News, the magazine for members of the Society for Industrial and Applied Mathematics (SIAM). The audience for this magazine, in other words, is professional mathematicians and related researchers working in a wide variety of fields. While this article contains equations, I wrote it to be understandable even if you gloss over the math.

[ This blog is dedicated to tracking my most recent publications. Subscribe to the feed to keep up with all the science stories I write! ]

Balancing Homeostasis and Health

For SIAM News:

Human beings are not bicycles. However, mechanistic metaphors for the human body abound. For instance, we compare athletes to finely-tuned machines and look for equations that are derived from mechanics to describe biological processes — even when the relationship is no better than an analogy.

However, the concept of homeostasis clearly exemplifies the breakdown of mechanistic models when one applies them to the human body. Homeostasis is the process by which an organism maintains a stable output regardless of input (within reasonable limits). The most familiar example is human body temperature, which stays within a remarkably small range of values regardless of whether one is sitting in a cold room or walking outside on a hot day.

“In a bicycle, you know what each part is for,” Michael Reed, a mathematician at Duke University, said. “We are not machines with fixed parts; we are a large pile of cooperating cells. The question is, how does this pile of cooperating cells accomplish various tasks?”

[ Read the rest at SIAM News ]

Coding complicity in police violence

Occasionally people (usually my fellow white men) yell at me to “stick to science!” Well, sticking to science is a luxury that white women and scientists of color can’t afford, and pretending scientists aren’t complicit in violence toward underrepresented groups preserves inequality. At the same time, some within the broad tent of STEM (science, technology, engineering, and mathematics) actively perpetuate problems. My latest piece for SIAM News discusses one particular example — the ways in which computer scientists and other developers of code have helped increase racial profiling and police brutality — but many of the points apply more broadly to STEM. (Bonus: look for the Rage Against the Machine lyrics.)

[ This blog is dedicated to tracking my most recent publications. Subscribe to the feed to keep up with all the science stories I write! ]

When Software Harms, What You Reap Is What You Sow

For SIAM News:

As of July 2020, the CalGang database contained the names and personal details of nearly 90,000 people in the state of California who are suspected of being in gangs or associating with gang members. Despite its stated purpose to provide law enforcement agencies with accurate intelligence information, audits and independent investigations revealed that the database was riddled with errors, falsified material, racial profiling, and other serious problems.

Databases and algorithms are ubiquitous parts of our interconnected world, but CalGang illustrates a major way in which they can fail people. If a streaming service suggests a movie that you do not like, no real harm is done; but if your name appears in CalGang, you may face consequences like increased police harassment or harsher sentences if charged with a crime.

“[Most of] the people creating these technologies are not affected in negative ways,” Seny Kamara, a computer scientist at Brown University, said. “But if you’re a young Black male growing up in Chicago or New York or California, you know that you may end up as a false positive in a gang database, and that affects your life in a completely different way.”

[Read the rest at SIAM News]

Ecological stability far from equilibrium

toxic algae on Lake Erie, as seen by the Landsat 8 satellite

The linked article is for SIAM News, the magazine for members of the Society for Industrial and Applied Mathematics (SIAM). The audience for this magazine, in other words, is professional mathematicians and related researchers working in a wide variety of fields. While this article contains equations, I wrote it to be understandable even if you gloss over the math.

[ This blog is dedicated to tracking my most recent publications. Subscribe to the feed to keep up with all the science stories I write! ]

Ecological Transients and the Ghost of Equilibrium Past

For SIAM News:

The sight and smell of eutrophication—in the form of a layer of stinking green algae on a lake or pond—is likely familiar to many readers. The result is detrimental, even toxic, to other species that rely on the water, ranging from tiny animals to birds and even humans. For example, eutrophication on Lake Erie affects millions (see Figure 1). But the real culprit is actually the substance that feeds the algae: excess phosphorous that is produced by human activities like fertilizer runoff and leaky septic systems.

To manage eutrophication, one must know whether the affected body of water resides in a eutrophic stable state, or if its state is a long transient. The second case mimics stability because it can last a long time but is sustained by another source of phosphorous in the lakebed sediments. According to Tessa Francis, an ecologist at the University of Washington Puget Sound Institute, the wrong management choice has major consequences in terms of costs and trade-offs.

“You’re investing all of this social, political, and economic capital into management, but you’re getting no results from it,” Francis said. “If you gave the system a bigger smack by adding an alternative management strategy to tackle the phosphorus pool at the bottom of the lake, that would be more likely to get your lake back to the state you want. This is just one consequence of long transients in terms of how they affect management decisions.”

[Read the rest at SIAM NEWS]

The cost of “herd immunity” for COVID-19 is too high

My latest comic with Maki Naro is up at The Nib, the award-winning nonfiction comics site! This time we tackle the question of “herd immunity” for the COVID-19 pandemic, which has been suggested by a number of politicians as a strategy for beating the disease. As Maki and I describe, without a vaccine, this is less a strategy than a cynical throwing up of hands. Read on for an explanation of what “herd immunity” is and why it’s basically giving up.

[ This blog is dedicated to tracking my most recent publications. Subscribe to the feed to keep up with all the science stories I write! ]

Waiting For Herd Immunity is Not the Answer

Panel from “Waiting for Herd Immunity is Not the Answer” at The Nib. Click to read the rest. [Credit: Maki Naro (art)/moi (words)]

P.S. Do you like this comic? If so, please pledge to Maki’s and my forthcoming comics collection Who Owns an Asteroid? (from Unbound), which will include many such nonfiction science comics in full color!

Sizing up the weirdest objects in the universe

[ This blog is dedicated to tracking my most recent publications. Subscribe to the feed to keep up with all the science stories I write! ]

How big is a neutron star?

Astrophysicists are combining multiple methods to reveal the secrets of some of the weirdest objects in the universe.

For Symmetry Magazine:

Neutron stars are arguably the strangest objects in the cosmos. Born from the deaths of massive stars, they combine strong gravity with temperatures and densities higher than anything we can make in the lab.

While we’ve known about neutron stars for the better part of a century, astrophysicists still aren’t entirely sure how large they are. That uncertainty is related to two other unanswered questions: What’s in the middle of neutron stars, and how massive can they grow?

[read the rest at Symmetry Magazine]

Cold War treaties aren’t sufficient for the era of asteroid mining

Why did I, a physics/astronomy journalist, write about asteroids for a deep-sea mining trade magazine? Read on! Oh yes, and pledge to my book of science comics with Maki Naro, Who Owns an Asteroid?

[ This blog is dedicated to tracking my most recent publications. Subscribe to the feed to keep up with all the science stories I write! ]

The World Is Not Ready for Asteroid Mining, But It Needs To Be

For Deep Sea Mining Observer:

Nothing is less “deep sea” than an asteroid, yet parallels exist between these two domains, particularly when it comes to resource extraction. Asteroids are debris left over from the formation of the Solar System roughly 4.5 billion years ago. Due to our shared origin, Earth and asteroids contain the same basic materials: water, carbon compounds,  metals, and so forth. The “metals and so forth” part has drawn the interest of nations and private companies, since many asteroids are potentially rich in gold, platinum, and rare-earth elements. Astronomers have identified 957,798 asteroids as of December 2019, of which about 10,000 are known to orbit close enough to our planet to be classified as near-Earth objects — with some reachable by spacecraft.

With no biosphere, ecosystem services, or local stakeholders, extracting materials from asteroids carries few of the environmental concerns present in terrestrial or ocean mining on Earth.

Both the deep ocean and outer space are governed by international law, with much of said law constructed during the Cold War. Interested parties often bring a certain Wild West mentality to resource extraction in both instances. However, space law lags behind terrestrial laws on a number of fronts, and recent moves by individual nations and companies should be seen as a wake-up call.

[read the rest at DSM Observer…]

Fighting racial gerrymandering with math

The linked article is for SIAM News, the magazine for members of the Society for Industrial and Applied Mathematics (SIAM). The audience for this magazine, in other words, is professional mathematicians and related researchers working in a wide variety of fields. While this article contains equations, I wrote it to be understandable even if you gloss over the math.

[ This blog is dedicated to tracking my most recent publications. Subscribe to the feed to keep up with all the science stories I write! ]

The Mathematical Fight for Voting Rights

For SIAM News:

State and local governments will redraw voting districts based on new information following completion of the 2020 U.S. Census. Ideally, this process ensures fair representation. In practice, however, districting often involves gerrymandering: the deliberate planning of districts to dilute the voting power of certain groups in favor of others, which violates the law.

Racial gerrymandering—drawing districts to limit the power of voters of color to select candidates they favor—is a particularly pernicious problem. Section 2 of the Voting Rights Act (VRA) of 1965 specifically prohibits this practice, but that has not stopped authorities from doing it anyway. “A number of court decisions have purposefully asked mathematicians, political scientists, and statisticians to use specific methods to try and understand racial gerrymandering,” Matt Barreto, a professor of political science and Chicana/o studies at the University of California, Los Angeles, said.

Barreto and his colleagues employ powerful statistical methods and draw on census and other public data to identify gerrymandered districts. Utilizing these tools, mathematicians can test proposed district maps or draw their own, designing them from the ground up to prevent voter dilution.

[Read the rest at SIAM News…]

R0, mortality rate, and all that: the science of how disease spreads

[ This blog is dedicated to tracking my most recent publications. Subscribe to the feed to keep up with all the science stories I write! ]

The science of how diseases spread

How epidemiology puts the COVID-19 virus in perspective.

For Popular Science:

Scientists, medical professionals, and governments around the world are working to understand how the new respiratory disease ravaging Hubei province spreads—and how bad it could be for the rest of the world. Part of this effort is epidemiology: the study of how infections move through populations and how to control them.

Epidemiology incorporates everything from geography to complex mathematics in its effort to understand the spread of disease. Here are some basic epidemiological concepts that can help you get past the panic, misinformation, and xenophobia that tend to drive conversations around a newly emerging illness.

[read the rest at Popular Science]

Weird discrepancy in cosmic measurements has cosmologists puzzled

[ This blog is dedicated to tracking my most recent publications. Subscribe to the feed to keep up with all the science stories I write! ]

The growing crisis in cosmology

For The Week:

How rapidly is the universe expanding?

Since Edwin Hubble first discovered in 1929 that galaxies are getting farther apart over time, allowing scientists to trace the evolution of the universe back to an initial Big Bang, astronomers have struggled to measure the exact rate of this expansion. In particular, astronomers want to determine a number called the Hubble parameter, a measurement of how fast the cosmos is expanding as we speak. The Hubble parameter tells us the age of the universe, so measuring it was a major goal for many astronomers in the latter half of the 20th century.

The problem, however, is that measuring the Hubble parameter is, perhaps unsurprisingly, quite difficult. There are multiple methods for doing so, and modern observatories are coming up with different numbers depending on which method they use. It seems the number obtained based on the appearance of the universe shortly after the Big Bang is significantly smaller than the number obtained when looking at measurements involving objects closer by.

[Read the rest at The Week]