Herd immunity. What is it? What can it do for us? Or to us?
It can be our best friend and our worst enemy.
Herd immunity—friend or enemy?

Herd immunity. What is it? What can it do for us? Or to us?
It can be our best friend and our worst enemy.
COVID-19 may infect much of population in many countries. From its origins in Wuhan, China, it has proven lethal in a small but alarming fraction of cases. The principal risk is pneumonia in elderly or already ill patients. There will be no vaccine for at least a year. The world needs an effective treatment right […]
We’ve all seen that vast black hole. Its six billion solar masses are so dense no light can escape. It is so far away light from hot gas falling in takes 55 million years to reach us. Well actually, we’ve seen an image. Now that we’ve seen it, what do we know now we didn’t […]
These are exciting times. Every few months astronomy surprises us with insights into ancient secrets. New telescopes are scanning galaxies throughout the visible universe. Most galaxies are mind-bogglingly far away. Exactly how far has long been a fundamental issue. But we just got a whole new way to measure it. Today the universe is much […]
In 1849, gold gave a kick start to the new State of California. Its non-native population grew 100-fold in a single year. Its miners soon took 300 tons of gold ($12 billion at today’s prices) from the ground. How did the gold get there? A few months ago, an extraordinary event—maybe the most widely studied […]
In 2015 scientists at LIGO observed a wave of gravitation—a distortion of space itself that came from two black holes colliding more than a billion light years away. LIGO is a gravity telescope of exquisite sensitivity. Its observation shaped up as the top science story of the century. In record time, this week it nailed […]
We think of space as empty. It’s not. Quite aside from stray hydrogen atoms and fleeting quantum particles in the vacuum, space is substantial. It has mass. Indeed Planck-satellite measurements now show space is three times denser than the average of the universe’s matter. Yet like the rest of us most physicists still treat space […]
Is there life out there? has long been an issue. Recently the issue has been shifting to: How many planets harbour life? Winston Churchill (with whom I’m proud to share a publisher) was among the first to ask this question. In 1939—shortly before he became Prime Minister of Britain—he penned an unpublished work of careful […]
A quadrillion here, a quadrillion there, and pretty soon you’re talking about real money. – With a tip of the hat to U.S. Senator Everett McKinley Dirksen The economy has been sputtering for years; it sure could use a boost. How big a boost could it soon get from Planck-scale physics? A new answer to this question may surprise you. Science Seen […]