Knight Science Journalism @MIT

Science Journalism in the Public Interest

David Kaiser

The latest news, announcements, fellow and alumni updates, and other dispatches from the Knight Science Journalism Program.

by / November 21st 2018 / KSJ News & Events

David Kaiser on Einstein, Politics, and the Limits of Self-Policing Science

Physicist and physics historian David Kaiser spoke to KSJ Fellows about how culture and politics altered the fate of Einstein’s theory of general relativity.

When LIGO announced the detection of gravitational waves to the world in 2016, it was the discovery of a lifetime, hailed as the ultimate confirmation of a prediction made by Einstein’s theory of general relativity more than one hundred years earlier.

David Kaiser, both a physicist and a historian of physics at MIT, spoke to KSJ fellows and guests last week about the history of how Einstein’s theory traveled through the world, from the mind of a single man bound by his circumstances, to the subject of a billion-dollar experiment carried out a century later.

Kaiser argued that Einstein’s theory, which was otherworldly in nature – the stretching of space, the expansion of the universe – was very much tethered to the earth, its movement and adoption by the scientific community restricted by war and political ideology. This history tells us that scientific progress is not a series of eureka moments, but rather a product of the time, place, and culture of the messy human lives that endeavor to push it forward.

The story starts in November of 1915, when Einstein first described his new theory in a series of presentations to the Prussian Academy of Science. Gravity is not a separate force, he told them. Gravity is simply a matter of geometry. A large planetary object, such as a star, bends the shape of space-time, and the paths of neighboring bodies respond to this distortion.

The idea was revolutionary, but the timing was terrible. As Kaiser put it, November of 1915 in Germany was pretty chaotic, to say the least. It being a little over a year into World War I, Einstein’s ability to travel and spread his ideas was restricted. He could lecture only within certain countries and correspond only with German colleagues. His theory of relativity spread across borders almost by luck: by a Russian scientist who happened to be detained in Göttingen during the war, where Einstein often lectured; by a Dutch mathematician who trained under Einstein in the Netherlands (a neutral country) and then sent long letters describing the theory to an English astronomer.  The Englishman, Arthur Eddington, was ultimately able to confirm Einstein’s theory with an experiment during a solar eclipse in 1919, making Einstein a worldwide celebrity, overnight.

This is just one small fraction of the drama that played out over the course of the century that eventually led to LIGO. Kaiser told several other tales of how Einstein’s theory moved through the world, coming in and out of fashion, and influencing developments in other areas of science along the way, like military defense, the hydrogen bomb, and computing.

Kaiser is writing a book on the political history of gravity, and argues that science is and always has been political. The conversation turned to nuclear weapons research, and to the scientists involved in the hydrogen bomb who later became antinuclear activists. KSJ fellow Amina Khan brought up self-policing, saying that because journalists are not experts, they rely on the scientific community to check itself, to have dissidents and people who say, “you’re thinking about this the wrong way,” or “your idea is racist.” The history of nuclear weapons shows us that sometimes the process of correction takes time, and damage can be done in the interim.

Kaiser said that today, he worries more about the potentially harmful uses of biology. “To make really bad stuff happen biologically, you need this much bench space,” he said, pinching his fingers an inch apart. With nuclear physics, they needed an entire national laboratory, computers that filled the room, four thousand people, billion-dollar budgets. “Bad stuff happened there, but it was hard to go rogue.”

“Self-censorship sounds nice, but we all have our blinkers and our blinders, our limited horizons,” he said. “Even very smart people who dearly want to do right are gonna miss a lot of stuff because they’re coming from one perspective. Let’s not put all our faith in a glorious self-correcting system.”

by / March 7th 2017 / KSJ News & Events

Roll Over, Einstein

David Kaiser explaining what Einstein derided as “spooky action at a distance.” Photo: Fabio Turone.

“There’s no quiz today,” David Kaiser promised at the start of his KSJ seminar on February 28. With a title slide like “Testing Quantum Theory With the Cosmos,” he must have known his topic was intimidating. But Kaiser, the MIT physicist and science historian, is well versed at making quantum weirdness engaging for nonphysicists.

In addition to writing books like “How the Hippies Saved Physics” (2011), which explores the interwoven history of quantum theory and 1970s counterculture, Kaiser has written for publications like The New York Times and The New Yorker. In his presentation he spoke on the curious phenomenon of quantum entanglement.

Entanglement is but one item in a long list of quantum mechanical eccentricities. In the quantum world, certainty goes out the window, and objects can apparently exist in two opposite states at once (think Schrödinger’s cat, dead and alive). If this rubs you the wrong way, you’re in good company. “Quantum theory seemed an insult to many people,” Kaiser told the KSJ fellows. Prominent among them was Albert Einstein, who famously scoffed that God doesn’t play dice.

Einstein was similarly skeptical of entanglement, which describes two particles whose fates are inextricably intertwined. At any given time, even when they’re light-years apart, the likelihood of observing Particle A in a certain state depends on the current state of Particle B.

To illustrate this oddity, Kaiser invoked the analogy of twins Alice and Bob, who grow up together and eventually separate for college: Alice goes to Cambridge, Massachusetts, and Bob to Cambridge, England. In Massachusetts, Alice visits a restaurant where the waiter always offers her — with no clear pattern — a dessert choice between two baked goods or two frozen treats. She always has a 50-50 shot of choosing one baked good over the other; same with the frozen dessert. When Alice reunites with Bob at Christmas, she learns that he, too, has been visiting a restaurant where he’s been offered this same set of choices. And when the twins compare their history of dessert orders, their selections are correlated far more often than mere chance should allow.

Many people, like Einstein, have found entanglement unnerving. When asked why he thinks it’s such a disconcerting notion — because it contradicts everyday experience? because it apparently limits free will? — Kaiser replied that it’s probably both. Furthermore, because of the accepted cosmic light-travel speed limit, “playing around with instantaneousness makes many physicists concerned.” Also, it “just sounds spooky, like ESP or mind reading.”

But over several decades, experiments have come down on the side of entanglement time and time again. In these experiments, some source of entangled particles spits out particle pairs (analogous to Alice and Bob) toward measuring devices (American and British waiters) that can be set to observe different particle properties (a choice between baked goods or a choice between frozen goods). When researchers compare the particle characteristics measured by each detector (dessert orders), they match up enough to suggest the particles truly are entangled.

To be sure that something as counterintuitive as entanglement is real — especially when rising industries like quantum computing and encryption depend on it — physicists try to brainstorm and debunk alternative theories for explaining the data. “You really have to think like a conspiracy theorist,” Kaiser said.

He and his colleagues recently entered the entanglement-testing fray, pulling the drawstrings on what is called the “freedom of choice” loophole — a “conspiracy theory” arguing that when scientists have total control over their experimental setup, they can’t be sure that their choices don’t introduce “hidden variables” that produce entanglement-like results.

Thus, Kaiser’s team chose to “offshore some of the [experimental] decision making to the universe itself,” he said, by hooking up their particle detectors to telescopes trained on stars. Just before the entangled particles reached the measurement devices, each detector chose which property to measure based on the current color of the star it was observing. The researchers still got data that bore the hallmarks of entanglement. Sorry, Einstein.

“David is a really unique person to hear speak because he’s both a physicist and a writer,” said KSJ fellow Maura O’Connor, “so he has this rare ability to translate the science behind his research into big ideas that expand the interest and understanding of his audience.”

For his part, Kaiser thrives on inviting other people to ponder the enigma of entanglement. He loves that these awe-inspiring — and, yes, disquieting — ideas can be introduced in an hourlong seminar “without smacking people in the face with a bunch of mathematics.” Indeed, Kaiser dashed straight from KSJ to yet another quantum presentation — at the MIT Museum.