Eugene Linden
home   |   contact info   |   biography   |   publications   |   radio/tv   |   musings   |   short takes   

Latest Musing

Diary of a Tree Stump

Something lighter:                                    

  “I would vote for a tree stump if it could beat Donald Trump”

   [Timothy Egan, in his Nov. 8, 201...

continue

Latest Book

Deep Past
Buy from Amazon

more info

Articles by Category
endangered animals
rapid climate change
global deforestation
fragging

Books

Winds of Change
Buy from Amazon

more info
Afterword to the softbound edition.


The Octopus and the Orangutan
more info


The Future In Plain Sight
more info


The Parrot's Lament
more info


Silent Partners
more info


Affluence and Discontent
more info


The Alms Race
more info


Apes, Men, & Language
more info


CanWeReallyUnderstandMatter

BY EUGENE LINDEN


Monday, Apr. 16, 1990
Few tasks are more daunting than standing in the path of a charging theoretical physicist who is hell-bent on getting funding for the next particle accelerator. As practitioners of the hardest of the hard sciences, physicists do little to discourage their aura of intellectual supremacy, particularly when suggesting to Congress that a grand synthesis of all the forces of nature is at hand if the Government will only cough up a few billion dollars more. But what if this confidence is misplaced? What if the barriers to knowledge are higher than many physicists like to admit?

For much of this century, scientists have known that the comfortable solidity of things begins to break down at the subatomic level. Like the Hindu veil of Maya, the palette from which nature paints atoms proves illusory when approached. From afar, this world appears neatly separated into waves and particles, but close scrutiny reveals indescribable objects that have characteristics of both.

Physicists have prospered in this quirky realm, but neither physics nor the rest of science has fully digested its implications. Inside the atom is a world of perpetual uncertainty in which particle behavior can be expressed only as a set of probabilities, and reality exists only in the eyes of the observer. Though the recognition of this uncertainty grew in part out of Albert Einstein's work, the idea bothered him immensely. "God does not play dice with the universe," he remarked.

The set of mathematical tools developed to explore the subatomic world is called quantum mechanics. The theory works amazingly well in predicting the behavior of quarks, leptons and the like, but it defies common sense, and its equations imply the existence of phenomena that seem impossible. For instance, under special circumstances, quantum theory predicts that a change in an object in one place can instantly produce a change in a related object somewhere else -- even on the other side of the universe.

Over the years, this seeming paradox has been stated in various ways, but its most familiar form involves the behavior of photons, the basic units of light. When two photons are emitted by a particular light source and given a certain polarization (which can be thought of as a type of orientation), quantum theory holds that the two photons will always share that orientation. But what if an observer altered the polarization of one photon once it was in flight? In theory, that event would also instantaneously change the polarization of the other photon, even if it was light-years away. The very idea violates ordinary logic and strains the traditional laws of physics.

The two-photon puzzle was nothing more than a matter of speculation until 1964, when an Irish theoretical physicist named John Stewart Bell restated the problem as a simple mathematical proposition. A young physicist named John Clauser came upon Bell's theorem and realized that it opened the door to testing the two-photon problem in an experiment. Like Einstein, Clauser was bothered by the seemingly absurd implications of quantum mechanics. Says Clauser, now a research physicist at the University of California, Berkeley: "I had an opportunity to devise a test and see whether nature would choose quantum mechanics or reality as we know it." In his experiment, Clauser, assisted by Stuart Freedman, found a way of firing photons in opposite directions and selectively changing their polarization.

The outcome was clear: a change in one photon did alter the polarization of the other. In other words, nature chose quantum mechanics, showing that the two related photons could not be considered separate objects, but rather remained connected in some mysterious way. This experiment, argues physicist Henry Stapp of Lawrence Berkeley Laboratories, imposes new limits on what can be established about the nature of matter by proving that experiments can be influenced by events elsewhere in the universe.

Clauser's work pointed out once again that the rules of quantum mechanics do not mesh well with the laws of Newton and Einstein. But most physicists do not see the apparent disparity to be a major practical problem. Classical laws work perfectly well in explaining phenomena in the visible world -- the motion of a planet or the trajectory of a curveball -- and quantum theory does just as well when restricted to describing subatomic events like the flight of an electron.

Yet a small band of physicists, including Clauser and Stapp, are disturbed by their profession's priorities, believing that the anomalies of quantum theory deserve much more investigation. Instead of chasing ever smaller particles with ever larger accelerators, some of these critics assert, physics should be moving in the opposite direction. Specifically, science needs to find out whether the elusiveness of the quantum world applies to objects larger than subatomic particles.

No one worries about the relevance of quantum mechanics to the momentum of a charging elephant. But there are events on the border between the visible and the invisible in which quantum effects could conceivably come into play. Possible examples: biochemical reactions and the firing of neurons in the brain. Stapp, Clauser and others believe that a better understanding of how quantum theory applies to atoms and molecules might help in everything from artificial-intelligence research to building improved gyroscopes. For now, though, this boundary area is a theoretical no-man's-land. Certainly physicists are a lot further from understanding how the world works than some would have Congress believe.

contact Eugene Linden

Short Take

THOUGHTS ON WHY THE EARLY IPCC ASSESSMENTS UNDERSTATED THE CLIMATE THREAT

 

An oped involves extreme compression, and so I thought I’d expand on why I think the initial IPCC reports so underestimated the threat. Make no mistake, the consensus in the summaries for policy makers in the first two assessments did underestimate the threat. The consensus was that permafrost would be stable for the next 100 years and also that the ice sheets would remain stable (there was even a strong sentiment at that time that the East Antarctic sheet would gain mass). Moreover, in 1990, the concept of rapid climate change was at the periphery of mainstream scientific opinion. All these things turned out to be wrong

Of course, there were scientists at that time who raised alarms about the possibility of rapid climate change, collapse of the ice sheets, and nightmare scenarios of melting permafrost, but, fairly or not, the IPCC summary for policy makers was and is taken to represent the consensus of scientific thinking.

In my opinion such documents will always take a more conservative (less dramatic) position than what scientists feel is justified. For one thing the IPCC included policy makers, most of whom were more incentivized to downplay the threats. For another, many of the national governments that were the customers for these assessments barely tolerated the exercise and gave strong signals that they didn’t want to see anything that called for dramatic action, and this being the UN, there was a strong push to present a document that as many governments as possible would accept.

And then there is the nature of science and the state of climate science at that point. There is an inherent structural lag built in to the nature of science. For instance, the 1980’s were marked by the rapid development of proxies to see past climate changes with ever more precision. By the mid-late 80’s the proxies and siting had been refined sufficiently that the GISP and GRIP projects could confidently get ice cores from Greenland that they felt represented a true climate record and by then they also had the proxies with the resolution to see the rapid changes that had taken place in the past. Given the nature of data collection, interpretation, peer-review and publishing, it wasn’t until 1993 that these results were published.

It took nearly another decade for this new, alarming, paradigm about how rapidly global climate can change to percolate through the scientific community, and, even today, much of the public is unaware that climate can change on a dime.

As for the ice sheets, when I was on the West Antarctic Ice Sheet in 1996, there was talk about the acceleratio of  ice streams feeding the Thwaites and Pine Island glaciers, but the notion that there might be a significant increase in runoff from the ice sheet over the next hundred years was still very much a fringe idea.

With permafrost, the problem was a sparsity of data in the 80s and early 90s and it is understandable that scientists didn’t want to venture beyond the data.

The problem for society as a whole was that the muted consensus on the scale of the threat diminished any sense of urgency about dealing with the problem. Perhaps the best example of this was the early work of William Nordhaus. Working from the IPCC best estimates in the early 1990s Nordhaus published one paper in which he predicted the hit to the US GDP from climate change in 2100 would be about ½ of 1%. Nobody is going to jump out of their chair and demand action if the hit to the economy was going to be 0.5% of GPD a hundred years laterLibertarians such as William Niskanen seized on this and testified before Congress that there was plenty of time to deal with global warming if it was a threat at all.  

And then there was the disinformation campaign of industry, particularly fossil fuel lobbyists, as well as pressure from unions (the UAW in particular) and the financial community. These highly motivated, deep-pocketed interests seized on scientific caution to suggest deep divisions among scientists and that the threat was overplayed. Little wonder then that the public failed to appreciate that this was a looming crisis that demanded immediate, concerted action.

 



read more
  designed and maintained by g r a v i t y s w i t c h , i n c .
Eugene Linden. all rights reserved.