Paradigm Shifts?

20 March 201415 June 2014 / raminskibba / 6 Comments

In addition to physics and astronomy, I used to study philosophy of science and sociology. In my opinion, many scientists could learn a few things from sociologists and philosophers of science, to help them to better understand and consider how scientific processes work, what influences them and potentially biases scientific results, and how science advances through their and others’ work. In addition, I think that people who aren’t professional scientists (who we often simply call “the public”) could better understand what we are learning and gaining from science and how scientific results are obtained. I’ll just write a few ideas here and we can discuss these issues further later, but my main point is this: science is an excellent tool that sometimes produces important results and helps us learn about the universe, our planet, and ourselves, but it can be a messy and nonlinear process, and scientists are human–they sometimes make mistakes and may be stubborn about abandoning a falsified theory or interpretation. The cleanly and clearly described scientific results in textbooks and newspaper articles are misleading in a way, as they sometimes make us forget the long, arduous, and contentious process through which those results were achieved. To quote from Carl Sagan (in Cosmos), who inspired the subtitle of this blog (the “pale blue dot” reference),

[Science] is not perfect. It can be misused. It is only a tool. But it is by far the best tool we have, self-correcting, ongoing, applicable to everything. It has two rules. First: there are no sacred truths; all assumptions must be critically examined; arguments from authority are worthless. Second: whatever is inconsistent with the facts must be discarded or revised.

As you may know, the title of this post refers to Thomas Kuhn (in his book, The Structure of Scientific Revolutions). “Normal science” (the way science is usually done) proceeds gradually and is based on paradigms, which are collections of diverse elements that tell scientists what experiments to perform, which observations to make, how to modify their theories, how to make choices between competing theories and hypotheses, etc. We need a paradigm to demarcate what is science and to distinguish it from pseudo-science. Scientific revolutions are paradigm shifts, which are relatively sudden and unstructured events, and which often occur because of a crisis brought about by the accumulation of anomalies under the prevailing paradigm. Moreover, they usually cannot be decided by rational debate; paradigm acceptance via revolution is essentially a sociological phenomenon and is a matter of persuasion and conversion (according to Kuhn). In any case, it’s true that some scientific debates, especially involving rival paradigms, are less than civil and rational and can look something like this:

I’d like to make the point that, at conferences and in grant proposals, scientists (including me) pretend that we are developing research that is not only cutting edge but is also groundbreaking and Earth-shattering; some go so far as to claim that they are producing revolutionary (or paradigm-shifting) research. Nonetheless, scientific revolutions are actually extremely rare. Science usually advances at a very gradual pace and with many ups and downs. (There are other reasons to act like our science is revolutionary, however, since this helps to gain media attention and perform outreach in the public, and it helps policy-makers to justify investments in basic research in science.) When a scientist or group of scientists does obtain a critically important result, it is usually the case that others have already produced similar results, though perhaps with less precision. Credit often goes to a single person who packaged and advertised their results well. For example, many scientists are behind the “Higgs boson” discovery, and though American scientists received the Nobel Prize for detecting anisotropies in the cosmic microwave background with the COBE satellite, Soviets actually made an earlier detection with the RELIKT-1 experiment.

Let’s briefly focus on the example of quantum mechanics, in which there were intense debates intense debates in the 1920s about (what appeared to be) “observationally equivalent” interpretations, which in a nutshell were either probabilistic or deterministic and realist ones. My favorite professor at Notre Dame, James T. Cushing, wrote a provocative book on the subject with the subtitle, “Historical Contingency and the Copenhagen Hegemony“. The debates occurred between Neils Bohr’s camp (with Heisenberg, Pauli, and others, who were primarily based in Copenhagen and Göttingen) and Albert Einstein’s camp (with Schrödinger and de Broglie). Bohr’s younger followers were trying to make bold claims about QM and to make names for themselves, and one could argue that they misconstrued Einstein’s views. Einstein had essentially lost by the 1930s, in which the nail in the coffin was von Neumann’s so-called impossibility proof of “hidden variables” theories–a proof that was shown to be false thirty years later. In any case, Cushing argues that in decisions about accepting or dismissing scientific theories, sometimes social conditions or historical coincidences can play a role. Mara Beller also wrote an interesting book about this (Quantum Dialogue: The Making of a Revolution), and she finds that in order to understand the consolidation of the Copenhagen interpretation, we need to account for the dynamics of the Bohr et al. vs. Einstein et al. struggle. (In addition to Cushing and Beller, another book by Arthur Fine, called The Shaky Game, is also a useful reference.) I should also point out that Bohr used the rhetoric of “inevitability” which implied that there was no plausible alternative to the Copenhagen paradigm. If you can convince people that your view is already being adopted by the establishment, then the battle has already been won.

More recently, we have had other scientific debates about rival paradigms, such as in astrophysics, the existence of dark matter (DM) versus modified Newtonian dynamics (MOND); DM is more widely accepted, though its nature–whether it is “cold” or “warm” and to what extent it is self-interacting–is still up for debate. Debates in biology, medicine, and economics, are often even more contentious, partly because they have policy implications and can conflict with religious views.

Other relevant issues include the “theory-ladenness of observation”, the argument that everything one observes is interpreted through a prior understanding (and assumption) of other theories and concepts, and the “underdetermination of theory by data.” The concept of underdetermination dates back to Pierre Duhem and W. V. Quine, and it refers to the argument that given a body of evidence, more than one theory may be consistent with it. A corollary is that when a theory is confronted with recalcitrant evidence, the theory is not falsified, but instead, it can be reconciled with the evidance by making suitable adjustments to its hypotheses and assumptions. It is nonetheless the case that some theories are clearly better than others. According to Larry Laudan, we should not overemphasize the role of sociological factors over logic and the scientific method.

In any case, all of this has practical implications for scientists as well as for science journalists and for people who popularize science. We should be careful to be aware of, examine, and test our implicit assumptions; we should examine and quantify all of our systematic uncertainties; and we should allow for plenty of investigation of alternative explanations and theories. In observations, we also should be careful about selection effects, incompleteness, and biases. Finally, we should remember that scientists are human and sometimes make mistakes. Scientists are trying to explore and gain knowledge about what’s really happening in the universe, but sometimes other interests (funding, employment, reputation, personalities, conflicts of interest, etc.) play important roles. We must watch out for herding effects and confirmation bias, where we converge and end up agreeing on the incorrect answer. (Historical examples include the optical or electromagnetic ether; the crystalline spheres of medieval astronomy; the humoral theory of medicine; ‘catastrophist’ geology; etc.) Paradigm shifts are rare, but when we do make such a shift, let’s be sure that what we’re transitioning to is actually our currently best paradigm.

[For more on philosophy of science, this anthology is a useful reference, and in particular, I recommend reading work by Imre Lakatos, Paul Feyerabend, Helen Longino, Nancy Cartwright, Bas van Fraassen, Mary Hesse, and David Bloor, who I didn’t have the space to write about here. In addition, others (Ian Hacking, Allan Franklin, Andrew Pickering, Peter Galison) have written about these issues in scientific observations and experimentation. For more on the sociology of science, this webpage seems to contain useful references.]

An introduction to “space security”

7 March 201426 August 2014 / raminskibba / 3 Comments

I’m curious about what people refer to as “space security”, as well as space policy and sustainability, and if you’re interested, you can learn with me. This post will just be an introduction to some of the issues involved. Note that I’m not an expert on many of these issues, so take my comments and thoughts with a grain of salt.

The idea of “space security” might conjure images of invading aliens, but as much fun as that is, that’s not what I’m talking about. I’m also not planning on talking about killer asteroids and dangerous radiation, though these are much less far-fetched. For example, the Pan-STARRS survey (of which I was briefly a member a few years ago) received funding from NASA to assess the threat to the planet from Near Earth Objects, some of which pass closer to us than the moon. (A limitation of Pan-STARRS, however, was that images that happened to contain passing satellites had software applied to black out or blur the pixels in the region.) On the other hand, solar flares can produce “coronal mass ejections” and intense cosmic rays that could be hazardous to spacecraft but on Earth we’re somewhat protected by our atmosphere and magnetosphere. This and other forms of “space weather” could be the subject of another post later.

I’d like to talk about the issue of satellites, as well as weapons and reactors, in space. More than 5,000 satellites have been launched into orbit and about 1,000 are in operation today. The act of destroying a satellite or of colliding satellites can damage the space environment by creating dangerous amounts of debris. (If you’ve seen the Oscar-winning Gravity, then you know that debris from satellites can be a serious problem.) For example, in a demonstration of an anti-satellite weapon in 2007, China destroyed one of its own satellites; the resulting “space junk” then struck and destroyed a small Russian satellite last year. The following computer-generated images of the growing number of objects in low-earth orbit (courtesy of the NASA Orbital Debris Office) illustrates the problem. Only 5% of the objects are satellites; the rest are debris. Currently more than 21,000 pieces of debris larger than 10cm are being tracked, and there are as many as 500,000 additional untracted pieces larger than 1cm.

In addition, the loss of an important satellite could create or escalate a conflict, especially during a time of tension between states. The US and other countries possess “anti-satellite” weapons (ASATs) and have or are considering space-based missile defense systems. Attacks on satellites are a very real possibility, and it is important to beware of the destabilizing effects and potential for proliferation with such weapons. Moreover, since the Cold War, the US and other governments have considered deploying nuclear reactors on spacecraft, which have proven to be controversial (such as the dubiously named Project Prometheus, which was cancelled in 2006); an intentionally or unintentionally damaged nuclear reactor in space could have major consequences.

Considering that we are increasingly dependent on satellites and that there are military, commercial, and civil interests in space, how can we attempt to ensure space security and sustainability in the future? In the US, the Obama administration has a National Space Policy, which was released in June 2010. The policy mainly consists of: (1) limit further pollution of the space environment; (2) limit objects from colliding with each other and/or exploding; (3) actively removing high-risk space debris. The policy a good start, but much more could be done. An emphasis on international cooperation rather than unilateral action would help; space debris are clearly a global problem requiring global solutions. It is also important to negotiate on the control of space weapons. The US and other space powers should declare that they will not intentionally damage or disable satellites operating in accordance with the Outer Space Treaty and that they will not be the first to station weapons in space. Moreover, “space situational awareness” (SSA), which allows for the coordination of space traffic, can be improved in collaboration with other countries, and satellites can be made less vulnerable to collision or attack. Finally, the US should play an active role in negotiations with the international community on space security and sustainability. The United Nations has the Committee on the Peaceful Uses of Outer Space (COPUOS), with 76 member states, has been working on a variety of programs to improve the long-term sustainability of space activities, and in particular, to develop and adopt international standards to minimize space debris.

Scientific Integrity

1 February 2014 / raminskibba / 4 Comments

In this blog post, let’s discuss scientific integrity–specifically, efforts to keep scientific research as independent as possible from political, corporate, or other influence. Such influences are important for a variety of policies including energy policy (especially related to climate change), health and drugs, food and nutrition, education, etc., when particular companies or organizations have a financial or other stake in the outcome. For example, fossil fuel companies support the “denial industry“, claiming that the science of global warming is inconclusive, agribusinesses promote genetically modified crops, and drug companies promote antidepressant and ADHD drugs, while funding scientific research that often supports their campaigns.

Science informs political officials and agencies when they’re designing regulations for air and water pollution, when determining whether a particular drug is safe and efficacious, when assessing whether particular foods or products are safe for consumers, etc. In my opinion, science can rarely be completely “objective” and “unbiased”; scientists are humans, after all, and they have their own motivations and considerations that can affect their work. The important thing, however, is to reduce political and commercial influence as much as possible so that scientists can do their research and then present their results as clearly and accurately as possible.

In all fields of science, scientists to some extent are affected by funding constraints and grant agencies. These constraints can affect exactly what is studied, how it is researched, and how the results are presented in the media and to the public. Nonetheless, scientific research is particularly important–and susceptible to more outside influences–when it is related to public policy, including the topics above. In addition, politically-related work in the social sciences, especially economics, can be contentious as well.

In the US under the Bush administration, many felt that scientists were under attack. For example, a “revolving door” appeared to be in place when former lobbyists and spokespeople for industries later worked at agencies having the task of regulating their former industries; in particular cases, they appeared to write or advocate for policy shifts that benefited these industries. In 2004, the Union of Concerned Scientists (UCS) released a report, “Scientific Integrity in Policymaking: An Investigation into the Bush Administration’s Misuse of Science”, claiming that the White House censors and suppresses reports by its own scientists, stacks advisory committees, and disbands government panels. There later appeared to be political influence on the Food and Drug Administration (FDA), on researchers working on embryonic stem cells, on sex education (because of arguments about the effectiveness of abstinence-based programs), and on the teaching of biological evolution.

Although the Obama administration appears to have more respect for science and scientists (see this 2013 UCS report), the politicization of some scientific work continues. The assessment of the social and environmental impact of the Keystone XL pipeline may be such an example. The final environmental impact statement, which was released by the State Department yesterday, appears to endorse the pipeline, but the interpretation is unclear (see this coverage in the Wall Street Journal and Scientific American blog).

In any case, these contentious situations will be easier when government agencies have explicit policies for scientific integrity and when the affiliations and employment histories of officials are transparent. It’s also important to keep in mind that the struggle for independent and transparent science never ends. Scientists should always try to be as clear as possible about their views or beliefs when they are relevant to their work (see this NYT blog for useful advice), and results and data should be made publicly available whenever possible.