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Category Archive: Relativity

Feb 23 2012

Neutrinos not so fast after all?

The news that some neutrinos may travel faster than the speed of light caused a sensation when it broke in September of last year. Like many physicists who have lived through similar reports in the past, my reaction was one of skepticism, both of the claim and

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Nov 18 2011

Relativity-14: Revised OPERA experiment finds same result

The OPERA experiment that caused such a flurry of interest with its reports of faster-than-light neutrinos has been repeated to take into account one of the criticisms and they find that the neutrinos still seem to be traveling faster than the speed of light. You can read the paper on the revised experiment here. (For …

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Nov 10 2011

Relativity-13: Some concluding thoughts

(For previous posts in this series, see here.) A lot of things need to happen before the extraordinary claims of faster-than-light neutrinos are accepted as true. As Carl Sagan once said, “Extraordinary claims require extraordinary evidence.” The required evidence needs to take many forms: the results should be consistent and reproducible, corroborating evidence will have …

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Nov 08 2011

Relativity-12: David Hume and causality

(For previous posts in this series, see here.) Suppose that the claim that neutrinos can travel faster than light holds up. What are the implications? As I said earlier in the series, this does not mean that Einstein’s theory of relativity is overthrown, since it always allowed for faster than light particles, though we had …

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Nov 03 2011

Relativity-11: The cold fusion debacle

(For previous posts in this series, see here.) The ‘cold fusion’ episode from back in 1989 illustrates the danger with issuing press releases announcing a major scientific discovery before the scientific community has had a chance to weigh in and sift through the evidence. Two respected scientists Stanley Pons and Martin Fleischmann at the University …

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Nov 01 2011

Relativity-10: Science and public relations

(For previous posts in this series, see here.) Scientists want their work to influence the field and so they would like it to gain the widest possible audience. Most of the time, their peers (and funding agencies) are their target audience because they are the only ones who really understand what they do. But when …

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Oct 27 2011

Relativity-9: The importance of corroborating evidence in science

(For previous posts in this series, see here.) In my series on the logic of science, I recounted how philosopher of science Pierre Duhem had pointed out as far back as 1906 that the theories of science are all connected to each other and changes in one area will have unavoidable effects on others that …

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Oct 24 2011

Relativity-8: General relativity

(For previous posts in this series, see here.) To understand the role of Einstein’s general theory of relativity, recall that the original OPERA experiment claimed that they had detected neutrinos traveling faster than the speed of light. This posed a challenge to what is known as Einstein’s theory of special relativity, proposed in 1905, which …

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Oct 21 2011

Relativity-7: What could be other reasons for the CERN-Gran Sasso results?

(For previous posts in this series, see here.) The reactions to the reports of the CERN-Gran Sasso discovery of possibly faster-than-light neutrinos open a window into how science operates, and the differences in the way that the scientific community and the media and the general public react whenever a result emerges that contradicts the firmly …

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Oct 19 2011

Relativity-6: Measuring time and space more precisely

(For previous posts in this series, see here.) In the previous post in this series, I said that Einstein’s claim that the speed of light must be the same when measured by all observers irrespective of how they were moving led to the conclusion that the rate at which time elapsed must depend on the …

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