It’s unsettling to hear scientists say that long-held beliefs might be wrong, but that’s the nature of science. Scientific “findings” are tentative, not absolute. Some see this as a strength of science, but unless actual progress is demonstrated, that strength is called into question. Recent news casts doubt on various beliefs that had been trusted for a long time.
1. We were wrong about Neanderthal Man: For well nigh a century or more, Neanderthals were thought too brutish to make art. Not any more. Cave paintings alleged to have been created by Neanderthals have been discovered in Spain, New Scientist reported. Dating tests are still being done on the figures, which appear to be representations of dolphins. The correctives are more serious, though. The article also pointed out that dating of other cave art is uncertain. Paul Pettitt from the University of Sheffield let that cat out of the bag: “Even some sites we think we understand very well such as the Grotte Chauvet in France are very problematic in terms of how old they are.”
2. Rings around the tree dates: What could be more reliable than tree ring dating? Trees make annual rings; count them and you’ve got an absolute date. Why, then, did PhysOrg report, “Tree rings may underestimate climate response to volcanic eruptions”? A study re-evaluated some estimates, and found them overall quite good, with one “glaring error” – trees might not produce rings after a volcanic eruption strong enough to affect climate. But if dates could be underestimated by factors not previously considered, could they be overestimated by other unknowns? The article exposed some of the assumptions that go into the dating method:
The potential absence of rings in the first one to three years following eruption further degrades the temperature reconstruction. Because tree-ring information is averaged across many locations to obtain a representative estimate of northern hemisphere temperature, tree-ring records with and without missing rings for a given year are merged, leading to a smearing and reduced and delayed apparent cooling.
3. Power Law, or lawless power? One of science’s great strengths is the ability to describe nature mathematically. But now, PhysOrg said, it’s time for a “frank discussion,” about the use of power laws. These are widely-used techniques to describe relationships between phenomena so as to show causation, instead of just correlation. Causation is a vexed question in philosophy of science. There’s nothing like a graph to give the appearance of objectivity. Not so fast; Michael Stumpf [Imperial College London] and Mason Porter [Oxford], wrote in Science about “the inexact science of trying to apply the power law to situations in science where it’s not always easy to show a direct link between correlation and causation, a key problem they say, in much of the science that is conducted today.” The original paper in Science began,1
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