Sometimes you need to let go

By Brian Clegg

When you really get engaged in a scientific theory, just as when you support a particular political viewpoint, it can be very difficult to let go. This might run counter to the theoretical nature of science, which supposedly delights in overturning old theories – but the reality is that scientists are human beings and don’t like to change deeply held views.

This need to sometimes push through a major change of viewpoint is behind Kuhn’s concept of a paradigm shift – for a considerable time the old guard cling onto their theory until it become untenable and suddenly the consensus undergoes a heavy duty shift, which can be distressing to those left behind.

It happened to me, not as a scientist but as a young science enthusiast, when my passionate support for Fred Hoyle and the steady state theory had to be swept aside for the Big Bang theory. Now, it’s entirely possible that something similar is happening to upset the equilibrium of supporters of the existence of dark matter particles.

There is no doubt at all that there is an effect, resulting galaxies not being under gravity as expected and that is commonly assumed to be due to dark matter. But the particles have stubbornly failed to turn up in experiment after experiment. There are alternative theories based on modified gravity: the original, MOND or MOdified Newtonian Dynamics, has some issues, but arguably fewer than those arising from attempts to explain the effect with massive particles that don’t interact electromagnetically.

The Big Bang triumphed when evidence came to light that the early universe was very different to the way it is now. It may be that a similar failure of expectation of the early universe will do for dark matter particles, as it has turned out, thanks to new data from the James Webb Space Telescope, that there were massive galaxies in the early universe – something predicted by modified gravity theories, but not by dark matter particle theories.

Of course, we could still discover dark matter – but this is certainly a major blow. To find more details on this, please take a look at this summary in Stacy McGaugh’s excellent Triton Station blog.

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Now Appearing is the blog of science writer Brian Clegg (www.brianclegg.net), author of Inflight Science, Before the Big Bang and The God Effect.