Monday, 9 January 2017

Fun Online Polls: Competing theories of gravity & groupthink

The results to last week's Fun Online Poll were as follows:

Which theory better explains the high rotational speed of stars in the outer arms of a galaxy?

Existing gravitional theory plus dark matter - 11 votes
Erik Verlinde's Modified Newtonian Dynamics aka Entropic Gravity - 21 votes

Ed P threw a curve ball, with Derek seconding, pointing out that there is another explanation of gravity. I don't have the faintest understanding of the two alternative theories, even gravity itself is a mystery to me - how objects light years a apart can attract each other, what keeps us glued to the earth's surface and so on - but the whole 'Dark matter' concept seems like a bit of a fudge to me, and the two alternative theories seem to be able to predict what actually happens quite accurately without it. Whether 'predicting' is the the same as 'understanding' is a philosophical point. There again, they might be complete hokum…
This week's Fun Online Poll was suggested by Ralph Musgrave:

Who is most in thrall to group think?

Multiple selections allowed, vote here or use the widget in the sidebar.


Dinero said...

Predicting and understanding are different and in an important way. For example the ancient Mayans could make very accurate predictions about the patterns of the night sky over a thousand years, but they didn't even know the lights were physical objects.