Scientists get very attached to the accepted theories about how the universe works, to the extent that the theories get treated as immutable laws, in effect as facts; and reality – the place of real facts – is contorted to fit around the theories. This is the Sagittarius-Gemini axis: faith versus fact/information. Religion functions in the same sort of way.
The conclusion that was increasingly drawn was not, as you might expect, that we do not understand gravity. That would be too simple. No, the conclusion that was drawn was that there must be large amounts of matter out there in a form that we cannot see or detect that is distorting the picture.
Decades on, the hunt for dark matter continues, and we still haven’t found any.
Gravity as we understand it is full of anomalies. The clockwork universe as described by Newton and modified by Einstein no longer seems to hold up very well.
But galaxies, unlike planets, do not behave like this. The outer arms of the galaxies all seem to rotate at about the same speed, regardless of their distances from the centre.
We are dealing with huge distances here – light years – in which gravity is infinitesimally weak. Obvious conclusion: just as the laws of matter change when we get down to the quantum level, so do the laws of gravitation change when it becomes extremely weak.
To give science some credit, there are modified theories of gravitation out there, such as scalar-tensor-vector gravity (STVG), (or MOdified Gravity (MOG)), which deals with the galaxy rotation problem. But the generally accepted theory is that the universe must be 80% undetectable, transparent dark matter. The hunt for it is a bit like the hunt for WMDs in Iraq. The difference being that with the WMDs, they were eventually forced to admit they weren’t there. If what you are looking for is invisible, such logical constraints do not apply. You couldn’t make it up!
And so we come to our title: The Hunting of the Snark is a nonsense poem by Lewis Carroll that “describes with infinite humour the impossible voyage of an improbable crew to find an inconceivable creature".
Other gravitational anomalies include:
The two Pioneer spacecraft (which are currently leaving the solar system) seem to be slowing down in a way which has yet to be explained.
Various spacecraft have experienced greater accelerations during slingshot manoeuvres than expected.
The expansion of space seems to be speeding up.
Recent measurements indicate that planetary orbits are widening faster than if this was solely through the sun losing mass by radiating energy.
The behaviour of photons travelling through galaxy clusters indicates that gravity may fall off faster than inverse-squared at certain distance scales.
Surveys of galaxy motions have detected a mystery dark flow towards an unseen mass. Such a large mass is too large to have accumulated since the Big Bang using current models and may indicate that gravity falls off slower than inverse-squared at certain distance scales.
Hydrogen clouds are more clumped together at certain scales than expected and, like dark flow, may indicate that gravity falls off slower than inverse-squared at certain distance scales.
So there you have it. Gravity, which was always the awkward squad when it came to developing the theory of everything (the Unified Field Theory, for which 11 dimensional M-Theory seems the most promising candidate), ain’t quite what it seems to be.
One of the big problems when it comes to science or religion or metaphysics is people’s need for certainty. This is where it all goes wonky and where you can end up with one system of belief attacking another. I don’t think it matters too much what you believe, because you can generally make a case for the opposite anyway. What matters is the ability to dwell happily in not knowing and to be able to see the unknowability of things. In this lies awe and freedom. But this is too difficult for many people, even very clever people, maybe especially them. It is subtle, and requires psychological security. It is ‘negative capability.’
This is why the Buddhists continually set up teachings about the nature of existence only to refute them a few steps down the line. I don’t know how effective it is as a method, for it can seem a bit abstract and clumsy, but you can see the point.
So the need for certainty gets in the way of the progress of science, just as it does with any other system of knowledge. Old truths automatically become deeper truths, instead of what they might well be, which is old mistakes.
Death is unknowable, so any belief about it – if you wish to have one – needs to be provisional to have any kind of sense to it. Death is something we get a feeling, an intuition about, like all ‘deeper’ realities. That feeling/intuition develops and becomes more subtle over time. That is how a human progresses metaphysically. Any belief held too firmly impedes this progress.