The Roche phenomenon in the article is always an interesting one, for me. I know this will sound silly to most people here but my experience with the Bernoulli “explanation” for lift in aerofoils makes me feel a little uneasy about tidal forces in general.
I don’t mean that I find the Bernoulli explanation non-sensical — that’s a very common thing these days — more that the experience of listening to the falsehood presented as truth by so many people now means I am suspicious of other non-intuitive explanations.
In this specific case, I can’t get a good intuition about how tidal forces explain (1) Earth’s moon causing ocean bulges on both sides of Earth; and (2) tidal friction making Earth’s moon stop spinning and move further away. I feel like it’s one of those phenomena, like aerofoil lift, whose explanation is glossed over far too quickly given how odd the explanation is.
I agree, I find those deeply counterintuitive too. For other readers, the tidal explanation I have read is yes, the moon’s gravity pulls on the sea to raise a tide on the side facing the moon. The reason there is a tide on the opposite side is that the moon also pulls on the earth’s solid mass (also water, but the solid part it’s important here), creating displacement that causes the water on the other side to rise. There is a difference in the gravitational acceleration across the diameter of the earth and it’s less on the far side, thus the unequal pull, thus displacement. Since they are orbiting, this gravitational pull doesn’t cause the two (earth and moon) to meet, though.
This is an amateur’s explanation and I’d welcome input from someone with more understanding. For tidal friction, I can’t answer at all, I need to research.
What's the probability that a moon was occluded? The star, the moon, and the Earth would have to be perfectly aligned on a straight line. It seems a vanishingly small probability. A dense asteroid belt seems more likely except that the star was only occluded once.
If it is an asteroid belt, maybe it is on a different (high inclination) plane, which is why the star only hit one part of it.
Second ‘impossible’ ring found around distant dwarf planet - https://news.ycombinator.com/item?id=35762112 - April 2023 (61 comments)
Ring discovered around dwarf planet Quaoar confounds theories - https://news.ycombinator.com/item?id=34714024 - Feb 2023 (1 comment)
I don’t mean that I find the Bernoulli explanation non-sensical — that’s a very common thing these days — more that the experience of listening to the falsehood presented as truth by so many people now means I am suspicious of other non-intuitive explanations.
In this specific case, I can’t get a good intuition about how tidal forces explain (1) Earth’s moon causing ocean bulges on both sides of Earth; and (2) tidal friction making Earth’s moon stop spinning and move further away. I feel like it’s one of those phenomena, like aerofoil lift, whose explanation is glossed over far too quickly given how odd the explanation is.
This is an amateur’s explanation and I’d welcome input from someone with more understanding. For tidal friction, I can’t answer at all, I need to research.
If it is an asteroid belt, maybe it is on a different (high inclination) plane, which is why the star only hit one part of it.