Visualization of Earth with an equatorial ring
There's a problem, though - there was 20th century warming in the summers too, albeit weak and inconsistent. Trends were not only in winters. And an equatorial ring can't do that.
But a few years ago, a new kind of ring was found at Saturn, a ring not around Saturn's equator but significantly tilted, a ring in the plane of Saturn's moon Phoebe. Here is a terrific graphic from BBC about that discovery:
Saturn's Phoebe ring - a graphic from the BBC. http://news.bbc.co.uk/2/hi/8291905.stm
That was a big discovery, really big. Up until that discovery, all the planetary rings were around equators - Saturn's, Jupiter's, Neptune's, Uranus's. (I've embedded a video below. Press refresh if you just see a big blank. That seems to help.)
A computer visualization of Neptune's ring, which is around its equator.
Maxwell explained in 1859 why rings are likeliest around the equator. It's because, no matter where dust and rocks come from, as they get near a planet they will interact with the planet's atmosphere and with stuff thrown up from the planet, all of which is rotating along with the planet. Directly or indirectly, over time, any material orbiting a planet will be smacked again and again until its orbit is also aligned with the rotation of the planet. Imagine somebody trying to drive slantwise back and forth across Route I-95. The car would be broken up and its pieces would be carried along with traffic. So imagine the equatorial plane as the I-95 of the planet-moon-rings system.
Yet somehow here is this new Phoebe ring. How is it possible? Maybe because it's remote? Maybe because it's young?
Anyway - what exists is possible. And if we add a Moon-plane ring to the Earth ring hypothesis, then we are able to get out of the hypothesis an explanation for any sum of: (a) global trends in winter only, from the equatorial ring, and also (b) global trends, erratic and inconsistent, and possibly in the opposite direction from the winter trends, that affect any part of the year. How convenient. A ring system fading and brightening and fading again can't explain absolutely any arbitrary thing, but it can explain more things than a one-ring system can and thus far it appears it can explain the trends that actually happened.
one in the plane of the equator and one in the plane of the Moon's orbit
There's another reason to look for a two-ring Earth system: Newgrange. About five to seven thousand years ago, whoever was then living in Ireland built about a lot of stone monuments with rock carvings all over them. Among these: Newgrange, Loughcrew, Fourknocks, Knowth, Tara..... Besides the very big sites, there are also dozens of smaller ones, also with carvings.
A smaller site near Loughcrew. Photo by Renee Tatusko.
Its carvings. Photo by Renee Tatusko.
This whole phenomenon is somehow connected to astronomy. In all these places, similar motifs were carved again and again: sawtooth lines that seem to be be counting out days of the month, and spirals that seem to represent the sun in the sky approaching solstice and moving away, and some starry shapes.
Also Loughcrew. Photo by Renee Tatusko.
Among all these is an unexplained motif of loops. Ireland's astronomical sites are covered with carvings of loops, heaps and piles of loops. They are obviously important because this motif is often repeated, but nobody can work out what the carvers had in mind.
What is this about? Photo by Renee Tatusko.
Some people think the loops were carved by people on drugs trying to recap their hallucinations afterward. Maybe. But it's weird they're there among a lot of hardworking astronomy. Instead, maybe the ancients were carving things in the sky that we don't recognize because we don't see those things anymore. Such as rings, which would have been brighter thousands of years ago back nearer the Ice Age.
Here is a visualization of how the sky at Newgrange would look if the Earth had a two-ring system. (The visualization is for September 2012, not 5000 BC, but it doesn't matter much.) The video is slow coming up sometimes, but pressing refresh seems to help.
Sky position of a hypothetical two-ring Earth system, for 54N, September 2012. View is due south.
In this video, you see one set of loops that never moves, and another one that moves constantly. The never-moving loops are the sky position of an equatorial ring. The always-moving set of loops are the sky position of a ring in the plane of the Moon's orbit. This is parallel to the ecliptic (the path of the sun on the sky, runs through the zodiac).
Taken altogether, the total picture does indeed look sort of like heaps and piles of rings. That, apparently, is the look of a two-ring system, and to me it does look a bit like carvings at Newgrange.
Next: Haystack and YORP - Very dusty rings.
Support this vital effort!