# Discovery of what causes the 11 year long solar cycles

humy
Science 07 Dec '20 10:39
1. 07 Dec '20 10:394 edits
This video is actually over a year old but I had somehow missed the study this video is about;

So, basically what causes the 11 year long solar cycles is the tidal effects from Jupiter Earth and Venus being all aligned in their orbits around the sun, which happens about once every 11 years.

But I find it strange then that this explanation isn't explained in the wiki page for solar cycles (see https://en.wikipedia.org/wiki/Solar_cycle ) which begs the question to me, why not!? This discovery was made over a year ago and I assume it has gone through peer review so why hasn't wiki been updated accordingly? Has something since been found to be wrong about the study that gave that conclusion? -that would seem to me pretty unlikely as their explanation seems pretty good and even if their theory hasn't been proven beyond doubt I would still find it very strange nobody bothered to edit at least a mere brief mention of it in that wiki page!
2. DeepThought
Losing the Thread
07 Dec '20 16:20
@humy said
This video is actually over a year old but I had somehow missed the study this video is about;

https://www.youtube.com/watch?v=tBScyiYIhS4

So, basically what causes the 11 year long solar cycles is the tidal effects from Jupiter Earth and Venus being all aligned in their orbits around the sun, which happens about once every 11 years.

But I find it strange then that this ...[text shortened]... find it very strange nobody bothered to edit at least a mere brief mention of it in that wiki page!
The Wikipedia editors are probably biding their time due to this type of theory emerging every few years, see the last section in the article below.

I haven't read the full article because it's pay to read. However...

According to Wikipedia the Earth and Venus go into alignment, i.e. are at the closest point in their orbits, every 584 days on average. That's 1.6 years (1.5958). The solar cycle takes 11.07 years divided by 1.6 is 6.9235 or about 1% shy of 7. This is promising as the point where the orbits line up needs to be an integer. Jupiter's orbital period is 11.86 years so it should be gaining about 7% of an orbit on the Earth and Venus each cycle. This leaves me suspicious of their result as it seems to make the solar cycle a temporary phenomenon, despite the belief based on fossil records that the cycle has been stable for at least 700 million years.

https://en.wikipedia.org/wiki/Solar_cycle#Speculated_influence_of_the_planets
3. 07 Dec '20 20:513 edits
@deepthought said

According to Wikipedia the Earth and Venus go into alignment, i.e. are at the closest point in their orbits, every 584 days on average. That's 1.6 years (1.5958). The solar cycle takes 11.07 years divided by 1.6 is 6.9235 or about 1% shy of 7. This is promising as the point where the orbits line up needs to be an integer. Jupiter's orbital period is 11.86 years so it should be gaining about 7% of an orbit on the Earth and Venus each cycle.
But what counts here isn't how often Earth and Venus alone go into alignment but rather how often all three i.e. how often Earth and Venus and Jupiter all go into alignment (not that I am implying here you didn't know that obvious) and according to the links I have read that happens about every 11 years and not as a temporary phenomenon.
See;
https://www.sciencealert.com/the-sun-s-11-year-cycle-have-may-have-something-to-do-with-the-gravity-of-the-planets
"...the tidal forces are strongest when Earth, Venus, and Jupiter align, and that this alignment occurs every 11.07 years - falling at the same time as the solar minimum...."

and

https://dailygalaxy.com/2019/05/suns-11-year-cycle-powered-by-tidal-forces-of-venus-earth-jupiter/
"...Tidal forces are strongest when there is maximum Venus-Earth-Jupiter alignment; a constellation that occurs every 11.07 years. ..."

and, incidentally, the above is yet more links on the same subject of that solar cycle theory that I accidentally found when I googled; "how often do Earth and Venus and Jupiter go into alignment 11 years"
4. sonhouse
Fast and Curious
08 Dec '20 16:215 edits
@humy
Jupiter at about 800 million Km works out to about an accel of 0.3 mm/second^2.
How can there be enough interaction gravitationally to effect something that I think starts deep inside the sun.

I just don't see enough force to effect stuff buried thousands of miles deep in the sun.

So if you were standing on a pole 800 million Km long and weighed yourself, if you weighed 100 Km on Earth you would weigh about 3 or 4 Kg on top of that long long pole.

Doing the math of gravitational force between Jupiter and the sun, seems to give an answer of about 4 E29 Newtons or about 4 E28 kg.
That was a rounding off, my stupid cell phone calculator doesn't let me enter negative exponents so I had to do it on paper, roughly.

Would that be enough force to affect the sun at several thousand miles deep?

Couldn't the observed timelines be coincidence where the real reason is totally different, like the changing flux of magnetic fields inside the sun which I would think overwhelm the gravitational force exerted on the sun by Jupiter and even adding the planets in a straight line wouldn't add that much.

Just don't see the forces at work being enough to cause solar cycles. BTW we are actually in the next cycle, a lot of sunspots on the sun visible now and that affects my hobby of amateur radio, more sunspots means more long distance communications from around 7 megahertz to 1000 Mhz, the sunspots somehow changes the ionosphere to more of a reflector whereas in solar minimum, the ionosphere is mostly transparent to RF and those waves tend to just go right through the ionosphere meaning the signals don't get to the destination and now instead are aiming at the moon or some such.
5. 08 Dec '20 18:002 edits
@sonhouse said
@humy

How can there be enough interaction gravitationally to effect something that I think starts deep inside the sun.

I just don't see enough force to effect stuff buried thousands of miles deep in the sun.
You really need to read the links to see how.
see;
https://dailygalaxy.com/2019/05/suns-11-year-cycle-powered-by-tidal-forces-of-venus-earth-jupiter/
"...
the HZDR researchers then found evidence of a potential indirect mechanism that may be able to influence the solar magnetic field via tidal forces: oscillations in the Tayler instability, a physical effect that, from a certain current, can change the behavior of a conductive liquid or of a plasma.
...
In the hot plasma of the sun, the Tayler instability perturbs the flux and the magnetic field, itself reacting very sensitively to tiny forces. A small thrust of energy is enough for the perturbations to oscillate between right-handed and left-handed helicity (the projection of the spin onto the direction of momentum). The momentum required for this may be induced by planetary tidal forces every eleven years—ultimately also setting the rhythm at which the magnetic field reverses the polarity of the sun.
...
As with the gravitational pull of the Moon causing tides on Earth, planets are able to displace the hot plasma on the sun’s surface.
..."

To cut a very long explanation short, they found a physical mechanism whereby a very tiny tidal force on the Sun can have a huge effect on some of the properties of the plasma, including magnetic effects in the plasma, at and near the surface of the Sun.
The tidal effects don't need to extend down anywhere near to the core of the Sun for this to work; just near and at its surface.
6. sonhouse
Fast and Curious
08 Dec '20 22:00
@humy
I wonder if therefore we could make an educated guess as to planets going around stars, by the solar cycle, obviously it would not be 11 years like here but it would interesting to see if this theory holds up when comparing solar cycles around nearby stars, not sure how much the total light changes when sunspots are high V when there are no spots, detecting such would require something like the James Webb scope now in final construction phase, the plan is for that scope, some 3 times bigger than Hubble, and placed in a lagrangian about 2 million Km from Earth, where it needs heat shields so the refrigeration can keep the sensors very cold.

https://www.nasa.gov/feature/goddard/2020/a-new-look-at-sunspots-is-helping-nasa-scientists-understand-major-flares-and-life-around/