Editing 2725: Sunspot Cycle

{{comic
| number    = 2725
| date      = January 16, 2023
| title     = Sunspot Cycle
| image     = sunspot_cycle_2x.png
| imagesize = 740x503px
| noexpand  = true
| titletext = Who can forget the early 2010s memes? 'You know you're a 90s kid if you remember the feeling of warm sunlight on your face.' 'Only 90s kids remember the dawn.'
}}

==Explanation==

The {{w|solar cycle}} is a roughly 11-year cycle of changes in the Sun's activity (sunspots,  solar radiation, ejecta, and solar flares), from a period of {{w|Solar minimum|minimal activity}} to {{w|Solar maximum|maximum solar activity}}. Researchers use specially modified telescopes to study the sun. Sunspots are areas on the sun which are slightly less hot than the surrounding material, so they appear as black patches when viewed through these telescopes, but they're not visible to the naked eye and do not meaningfully impact the amount of light that reaches the Earth.

This comic imagines an alternate reality where sunspots are literally black patches on the surface of the sun, void of all luminance, so the amount of light that the Earth receives swings drastically over an 11-year cycle. As the text above the chart suggests, the inhabitants of Earth in this reality are so accustomed to the extreme decade-long cycle of darkness and light that they don't even consider ''why'' it's pitch black for 10 years straight, and so Randall helpfully created this chart to explain.

Below is a graph showing the number of sunspots as a function of time from around 1965 to 2025. During the periods of heightened solar activity, the area of the graph is shown in black, while lighter periods are shown as white. For clarity the troughs are labeled with the sun being bright or dark. It is always when there are few spots that the sun is either completely free from spots and thus bright, or completely covered and thus dark. The maxima are always during the height of the transition between the two extremes, with a wide swathe of the time around the minima being mostly light or mostly dark, alternating at around a decade of each predominating.

All this would obviously be catastrophic if it happened in our version of the universe, as during a dark phase insufficient light would be coming from the Sun, and the Earth could freeze if all the energy from the Sun was reduced. If the spots only affect light in the visible spectrum, then Earth would not freeze but plants would have trouble with photosynthesis and other natural processes would be interrupted. In our universe sunspots cool the area of the Sun where they appear, relative to the rest of the surface (50-75% of the nearly 6000K 'norm'), but they are far from being actually dark; [https://image.gsfc.nasa.gov/poetry/workbook/sunspot.html NASA says] that each sunspot on its own would glow orange, brighter than the full Moon. So even in a completely sunspot-covered Sun, the Sun would still be brighter than (with a typically bright Sun illuminating it) the Moon, and far brighter than the dark-time Moon would become (possibly causing issues for nocturnal life, as well). It would be possible to see it (and see by it) even if the heat delivered were very low and even noon would seem to be {{wiktionary|crepuscular}} by our normal expectations. These problems are obviously not a serious threat in the reality of the comic, as the Sun is truly dark and yet people and natural systems have long survived these dark periods and adapted accordingly.

The title text indicates the effect on internet memes that the special solar cycle has had. During the 2010s in our universe there were many '90s kid' memes. Those were also popular in this universe, but they reflect that the Earth had at that time been dark since the 2000s, and thus only those born in the 90s and before would remember dawn or the feeling of the warm sun on their faces.

==Transcript==
:[This comics shows two graphs, one also with several images of the Sun in different times in the solar cycle. The top graph is much larger than the bottom graph, and above them is a explanation of what the graphs shows:]
:Ever wonder why the sun disappears for about 10 years every other decade? This terrifying period of worldwide darkness is a natural consequence of the 11-year sunspot cycle:

:[A graph is shown with a label above the arrow on the Y-axis and a label written above the left part of the X-axis with an arrow pointing from it to the right (there is no arrow on the X-axis line). The graph shows a sine curve with a dashed line. It starts close to the bottom and then increases, then decreases before it finally slightly increases again. Above the dashed line are eight circles representing the sun with various levels of sunspots, with an arrow between each circle pointing to the next to the right. All circles are just above the dashed curve and the small arrows between them also follow the curvature of the line, so this string makes the same shape as the curve. along the eight representation of the sun there are five labels. The eight Suns are described below with labels given when relevant.]
:Y-Axis: Sunspot number
:Y-Axis: Time

:[The first Sun's circle is completely white.]

:[The second Sun's circle has a few sunspots. A label is written to the left of it:]
:Dark sunspots appear

:[The third Sun's circle has several sunspots. A label is written to the left of it:]
:Sunspot number rises

:[The fourth Sun's circle is half covered in sunspots.]

:[The fifth Sun's circle is mostly black with a few lines of white dots. Between the fourth and fifth circle is a label:]
:Number falls as sunspots merge.

:[The sixth Sun's circle is almost completely black with just a few small white spots. A label is written above it:] 
:Sunspots envelop sun, Earth enters years of darkness.

:[The seventh Sun's circle is mostly black with a few light areas.] 

:[The eighth Sun's circle is still mostly black but with some larger white areas. A label is written above and left of it:] 
:Bright sunspots appear, cycle reverses.

:[Below is a second graph with a label written near the top of the Y-axis which is otherwise not labeled. The X-axis also has no label, but six years are written beneath at equal intervals. The graph shows a similar sine curve as the one above, but with almost five cycles shown. Also, each cycle is not close to being a perfect sine curve, but has the property with a peak followed by a trough. The five troughs are labeled. The area beneath the curve alternates from being black and white when there is a trough, with the peak in between having several vertical lines, indicating transfer from black to white and vise versa. There are not same distance between peaks and there are also features on the graphs, for instance the two peaks in the middle has a drop, so they look like volcanoes. And the last full peak has a clear outlier year with many sunspots.]  
:Label: History:
:X-axis labels:  1970 1980 1990 2000 2010 2020
:Through 1970-1980: Sun is bright
:Through 1980-1990: Sun is dark 
:Through 1990-2000: Sun is bright
:Through 2000-2010: Sun is dark
:Through 2010-2020: Sun is bright

{{comic discussion}}

[[Category:Astronomy]]
[[Category:Timelines]]
[[Category:Line graphs]]
[[Category:Internet]] <!--memes-->
[[Category:Kids]]