The Sun DOES NOT get bigger at the horizon. This is a variation of the extremely well known and documented "Moon Illusion"...and the answer is precisely the same in RE and FE theories - so nobody need argue about it!
https://en.wikipedia.org/wiki/Moon_illusionLet me describe a SIMPLE experiment that everyone here can do. Since it's kinda dangerous to stare at the sun - do the experiment with the moon (the result, the reason and the answer to this question is exactly the same).
When the moon is high in the sky - grab a coin - a US quarter or something similar that's about an inch across. Stretch out your hand as far as you can reach towards the moon - and compare it's size to the coin...unless you have very short/long arms - you should be able to just about cover up the moon with your coin at full arm stretch. But get familiar with how big the moon looks compared to that coin.
Now wait until the moon is rising or setting - and repeat the experiment.
Same exact deal with the sun - except I'm not going to tell you to stare at it - but you can do the same experiment with appropriate eye protection and because the apparent size of sun and moon are almost exactly the same (in both FE and RE) - the results are also the same.
AMAZING though it seems - the size of the moon doesn't change. In both FE and RE theory - it's an optical illusion. When the moon is far away from other objects who's size you know, our brains assume that it's a long way away (which it is...although more so in RE than FE)...but because daily experience doesn't prepare us for looking at things that are 3000 miles away (FE) or 300,000 miles away (RE) - our subconscious vision system assumes that it must be closer than it really is - and therefore rather small.
When the moon is close to the horizon, we are suddenly able to compare it's apparent size to things like trees and houses out near the horizon...and now it's very clear that this thing is ENORMOUS - because it's so much bigger than a tree or a house. Our brains adjust accordingly...and the sun/moon looks MUCH larger...some would say twice or even three times larger...but the coin experiment says otherwise. It's the same exact size.
So in both RE and FE, the "change in size" of sun and moon when they're close to the horizon is an optical illusion - and one that you can check for yourself with two quick observations and no tool fancier than a coin.
We should put this one to bed - it's the same deal in RE and FE - it's explainable and testable by trivial means - it's not even worth further debate. I beg you to do the experiment yourself before you argue *any* more!
(CAVEATS:
1) There is a TINY amount of atmospheric distortion/mirage that happens over about a 1/4 of the sun's diameter as it rises or sets in some weather conditions - which results in that bulge it seems to have right when it touches the horizon.
2) In RE theory - the sun and moon are about 1.2% SMALLER at the horizon because they are each further away by the radius of the earth than they are at noon...1.2% is too small to measure without instruments...so this isn't a way to easily dismiss FE theory...and in any case, the distance to the FE moon varies too.)
Do the experiment with the coin - and you'll see immediately what I mean - and we can perhaps put this thread to rest.
The Wiki is wrong though - and the coin test proves it.