Jupiter's horizon

In The Struggle For Empire, the source book for FF XII, Jupiter, Saturn, Uranus and Neptune are earth-like and habitable, just very big (but don't have crushingly high gravity). So I've started to think about what things would be like there, ignoring the sheer implausibility of this idea and assuming Earth-normal temperature, pressure, atmosphere etc.

One of the questions to cross my mind is if it would be possible to see things coming over the horizon. Which leads to the question "how far away is the horizon?" Fortunately someone has already worked that one out:
http://vastfrontier.blogspot.com/2010/07/horizon-distance.html

So the next question is how far it is theoretically possible to see through the atmosphere at sea level pressure? The answer seems to be more than far enough - the definitive source for this is probably Ringworld, which has visibility in the thousands of kilometers, and it seems plausible given that we can see stars from the bottom of our atmosphere. Anyone able to confirm this? And what would refraction effects do? Extend the distance?

While looking up Ringworld I found this rather nice animation

and there appear to be dozens of others on Youtube, Nifty!

Well well...

I just broke Microsoft Spider Solitaire.

The way the game works, you start out with 54 cards on ten piles, and are then dealt ten cards at a time until 104 have been dealt. You get rid of 13 cards at a time, and the aim is to get rid of all the cards. This means that there is a small chance that at the end of the penultimate hand you will only have three cards left, at the end of the previous hand you will only have six cards left, and so forth.

I've played the game at least a couple of times a week over the last 15 years or so and this has never happened; I've generally assumed that it is coded to prevent it. But tonight, for the first time, I ended the penultimate hand with only three cards left. At this point I discovered that it won't deal more cards if any of the ten card spaces are empty... In other words, if you play the game really well you can't win.

Nice one, Microsoft!