I noticed a small Easter egg in chat rooms parented to this site: the "world map" figure on the bottom bar zooms in and out depending on how far the page is scrolled.

As I was using this Easter egg, however, I tried to keep track of the "center" or "pivot" point being used for the effect (just like when you zoom a page or map out, the pivot point is where your mouse cursor or the midpoint of your fingers is). I eventually found it to be approximately near Chicago, Illinois, USA.

Why was Chicago chosen as the center point of the image? Does it have any significance?

  • Do you live near Chicago? Or is your ISP from there? When I use it the centre isn't near Chicago, but approximately near where I live. – curiousdannii May 17 '19 at 3:53
  • @curiousdannii Let me guess...somewhere in the Midwest, possibly Wisconsin? – gparyani May 17 '19 at 4:54
  • No, in Australia. – curiousdannii May 17 '19 at 4:56
  • @curiousdannii That is really strange...mind posting a GIF? – gparyani May 17 '19 at 4:57

I'm going to put it down to coincidence, based on an admittedly very superficial look through eggs.js, which supplies the zoom effect.

The map image, https://cdn.sstatic.net/Sites/travel/img/bg-map.png , is inserted as a background and positioned an arbitrary 750 pixels to the right so that it is not blocked by the input textarea. This positioning is not affected by the width of the window or screen at loading time.

The map is not intended to be completely accurate, of course, and is cropped in a way that excludes the polar regions. As such, the north-south midpoint on the map is a good 32° or so north of the equator. Additionally, part of the background is obscured by the border bar that runs across the top of the footer.

The image is both resized and repositioned based on the scroll position, and since the longitudinal center of the map is fixed, and the latitudinal center is biased north, you could get the impression that Chicago is roughly the center, but it's hard to say whether that was intentional or not.

From a U.S.-centric perspective, Chicago isn't a bad choice for a travel site, as it was the country's most important transportation hub for at least a century and a half, starting with steamships, then railroads, then passenger airlines.


From poking around in the code, it's not actually meant to be specifically Chicago, although that may be where it ends up. Basically it's showing a map and then attempting to do some clever tricks to try to center it near where you are based on the time zone and language you have your browser set to.

I think what's going on is that it's first using your time zone to horizontally offset the image, and then it's trying to use your time zone's compliance with daylight savings time to figure out if you're in the northern or southern hemisphere, and then trying to specify your latitude based on the north/south bit and/or your language, depending on whether it's Spanish/Portuguese/English/French/Arabic/Russian/Chinese. Depending on your point of view it can be a clever hack or a slightly worrisome demonstration of how closely you can be geolocated based on only two pieces of data your browser makes available to websites.

Also, it appears like there's also further easter eggs named MovieStrip (some kind of scrolling image?), Assistant (looks like Clippy), Console (fake terminal of some sort), Asteroids (the video game), Cthulu (not sure, but various references to regexes), WOB (wheel of blame?), and MTG (probably a popup for displaying Magic:The Gathering cards).

  • Yes, I'm aware of the other Easter eggs; in fact there exists a user script that manually triggers most of the ones you mentioned. (Thanks for letting me know of the other two; I've notified the author of the script of their existence so they can be added.) – gparyani May 24 '19 at 2:35

Could it be detecting where you live or your ISP? I don't see it centred on Chicago but near where I live in Australia.

Screenshot of what I see

Edit: From looking at the code it's doing some sort of strange time zone and locale detection.

  • Ah, for me, the map image renders to the right of where yours renders, and as pointed out in the other answer, the "zoom" script picks the point 750px to the right as the "pivot". So as the map is positioned in what appears to be an incorrect spot (it should appear to the right of the box, not underneath it), it's centered in Australia for you. – gparyani May 17 '19 at 5:06
  • @gparyani It's not a fixed 750px, but some odd time zone and locale detection system. – curiousdannii May 17 '19 at 5:16
  • I'm nowhere near the Chicago area, but in Texas at the moment. I'm slated to fly to the West Coast of the U.S. and will report back in a few days. – gparyani May 17 '19 at 5:54
  • @gparyani I am living in Germany and my center point is somewhere in West Europe. I can imagine, that the calculation is not meant for the exact country or state, but the continent. – Dirty-flow May 17 '19 at 6:39
  • @Dirty-flow And indeed, after flying to the West Coast, my zoom point is somewhere in Oregon. – gparyani May 22 '19 at 23:26

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