this post was submitted on 28 Jul 2025
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xkcd #3121: Kite Incident

Title text:

Detectives say the key to tracking down the source of the kites was a large wall map covered in thumbtacks and string. 'It's the first time that method has ever actually worked,' said a spokesperson.

Transcript:

Transcript will show once it’s been added to explainxkcd.com

Source: https://xkcd.com/3121/

explainxkcd for #3121

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[–] kayzeekayzee@lemmy.blahaj.zone 37 points 5 days ago* (last edited 5 days ago) (14 children)

Doing some quick math here:

Circumference of the Earth is about 24k mi = 44M yds.

The cheapest fishing line I could find online (from Amazon) (I didn't search very hard though) was $10 for 440 yds of line. To circle the Earth, you'd need 44M / 440 = 100k spools = $1M for the fishing line.

Let's assume every spool needs about 1 kite. That's 100k kites. You can find kites online for like $5 each, but the cheapest way to get a kite is probably to bulk order wooden sticks and plastic film and make them yourself. Let's do the math on that.

Assume each kite requires a generous 5 ft^2 of film, and 10 ft of sticks. I found some bulk plastic film rolls online (from McMaster Carr) for about $0.02 per ft^2, and some wooden marshmellow sticks (on Amazon) for about $0.10 per foot. That makes $0.02*5 + $0.10*10 = $1.10 per kite. That totals $1.10 * 100k = $110k.

So using these estimates, this kite ring costs around $1.11M.

No clue if it would actually work though.

Edit: corrected a math error

[–] criticon@lemmy.ca 7 points 5 days ago* (last edited 4 days ago) (2 children)

The jet steams are above the equator, so they would be smaller

Edit: above as in northern or southern latitudes

[–] kayzeekayzee@lemmy.blahaj.zone 11 points 5 days ago (2 children)

I assume you meant to say they're not above the equator, which I didn't actually know until now.

We can find the new length by simply multiplying the equator total by cos(latitude), since circumference is linear to radius.

For subtropical jet streams, latitude is around +/-30 degrees, so our adjusted price comes out to around $950k.

For polar jet streams, the latitude is around +/-60 degrees, bringing the price to $555k.

Extra note: The jet streams can reach speeds of >100mph, so I don't think our poor little toothpick and plastic film kites will survive!

[–] criticon@lemmy.ca 1 points 4 days ago

Yes, meant not on the equator, above as in northern (or southern)

[–] Deebster 1 points 4 days ago* (last edited 4 days ago)

I think OP means it's above on a map, i.e. north, like how the Mediterranean is above Africa.

Edit: to head off any pedants: there are jet streams in the south too, but the point was that the length would be less than Earth's circumference (plus xkcd comics seem to be set in north America).

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