# @stem_antics on Instagram

- **Type:** Video
- **Original URL:** https://www.instagram.com/p/DZLYSVgyDh4
- **Gondola URL:** https://gondola.cc/posts/66312617-stem-antics-instagram
- **Thumbnail:** https://img.gondola.cc/tr:w-,h-,fo-auto/postThumbnails/122823c64c.jpg
- **Posted:** 2026-06-04T20:46:33.000+00:00
- **Account Owner:** Stem Antics (@stem_antics) — https://gondola.cc/stem_antics

## Caption

Boarding an aircraft looks like a logistics problem. It is really a queueing problem, and the math says almost everything airlines actually do is wrong.

The enemy is interference, and two kinds dominate:

	•	Aisle interference: a passenger stops to stow luggage and blocks everyone behind them
	•	Seat interference: an aisle or middle passenger has to stand and clear out so a window passenger can sit down

Both serialize the process. One useful action happens at a time, and the aisle, your highest-throughput resource, sits mostly idle.

Back-to-front feels orderly, so airlines love it. But filling the rear rows first packs passengers into the same zone, where they queue to stow bags one at a time. In simulation it performs about as badly as front-to-back, near the theoretical worst case.

Random boarding beats it. With no structure, passengers spread along the cabin, so several people stow luggage at once. Chaos parallelizes the aisle better than a tidy back-to-front block does.

The Steffen method, found via Markov Chain Monte Carlo optimization, is the standout:

	•	Board window seats first, then middle, then aisle
	•	Within each pass, skip every other row, working back to front
	•	Adjacent people in line sit two rows apart (12F, 10F, 8F, 6F)

That spacing lets multiple passengers load bins simultaneously with elbow room and zero seat interference. Result: roughly twice as fast as back-to-front and 20 to 30 percent faster than random. On some layouts the optimum cuts boarding time by a factor of four.

No major airline uses it. The bottleneck was never the cabin. It is getting 180 strangers to stand in a precise order.
#
The fastest system is rarely the one that feels the most organized.

#stemantics #operationsresearch #queueingtheory #appliedmath

## Stats

- **Views:** 746,775
- **Likes:** 12,747
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## Tags

queueingtheory, appliedmath, stemantics, operationsresearch

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