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Comment by josephwegner | Hacker News Reader

I had an interesting discussion with my 8yo recently about the highest mountain. It had never occurred to me, but "highest" does not have an agreed upon definition. There are actually a few competing definitions[1]:

There's Muana Kea, which is the _tallest_, meaning the furthest distance from the mountain's base to its peak.

There's Mount Everest (which I had assumed was the agreed upon "highest"), which has its peak at the highest altitude.

Chimborazo has the most unexpected definition of "highest", which is a peak that is furthest from the center of the Earth! We don't live on a perfect sphere, so some mountains can be "shorter" but still further from the core!

Would be interesting to see if the "highest websites" differ for each of these definitions!

[1]: https://geology.com/records/highest-mountain-in-the-world.sh...

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I share a propensity for getting interested in things like this more than I perhaps should(!) In most cases, Everest doesn't really look particularly impressive given its low prominence in relation to its neighbors, although Wikipedia seems to treat sea level as being its true "base" as a sort of special case so it still comes in at #1 on https://en.wikipedia.org/wiki/List_of_mountain_peaks_by_prom... !

Chimborazo is a fun one and I would accept a strident enough argument for it to be #1. It truly looks like a magnificent mountain too, indeed perhaps the archetypal 'mountain', if we can take aesthetics into account ;-)

> Wikipedia seems to treat sea level as being its true "base" as a sort of special case so it still comes in at #1

This is due to the definition of prominence, which is roughly "how far down do you have to go from the summit before you can go up to a higher point." This is undefined for the highest mountain, since there is no higher mountain to go up to, so height above sea level is used instead.

You make it seem that something funny is going on with Everest's prominence. That's just the definition of prominence:

> prominence measures the height of a mountain or hill's summit relative to the lowest contour line encircling it but containing no higher summit within it

By definition, this means that the highest mountain's height is its prominence.

I don't think there's anything "funny" logically ;-) It's hard to explain, but I just don't find it very gratifying as a measure given Everest is surrounded by almost equally tall mountains with small prominences (Lhotse's is about 600m) and the way Wikipedia refers to a "special definition for Everest" just illogically raises my hackles much in the same way as 1 not being considered prime does and at least that's useful ;-)

Prominence is a weird property. Consider Grays and Torreys in Colorado, two 14,000ft mountains that are very close to each other. Both are some of the tallest mountains in the country and almost the same height, but because Grays is about 3ft taller than Torreys it ends up having 5 times the prominence (2750 vs 560).

I live in Teton Valley, Idaho (6,500 feet above sea level) and I see the Grand Teton (13,775 feet) everyday (looking at it now actually). That's a prominence of 7,275 feet. I have also been to the base camp (13,550 feet) of Annapurna (26,545 feet). That's a prominence of 13,000 feet or almost double what I'm used to seeing - and that difference is stunningly obvious. I've mentioned this to people often - that just standing in the Himalaya creates a feeling of majesty that is (literally) not possible to experience anywhere else unless something like Mt. Rainer were a couple thousand feet from the Pacific coast (instead of 112 miles) or unless the oceans were drained.

I think the Matterhorn looks even more like an archetypal mountain, even if a bit tobleronish :)

The joke being that the Toblerone bar has a mountain based on the Matterhorn as it’s logo. Either that, or someone very dedicated to Toblerone chocolate created the world’s largest advertisement in the Alps. That would be quite the story. If so, they forgot the bear.

> There's Muana Kea, which is the _tallest_, meaning the furthest distance from the mountain's base to its peak.

I had thought Denali in Alaska held this honor, but apparently the base of Mauna Kea is considered to be the ocean floor which makes it taller. Interesting.

Denali has the highest prominence with 20,157′. Mauna Kea's prominence is only 13,803′

You're thinking about a peak's prominence. A lot of people put a lot of thought into that, which is summed up by Wikipedia [1], including a list of talles peaks by prominence. By definition, Mount Everest wins again, as there is no col to be considered it's parent.

[1] https://en.wikipedia.org/wiki/Topographic_prominence

The Muana Kea claim is highly questionable. The only complete and sound definition of the "base" of a mountain would make the height the same as topographic prominence, and by definition the highest peak must also have the greatest prominence (whereas other peaks will vary wildly in ordering).

Nice. I tried to think which of Everest or Chimborazo has the thinnest air. I'm guessing the atmosphere bulges at the equator too so it'd be Everest?

Muana Kea is the second tallest peak, the tallest is Puncak Jaya is New Guinea.

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