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0 pointsJtsummers5y ago0 comments

I had never heard of "tropical algebra" so I have no idea of its utility here. I'm only commenting on the distinction between learning about something and learning something.

The former enables you to direct your learning towards learning the thing itself when you realize it's applicable (JIT for learning) if that's your role. And if you're in a leadership position it helps you to recognize the insights those you are in charge of are bringing to you and their relative applicability, or to direct them towards a line of work that may be useful. (Of course, there's a level of incompetent awareness that often happens as well, and that's how SAFe shops are born.)

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spekcular5y ago· 5 in thread

Let me be more direct. Tropical algebra is no of practical relevance to rail route planning. My understanding is that there's some highly speculative work in this direction, but nothing ready to be applied, or any indication this approach is more useful than standard methods. What you are seeing is someone who previously did pure mathematics wheel out a personal obsession and then (unwisely) chastise people for not caring about it.

Therefore, we should we should not care whether rail managers learn, or learn about, tropical algebra.

(Another observation: look at all the highly efficient European and Asian railways. As far as I can tell, algebraic geometry was used in the planning of exactly zero of them. American rail isn't going to be fixed by the application of high-powered mathematics.)

scythe5y ago

>What you are seeing is someone who previously did pure mathematics wheel out a personal obsession and then (unwisely) chastise people for not caring about it.

Hanlon's Razor suggests it's more likely that tropical algebra is just one of a relatively few examples of rail planning theory that the author is familiar with, not that he has a pernicious drive to promote the study.

As I understand it, it mostly is a transformation of expressions like:

Exp(vars, max(,), plus(,))

to give expressions like

Exp(vars, plus(,), times(,))

where solutions to the latter can give solutions to the former under some conditions. It seems plausible that some specialized versions could be explained to someone with a reasonably good understanding of high school math. New math doesn't have to be abstruse.

But all I know is I ran into a tropical algebra problem once and it was intractable.

resonantjacket55y ago

I thought it was used for the railway timetables

spekcular5y ago

Does there exist any evidence tropical algebra is used in practice, and is significantly better than older approaches to the problem? As far as I know, the answer is negative.

gregsq5y ago

It’s a research field in the UK at least. For the UK’s extensive rail network.

https://www.birmingham.ac.uk/research/railway/index.aspx

Edit:

Further symposium on this subject.

https://www.birmingham.ac.uk/schools/mathematics/news-and-ev...

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dundarious5y ago

My reading of the single mention of tropical algebra in the article wasn't that its use is another example of established European rail superiority -- though I think the text is ambiguous.

> Worse, this is a nationwide problem. Amtrak can and should fully replace its senior management with people who know how to run a modern intercity railroads, who are not Americans. But then middle management will still think it knows better and refuse to learn what a tropical algebra is or how it is significant for rail schedule planning. They do not know how to learn, and they do not recognize that it’s a problem. This percolates down to planners and line workers, and I don’t think Americans are ready for a conversation about full workforce replacement at underperforming agencies.

Rather the thesis is more like like:

- upper management don't know how to learn the major established lessons from Europe (one might call this strategy)

- middle management don't know how to learn about new (not yet standard anywhere) refinements that augment the existing system (one might call this tactics)

You may be right that it's just an unsupported and false claim, not a hypothetical, and probably if the wind changes direction and I read it again, I'd agree with you on the author's meaning. Nevertheless, I find the "need to learn to learn strategy and tactics" argument plausible.

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