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Finding the Air Cannon

twobraids.com

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Re: Finding the Air Cannon

#31

Post by mixedmath »

yorwba wrote: post #7
mixedmath wrote: post #3

This is an unexpected programming application. It's nice that the farmer actually changed behavior after receiving the phone call. At first, I thought there was a clear improvement. This problem essentially boils down to finding the intersection point of three circles. But it's also likely that with the small fuzz from imprecise time measurement that the three measured circles wouldn't actually intersect. I would gue…

Since the time of the cannon shot is unknown, only the time when it can be heard at a known location, you can't even pinpoint its unknown origin in space to a circle. Instead, the range of possibilities forms a cone in spacetime (exactly like the lightcone of electromagnetic waves, except with sound and also treating space as two-dimensional for simplicity). The intersection of two such cones is a parabola. The inter…

Ah yes, you're right! Thank you.

Re: Finding the Air Cannon

#32

Post by burkaman »

sandworm101 wrote: post #22
beAbU wrote: post #20

Earlier quoted context omitted.

Not sure why you are being downvoted, this is the best kind of pedanticism.

A large number of people believe it impolite to correct someone's language. I've seen it even called "colonial" to correct written grammar, that we should just let language evolve naturally and not try to enforce rules on others. I am not of that mindset.

I don't think it's obvious that Canadian Goose is any less correct. It's in most dictionaries, and the scientific name "canadensis" is supposed to mean "from Canada", which is what Canadian means. Canada Goose is more common, but that doesn't mean it's better.

It's also pretty likely that the geese in question in this story are literally from Canada.

Re: Finding the Air Cannon

#33

Post by avidiax »

xnx wrote: post #4
xnx wrote: post #2

Nice work. I feel like there must be some way to triangulate the sound source through direct calculation, but that trigonometry is too advanced for me.

ChatGPT tipped me off that it's called multilateration and provided the formulas. I Google search turned up this Python code: https://github.com/glucee/Multilateration

This is not the same problem. We don't have the distance to the source, only the difference in arrival times.

Re: Finding the Air Cannon

#34

Post by pokey00 »

echelon wrote: post #25
paavope wrote: post #14

Earlier quoted context omitted.

In this case it’s the fault of the author in either not including all the source code, or having undocumented dependencies

This is a valid criticism of the Python community and something the core language maintainers should look to address. Working in Python in the 2000s, I was extremely happy. Working in Python (especially ML and data science applications) in the 2020s is a nightmare. The world has come a long way, and Python has actually taken a backslide. Python would do well to learn from the Rust project and their Cargo package mana…

> This is a valid criticism of the Python community and something the core language maintainers should look to address.

The author didn't include one of his custom source libraries that's not needed to understand the code, so that makes this a valid criticism of the Python community? lol

Re: Finding the Air Cannon

#35

Post by opwieurposiu »

PaulHoule wrote: post #27

I cannot understand why the Canada Goose is protected under federal law. There are so many in Stewart Park that I think about taking one down with a net or a bolo but (1) I could get in trouble and (2) I find commercial goose meat to be disgusting (when they talk about eating a goose in a Dickens novel I gag) and can't imagine a wild goose is palatable at all. (I do have reports though that the eggs are great, I thin…

The Canada Goose is protected under federal law in the United States primarily due to the Migratory Bird Treaty Act of 1918.

This was a treaty between Canada and USA, enacted to prevent more extinctions due to hunting, as happened to the passenger pigeon.

You can hunt them in the fall in most states, but you can't hunt the most annoying ones that live inside city limits year round. They do not taste great, good for dog food though.

Re: Finding the Air Cannon

#36

Post by xnx »

avidiax wrote: post #33
xnx wrote: post #4

Earlier quoted context omitted.

ChatGPT tipped me off that it's called multilateration and provided the formulas. I Google search turned up this Python code: https://github.com/glucee/Multilateration

This is not the same problem. We don't have the distance to the source, only the difference in arrival times.

"multilateration (MLAT) ... is a technique for determining the position of an unknown point, such as a vehicle, based on measurement of the times of arrival (TOAs) of energy waves traveling between the unknown point and multiple stations at known locations."

https://en.wikipedia.org/wiki/Pseudo-range_multilateration

Re: Finding the Air Cannon

#37

Post by [deleted] »

burkaman wrote: post #32
sandworm101 wrote: post #22

Earlier quoted context omitted.

A large number of people believe it impolite to correct someone's language. I've seen it even called "colonial" to correct written grammar, that we should just let language evolve naturally and not try to enforce rules on others. I am not of that mindset.

I don't think it's obvious that Canadian Goose is any less correct. It's in most dictionaries, and the scientific name "canadensis" is supposed to mean "from Canada", which is what Canadian means. Canada Goose is more common, but that doesn't mean it's better. It's also pretty likely that the geese in question in this story are literally from Canada.

[deleted]

Re: Finding the Air Cannon

#39

Post by echelon »

pokey00 wrote: post #34
echelon wrote: post #25

Earlier quoted context omitted.

This is a valid criticism of the Python community and something the core language maintainers should look to address. Working in Python in the 2000s, I was extremely happy. Working in Python (especially ML and data science applications) in the 2020s is a nightmare. The world has come a long way, and Python has actually taken a backslide. Python would do well to learn from the Rust project and their Cargo package mana…

> This is a valid criticism of the Python community and something the core language maintainers should look to address. The author didn't include one of his custom source libraries that's not needed to understand the code, so that makes this a valid criticism of the Python community? lol

One million percent yes.

The code shouldn't build, go green, or be in any shareable state. This is horrifically bad practice.

A language should remove all of these thorns in a first-class manner.

Until you use a package manager like Cargo, you probably can't intuit the wide gulf here. A good analogy might be imagining the world before version control.

Dependency control matters immensely. Hermeticity and repeatability matter immensely. We should strive to build these into the very foundations.

Re: Finding the Air Cannon

#40

Post by titanomachy »

yorwba wrote: post #7
mixedmath wrote: post #3

This is an unexpected programming application. It's nice that the farmer actually changed behavior after receiving the phone call. At first, I thought there was a clear improvement. This problem essentially boils down to finding the intersection point of three circles. But it's also likely that with the small fuzz from imprecise time measurement that the three measured circles wouldn't actually intersect. I would gue…

Since the time of the cannon shot is unknown, only the time when it can be heard at a known location, you can't even pinpoint its unknown origin in space to a circle. Instead, the range of possibilities forms a cone in spacetime (exactly like the lightcone of electromagnetic waves, except with sound and also treating space as two-dimensional for simplicity). The intersection of two such cones is a parabola. The inter…

Good point. I think my intuition about triangulation comes from GPS, where pulses are emitted simultaneously from many points at a known time. This problem is a little trickier.
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