Light isn't slow it is just the universe is mind bogglingly huge. Our Milky Way is part of a much larger group of stars known as the Local Group, which in turn is part of the Virgo Supercluster, there are a great many superclusters out there spreading out over our universe. https://youtu.be/ochPHsx8O88

Bear in mind this is a layman's version: I'm not a qualified sound engineer so this is based on a small amount of knowledge, not expertise. Most echolocation can only tell you where sound bounced back from in terms of a 3D space around the detector. It's basically 'line of sight'. A signal could end up bouncing off an angled wall ahead of it, around a corner, and back to the wall, then back to the detector, but all it'll really know is that the sound fired at the wall ahead of it took a long time to come back. If it's a low cost system, it'll probably just think that the angled wall is further away than it really is. If it has amazing software and incredible sensitivity, it might be able to detect the signal differences caused by hitting material, travelling, hitting material, bouncing back to the angled wall, hitting that and then returning...but it still can't 'see' around the corner - the techs analysing it will just be able to assume that the soundwave may have bounced onto something else before it returned.

Also, the strength and reliability of a returning sound echo - like radar etc - degrades with distance and contact with certain materials (it's one of the principles used in 'anechoic tiles' etc used to try to help submarines be more stealthy and minimise sonar detection in the seas). Probably your best odds for getting echo-location mapping of the catacombs would be via autonomous drones that can fly their way through the system while somehow carrying the necessary broadcast/receivers...but there are problems with that too: -

• Current drones use large, noisy rotors which doesn't make them a great choice for sonic sending/receiving.
• They're not able to fly for long and that gets worse if they carry heavy equipment. The equipment needed for this would probably be mounted to 6 axes (front, left, back, right, up, down) and too heavy
• Unless you're willing to risk having the drone save all the data and trust that it'll return intact, you'd need a way to broadcast it back. That's going to be a really big problem in the catacombs, where signals won't travel well.
• GPS won't be any use for navigation or updating the drones' positional data, so you'll need drones that can record every variation of their movement to give you accurate mapping upon their return. More electronics = more weight and power demands.
• And yes, the mapping drones in Prometheus are awesome ;) Lol

We can ... sort of. Using conventional sensors to build a 3-D map of the space you're in isn't all that hard. The challenge is linking the map of the space you're in to the next map you'll make after you move an imprecise distance in an imprecise direction. GPS doesn't work underground, a magnetic compass can be misled by local geology, and dead reckoning accumulates errors pretty quickly.

We are working on developing such things, but so far they are still science fiction.

There's a scene in Prometheus where they map a cave system that turns out is part of a space ship (as I recall).

It made me think why couldn't we do something like that with modern technology - like drones, IR cameras, echo-location style sensors, etc?

While there are many differences between sound and light, for our purposes here those differences do not matter too much. Trying to map extensive catacombs with sonar is a lot like trying to do it with a flashlight.

You certainly can, but it's not exactly easy.

Echolocation can do interesting things, but it cannot really go through an underground tunnel system and give you a map. This is made up for movies and TV, at least at our current level. It would actually be a lot more like what you would get by shining around a big flashlight. It locates things in an area in the dark but doesn't generally go around corners or allow the mapping of anything but what is there in the room.

Sending seismic tremors through the ground so as to find all the empty areas below would be better, but still is quite a bit short of giving you a 3D map. It really isn't that easy.

And if you used seismic tremors, you might damage the catacombs.

...yeah, I know, that's literally what I've been saying. It's actual bootlegged alcohol. Like, you know, traditional moonshine, not Moonshine™

Because that was the original point. That moonshine, until circa 2010 apparently, was the colloquial term (slong with hooch) for bootlegged alcohol.

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Prison whiskey is not whiskey, friend.

It's sad to see someone work so hard to still show so little knowledge.

What you mean is fermentation. As others have said most things with sugar can be used (just ask anyone in prison). Distillation is used afterwards to remove impurities (think if you boiled water and only collected the steam/condensation)

>Not knowing about a thing doesn't mean it's not a thing.

I believe you that it's a thing now, but it's just funny how offended you are when you just said it's literally only a ten year old thing, considering "moonshine" has been a thing for well over a 150.

So yes, I didn't know a bunch of corporations appropriated a pre-existing term about the same time the first Avatar came out. My bad, lol.

>And whatever you had was probably not made by a commercial distiller

Wow, how did you know!?

>Because I did have alcohol from an amateur still, fermented from whatever was available

Oh, right

Search for Midnight Moon and Old Smoky to get a basic handle on it. Those are the most common commercial brands.

And read this.

https://www.npr.org/sections/thesalt/2018/01/02/574367086/from-hooch-to-haute-cuisine-a-nearly-extinct-bootleggers-corn-gets-a-second-shot

It's been a thing for distillers and liquor industries for well over ten years in America, and while it's not exactly well-known outside of Americana liquor historians and modern distilling, it's a significant share of the market.

And whatever you had was probably not made by a commercial distiller or even someone who knew how to toss the heads and tails correctly, which is why you had that taste. Well-made moonshine is delicious and has tasting notes as specific as any top shelf liquor.

Not knowing about a thing doesn't mean it's not a thing.

Honestly, you saying "I had illegally distilled liquor once and it was Terribad" leads me to the conclusion that you just make poor life decisions. Not that you know anything about alcohol.

I wasn't aware that Moonshine has become a "brand", made to a particular recipe, like raki or rum.

Because I did have alcohol from an amateur still, fermented from whatever was available (mushy fruit and potato peels, probably). You know, like something a moonshiner would have made back in the day. It just tasted like shit vodka.

... have you had moonshine?

It ain't vodka.

You're using "flavour" not "flavor", so I am going to say you have no idea what moonshine actually tastes like, regardless of whether it was a commercial version of Johnny Red Corn or a snort from an actual still back in the holler.

I mean I suppose you could be Canadian, but you'd be calling it white rye if you were East Coast Canuckistani.

I don't assume I know anything about Scotch, but I do know American moonshine, and when the word is used to describe liquor, they are not talking about potsheen or garage brandy.

So no. Moonshine is not vodka any more than ararak is vodka or raki is vodka or cachaca is vodka.

The flavor is different, the mash ingredients are different, and the cultural taste is very different.

And you'd know that if you'd had any of those and were in a position to taste, had any idea what the distillates tasted like, or had any clue what the actual flavor of those specific distilled spirits are in commerical brands or not.

The only other way you could not discern the difference between moonshine, vodka, cachaca or other distillates like unaged sugar cane rum is if you have no sense of smell or an incredibly weak palate.

banana brandy is a thing, moonshiners will do it when there's a surplus of it cheap. but its usually added to a sugar wash.

its mostly for flavoring. alcohol comes from fermentation of carbs/sugars. That's why the most common ingredients are barley, wheat, grapes, sugar cane, potatoes, apples.

Moonshine is literally just illegally distilled alcohol, not a flavour. It's called that because it was done secretly, often out in the middle of the woods or somewhere... In the light of the moon, if you will.

I mean, it can have SOME flavour, I suppose, if it wasn't properly distilled. Which isn't unreasonable if it was done in a slap dash setup in the woods.

Distilled spirits from corn is usually called moonshine.

Distilled spirits from sugarcane? Rum.

I get where you're coming from, though the flavor profiles are substantially different from a 100% rye grain mash vodka or a hard northern wheat vodka, and most people can tell a sugarcane vodka from a rye vodka.

Adding to the other reply. Vodka is a clear, neutral spirit. It is made by distilling all the sugar out until it's 90+ % ethenol, then cutting it back down to about 40% with water. You can make it from anything. Ocean Vodka on Maui is 100% from sugarcane.

You can still do it once.

However, many liquids cannot be fully separated by distillation, including ethanol plus water. The best one can reach by pure distillation is an azeotrope, where the liquid and gas phases both contain the same percentages of constituents. For drinking alcohol that's at 95.6% ethanol, above what almost all drinks offer, so most people don't care. Chemists and industry do, though.

you can make vodka from corn and sugarcane. vodka has moreso to do with the proof you distill it to than what it’s made out of.

With the caveat that some fermentation processes will yield too much methanol and then the subsequent distillate will be too toxic to drink.

Distilling is a way to purify a mix of liquids by heating it up and cooling it down. But just 'cause you can distill some plants and fruits to make booze, it don't mean you can distill any ol' thing. Bananas might have some sugars in 'em, but it ain't enough to make a decent amount of hooch just by fermentin' 'em. But you can make banana wine if you add some sugar and yeast to mashed-up bananas and let it ferment. And that ain't distillation, that's just mixin' stuff up and lettin' it sit.

Distilling is really just the act of separating two liquids that have been mixed together. The alcohol itself in alcoholic beverages is made by yeast eating sugars in a process of fermentation. This is how we make bear and wine and mead.

However this fermented liquid will contain a relatively low amount of alcohol. If we want something stronger we need to separate the alcohol from the rest of the liquid, and this is where distillation comes in.

So if we're using bananas as a source we could start by fermenting banana juice, creating an alcoholic banana wine. If we wanted to make it more potent, a higher percentage of alcohol, we could then distill our banana wine and end up with banana brandy.