Interesting. Had never really thought through it before now. But reasoning through it with an understanding of manufacturing makes sense that the ballistics matching wouldn't be anywhere near a "fingerprint"

More like a copy of a fingerprint 😄

I've always wondered about this, as the whole point of mass production and interchangeable parts is to make functionally identical components.

So if two barrels from the same lot of steel are made on the same machines and rifled with the same button, one after the other - how much difference can there really be? There should be nothing but the tooling wear to change it.

Sure one could tell by looking at a bullet if there's a difference in number lands and grooves. Or with some knowledge of various designs' barrels you could say Beretta vs Ruger 9mm etc. But to tell between two Rugers of the same model?

Seems like a stretch to me. But idk.

Who did you consult with for the agronomy part of it? Does the system measure cues from the plants (NVDI etc) to determine water and fertility needs? Or does it just follow a recipe that dictates nutrient/water timing?

Also, what do you use for fertilizer? Recycling the N and Phosphate from astronaut waste and uneaten plant material would be ideal in terms of self sufficiency. Otherwise nutrients will eventually limit growth. And most of the fertilizers used in agriculture are corrosive, reactive etc so not ideal in space. Curios what the choice is there.

You do not want batts in the floor joists overhead. It's difficult, they don't stay put, and a comparison of the surface areas of floor vs perimeter foundation wall is illuminating here.

It will require 3-10x MORE insulation to do the floor than it will to do the foundation. For all that extra effort and expense, what do you get? You will have insulated the boundary with the SMALLER temperature difference (crawl-interior) rather than the larger one (crawl-exterior).

Since heat loss is proportional to temperature difference, that means you have spent more and worked harder to achieve a less effective insulation job.

The way to do it is to encapsulate the crawl with plastic bonded to the foundation walls. Air seal, use rigid foam inside the foundation, leave a termite inspection gap.

There are many sources on how to do this right. Read those. The very best energy efficiency renovations do it this way.

Vented crawls with overhead insulation are so dumb it makes my brain ache.

Yup. It can vary with the texture, but it's probably going to have some kind of halo about it even after blasting if the color varied markedly.

This is why masonry should never be painted. They should teach this in schools.

Because it permanently and irrevocably converts a surface with a major selling point of not needing painted... into one that does.

Forever.

You can get close to original with abrasive blasting, but it's still going to have a hue of the paint to it.

Sorry.

You won't hurt your floor.

Radius gauges in a machine shop environment.

Less precisely, you can press the profile into clay, and then see which drill bit fits that shape best.

In manufacturing this is always specified as a radius callout. So half your drill bit diameter if you do that.

I'm just about as anti flex duct as they come, but I do think this is a reasonable way to do it. It uses it where it's strengths are. I used to do HVAC design and this was common and good practice there, from a properly sized branch system, with flex from the ends to the diffusers.

As the whole duct run, as is common in residential, it's no good. It falls into the realm of things that while theoretically possible to do well, just require a level of diligence and effort that aren't going to happen the vast majority of time.

Nothing you put on the outside of the duct is going to help this, because the sound is traveling along the duct. The same as the speaking tubes they used to use on ships.

You may be able to cheat and absorb some sound with an air filter. Or if ducts are way oversized (as in plenum or joist chase returns) you could line them with acoustic board at openings. You may also be able to get noise blocking diffusers.

But mostly I think you're going to be stuck with this unless you remove and replace with duct board or similar.

There's a big tradeoff with efficiency going this route.

Your proposal violates the first law of thermodynamics, in that it requires wholesale creation of energy.

That is not possible. That is what is known as a perpetual motion device. They have been proposed and claimed many times.

There has never, and will never, be such a thing. In layman's terms, you can't make something out of nothing. You can't turn the chemical energy contained in one battery into heat, then mechanical work, then electricity, then mechanical work again, while somehow multiplying it.

In fact, the real world does the opposite- entropy and inefficiencies bleed some off at every conversion.

Which means simpler conversions are more efficient ones.

As for electric drive ships, they have been and are still built. The reason internal combustion prevails is because it is cheaper to operate, requires less space so more payload, is relatively efficient, and takes less crew, training and maintenance.

This. An oscillating tool will get it out in almost less time than it takes to type this.

The right box can be placed against a new piece of wood, and a block wedged against the ceiling from below will help OP get it flush while fastening.

You don't want to use fiberglass batt for this. It's permeable and a chimney has a powerful draft effect even without a fire. It will still leak and will probably get wet and moldy.

You can always spot where the air leaks are in tops of walls up in attics because the fiberglass insulation gets filthy there. It's just an air filter in that case.

Chimney balloons are cheap and effective. Rigid foam insulation spray foamed into place is even better. Whatever it is should be damp proof and air impermeable.

For OP, there will still be enough air movement for the brick to dry itself above the plug if you do this fix.

Guys do it to wind up barbed fencing wire on a spare wheel when removing fences.

It works, but it's sketchy. By yourself, it's a good way to lose life or limb.

I rewired my whole house and only had to cut about 3 holes into the walls, so let me share my tips:

First - get somebody to push wire in on one side so you can pull on the other.

When you pull with string, I trim the wires to leave a nice taper, and tape it all so it doesn't snag.

Get a borescope, you can drill a 1/4" hole in the wall cavity and see what's happening in there. That patch takes like 30 seconds.

I pull the electrical box out before cutting holes, as that's where you need to see.

Don't use a sawzall anywhere - holesaw and hand stab saw with drywall fleam teeth are your best tools. I use the hand saw to gently open around boxes so I can see where wire goes, and then remove box if needed.

This is the answer. I've done this exact job and the float switch manufacturer had wiring diagrams for all the various pump control options to show how to do it. OP can find one for his or use a generic one.

This is how Chicago was raised. It was screws instead of hydraulics, but the principal is exactly the same - not one big jack, but many small ones.

Oh this is fascinating, please expand on these! It's crazy to think they can survive that long, what's the predominant force at that scale that keeps them from collapsing or dissolving?

Also, is this a significant source of dissolved oxygen in water for fish etc?