I’ve owned eco fans for years. After 5-7 years I had replace the electric motor behind the blades , but that was pretty cheap and very simple. They are great fans, just pay attention to their intended use. I bought one that was meant for lower temperature and burned it out quickly on a wood stove.

...What was even their business plan for making that many then?

Yes and all of that is not mutually exusive to my statement.

Compared to gophers that is nothing lol

I grew up in Amish country (even been to an Amish wedding reception), and know they use steam engines... never a Stirling engine. But those steam engines are beautiful.

I interviewed at a company that was planning on building Stirling engines back in 2008. They told me (no idea how true) that other than little toys and novelty sterling engines, there were less than 300 large sterling engines in the world (and they wanted to produce 3000 a month). They went out of business.

Can you recommend a good brand? I’ve been on the fence for years because the review are all over the place

happy to help. The question you're asking here concerns a massive chunk of biology so theres a tremendous amount to learn. If you want to learn more, the key is to take it in bite sized chunks and go at your own pace. To start, you could look at a simple case and search "explanation of the lac operon" which was one of the first systems in which gene regulation was well studied, or you could just search the term "gene regulation". Alternatively any biology textbook will have tons of information on gene regulation, even the slightly out of date ones. Finally you can check out the book "Endless Forms Most Beautiful" for a slightly lighter read, written by an expert in the field and a great science communicator. This last option might be the most enjoyable because of the digestible writing style compared to a textbook.

This ingenious stovetop fan for wood-burning stoves is completely silent and costs nothing to operate. Based on a phenomenon known as the Seebeck effect, the fan uses thermocouple technology to generate an electrical current by exploiting the temperature difference between the stovetop and the ambient air. The fan speed varies with the temperature difference (greater difference, greater speed), quietly moving warm air from the stovetop. Made largely from anodized aluminum, it is an efficient way to disperse heat.

The fan can produce up to 125 cfm of air movement, stands 9" tall and has an 8" diameter brass blade; it operates on surface temperatures from 212° to 650°F (100° to 345°C).

Borrowed from Lee Valley Tools

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I collect and restore antique steam engines, the Amish really do love these things. Some of the best, and worst, running engines I've seen have come from Amish hands. They either meticulously take care of them, or they run them into the dirt.

Can't say that I've ever seen them use a Stirling engine, however large Stirlings are pretty rare. Wouldn't be surprised to see one in Amish country though

Some types of rats actually form colonies that can grow over 100 individuals. Norway Rats are a good example of this. They'll have burrows with 150+ members and even have individual rooms, food caches and rooms for feeding their young.

Motor units (and single muscle cells) are almost operating as on/off. There is some minor modulation possible with changes in firing frequency. Each muscle has many (typically >>100) motor units varying in size, each with an on/off switch. The net result of having so many motor units is the muscle behaves as if it is operating with a dimmer switch.

I should have been more specific.

Rats will organize themselv s.on this small of a scale yes, but there won't be thousands working in unison like gophers.

Yeah the most common thing as I understand it is that they are to be "un-yoked" from modern world. Thus off grid electricity is okay, grid tie isn't. ... Varying degrees here but many also use cell phones.

There are engineering size limits if you want it to be seaworthy. This is a constraint imposed by how well the materials used can tolerate the stresses that the ocean applies to the hull. For example, wooden ships can’t be much larger than 400 feet. The largest wooden ship ever made was the Wyoming, and it required many pumps to keep it afloat, because the constant twisting and bending of the hull would create gaps between the boards, allowing seawater in. It eventually sank in heavy seas.

https://en.m.wikipedia.org/wiki/Wyoming_(schooner)

Thank you so much! I understood it now. (but i am pretty sure if i tried to research more into the topic, i wouldn't understand so much...lol) Regardless, I enjoy learning about biology (I actually participated in a biology competition a couple days back and lost xx)

> Stuff farther away moves faster away than stuff closer to us. So we know relative distances to us.

I blame this on poor science communication, but I see people talking about redshift being used to measure distances in all the wrong contexts.

Redshift ONLY works when measuring the distances to GALAXIES outside our local group. So relative velocities are meaningless even when talking about andromeda, much less stars in the milkyway.

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> With an estimate of the gravity of the center of the milky way we can estimate how from out the hydrogen we observe must be for it to be moving at the velocity that it does.

This would be a terrible way of doing this since you have know the geometry and mass distribution of the galaxy to have a model of how stars should be rotating. On top of that, even if you had a good model, you only measure line-of-sight velocities, making this pretty useless.

Shame you are getting downvoted, these are mostly good points.

Contrary to the instructor who once said there is only "On or Off" for muscle engagement. I really hope I misunderstood their intention with that.

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