K is determined by using a torque transducer, load cell, and the other hardware like washers and nuts that you are going to use in your joint. You want to make sure your setup is as close to actual production as you can get. You then tighten to 75% of the bolts proof load as measured by the load cell while also measuring torque. That gives you enough information to use the formula to determine K.

K = T/(DP)

T = Torque achieved at 75% of bolts proof load

D = Nominal thread diameter

P = Proof load of bolt

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Using our example above:

111/(.250*2025 = ~.22

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This would be an example setup from work:

https://pieng.com/testing-overview/torque-tension-testing/

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Do you determine K with a bolt stretch gauge?

Okay so there are many kind of antibodies - IgG, IgM, IgA and IgE.

IgA are only functional outside of the body (in your intestines and in your respiratory tract). IgE are only functional once bound to a very specific type of cell - they cause allergies. IgG and IgM, on the other hand, have many purposes. Which…are complicated. You have something floating around in your blood called complement. When Complement lands on something, it tells your immune system to kill whatever it lands on. So your body only wants complement to land on diseases. One of the ways it gets it to do this is by haveing antibodies (IgG and IgM antibodies) make complement settle onto diseases. In this case it isn’t really gobbled up - it makes proteins form that literally punch holes in pathogens (and ramp up your immune system so any survivors can get gobbled up).

The other thing it can do it make you immune cells gobble up whatever it binds too so it can kinda do both!

Motorcycles are subject to significantly more vibration, and some motorcycles are even designed such that the fasteners aren't guaranteed to not back out (in cars, they are guaranteed to not back out, at least if designed right)

I've seen the paint on the mating surface of the lug nuts sometimes degrades and causes the nut to loosen.

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get the idea, that a photon is some kind of physical object, out of your mind. light is energy, that is transmitted over the electromagnetic field as a wave. but that wave can not take arbitrary values but only discreet multiples of a fixed value. kind of a packet of energy. and we call this packet of energy a photon. light is still an electromagnetic wave but it can only be produced and absorbed photon per photon.

there is this electromagnetic wave. and if this wave has the right wavelength (=energy density), it can excite a special molecule (the chlorophyll) in a special way that it can break the chemimal bonds between carbon dioxide molecules (co2) and water molecules (h2o) to form glucose molecules (c6h12o6) releasing some free oxygen in the process. (of course it is much more complicated than that). the chemical energy stored in glucose is higher than that of carbon dioxide or water. thats the reason, why the plant does this in the first place - glucose can be used to store energy. that energy must come from somewhere. and you guessed it: it is transformed from the light, the chlorophyll has absorbed.

the speed of the wave is irrelevant. one moment, there is no wave (just the "flat" electromagnetic field) and the chlorophyll is kind of in a dormant state. the next moment, there is a wave, consisting of - lets say, 10 packets of energy (10 photons). that energy is enough to excite the chlorophyll. it can catalyse carbon dioxide and water to glucose and free oxygen. the next moment, there is no wave anymore. aka: no more energy packets. the chlorophyll gets dormant again. photosynthesis stops.

it's not miniature balls zipping past at incredible speed! it's energy transmitted as waves. the speed of that wave is irrelevant. what matters is: is there NOW enough energy you can sap from the electromagnetic field to do something or not.

and to hammer down the obvious: if you turn on the light for 10 seconds in an otherwise dark room, there is kind of a wave front, that lasts for 10 seconds. in that 10 seconds, the electromagnetic field in direct vicinity around the chlorophyll molecule carries enough energy to do something. you only notice, that this wave arrived at the speed of light, if you compare the field strenghs of your own point with other points in the distance.

> The thing to understand about photons is that they are just little bits of electromagnetic energy.

This is a big thing to understand. Photons are essentially just little energy fluctuations. When they're absorbed, that means their energy is taken up by a charged particle (generally a proton or electron), and that energy is converted into another form of energy, which could be, for example, heat, electrical current, or chemical reactions.

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Sure, but I’m not an expert by any stretch of the imagination. So the cell is surrounded by a membrane. That membrane is absolutely covered in tons and tons and tons of proteins which stick out above the surface of the membrane. We call these surface proteins because they extend above the surface. Those proteins can be used to mark what type of cell the cell is, interact with chemicals floating around outside the cell, bind the cell to various structural components or other cells etc. These are sometimes called surface antigens, because antibodies can be bind to them.

The normal blood group markers, the ABO system, represent a set of surface antigens. The ABO and Rh (that’s the +/- part) happen to be particularly important to how the body recognizes self vs foreign cells. So it’s really important to match those correctly.

But the blood cells have hundreds of different antigens. And just because the ABO and Rh groups are particularly important for recognition doesn’t mean those other antigens aren’t also used. And to make it even more complicated, different people seem to respond more or less strongly to different groups (although ABO seems to be close to universally important)

Here’s an article I found on the topic

Also interesting to note that the blood type O started out as 0 because those red blood cells had none of A or B.

Very interesting history of learning of blood types and early stages of trying transfusions.

Everything deforms when pressure is applied. Alloy wheels are actually considerably less stiff than steel so they will deform more under the same load.

Um, pressure drives flow from regions of high pressure to regions of low pressure.

Also, Betz's law isn't a law to maximize efficiency. It tells you that because fluid has to leave the back of the wind turbine, it has to have some energy. It can't move at zero velocity. It's impossible to extract 100% of the kinetic energy from the flow for this reason. Betz used a simplified but reasonably accurate model of how a wind turbine works to derive a limit on exactly how much kinetic energy can actually be extracted, even from a perfectly efficient turbine, to be compatible with the fact that the air has to go somewhere.

Would you be willing explain the other, rare blood types? For example a family member has the Kidd blood type) Found out the 8 blood types are just the most common, and there’s actually a bunch more.

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We have put millions of kms on our vehicles. We know about them loosening, however, there will always be people saying it is nonsense or an error in the initial torque. Follow your pattern, set the proper torque, every once in a while some will loosen on their own. That’s why we have pre trip inspections and a ton of regulations on our vehicles.

And if you over tighten then you are weakening the studs and can ruin your threads. Ounce of prevention as they say.

I think XKCD said it best:

>Yes, everybody has already had the idea, "maybe there's no dark matter — gravity just works differently on large scales!" It sounds good but doesn't really fit the data.

The bottom line is that, even though we've explored quite a lot of modified-gravity / alternative-cosmology models, none of them have been able to fit all of the data even with some of the wildest and most contrived parameterizations. In basically every case, we can choose parameterizations that work to fit some datasets, but then those same parameterizations then go on to fail miserably at fitting other datasets ... and there just isn't any parameterization that works for them all at the same time, which means none of those models are actually viable as models of cosmology.

On the other hand, not only are dark matter models incredibly simple by comparison, but it is straightforward to parameterize them such that all of the datasets are well-fitted with the same parameterization, and getting to that point doesn't even require any specific model of dark matter — the generic idea of dark matter works so well that there are many different possible models of dark matter that work. It could be sterile neutrinos, or axions, or WIMPs, or light supersymmetric particles, the list goes on and on ...

When an idea works so well and with such simplicity and generality while every other idea explored falls flat on its face no matter how complicated you make it, you just have to take a step back and admit that maybe, just maybe, the simple and general idea is actually the correct one. It's kind of like ... if you're sitting there with pegs of different shapes and you find that the round peg fits the round hole but none of the other pegs fit it, well ...

It has nothing to do with the torque value and everything to do with the material. I have had dozens of vehicles, driven hundreds. Aluminum rims often come loose. The nature of the material. I have torque wrenches and a big shop.

On one set of rims it takes about 15 minutes to torque each wheel the first time then a short drive and some of the nuts loosen. 2015 f350. The Ford diesel mechanic noted the same thing and he hates those rims too.

I was at a garage where the mechanic told the customers that retorquing was bull and he had never done it once in his life. He was a fool.

Wheels come off less often now then 30 years ago, after which they introduced retorquing tires.

3Blue1Brown is a YouTube channel that covers mathematics. They made a 4 part video series on neural networks and how they work, and specifically what it means to train a neural network to accomplish a task.

Link to the series here

There is a lot of info that is well explained, but would be too much to write down in a post, so hope this helps. It helped me understand neural networks much better.

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Another example is, as a machinist, we tighten the collet chuck nut to different torque specifications depending on the collet holder (tool holder) size. As different torque settings can have different effects on the tool as it spins up to 10,000 rpm (and many even higher). Can cause the tool to be held to tightly and deform the holder, or to loosely and the tool could come out. And if the torque is too high or low it can cause deflection as well (deviation in the center of the tool over a distance).