That is possible. However:

The early-universe evidence for dark matter is so strong that even the (non-mainstream) researchers who favor modifications to gravity to explain dark matter in galaxies still have to include dark matter in the early universe. Then they have to get rid of it by the time galaxies start to form to make way for their gravity theory.

Another perspective is that dark matter is a much simpler hypothesis than a modification to gravity. We already know of one dark matter species -- neutrinos -- and it's really not a stretch to suppose that there is another. The only special feature that we know it has to have is that it has to reach the observed abundance.

Thanks for the fantastic explanation

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One of the ways we know is that we have detected galaxies that underwent a normal matter interaction that caused the normal matter to be displaced from the dark matter like this one. The collision of 2 galaxies exerted gravitational forces on both regular and dark matter, but other forces on just the normal matter make it get displaced from the dark matter.

You can do this without a microscope as well, I've done this in uni somewhere in my first year. It's very easy and quick indeed.

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Damn interesting from a professional perspective. Thanks for the thorough explanation.

I just watched a really cool documentary on Amazon called Everything and Nothing. Basically it goes through the history of discovering first how big the universe is and what we generally know about it, and then how small things can get/ what is space in a vacuum.

If you learn what we know from math and scientific observations, and learn what we don't know, it gives you a good idea on why we think there is dark matter. It's essentially a place holder for observations that haven't really been explained yet.

Basically, from what we know about matter already, there are effects of only some of the Properties of matter in the universe, like gravitational lensing without any kind of black hole or star cluster or blob of gas.

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Lethal dosis needs to be determined, which is called LD50 (meaning at this dosage 50% of test animals died). Then lower dosages are tried to show effects. The usable dosage is called "therapeutical range" which describes the dosage range in which the desired effect takes place without being toxic. The broader this range, the safer the med. Many meds have a tight range which means the dosage needs to be monitored and adjusted closely (e.g. certain seizure meds).

There are different ways, some of them involve a lot of math but one way is to start with multiple randomized neural nets which modify inputs you give them to outputs. You then test them, rank them by performance and get rid of the bottom half (doesn’t have to be the bottom half can be another fraction and can be that the lower the score the higher the chance to be removed but random). Then you make copies of the remaining ones with a random change to each and repeat.

This is all automated of course except for setting parameters like how many are removed how many are in each generation etc.

If you want an explanation of a neural net you should look up a video because it’s a lot easier to explain with visuals.

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Couldn't we just be wrong about some aspects of cosmology, something like relativistic gravity?

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If you look at my explanation in this thread, (almost certainly the longest one) the primary factor dictating how much torque you need to apply is friction. The better you control that friction the more accurately the torque you call out gets you to the clamp load required. Unfortunately friction is sometimes hard to control.

One of the other ways you can get an accurate tightening is by turning the fastener the same amount every time. Stretch in the fastener, and therefore clamp load, increases linearly with rotation of the fastener. If the distance between my threads is 1mm and I turn the bolt 360 degrees, I will have stretched my fastener by 1mm.

In practice though the challenge is determining where to start measuring that rotation. Everybody has their on definition and perception of where a thread starts to engage. You need to establish a starting point that is relatively consistent for everybody. That is where the torque comes in.

At lower torque values, the variability in friction has less of an impact on the clamp load you ultimately achieve during tightening. So I can pick a lower torque value, and then once I hit that value I can start counting degrees of rotation. This would get me to roughly the same location every time. This is much more accurate than purely relying on a maximum torque value for joints that have a lot of variability in friction.

And to be clear, 'you' don't make changes to the parameters, or check the output: Its all done by a computer program in a loop and because you need lots of input data then it can take a long time.

Torqued bolts/screws exist to provide a certain amount of clamping force. You do not choose a torque spec based on the threads, you choose the bolt size, material, and thread profile based on the clamping force requirements.

Anyways, I prefer angle control over torque control since it's much more repeatable, assuming your bolts are to spec.

I used to work for a fastener company in QA.

Not meaning to Hijack OP’s question. But after reading the answers regarding larger heart, larger lungs, etc. what would happen if you inverted a giraffe the way we humans sometimes do. When I get on an inversion table I get a head rush presumably from the blood to the head. Would a creature like a giraffe die from this experience?

Depending on how you dye/stain the cell, yes. The surface proteins are distributed all across the surface. So if you use a dye which only sticks to those proteins it would color the whole surface of the cell.

There are ways of binding dyes to targeting moeties, like antibodies, that only stick to one type of target. So you could theoretically make different batches with different colors of dyes and bind them to different targeting moeties so only blood cells with that group get stained that color.

There are way, way, way easier and more practical ways to type blood though. So I don’t know that anyone would actually go through the work to do this or what it would accomplish. Just saying this is a way to achieve what the OP asked about and actually see a clear difference under the microscope.

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