Just as an example, there were evidently reports during the 2007 Glasgow airport attack that someone attempting to subdue the assailant and assist police kicked said attacker in the testicles… but somehow managed to do so hard enough to injure one of their own foot tendons.

I'm in NorCal and the weather has been all over the place this winter. It is hard to get a reliable forecast, sometimes even for the same day. I was wondering if it has something to do with the weather prediction models that were built before the climate change?

I saw something yesterday talking about how Australia is geologically dead with the lowest tallest mountain range of any continent due to no landmass collisions. Does that make it the last visage of a supercontinent that everything else broke away from?

I wonder of Australia's relevance to the mantle anomalies speculated to be part of the Theia collision.

Geology Hub (active geologist/mantle anomalies possibly relevant to magmatic activity): https://www.youtube.com/watch?v=WdCckYI62yM

Anton Petrov (cites valid sources/mantle anomaly research summary): https://www.youtube.com/watch?v=q0utwP9J6mA

Atomic Frontier (journalist?/source of quote about Australia being geologically dead/not a valid source reference and nothing cited): https://www.youtube.com/watch?v=v29ou094luc

I'm just curious.Strange matter, according to my research, is a perfect state of matter with perfect density, etc. If it is like this, does that also mean that it violates the law of entropy?Because let's see, if it converts matter around it into stranger matter, and after that it doesn't react with anything else, I mean are we going to reach a point where there is no more entropy to grow?Or worse is it decreasing entropy? Since it converts everything to a type of matter that does not seem to interact with itself.

I don't know much, so thank you for being patient in reading in case I have some absurd misconceptions =D

I unfortunately live in a very polluted area, one where air quality apps mark in red and recommend that I never get out of my lair.

When it rains enough the air quality becomes more bearable and here comes the question: where does pollution go when it rains hard? Does it get pushed to the ground and stays there? Does it get embedded in the water (so instead of breathing it, I get to drink it later in the tap water)?

I'm curious to know where it gets dispersed or stuck (to possibly avoid it)

I'm curious what your take is on the finite nature of Science. I imagine the fractal "edge" will always remain illusive, but when do we hit 98% or 99.999% documented confirmed, distilled, and well explained? (Centuries? Millennia?) When does it become an engineering corpus?

(thinking of SciFi futurism as a much needed pick-me-up rn, please be kind)

You dirty dirty... It's time to show off! What is the most extreme cleaning you've ever performed?

I am creating a simulation to evolve simple, multi-cell organisms. (Just for fun!)

Neural networks are fairly easy to evolve, even more so when it's done by random mutations and not actual training. Build an ANN at random and introduce mutations with every generation. The ANNs that accomplish simple goals (by pure chance) live to duplicate with every evolutionary cycle. Fairly easy stuff.

I am stumped when it comes to creating something that would simulate the genes that represent a body. After some reading today, there isn't much info on how cells form into specific shapes for arms, hands, organs, etc. (I am sure there is a ton of data, but I don't know what subject to Google.)

Genes can create the patterns for specific chemicals and cells. How to cells then develop into functional body parts? What makes a heart the shape of a heart?

I think that having a better understanding of that concept can help me develop a framework for physical evolution, even if it as a very tiny scale.

(Putting the ANN in charge of controlling those different body parts is also easy. It's just a matter of allowing those physical traits to evolve first.)

Is the CMB only red shifting in frequency or is there more to it, and over what time scales and distances would one notice a significant difference?

I recall an explanation of the formation of Jovian moons on the Harvard Smithsonian "CfA Colloquium" YT channel that casually mentioned how various elements freeze out of the solar wind forming ices, and this is the mechanism that allows formation of moons with large amounts of water and elements that are not found in larger quantities within the inner solar system.

I will admit I have a strong bias where I want to believe Theia was an ejected first generation Jovian moon. I don't like the idea of planets (Theia) forming around Lagrange points as it feels like fitting a theory to the evidence. There is apparently evidence of an earlier generation of Jovian moons and it is the most logical source for such a rogue object traveling slow enough on the solar plane.

With that aside, Earth's large amount of nitrogen in the atmosphere seems weird. Not that Earth has it as much as why Venus and especially Mars do not. I understand Mars lacks the gravity to hold onto gaseous hydrogen that is stripped away by the solar wind over time, but it can hold onto carbon dioxide. So shouldn't Mars hold onto nitrogen too?

IMO scientific explanations of Earth's formation seem to lack the broader perspective of Earth among the solar system as a whole. Earth should look like a Venus:Mars hybrid. Theories seem to start with Earth as a baseline and explain away Venus and Mars as exceptions. It is like we are taking a sample size of 2 and throwing it away in favor of a (much more thorough) sample size of 1, when that sample of 1 has an enormous error source in orbit around it, which most old theories have simply ignored. Like the water isotopes on Earth do not match the comets/asteroids theory, but do match a Jovian source.

So how does Earth acquire a bunch of nitrogen when it is well inside the nitrogen ice line of the solar wind and how does this account for Venus and Mars?

I'm curious about building cat toys that are impractically over complicated with Arduino/Maker stuff. Thus the casual curiosity about persistence of vision. I wonder if other animals have something like a different internal clock frequency where the image only forms at higher (or lower) frequencies than most humans.

In physics, it's common to develop a formula and then stick a constant to explain the unknown. For example, Newton's theory of gravity uses the gravitational constant G on the formula F = G * m_1 * m_2 / r^2, later on Einstein gave a more accurate explanation with the theory of relativity which does not rely on a constant E = m * c^2. Constants provide a good enough explanation of the laws of physics that's useful for centuries.

I was wondering what's the equivalent in social studies? How do researchers deal with the uncertainty of human behaviour?

Edit: Comments made me remember how much I don't understand the theory of relativity, terrible example, sorry for the confusion. I need to rephrase the question but I don't know how.

I am looking for "glue" concepts, things that help connect observations with theory, aka if I calculate m_1 * m_2 / r^2 the result is slightly off but if I account for G, an empirical constant derived from observation, then everything makes sense for the observable universe.

Also, as someone said, I am referring to social studies.

I was reading about the production of calcium carbide, and that it involves mixing lime and coal in an arc furnace. Is there something unique about arc furnace heating that, say, an induction furnace could not provide?

What are the consequences of not severing it? I imagine you'd have the weirdest bellybutton on earth if nothing else.

Cheers!

Assuming we are talking about an era when Sol has a thriving space industry and the Solar system is broadly colonized. Current materials science supports structures up to 8 kilometers in diameter, and if large scale graphene production is possible, up to 100km in diameter, at least according to Isaac Arthor.

I am wondering what resources would be difficult for a colony ship to reproduce in-situ on an one way trip to the first interstellar expansions of humanity. I picture a true generation ship might be primarily designed around the transport of some of the largest prefabricated sections of a future centrifugal spin gravity habitat.

1. Using hard science to speculate, what types of materials and components would only be available with the massive industry present in humanity's original home?

I picture the main outer ring frame structure of an O'Neil cylinder, like some kind of curved beam, would be prefabricated and sent in a few pieces for later assembly. If the O'Neil cylinder was to be 8km in diameter, 3 pieces would make the generation ship at least 5.7km long.

2. What is practical to transport assuming fusion is in the cards, as are self replicating drones for resource extraction in a region like the astroid belt, and assuming planets are resource poor gravity prisons we avoid in favor of mobility?

3. How might carbon get utilized for large structure fabrication in space as far as processes?

4. What about metals and space based fabrication. How can you picture the production happening in ways that would only be possible in a highly advanced space based economy?

I know this is highly speculative and I hope the mods will let it fly to ask this. I know most nerds are curious about this kind of thing. I'm only interested in the most conservatively realistic of hard science fiction/futurism.

This is something I always wondered because some people have a bunch of theories about whether your head should face north or south or whatever, because of the earth magnetic field. Is there any science in this or just "superstition"?

Also, would it be better to have the head towards a window or away from a window, even if closed (e.g. in winter)?

I'm basically asking whether there exist "recommendations" on how to structure a bedroom backed by science.

I feel like we are ways out from seeing anything like it. From what I've seen non-Newtonian fluids typically take a decent amount of energy to stop something and sound wouldn't have much energy compared to something like a bullet.

On a sidenote does Decibullz own a patent on percussive hearing protection or am I looking up the wrong term? I feel like there must be other hearing protection out there that is effective against sudden loud sounds.

After reading the abstract of the paper mentioned here I started wondering, why did human groups migrate away from southerner (warmer) places towards the north which is far colder and has less possibilities to grow crops and wild animals to hunt?

Was the population density too high?

And after they migrated, what did they mostly survive on? Were they hunters-gatherers? Did they cultivate? Was it not more difficult to survive in colder climates?

People talk of potential human flight on planets. Somewhere in the recesses of my mind I still wear my inner 5 year old's caped Superman pajamas, stressing over how many stairs one must jump from to take flight. So is it possible to flappy bird a flying monkey?

I don't care about the math and statistics. I went looking for visual comparisons, where image exposure is adjusted to show how a sunny day on both planets really compares, but I didn't find anything.

During the last partial solar eclipse in SoCal, I thought, "I wonder how close this really is to how Mars feels." It was eerie (as always) with a clear sky, and sun near noon, but feeling colder than I should (obviously Mars is FAR colder), and with dimmer light.

Our eyes have an enormous dynamic range. That is not exactly intuitive to most people. Still, I was hoping to find some way or reference that captures the experience of the sun on Mars, and really the emotional impact of what it means to stand on Mars at solar noon with human eyes.

Our pictures of Mars are all adjusted for optimal exposure, but that makes it intuitively seem very Earth like when in reality it is like a next level Neo Exo-Antarctic, even under the warmest of days under direct sunlight. What is that really like?

I'm trying to wrap my head around something that appears far more complex than I first thought. I don't understand the explosive elements and chemistry that drives ash production and the heat to create the eruption column. I'm aware of how molten metal behaves in a foundry crucible with flux and degassing required. So I understand how magmas can have a tremendous amount of dissolved elements that can release like CO2 from a shaken soda bottle being opened. I can picture this kind of pyroclastic flow easily; the "shaken soda bottle" type.

I don't have a very good grasp of how the ash column can reach enormous heights and then collapse, or how composition impacts this kind of collapse. I just can't picture in my mind how this type of collapse results in a flow, like some kind of avalanche or pronounced river of material as opposed to more of a micro-regional rain like ash fall event that is very intense and superheated. What is the trigger and how does it overcome any hotter material lower in the column?

https://en.m.wikipedia.org/wiki/Pyroclastic_flow

I bought a torch that has a 365nm UV light, which I believe is UV-A?

When doing a poke around my house to see what I could see with UV, I noticed that my freshwater fish tanks looked "cloudy" / "milky" under UV, yet they are crystal clear under normal light.

I checked tap water and bottled water with the same torch and they do not react and look perfectly clear under both UV and normal light

I also have an auto top off for one of the tanks which is full of ~50L of a mix of RO water and tap water treated with dechlorinator and this also does not react.

I have 3 tanks inside of various volumes (700L, 150L, 20L) and various stocking levels which all show the water as a pale flourescent green colour under UV. The colour is uniform and completely spread out through the water volume, not concentrated on any area or in layers or whatever.

The currently empty 20L tank reacted the least, leading me to believe that it may be some sort of organic material that is causing the UV light to react so much?

I know that sound doesn’t travel in a vacuum, you can hear it muddled in water, and different temperatures of air transmit better. But which is the “best”. Let’s say you had a speaker and a microphone in an enclosed case filled with whatever you wanted, which would be the best medium to ensure the best sound transmission?