Your question made me realize I had never thought about this at all so I spent some time searching. If I am understanding this article correctly it essentially boils down to the factors that would cause rotational symmetry at a smaller scale ie spinning sand on a plate apply at the galaxy scale as well.
There’s several factors at play here. An athletic heart is not only more efficient down to the conductance of the cardiac tissue, but it also has a larger stroke volume. With those 120 bpm each beat could be pumping 40cc of blood while in the other heart each beat might only be able to pump 30cc. This is because an athletic heart is able to more fully contract to squeeze out all of the internal volume. Think of the conductance of the heart as a snowy hillside. The first time you take a sled down the hill the snow hasn’t been compacted to make a path. The more often you take your sled down that path, the more compacted it gets and the faster you and your sled will go down the hill the next time. Plus I haven’t even mentioned blood pressure decreasing in an athlete due angiogenesis and dilation of already present veins and arteries.
So to summarize, it’s not just bpm that need to be accounted for here. You also have to consider:
conductance lowering the cardiac impulse threshold
I think their point was that there isn't anything humans could do during the night. Stars might give some light, but without a full moon you really can't do anything at night without lights.
i mean yeah, but even then starlight is basically fuck all. The moon overpowers those, it just makes the sky look pretty. That's it.
Cloud cover would be primarily lit by moonlit. And even then, moon light is very dim. Just look at early moon light towers used to light up residential areas early in the electrification period.
It's literally the difference between being in your home, at night, and you can't see shit. Vs you can just barely make out where things are, and navigate properly.
Also semantic point, light pollution is not "dark" that's why you can't see any stars. Ever looked at a highway lit with LEDs recently? They have tons of light pollution that can be seen as what's referred to as "sky glow" My point here being, when you go outside in a light polluted area at night, it's literally not dark.
I also just don’t care about plastic pollution that much… at least not compared to carbon emissions. I mean don’t get me wrong, I’d rather we didn’t have crap everywhere… but I’d rather we focused on minimizing carbon, even if the low carbon options happen to involve plastic.
Im dealing with all rule breaking behavior. The unsourced comments have now been removed as the user is unable to provide a source to backup their claim. The comments that break civility rules, including this one, are also being removed.
Please report rule 9 violations so that we can act on them.
The source provided by another user gives a definitive counter argument.
From the article: “ The wheat kernel contains 8%–15% of protein, from which 10%–15% is albumin/globulin and 85%–90% is gluten (Fig. 1).1 Gluten is a complex mixture of hundreds of related but distinct proteins, mainly gliadin and glutenin. Different wheat varieties vary in protein content and in the composition and distribution of gluten proteins.”
loads of organisms that can digest gluten already exist. Not so much for polyethylene etc. Also gluten is made of proteins with definite length not polymers
Let me school you on this one, too. There are polymethylsilanes, polyphosphazines, etc. You aren’t even aware of common polymers like PVC that fall outside of your categories. There’s more exotic stuff like polyferrocenes. You ought to quit spouting off about things you know nothing about.
It does, but as more air drops down, the pressure increases. This pressure then starts to push back against the air above it. Which is why we have atmospheric pressure at the surface, but that goes down to pretty much 0 in space.
Even in low earth orbit there are still some particles, which causes satellites and such to slow down, requiring them to fire some thrusters every once in a while.
Depends how you’re using “why”. In Russian, they actually have two words for why, one of which implies teleology, and one which doesn’t, and merely requests some explanation for a phenomenon. I wish we had that in English.
In this case, it’s such a general question you can’t do much better, but you could, for example, talk about why oxygen-carrying proteins pretty much always incorporate an ion of something, in a merely cause-and-effect way. (And I actually don’t know the answer to that one)
The answer to the question, “How did this evolve?”, is the same as the answer to a non-teleological “why”. People just need to learn to use “how” because “why” is such a loaded word.
When using “how” in this sense and “why” in the non-teleological sense, they have the exact same meaning (at least to my ear), but then the “how” version isn’t ambiguous.
If I say to myself, “How did this evolve?”, the question feels good. It feels clear, and my mind leaps into thinking about the function of the mineral in the body and the chain of evolutionary steps that could have caused it.
If I say to myself “Why did this evolve?”, I just can’t get the teleology sense of the word out of my head. If someone didn’t want a teleological answer, why did they say “why” when “how” is clearly better? So I assume they mean why.
I feel like even if I answered their question, the next one would be, “Yeah, but why?” Making me feel like I wasted my time explaining the “how”.
That’s might be an option too, I guess, but in some situations it’s a different question. If I make a mistake and you ask “how”, you might just get more details. If you ask “why” I might respond with “I was tired”, which doesn’t really imply teleology. As I understand it почему would be more specific to cause rather than just means, but then again my Russian is pretty basic. The word “how” would be как, and it even works as an intensifier the same way.
Animals whose biology that used the metals reproduced more successfully is the explanation. It could longer lives, better reproductive outcomes, or a ton of other reasons but it all comes down to reproduction.
Well, genes, if we want to get really technical. Otherwise you can find counterexamples where genes are detrimental to the organism, but manage to spread anyway do to some quirk.
Generally they don’t impact the reproduction rate enough.
Let’s take reproductive cycles as an example of there being no single benefit or negative. Some species reproduce in mass quantities and that works for them, while others are slower. The fast one having genes that slow reproduction would probably die out because their adaptation of mass reproduction is what keeps them around. A slower reproducing species won’t necessarily benefit from higher rates as they might overpopulate their range. So what looks like a detriment could just be a thing that neither benefits nor is a detriment depending on the complex context of the species and where they live.
And sometimes detriment are offset by other benefits, like sickle cell anemia having some terrible outcomes but it also protects against malaria so in the context of somewhere with a high rate of malaria it is beneficial to survive to a reproductive age, which would explain it sticking around.
Ah, so you haven’t heard about this thing. It’s not really lucky 10,000 territory, but it’s still cool.
There are situations, where in sexually reproducing organisms, an unambiguously bad gene can spread through the population, just by ensuring it’s more likely to appear in the next generation. As long as it’s not so bad it kills the species off, you’re still likely to observe it a lot in a future population. We’ve actually harnessed this idea technologically, with genetically modified mosquitoes that crash their local population by skewing all offspring malewards.
That is one example of ‘not detrimental enough to impact reproduction’ which I meant in the context of a population and not an individual, but I guess that my wording wasn’t clear enough.
Theoretical biologist here. I’m going to push back on that just a bit. I think that you might have mentioned Selfish Gene, too. That was not the best book even at the time of publication (most biologists had a number of problems with it oversimplifying in a way that’s probably similar to what anthropologists think about Guns Germs and Steel). It also has been getting worse the more we learn.
Evolution acts on the phenotype, not the genotype. It affects the gene makeup of the population through differential reproduction rates. “Fitness” can be measured as a value relative to the rest of the population specifically by using the number of offspring. So what I’m saying here is that all factors that affect phenotype, whether genes or other factors, affect evolution.
So, of course genes are important. But you have epigenetic factors, too. link here You also have extensive non-coding regions that regulate transcription. You have rna editing. And so on.
If you’re interested, I would highly recommend a book called How Life Works by Phillip Ball. It was just published in November and is an outstanding summary of how much our understanding of life has evolved (heh) in the last 20 years or so.
Well, you would know a lot better. And thanks for the reading recommendation.
What are your thoughts on viruses as a form of life? Asking what natural selection is in exact terms is pretty closely related to asking what life is, since life is probably some subset of things that can do natural selection.
Personally, I do think of viruses as a form of life, and although it’s not universally held by any means, I think there’s a growing consensus around the idea.
That’s probably as minimalistic as I would go, though. I mean, you can make a similar argument to some extent about prions, but prions are too close to being “just chemistry” for me.
Viruses on the other hand cooperate and compete in complex ecosystems, which in my opinion magnifies the complexity of a virus as an element of a complex adaptive system. They don’t have a metabolism as such (which is why so many don’t consider them living), but their ability to conduct theft of resources of more complex and obviously living systems makes me push them to group of living things.
One of the nearest things about biology is that there’s always an exception to the rules and examples, and the simplifications we make when teaching bio 101 are really best learned as rules of thumb. Things like what a “gene” really is, the operation of selection, and even what constitutes a “species” can lead to some really interesting discussions.
A few fields are a bit like that. I remember my chemistry teacher in high school saying something similar.
As mostly a math person, it kind of bugs me. There definitely is one set of rules that a field obeys, and while it’s usually necessary to simplify I’d really like to know how not to. Sure, water is mostly incompressible, but it’s not exactly so, and that’s how sound works and can translate to other mediums. And then once you get down to small scales, high energies or low pressures you start seeing the individual water molecules being relevant and doing all kinds of different things. Those factors were always there, even if they weren’t relevant.
Sorry, maybe that’s a bit of a rant, but all that to say I’m sure you can find a consensus on these questions eventually.
Using bioelectric microcurrent waves to disturb the biological metabolic reaction and structure of bacteria that forms an impenetrable biofilm
Well, it certainly sounds like jargon designed to obfuscate the actual process. At a minimum they’re relying on scientific opacity to render a buyer “convinced because it sounds smart”.
I’m always skeptical of these things. Anything that can truly destroy the biological elements that make up plaque bacteria will also likely destroy the cells in your gums. So you’re left with either a very mild human-cells safe process that is so mild that it also does little to nothing to the other things, or you actually have a dangerous process that is also dangerous to your human cells. Like drinking bleach to cure COVID… I’d rather that, if they are doing anything at all here, it’s entirely placebo (beyond the usual brushing effects).
We learned 9.82 m/^2. But in the classes I have as an engineering student we use 10 m/s^2. And I wish I was kidding when I say it’s because it easier to do the math in your head. Well obviously for safety critical stuff we use the current value for wherever the math problem is located at
Going to guess civil. I work on space systems and we don’t have one number. We have the g0 value, which is standard gravity out to some precision, but gravity matters enough we don’t even use point mass gravity, we use one of the nonspherical earth gravity models. It matters because orbits.
Interesting that I learned 32.2 ft/s, but only 9.8 m/s - one less significant figure, but only a factor of two in precision (32.2 vs 32 = .6%; 9.81 vs 9.8 is only 0.1%). Here's the fun part - as a practicing engineer for three decades, both in aerospace and in industry, it's exceedingly rare that precision of 0.1% will lead to a better result. Now, people doing physics and high-accuracy detection based on physical parameters really do use that kind of precision and it matters. But for almost every physical object and mechanism in ordinary life, refining to better than 1% is almost always wasted effort.
Being off by 10/9.81x is usually less than the amount that non-modeled conditions will affect the design of a component. Thermal changes, bolt tensions, humidity, temperature, material imperfections, and input variance all conspire to invalidate my careful calculations. Finding the answer to 4 decimal places is nice, but being about to get an answer within 5% or so in your head, quickly, and on site where a solution is needed quickly makes you look like a genius.
I gotta say, that explanations sounds way better than shrugging and saying “close enough”. But then again our teachers usually say “fanden være med det” meaning “devil be with that” actually meaning “Fu*k it” when it comes to those small deviations
Dick Tracy’s communicator watch actually seems pretty shitty by today’s standards. His didn’t have a high def LCD screen in it.
Star Trek’s PADD also seems obsolete by real world standards. Those were just e-readers. A tablet is an entire computer, and a smartphone is an even smaller, pocket size computer. There are even phones and devices that connect to phones that do tricorder like scanning of vital signs, the atmosphere, even analyzing the elements that make up an object through spectrographic analysis. Meaning we have the ability to combine the ship computer, a PADD and a tricorder into one device.
Well, the Tricorder had very advanced scanning capabilities. We can’t diagnose and cure cancer with a handheld device yet, but I did get some viral and bacterial tests done in a manner of moments by some desktop lab equipment the other week, so we’re definitely getting there.
A species of fig (Ficus, family Moraceae) from the Transvaal of South Africa was determined to have roots reaching at least 122 meters - source, google fu
Using your choice of words it would be "stable/static". Effects of gravity moves at the speed of light. Perhaps a better example would be Earth orbiting the Sun.
The Earth is 8 light minutes away from the Sun. Meaning, the sunlight we see on Earth at this exact second left the Sun about 8 minutes ago. If we wave a magic wand and make the Sun blink out of existence in a fraction of a second, the Earth would continue to orbit the, now non-existent, Sun for the next 8 minutes. After 8 minutes the Earth would stop its circular orbit and head straight out of the solar system at what ever direction it was traveling at the end of the 8 minutes.
That's amazing, thank you! A ghostly remnant of gravity still exerting 8-ish minutes of influence on earth (in the event of the sun's instantaneous disappearance) is something I never heard or thought about before, but it makes sense. It's hard to visualise it though. Like the earth is a marble circling a drain after plug has been pulled and the water is all but gone. Then the minute it is gone, the marble just keeps going in a straight line 👀
That’s amazing, thank you! A ghostly remnant of gravity still exerting 8-ish minutes of influence on earth (in the event of the sun’s instantaneous disappearance) is something I never heard or thought about before, but it makes sense.
Also for us standing on the sun facing side of Earth when the magic wand was waved would still see the sun shining in the sky for 8 minutes because that light had already left the sun before it blinked out of existence. We on Earth would experience the loss of the Sun's gravitational influence on the planet and the light of the sun at the same moment as both light and gravity travel at the speed of light.
I think it's easier if you imagine space/time like a flat plane that dips depending on how much mass the central object (like the sun for example) has. Earth circles around that dip much like your drain plug analogy. If the sun disappears, it still takes time for that dip to rise back up to a flat surface. That's the speed of gravity.
As soon as space/time begins to flatten beneath the earth, its momentum begins to turn into a straight line, rather than an orbit.
You are seeing the exhaust plume while it is still dense enough to reflect enough light from the sun.
There are several massive thermal layers in the atmosphere that effectively make isolation barriers at various heights. That is why the exhaust on the left appears unique in structure within a certain boundary. The upper layers of the atmosphere get really hot before getting really cold again. Like commercial jets fly in the cold part, but it gets hot, then cold above that. The rocket plume on the right is in that upper cold region; the outer most puffy/sparse/low Earth orbit region. You can tell because of how enormous the exhaust plume is expanding when there is very little atmospheric pressure to contain it.
There is very little atmosphere way up there and certainly not enough to produce Rayleigh scattering. If there was enough to produce Rayleigh scattering the exhaust plume would be hard to see with very little contrast against the background, but without, it makes a much higher contrast view against the mostly empty void of LEO space.
Exhaust products and a small amount of either O^2^ or unburnt. IIRC SpaceX is a fuel rich cycle, so mostly +unburned fuel.
Think of it kinda like you’re seeing an isolated atmosphere made by the rocket suspended in a place nearly without atmosphere. It is like a cloud of atmosphere in space where there is no atmosphere.
It’s mostly in the sun which is super hot without the filter of an atmosphere and how it buffers temperature. As soon is the particles are below the shadow of the Earth, they get super cold and likely freeze.
The rocket is clearly not at orbital velocity yet and that stuff is going backwards fast, so it will all deorbit fairly quickly.
You’re not seeing turbulent flow quite like what happens on the ground or what is seen in other parts of the exhaust plume because there is not very much pressure in the surrounding region to create the Eddy currents that make the mixing/chaotic flow patterns seen within another medium. I don’t think it is entirely linear flow, but it is much closer to linear flow than what happens in a thick atmosphere.
The problem would be that you would need a very heavy gas in that mixture. Which would soon unmix, with the heavy gas at the bottom and breathable gas at the top.
Also be careful with breathing even minute amounts of such heavy gasses, as they will accumulate at the lowest parts of the lungs.
I remember a TV show where they breathed such a heavy gas to show what it does to your voice (it transfomed it way down, just like helium transforms it up). They had to stay upside down after that for some time to get the stuff out again.
According to your link, this is actually used in big plants:
Vacuum distillation is often used in large industrial plants as an efficient way to remove salt from ocean water, in order to produce fresh water. This is known as desalination. The ocean water is placed under a vacuum to lower its boiling point and has a heat source applied, allowing the fresh water to boil off and be condensed.
In the US PNW coast area Douglas Fir trees are harvested for lumber within about 30 years, plus or minus. Maybe the person you were talking to was considering the harvest of the tree to be the moment when the CO2 is "reclaimed"?
Wrt to when the tree pays off the carbon footprint generated by raising and planting the seedling, I guess it's less than three years.
Fun fact: Douglas Fir reach peak carbon fixation rate at about 120 years.
I highly question this. A Dougie at 30 is about a foot across. I just took 7 Dougie’s down on my lot, the largest was 24in at chest height. I can see Puget sound from my place. In fact, I actually counted the rings on one of them and it was 101 years old. Shit. Now I’m gonna go look and measure the 30. I dyed every fifth ring when I counted it initially.
K, so at 30y/o the only stump I left in the ground was only 8.5 inches across and 20in in diameter at 101, so that’s an easy 24in with the bark. The tree was 120ft tall when I felled it in July. A real shame too, I wanted to keep all of them but fire damage. The next day beetles had already hit all of them. I dropped the trees a week after the fire and debarked them to help protect the wood before i could mill them, and there were hundreds of beetle tracks under the burned bark. Pine beetles live under the bark, in the cambium, no bark=no beetle. But the California wood wasps showed up the day I dropped the bark. Those things are terrifying, jet black, 2.5 inches long with an inch long stinger on top of that, so about the width of your palm. Adult pine beetles are about 3inches long when they emerge too. Wicked little fuckers, the both of them
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