The potential energy of the spring is “stored” in individual molecules that are pushed into some configuration that they don’t quite want to be in, and they exert force on each other trying to push themselves back apart / back together into being the way they like. As the spring disintegrates, you could model those individual forces, and molecules exerting force on each other would release it into kinetic energy one by one or in groups, as the spring gradually lost its integrity to exist as a singular entity.
(I think that in practice, metals are made of grains, big groupings of molecules which stay pretty much as rigid bodies unless something really crazy happens, so most of the potential energy is force of the grains wanting to go back into their preferred arrangement in relation to other grains. I.e. not in practice at the level of molecule to molecule. But I’m not 100% on that part.)
Depends. If the antennas were resonant dipoles placed some fraction of a wavelength away from each other (1/4 wave away), you may get some cancellation of the signal.
Look up the “yagi uda” antenna, it’s the classic rooftop tv antenna. The elements are spaced by fractions of a wavelength to achieve directivity. One single element is driven, the others are just resonant lengths of wire.
Fully-aquatic mammals that I can think of, like whales or dolphins, aren’t furry, so I’d say that while fur may be a net positive for animals that spend some time out of the water, it’s probably not because of their time in the water.
It’ll increase drag, which means that they have to expend more energy to move through the water.
It might have some insulation benefit, but I’m not sure how significant that is in water, and I’d guess that fat is probably preferable in that case.
My guess is that the main benefit is for outside water.
First, thermal insulation, where the fur limits convection of air, so you get air pockets, which doesn’t conduct well.
Second, as a disposable, dead layer, it also provides protection against UV light and such. We don’t think of living out of water under the direct radiation from the sun as being particularly difficult or the environment harsh, because we casually do it every day, but it was a very hard problem for life to solve.
Ourasphaira giraldae is an extinct process-bearing multicellular eukaryotic microorganism. Corentin Loron argues that it was an early fungus. It existed approximately a billion years ago during the time of the transition from the Mesoproterozoic to Neoproterozoic periods, and was unearthed in the Amundsen Basin in the Canadian Arctic. This fungus may have existed on land well before plants.
I know that when people are moving dolphins and whales around, they keep them covered, partly to keep them wet, but also because they will suffer badly from sunburn if not done. This dolphin had a lot of its skin get destroyed and fall off its body after being exposed to the sun for some hours:
Second, as a disposable, dead layer, it also provides protection against UV light and such. We don’t think of living out of water under the direct radiation from the sun as being particularly difficult or the environment harsh, because we casually do it every day, but it was a very hard problem for life to solve.
Oh yeah, that’s a good point! I’d typically be more concerned with the drying out part for a lot of aquatic life, forgetting about the UV exposure issues.
The required temperature depends on the mass of the particles you’re considering. You could say photons are always relativistic, so even the photon gas that is the cosmic microwave background is relativistic at 2.7 K. But you’re presumably more interested in massive particles.
If you apply the kinetic theory of gases to hydrogen, you’ll find that the average kinetic energy will reach relativistic levels (taken to be when it becomes comparable to the rest mass energy) around 10^12^ K. For the free electrons (since we’ll be dealing with plasmas at any sort of relativistic temperatures), this temperature is around 10^9^ K due to the smaller mass of the electron. These temperatures are reached at the cores of newly-formed neutron stars (~10^12^ K) [1] and the accretion disks of stellar-mass black holes (~10^9^ K) [2], but not at the cores of typical stars. Regarding time dilation, an individual particle’s clock would tick slower from the perspective of an observer in the center-of-mass frame of the relativistic gas, but I don’t think this would have any noticeable effect on any of the bulk properties of the gas (except for the decay of any unstable particles). Length contraction would probably affect collision cross-sections, though I haven’t done any calculations for this to say anything specific. One important effect would be the fact that the distribution of speeds would follow a Maxwell–Jüttner distribution instead of a Maxwell-Boltzmann distribution, and that collisions between particles could be energetic enough to create particle-antiparticle pairs. This would affect things like the number of particles in the gas, the relationship between temperature and pressure, the specific heat of the gas, etc.
You mention the early history of the Universe in your other comment. You can look through this table on Wikipedia to see the temperature range during each of the epochs of the early Universe, as well as a description of what happened. The temperatures become non-relativistic for electrons at some point during the photon epoch.
I think pretty much everything on land would be different: plant induced precipitation, river bank stabilization, carbon sequestration changing the climate and the timing/duration of ice ages and hydrocarbons being ignited by flood volcanism events. All of that would be gone, could even rearrange whole mountain ranges over time by by altering the pressure of glaciers ice on tectonic plates.
I’m hanging cannibalism on the end of extreme, but intending on the broader scope of most extreme behaviors. It is easier to approach than the sexual and predatory counterparts.
Like if there is no potential “greater” social authority likely to interfere, is there a population density that determines overall accountability? Is it the randomness of personalities and spectrums? Is there any evidence of a change over time and social evolution?
They are hard questions. I wonder if any observational evidence exists around the various dwindling native groups that exist(ed) in various degrees of isolation. It is also a question of how fixation, paranoia, and anxiety may have evolved in the human species over time. It would be really interesting to be able to contrast this kind of behavior potential now versus the deep past.
Neat! That’s a very specific, chain-like example, though, so not really in the spirit of the question even if correct to the letter. I’m also not sure what it does in the actual plastic deformation regime.
First it goes into the water, then it goes to the ground, which normally filters it very well. BUT if this is generally a polluted area, and also depending on the composition of the earth, it may not filter it at all. We assume that there’s some filtering though.
Now it gets really country-dependent. Some countries filter the tap water very well, some adds chlorine to ‘cleanse’ it, and some may not do a very good job entirely.
I’m no expert in which countries around the world do what, but it’s probably something you can look up for your area.
Generally though, it’s worse for you to inhale (unless the water is just polluted in other ways)
Thanks! You’re right that I wasn’t thinking about chlorine which does get added to the water where I live. I suppose that doesn’t entirely kill all germs and pollution going into the water, but it helps getting rid of it.
Also, yeah. When I am out breathing pollution, it feels really bad for me
Just a non-scientifc opinion: I think it binds to the rain/the humidity and does go into the ground, yes. Depending on where your water comes from, it might not seep into that, I think. And stuff in your lungs may be worse than the same stuff in your stomach, depending on the stuff, I guess.
What I really came to say: the only long term solution is guillotines
I suppose guillotines help in a variety of situations, though I would have not imagined them as an extreme way of filtering the lack of actions by politicians and corporations towards the environment 🤔
Just an amateur opinion: If we think of science as a beliefsystem (a system to arrive at a close approximation of truth), it is much more adaptive than any other explanatory system. I think for that reason alone it will ‘win’ in the long run, but emotional systems will carry on/blossom in some form or another as societal breakdowns occurs, or if Science incentives gets compromised by ideology/money, thereby resulting in less trust.
If we look at what science already know, some Physicists, (carrol etc) believe we already have an ‘engineering corpus’ of everything we see on a daily basis, but as soon as we look at the edges of non-human scales/focus there’s a lot to find yet.
Even if we ever find a theory of everything and know all the primary forces, we still need to learn all the ways these forces can be combined, and we cant readily predict ‘interesting phenomenons’ down the line from an algorithm, so exploring will continue in our current reductionist exploration, but will perhaps pivot to a more holistic exploration. Steven Wolframs ‘ruliad’ is supposed to contain all possible combinations of everything and all their derivations (forgot the def. ;) ), and he talks about theoretical science realms that we will have a hard time even seeing/understanding. Some argue that the primary forces also varies across the universe. Chaos theory argue that it will take endless energy to collect endless dynamic data - even if we compress it into math/axioms etc. All exploration of chaotic space will take time to compute. Also, If we want to utilize our knowledge we need to either store/retrieve, or compute based on data/algorithms. In Billions of years this use/pursuit of knowledge will cost a lot of energy.
There’s a lot to think about in such a question, but it’s interesting how we can send shit to other planets, but we completely lack the knowledge/technology to manage a large ecosystem, or organize our self in a way where we don’t harm each other or our habitat. The first is very easy compared dynamic systems. I don’t think we’ve even scratched the surface of what our dynamic systems can do for us if we learn to tame them.
Anyway, in the long now, thousands of years, I think the system of Science will evolve, improve, but we will not reach 42. There will always (billions of years) be combinations of forces that we cant predict easily and some we have to explore/create to discover/enjoy.
When Science ceases to be useful as a method to discover and explain things.
But on a more specific note, that’s impossible to answer, because you would have to know what that finite set of “knowledge of everything” is, if it is indeed finite. Since we can’t know what the upper limit of “what is knowable” is, it’s impossible to even roughly project when we might know almost everything.
To complicate matters, you can’t even break the problem down. How about half of everything? A third of everything? One-tenth of everything? How much do we currently know compared to those subsets? We simply don’t know.
And what if we discover other dimensions? Or what about another universe? What if there’s infinite universes to discover? Knowledge is emergent as a result of doing science, so as long as there’s something we don’t know, we’ll have scientists out there doing science (or whatever its successor is).
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