Undigested bile acid from the ileum being in the colon because of diarrhea?

So, really, you're one layer of an infinite relativistic spacetime-baklava of matter approaching the singularity...

That's more like saying relativistic effects mean that any matter that fell in less than infinity years before you is going to be between you and the actual singularity. It's not that the neutron star is 'in' there, it's that it can't ever finish falling in before you catch up with it's trailing edge...I think?

Kinda way out on a limb there. Can anyone help out if that's totally wrong?

Oh, yeah, it's actually pretty widely agreed that most stars are in multiple systems, although I have no idea how many of those are on the scale of thousands or more AUs. Close-in binaries and trinaries churn everything up in such a way as to ensure planet formation doesn't really happen, according to lots of simulations and some pretty solid first principles physics justifying all of that.

I think we don't have enough depth of data on even the best-known exoplanetary systems to really answer your question the way you mean it, but there are some things we do know, and some interesting comparisons and generalizations we can make because of that.

First off, a little cursory review of the data says it's actually 99.86% for our system, or only 14 parts out of 10,000 of the mass in the planets, not 2%. Of that 0.14%, around 70% is in Jupiter (and 20% in Saturn, and around 3-4% each in Neptune and Uranus).

That means ~98-99% of the mass outside the Sun is in the gas giants. THAT makes your question much more complicated, but also much more interesting!

The amount and composition of mass outside of the parent star, in a planetary system, is probably controlled mostly by what the protoplanetary nebula which the star and planets accreted/condensed from was like, very broadly. How dense the gas and dust was, what it was made of, how fast it was moving relative to other gas and dust and neighboring stars' stellar wind, the influence of shockwaves from supernovae, and so on. If you make cloud of matter dense enough, it makes new stellar systems, and what they come out like depends on what the cloud had in it and exactly how everything was arranged when it got nudged.

With that in mind, we can guess a lot about this from the star(s) that result by looking at the spectra of their light. Stars with more elements past Helium have a higher 'metallicity' (formal astrophysics term), which we can just measure from the gaps in the light wavelengths from the star. If there's more oxygen, nitrogen, carbon, silicon, iron, and heavier elements in a given stellar system, it's likely that it has more planets, period, but also more rocky planets.

Back to that 98% of the mass being in gas giants...well, if that's normal for a star the size, age, and metallicity of our Sun, there are a LOT of astronomical scenarios where metal-poor stars could have many gas planets, or a high-metallicity star could have had local orbital dynamics (in a binary/trinary stellar system) that meant no large planets could form at all, and ~100% of the mass in the system is in the star (or stars), or doing its own thing in some other object's gravitational influence after being flung away billions of years ago.

One important thing we don't know is how many planets are too small, too highly inclined in their orbits, too distant from their star, or otherwise undetectable by current methods in any given extraplanetary system. The thing is, if we're talking about 0.14% of the mass of the system, it could vary hugely and we wouldn't know from the effect on the parent stars. The wobble from Hot Jupiters face-hugging their parent red dwarf stars is teeny tiny. There might be planetary systems facing us flat-on with their ecliptic planes, too, among other things.

So, I guess that's a long way of saying 'it appears other planetary systems are similar to ours, but we have no way of knowing if that's because it's true, or because it just looks that way from the available data.'

All of that said, we're collecting an incredible quantity and quality of new data now, so a lot of this will be less...entirely based on physics simulations and extrapolating from what we can observe locally.

Many rock types are fundamentally the same -- basalt on the Moon, Earth. Venus, and Mars is all pyroxene, olivine, and plagioclase feldspar. It weathers into different minerals depending on the environmental conditions, so Martian sand is going to be different from Earth sand (unless you pick a weird place on Earth) in some subtle ways, but it's ultimately a pile of little pieces of the same minerals, just with some textural differences and maybe different trace minerals mixed with it.

Earth also has a lot of life and water. You won't find soil in any recognizable form except here. That's a mix of rotting plant matter and what we call regolith, or the powder to gravel sized pulverized rock that all solid planets have some form of at the surface.

So, you'd encounter familiar minerals and rocks making up texturally odd usually super dry sediments in weird contexts, to summarize.

The temperature does vary, but less than temps do just going from one part of Mercury to another.

1. Mercury has no appreciable atmosphere. This means the temperature rises and falls very quickly in response to changing light levels/solar energy.

2. Mercury rotates very slowly (59 days), so that heating remains extremely uneven.

So, on the dark side, it's actually probably close to the same exact temperature no matter where the planet is in its orbit. On the light side, it might be tens or more of degrees warmer when it's closer to the sun, but there's no global 'climate' to shift, if that makes sense?

Still I bed and don't have my glasses on yet, so I'm going to have to punt those requests to others.

The blackbody radiation is indeed choppy from solids, just with so much noise that it appears mostly continuous when measuring the spectra from sufficiently geometrically complex surfaces.

Real atoms have individual electrons at specific energy levels. A true perfect blackbody emits EVERY energy of photon along the curve, real matter in our universe can only do it at discrete energy levels on the curve. Some elements have bigger 'steps' between certain parts of the spectrum. Thorium collects and then reemits a lot of visible photons, other elements have spikes in the IR or UV range, some have only very small divergence from a blackbody Planck curve. The elements which make 'extra' visible light are inherently superior things to heat up to make light as a result.

So, you know how there's a 'fire triangle' for combustion? Oxidizer, fuel, heat (and ignition)?

I'd say there's another one for complete combustion: even mixing of fuel and oxidizer, sufficient but not overabundance of ambient airflow to equilibrate volume change by exhaust gases from combustion reaction, and sufficiently high total concentration of oxidizer and fuel in flame environment to maintain combustion with the energy released by the reaction.

In a normal fireplace, or a gas furnace, none of these conditions are met perfectly throughout the region where combustion is happening. (It's quite good in modern, to-code gas appliances compared to a wood fire or a really sooty, misadjusted propane burner, however).

For example, that means there are regions where there are oxidizer and fuel (usually the gaseous reactants) are well mixed, but too dilute with ambient air to burn. Other regions might have too much fuel and not enough oxidizer because of turbulent mixing with the ambient air, but plenty of heat, so the fuel will undergo reducing reactions instead of oxidizing, which turns hydrocarbons into hydrogen (which will burn somewhere in the fire) and carbon (which is soot), and then that carbon is able to cool before it's mixed with enough oxygen to combust.

Imagine trying to mix two colors of cold wax in a pot on the stove just by heating it up and letting the bubbling and boiling do the work. That's about the best a wood fire can hope for in terms of even mixing of the flammable gases coming off of logs and coals with the air it needs to combust. There are all sorts of pockets of reducing and oxidizing environments in there, and as a result you get soot as well as weird, icky nitrogen compounds which give us smog etc.

I don't know where you're going with this, but you have my hexwrench in this battle, friend

Puget Sound in WA state is a good exception to this, because the water is less salty and probably because the constant rain keeps the air from getting brackish.

Seriously, cars don't rust here. Sunroofs leak and mildew destroys them from the inside, but the green algae usually scrubs right off to reveal shiny clearcoat....

Then you go 50 miles west to the actual Pacific coast, and everything you say about rust is true again...

Either one requires a rigid ring or hollow sphere that can be evenly 'balanced' around the central star or planet in (usually) a rotation equal to a circular orbit at the sphere's equator. Closer to that ideal spin rate, the less the ring/sphere tries to implode or throw itself apart. Unfortunately, it still needs fantastical materials to be rigid enough even if it's perfectly spun for the ring, and the sphere's poles present a massive problem...

The best explanation I've heard is that all it takes is a population living with environmental access to vitamin C and enough time for mutations which interfere with synthesis of it to...not do anything, and get baked into the genome, to grossly oversimplify.

You don't need any advantage for a given mutation to continue, just survival. Advantageous ones lead to new body plans, behavior, and different ecologic niches, but 'neutral' or 'negative' ones that don't get the carrier killed before reproducing are stuck with your population. If the environment makes a negative mutation irrelevant, all the more reason it won't self-regulate out of the gene pool. If most of the species ends up with it, this way, then it becomes a problem to either adapt or become extinct over when external conditions change.

More likely, it was finished (ground, sanded, polished) differently either on purpose or as a side effect of manufacture (some bullion is just left how it cools in the mold, other bars are hit with torches to melt the surface and get it to re-puddle glassy smooth on the side that was down in the original casting, etc. etc).

That said, sure, different non-gold alloying metals (silver vs copper vs rhodium etc.) can affect how readily a lower-karat gold polishes, I guess, but you're probably seeing a variety of finishes/surface textures independent of the gold content, from what little you gave us to go on?

I'd argue that boosted fission bombs don't count as 'a-bombs' since they use physics only understood because of huge thermonuclear tests in the 'h-bomb' era. And they use fusion, of literal hydrogen isotopes, even if it isn't a major contributor to the explosive yield.

I've found myself in situations where between the light, the clouds, snow on the roads, and trees, you can quite literally feel like you're chasing our buddy Kulshan for a photo-op if you head up the Baker Highway too late in the day, too late in the year, from Bellingham...

Pardon the barely detectable difference in gravitational acceleration out of me. What is your problem?

Are you familiar with the hydraulic analogy in E&M? And how it's not perfect for all behavior in actual electrical circuits?

My analogy isn't perfect for the effect of many randomly dispersed tiny point masses (certainly <kg, we have to agree?) on the orbits of planets (10^20-25 kg?) around stars, but I get the intense impression that you're actively refusing to see how it might be useful in someone trying to understand undergrad-level astrophysics in spite of it not being a perfect analogous model for the nature and distribution of dark matter in and around our galaxy.

Yeesh.

Woops, you were right about that velocity, but I don't think you not understanding my analogy for Newtonian gravitation really has anything to do with OP's question, either. You're absolutely right that dark matter isn't in clumps, but to detect it at all ever, it has to be less homogeneous than, say, the cosmic microwave background. I made the analogy to show how little distant, diffuse masses affect orbits.

I mean, I'm gonna try my best to be there, too, but I feel like you don't have to go as far as I do :)

I think there are good odds that there could be lava and a total solar eclipse at the same place and same time in western Iceland in August of 2026, based on the eclipse path and what I know about the current volcanism...

The 'unlimited reagents' is kinda the thing that makes it trivial/uninteresting.

It's not only possible to know the sum amount you need of each element, if you know how much of each starting compound you have, you can estimate the energy input (or output) of the reactions to get from A to B regardless of which steps you take, depending on which parameters you vary and the type of thermodynamic system you're modeling.

The anatomy was named before they understood the evolutionary relationships between living reptiles and birds and extinct non-avian dinosaur lineages. There were dinosaurs unrelated to those which evolved into birds which had hip anatomy which looked similar to the hips of modern, living birds, so they described them as the group with 'bird-like hips,' not knowing how confusing a hundred more years of paleontology research would cause the name to become.

So, birds have bird hips, not lizard hips, in a purely descriptive sense that ignores established terminology, but these 'bird hips' are not hips of the type that put them in that named and defined group of extinct dinosaurs. Those modern bird-like bird hips happen to be descended from the hips of dinosaurs which had hips that didn't look as much like modern birds' hips at the same time as there were dinosaurs which, coincidentally, happened to have hips grossly like modern birds', despite not being direct ancestors of birds.

Coincidence, lack of current knowledge when anatomy was named, and the classic problem of taking descriptive morphological terms to imply origins, which is really the terminology's fault. Is this hip business really any more confusing than that we use the 'saur' affix which means 'lizard,' literally, for non-lizard species? Lizards are a specific thing, and dinosaurs (pardon the term) aren't lizards....but nobody's complaining about that term, are they? Because they were named when nobody knew any better, and we all acknowledge and agree that the name means they're like lizards, but real big and scary-like, to keep the term useful, not forget the literal etymology, and finally not ignore the newer science.

Evolutionarily, investing the time and resources while the offspring are gestating, after birth, or before fertilization is probably as good as the same thing. At least as far as K-strategy etc terminology is concerned, right? One new tarantula hawk per tarantula is a strategy based on it working most of the time, vs sea turtle hatchling death gauntlets for a vertebrate opposite example.

How fast you're spinning and your electrical and magnetic(?) charges might be enough to make you identifiably unique from a different black hole of the same mass, right?