It’s all sorts of fish-related detritus. You can use your yucky fish water to water your plants and they will love you for it, fish pretty much poop finished compost. Like rabbits.
Likely a person will, like livestock, put on less LEAN weight and be smaller in size. Quantity and quality water results in higher yields in all domestic livestock.
In this case, a very strong eruption ejects kids of super hot gas and rock upwards, like when you open a shaken bottle. After some time, pressure will decrease, and gravity will start dragging things down again.
Unlike a regular soda bottle, heat is significant. Hot gas rises in the atmosphere against gravity. During this rise, it loses energy ( so it cools down). When it reaches a high enough temperature where the lifting momentum is overcome by gravity, it starts falling again.
As the top starts to fall while there still is more material below in the column, the column gets compressed. As the center of the column is the hottest part, it still pushes material upwards. So the colder material falling from the top is pushed outwards, widening the column a bit. It also encounters the cold air outside and starts cooling even more itself, falling ever faster in the outside “ring” of the column. It still is only “cool” compared to the rising inner column, still thousands of degrees. Also, all the light glasses will have moved further up the atmosphere and either fall slower or not at all. This is where the long term effects such as your mentioned ash fall/ rain comes from. So most of the rapidly falling material that then form pyroclastic flows are actually fairly heavy liquids/solids and heavier-than-air gasses. They only seem so light and fast inside a pyroclastic flow because if their immense temperature and contained energy.
However, sooner or later the falling material encounters the ground, a solid obstacle. As the inner column is densely filled with super hot, probably still rising fresh material, the only possible way is outwards. And with continuous pressure from above from all the falling material, the material needs to move out of the way very rapidly. This is not dissimilar from how water behaves that flows from a bottle or faucet and hits solid ground. But a pyroclastic flow is a bit more viscous, and still very hot. While moving outwards, it quickly has to push away the cool, resting atmosphere. The only way for the air is to step aside upwards. Now, as the cold air likes to stay close to the ground and was compressed, it forms a seemingly paradoxical barrier layer of cold, dense air above the pyroclastic flow, pressing down on it, even squeezing it further outwards. This together with it’s own viscosity means there’s surprisingly little turbulence between the two layers, with the hot flow continuing to rush along below the cold barrier layer instead of mixing and rising through it upwards. If this interests you, look up inversion layers: they are a normal phenomenon in regular weather as well, especially winter time, and can sometimes even last many days.
Consider that ash columns reach many km in altitude, filled with many tons of material. It doesn’t all fall slowly at the same time. It’s literally rock falling from high atmosphere to the ground, carried by heavier-than-air gasses that also want to sit below the atmosphere.
Excellent question. From first principles: mars is about 1.5 AU from the sun. Using the intensity equation (inverse square law), Mars should receive about 1/(1.5x1.5) the amount of solar radiation, or about 44% on average.
Earth gets about 1400 W/m² hitting the top of the atmosphere, but most places on earth only see about 1000 W/m² after the column of air absorbs a bunch of it. Martian air absorbs almost nothing (being very thin), so you’d expect to see about 44% of 1400W/m² – or about 600W/m².
A quick Google search for “mars solar intensity” shows a result of 590 W/m², so that is pretty close to accurate, from first principles.
So 60% as bright, if talking pure intensity. As you say, the human eye has a pretty responsive dynamic range, and this is quite an acceptable number.
For point of comparison, this is the difference between the sun at high noon versus the sun at 4pm for most of the world. On Mars, high noon would have a solar intensity more like 4pm on earth. No where close to your darkness experience with the eclipse.
With regards to the eclipse it would depend on how much of the sun is covered though. I’d assume it’d about the same as you’d get during a partial eclipse when the sun is 40% covered?
Since you answered it, I figured I’d add that on the dark sides, Earth and Mars likely have similar light levels(ignoring the moon and light that’s bent through the atmosphere)
Mars is 1.52 AU from the sun, or 1.52x further than Earth, so the inverse square law says 43% less sun power. But the atmosphere is thinner and a different composition.
To know how the human eye actually operates on Mars, one would have to get a human eye to Mars.
I guess I meant more about how well you'd actually remember the brightness on earth after being on route so long rather than your eyes physically adjusting
This is more in line with what I was asking. The sun seems to have a psychological impact on humans. I wonder what that impact would be under both relentless cold conditions, but also when the sun never quite feels the same.
I mean, it is obviously subjective and not critical to the functioning of life or anything like that, but it just seems like one of those very subtle “death by a thousand cuts” kinds of elements that might become noticeable over time.
I don’t think anyone would directly perceive the effects in a binary logic kind of way. It would be like times when our local region is covered in thin high atmospheric clouds for weeks on end. It becomes more noticeable over time that this amount of light is not normal. I wonder about that awareness of “this is not normal” having more long term impact on psychology, not profound impacts, just some impact. I thought maybe someone had already posted images somewhere on the interwebs exploring this, but haven’t found any.
It’s toxic, but a useful reference point: tungsten hexafluoride is one of the densest known gases in existence. At a density of 13kg/m^3 at standard temperature and pressure, it is nearly two orders of magnitude shy of being dense enough to bring a human (~1000kg/m^3) to neutral buoyancy.
Compressing a gas to nearly 100x it’s natural density is going to dramatically increase it’s temperature. In simplified mechanics, you can basically think of it like all the energy that makes it the temperature it is naturally will still be there when it is 1% of it’s original size. So all that energy is “overlapping” and adding together to make it’s new temperature based on there being 100x as much energy in each place now. Even if it started at 10 degrees Kelvin, assuming a linear gain, it would be 1000 degrees Kelvin after compressing.
Of course all of that is super simplified and not the “real” math or mechanics in all their complexity. But it should help illustrate why it would not be possible or a good time.
And that is only the temperature half of it. Compressing an area to 100 atmospheres, which I’m presuming would be the level of pressure necessary to get that gas (or a safer slightly less dense one) to the needed density range, would also be pretty dangerous if not immediately fatal to the human. Again that level of pressure is assuming a linear gain, I don’t know for sure if it would be linear.
So even if you manage to find something you could breathe, you wouldn’t be able to at that level of pressure. You would need to be wearing a suit that can be pressurized and breathing from something that isn’t feeling that pressure. Which completely defeats the whole point of choosing a medium to be immersed in that doesn’t require a suit or tank like being in water does.
It is however, theoretically possible to breathe liquids. Just incredibly uncomfortable for humans. There are humans that have survived it in experiments. After an initial adjustment period where your brain is certain you are drowning for a few minutes, eventually you are able to over ride that when you don’t die. Then you can hang out for a bit not dying despite it seeming like you should be… and then when you are done breathing liquid, the terrible part starts, you have to get the remaining liquid out of your lungs so there is room to put air in them again. As much as the rest is not great, transitioning back to air was universally considered the worst part of the experiment.
You’re talking about adiabatic heating, which is where temperature changes due to change in pressure, without heat transfer. If we thermally isolate the gas as we compress it, the temperature will rise.
We don’t have to insulate it. We can allow the heat to transfer out of the gas as we compress it. Heatsinks on the pressure vessel will pass the heat from the pressurized gas into the ambient air until their temperatures equalize.
Since we can add or remove heat from the gas after it is compressed, the temperature of that gas is only relevant if it falls below the boiling or freezing curves, allowing the gas to condense into a liquid or solid.
You could likely fly using human power on Titan. It has a 50% denser atmosphere than earth as well as only 14% of the gravity. While that’s not neutrally buoyant, it is enough that if you had some big wings attached to your arms you could generate enough lift to fly by flapping. Comic by XKCD about this topic.
Of course, Titan is also insanely cold, so you’d need a pressure suit, which might throw off the calculation.
This also reminds me of a scene in Arthur C Clarke’s 3001: The Final Odyssey, a relatively less well known sequel to 2001. In this scene there are enormous space elevator towers that house humanity, and in the upper floors where there is low gravity they have a pressurized flight room just for the fun of it.
We have pressurized areas in microgravity today (space stations), which would obviously give you neutral buoyancy. Not a whole lot of room to maneuver around though!
Well that just kicks the can down the road, and is also probably not accurate. People move today for better jobs, to escape warzones, because they like a country’s laws, and more reasons. Most of those reasons didn’t apply to hunter gatherers living thousands of years ago.
Really? What if the better hunting grounds were taken? What if a rival tribe kept harassing another and people just didn't want to fight? What if the ambitious youth didn't agree with the tribal leaders, so they moved to make their own fortune?
At our core, we really haven't changed all that much from our ancestors.
Could really be the same reasons for them too.
People moved for better hunting/grazing areas. To escape areas of warfare. They didn’t like the tribes rules, and more reasons.
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.
I wonder if the Sahara turning into a desert could coincide with a mass migration. It used to be lush once upon a time we believe. But I can’t remember the timings of the two, so I’m purely speculating
New research indicates that Homo erectus likely capitalized on a “greener” corridor through the Sahara Desert in northeastern Africa, which was wetter and more vegetated than it is today, during their migration out of Africa. Climate cycles aligned to create this green passage, facilitating their journey.
Apparently the desertification of the Sahara is cyclic.
Approximately every 20,000 years, the Sahara transforms into a savannah covered with lush grasses due to the angle of the Earth’s axis changing. This axis change causes the position of the North African monsoon to shift, a monsoon that could revive the Saharan region. (source)
Here’s a graphic on the timings of early human migration. They list two migrations northeast, one occurring 120k years ago and another 100-90k years ago.
I don’t see how anything non-Newtonian would be better against sudden sounds. In fact it would be worse, as they’d get more solid and thereby transmit MORE of the noise you’re trying to block out. Or maybe they only get more rigid but their sound transmission properties don’t change at all. Either way, sounds somewhat pointless.
The only way I can think that something like this would work would be to have a molded vacuum chamber as an ear plug, with a specifically engineered sound transmission bridge inside. With too much energy trying to go through, it would break. But I doubt it would be quick enough to be effective, and they’d also be one time use, and extremely fragile.
It’s a bit oversimplified, actually. Sound bounces off of discontinuities in the medium, which is why foam works. You just have to control the scattering somehow.
The big problem with using oobleck or whatever is it responds to shear, and shear can’t travel through air. You could use it for earthquake protection, though, or if you could channel compressive waves from the air into shear form using a fancy bridge like in OP.
There are lots of strange options besides newtonian fluids. Would be interesting to see how dilatant, peusdoplastic, thixotropic etc react to sounds. Perhaps there is a way to make a material that allows quiet sounds to pass through and blocks all the loud ones. My guess is that dilatant liquids should be a good candidate.
A quick search tells me this have to do with shear forces. Sound would be entirely compressive, so those material properties would have no effect, or at least not change due to sound levels.
That’s unfortunate. Just like OP, I would have really liked the idea of using a non-newtonian fluid to filter out certain types of sounds without using electricity. Well, I guess, we’re back to active noise canceling then.
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