[cerealbad]

isn't the universe expanding at an accelerating rate? if the problem is excess planetary heat, you can use thermosynthesis to accelerate novel thermogenesis in pseudo-living species - imagine endothermic sea sponges cooling the oceans and helping to repopulate at risk ocean animals.

"this thing humans do cannot continue" is a weak argument. everything humans do is some expression of the natural state of conditions in their immediate environment, technology is just another convolutional cycle on top of the pre-existing ones, squeezing more efficiency from the raw resources existing there. the planet is not in balance, and ecosystems are not fixed. things are in a state of glacial flux with periods of extreme instability due to various cycle renewals - volcanic, tectonic, asteroid/comet impactor, solar, geomagnetic symmetry breaking, viral.

'man made causes' are a misnomer, they are just accelerated selection events, man happens to be a global selector for almost all living things, and man activity on the planet can be a mass extinction event due to many scaling factors, the most obvious one being the technology cycle mentioned previously, the efficiency it provides can be simplified to 'making more heat'.

it's easy to fall prey to goldilocks thinking - due to limited information and the tyranny of the present. try to think in terms beyond a human lifespan. look at the progress achieved in the past 300 years. if we wanted to we could spend the next 300 years returning earth back to a pre industrial epoch and wipe from the surface of the planet all traces of the modern advanced civilization we created, not by a cataclysm or destructive war but by planned intentional decolonisation. given that its possible and very likely to happen (perhaps a catalyst is required, like a new global religion) over the past 300k-1my this maybe happened multiple times. humans are still here in some form or another and they will continue to be here into the foreseeable future x10 my's, because they have shown capable of surviving (milankovitch scales, 100k, 41k, 23k years).

technology is dominant and makes the smartest humans think in brittle ways. the people shaping rocks for millennia were not stupid, they were just incapable of thinking beyond their stone paradigm. pretend to be a godlike alien silently watching the world from the largrangian point in the earth-moon system. millions and billions of years go by. once life begins on earth it continues into the present, the idea that humans, in the next few thousand years, will somehow pose an unconscious risk to a process that has survived and morphed for billions of years is a misreading of the story. what COULD happen is another mass selection event, where a human bottleneck eliminates 99.9% of all living things. that happened before and it's part of some larger cycle that humans are necessarily a part of (as living things) and what is considered causal could also be simply an expression of a deeper reason for living things to exist - to out compete other living things and monopolize the space available to them.

is the physicist a finitist? seems like he substituted growth which is the economists mantra, for change which is his. predicting the future is a waste of time, as an agent in the world you will either cause the future or be slave to it despite your best efforts either way. if it is knowable it will be unchangeable, given all your free actions will lead to the known outcome. it is clearly unknowable and therefore ununchangeable - since the capacity to measure any deviation or change does not exist. what will occur is as likely to occur or not occur had you participated or not.

my pet theory is that any time you see people attempting a cross-disciplinary leap of faith their parachute often fails to open. good 20th century examples being james watson and william shockley - both making the tempting leap from (bio)electrical systems to socio-communication ones, leading to self-embarrassment. the only interesting problem for the 21st century is how do you transform knowledge from one domain to another and retain it, the only way humans will survive their own extinction without reverting back to barbaric primitivism is to plasticize expertise and mass produce it.

[drdeca]

> if the problem is excess planetary heat, you can use thermosynthesis to accelerate novel thermogenesis in pseudo-living species - imagine endothermic sea sponges cooling the oceans

Uh,

Thermodynamics.

You can’t destroy heat, just pump it around.

A heater does not need to expel cold. A cooler needs to expel heat.

Stuff can feed on heat gradients. Things cannot feed on uniform heat.

[cerealbad]

a seebeck generator can exploit airflow above or depth below oceans to convert heat into electricity. what uniform heat? all human heat effects augment the existing temperature cycles which have baked in gradients. thermoelectric processes simply reverse this, it would cause a lot of rain and raise ocean levels as the excess atmospheric water vapor is returned to a liquid state- due to the transformation of heat into electricity which would be stored or used to move the little sea robots around.

is the sun uniform heat? how do ectothermic animals and plants using photosynthesis work? I'm not sure why you think you can magically break thermodynamic symmetry...

[drdeca]

A seebeck generator “converts a heat flux into electrical energy” (Wikipedia), it does not convert heat into electricity.

(Edit: by which I mean, it does not decrease the total amount of heat in the system.)

You need something colder on the other side.

The sun-earth system is not uniform in heat, no. The sun on average is hotter than the earth on average.

Edit: what thermodynamic symmetry are you referring to?

[cerealbad]

the mechanism that generates heat is reversible, that's how we got fossil fuels to begin with (hydrocarbon storage). if you think converting heat flux into electrical or mechanical energy doesn't reduce the total heat flux of the system then it's a perpetual motion engine? you get more energy out than you put in? think it through.

it's powered by a heat differential, you are draining the heat from the system and storing it or dissipating it under motion - reducing the overall flux - over time by cooling the hot side and heating the cool side eventually some equilibrium is reached, depending on how efficient the throughput is and how much heat you have, you then exhaust your temperature gradient and need to move somewhere hotter or colder.

one of us is very confused here. i claim "you can reduce heat locally in the earth system", and give examples: capturing and insulating it (trees, plants), converting it into other types of energy (genetically modified sea sponge/robots), as well as venting it into space through an atmospheric/orbital seebeck ring.

im not breaking any laws of thermodynamics, i am turning the planet into a refrigerator.

edit: to clarify i am claiming it's possible to move heat away from the habitable thin boundary layer by conversion: storage, mechanical use or venting.

[drdeca]

I agree that converting heat flux (or, uh, temperature gradient? I think I might actually mean temperature gradient) into electrical or mechanical energy reduces the amount of heat flux ( or temperature gradient) of the system.

Reducing the temperature gradient(s) of the system does not reduce the amount of heat in the system. When the temperature gradient decreases, that just means that there isn’t as much variation in the temperatures in the system. The temperatures become more uniform. When the temperatures are uniform, you cannot use the temperature in order to do useful work.

.. I now notice that I missed that you mentioned putting things into orbit?

I misunderstood and thought you meant putting the seebeck stuff in the ocean, as if that would cool down the oceans.

Yeah, if you pump heat into places that you can remove from earth, or have emit black body radiation more effectively, that would help.

But, Unless you are ejecting stuff away from earth, there is still a max rate you can radiate away heat at a given temperature? Oh, but, hm, if you made your thing in orbit really really hot, hm.

Is that what you were saying?

Sorry for misunderstanding what you meant about the ocean.

[cerealbad]

i did mean the ocean originally, you have heat sponges which sit near the surface and use the gradient between air flowing above the surface, the hotter temperature above, and the cooler temperature of the ocean. the sponges can use the heat to move or they can trap it like charging a battery so you transform heat into kinetic or chemical energy. it occurred to me that a third way is to build a ring that uses the heat exchange between the layers of the atmosphere and space, using the same ectothermic biological principle.

talking about the earth as a system here is a bit of a misnomer. the core up to the mantle is very hot, but that heat only escapes to the surface through lava tubes/vents because the tectonic plates are good insulators. im specifically talking about the part of the earth we care about affecting the temperature of - and you can do this by shifting the heat up, down, storing it or converting it. the atmosphere is more permissive than the hydrosphere, hadal zone or crust.

it's easier to imagine the earth as a ball and things leaving the surface as exiting the ball system. but really when we talk about the earth it's more like a layer on a ball, and if you go deep into the ocean, underground or exit the atmosphere it's all the same type of thing.

as far as i know the climate cycles are a surface feature of the planet, deep underground is more inaccessible to our technology than reaching another star system.

the term is called geosequestration.