So in a symbiotic bacteria/fungi/plant ecosystem, I can understand why CO2, H2O, and O2 might be able to remain in balance. But decomposition produces not only CO2, but CO, CH4, nitrate chemistry... I have trouble understanding why this cycle isn't at least a little bit leaky, since it seems like some of the trace gasses wouldn't automatically have all of the biological, solar, and marine sinks available in nature. I would be interested to know how the internal pressure of this experiment fluctuates due to phase transitions, especially chemical reactions which could potentially produce phase transitions that are not thermally or biologically reversible in the vicinity of STP.
A sealed bottle garden thriving after 40 years without fresh air or water
61–70 of 145 posts
Re: A sealed bottle garden thriving after 40 years without fresh air or water
#62Earlier quoted context omitted.
I don't think you could get them to be consistently warm on Earth. But the atmosphere on Venus is so thick you could have a bunch of these floating above the clouds.
Maybe you could replace some of the nitrogen with helium to achieve positive buoyancy without a temperature difference.
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Re: A sealed bottle garden thriving after 40 years without fresh air or water
#63I can't figure out what would be providing more CO2. The container is near full of greenery; where does it get air exchange? Maybe the cork leaks just enough is all I can figure.
Plants suck in CO2 when they are storing energy, but when they spend their energy they make CO2 just like us. Plants have a respiration process just like animals. They just tend to remove more CO2 than they put out (until they get burned/turn into coal, oil, etc)
Right, but when plants grow, they are net CO2 absorbers -- that's what photosynthesis and carbon offsets and "planting trees" is all about. There's a lot of carbon in those plants -- did it all come CO2 from the original supply in the bottle?
Re: A sealed bottle garden thriving after 40 years without fresh air or water
#64Earlier quoted context omitted.
I can't see how decaying plant matter would provide enough CO2 to keep the larger greenery healthy. Perhaps the original soil had an exceptional amount, but it would take time for it to break down; plants can empty a container such as that of CO2 in a day or so.
Isn't it how the world worked before animals evolved? Or is there some yet another source of CO2?
The world has a much lower plant:world ratio than that bottle does.
Re: A sealed bottle garden thriving after 40 years without fresh air or water
#65I can't figure out what would be providing more CO2. The container is near full of greenery; where does it get air exchange? Maybe the cork leaks just enough is all I can figure.
From what I understand the container was sealed 11 years after the initial planting. I guess all the carbon entered from the atmosphere before the final watering in 1972. The total biomass must have remained roughly constant since.
Re: A sealed bottle garden thriving after 40 years without fresh air or water
#66A clear balloon containing an ecosystem would heat up due to the greenhouse effect. If it's sufficiently large and allowed to slightly expand it could float freely in the air. Imagine closed gardens flying freely around the world.
I don't think you could get them to be consistently warm on Earth. But the atmosphere on Venus is so thick you could have a bunch of these floating above the clouds.
It really depends how big you are. A 5C difference in temperature in a sphere 5m in radius will easily hold a weight of 10kg.
Or like mikeash replied, you can replace most of the nitrogen with helium.
Re: A sealed bottle garden thriving after 40 years without fresh air or water
#67I can't figure out what would be providing more CO2. The container is near full of greenery; where does it get air exchange? Maybe the cork leaks just enough is all I can figure.
Bacteria in the soil. One of the reasons Biosphere 2 fell apart.
> Biosphere 2 fell apart
Wait, what's this? What happened?
Re: A sealed bottle garden thriving after 40 years without fresh air or water
#68My coworker had a smaller version of this in his cube. His son had made it in middle school and it had been going for 10+ years. I think his was sealed with wax or something.
It's an easy experiment to reproduce and works great if you have enough time to wait around.
Re: A sealed bottle garden thriving after 40 years without fresh air or water
#69I can't figure out what would be providing more CO2. The container is near full of greenery; where does it get air exchange? Maybe the cork leaks just enough is all I can figure.
Exactly, where is the plant mass coming from? Can bacteria break soil down into carbon that the plant can use to build more leaves/stems/roots?
The container was last watered twelve years after it was planted. Twelve years is plenty of time for most plants (especially something many people would consider a weed) to reach that size. At this point it's simply in maintenance mode - similar to a bonsai which never requires trimming.
Re: A sealed bottle garden thriving after 40 years without fresh air or water
#70Earlier quoted context omitted.
Bacteria in the soil. One of the reasons Biosphere 2 fell apart.
> Biosphere 2 fell apart Wait, what's this? What happened?
Biosphere2 was an experiment to seal humans and plants i to a dome and not open it for some time.
Fungus and other pests destroyed some important plants and the eco system collapsed.
It had been built in the middle of a desert but urban expansion means the site is reasonably near housing now.
There were a bunch of photos of the dusty derelict interiors floating around a few years ago.
I kind of wish people would try again, just becuase.