Recent comments in /f/askscience

Kattin9 t1_j8966k6 wrote

Reply to Do different types/colonies of ants have different architectural characteristics from one another? by RollOverBeethoven

Hi, in the mid1980s as a master student, I kept species of several genera like Tetramorium, Myrmica, Lasius in captivity. Clear glass clad with red foil, in a frame as housing. A space of 3mm between the glass plates. This housing allowed very clear observations. The architecture or shape of the holes in sand between the glass plates was different for each of the genera kept.

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duhvorced t1_j88h2il wrote

Reply to comment by SnekkyGlekky in Will a 400m long tube have breathable oxygen inside? by SnekkyGlekky

Since this is clearly not a hypothetical based on your other comments…

  • what is the nominal purpose of the tube? Drain pipe? Irrigation?
  • Is the tube open at both ends?
  • Is there any sort of airflow through it? (Take a handful of dirt/dust, let it fall directly in front of the tube opening, watch dust carefully for signs of air movement.)

If the tube is open, at that length I would expect the natural conditions (temperature and pressure differentials) to create a natural airflow, in which case it’s almost certainly breathable.

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Efficient-Damage-449 t1_j88e01u wrote

Reply to Will a 400m long tube have breathable oxygen inside? by SnekkyGlekky

Multiple posts have detailed how this can go off the rails and be a bad idea. Yes, it is a bad idea. But if the tube is open there is probably a pressure and temperature differential on both sides so there will most likely be a nice breeze keeping the air fresh. At least there will be a breeze until there isn't one.

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Kenna193 t1_j87zhbr wrote

Reply to comment by mhmyfayre in What are some of the mechanisms behind why long term physical inactivity and social isolation leads to chronic health diseases? by [deleted]

It can reduce appetite, not will reduce appetite.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5086738/#:~:text=When%20skin%20and%20the%20eye,reduce%20appetite%20and%20food%20intake.

Take this with a grain of salt though, there are studies showing that sun exposure can trigger food seeking behavior. I believe msh is more effective and working in concert with leptin when increasing satiety.

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vettrock t1_j87xteq wrote

Reply to Will a 400m long tube have breathable oxygen inside? by SnekkyGlekky

A tube that is open is going to be filled with air. How much of that air is exchanged, and how long you are in the tube are factors. If there is wind/fans you are probably fine. Also how long are you sitting in the middle? If stagnant, and there is other rotting material, it becomes much more problematic.

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colcob t1_j87vtch wrote

Reply to Will a 400m long tube have breathable oxygen inside? by SnekkyGlekky

In a hypothetical situation in which the tube is inert, clean, empty and open and one or both ends, then yes it will be full of air of the same constitution as the surrounding air.

In a real life situation where it could be full of rotting stuff, degraded materials etc. then at 400m long and 0.6m diameter it’s very possible that air contaminants in the middle could be build up enough to be hazardous.

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Swissaliciouse t1_j87vncy wrote

Reply to Will a 400m long tube have breathable oxygen inside? by SnekkyGlekky

Technically & hypothetically, yes. There is no reason why you can not have substantial airflow through this conduct. especially through a hill you easily can have wind or heat differences that creates a pressure difference leading to airflow.

From a risk analysis point of view: No it will not always be safe. See many of the other answers.

In reality you use blowers to make sure that the air insides such a tube is indeed ambient air.

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Captain_Poodr t1_j87qspm wrote

Reply to Do different types/colonies of ants have different architectural characteristics from one another? by RollOverBeethoven

Oh yeah. But I wouldn’t call it culture, more like pheromone-evolved instinct. With a sprinkle of geographic determinism.

Different regions have varying soils and food sources available to the ants. Much like humans and early cement, the little civil engineers have to make it work with what’s available. Sand is more often used to make mounds. Loamy soil is easier to dig into and has enough integrity to support multiple layers of underground networks.

Some ants have invented the ant toilet. Or rather a designated spot where they all put their poop. Some use their poop to grow fungal gardens. The queen will take a bit of the garden from her original colony with her in her mouth to start another when she goes off to found her own colony, like a sourdough starter. For real.

In the Amazon there are some wild examples of specialization (as the Amazon do). Leaf cutter ants make mega-cities and create ant “highways”. Fire ants build bridges with their bodies. Bullet ants are so metal they don’t really bother building nests and just inhabit trees.

All of this, and pretty much everything ants do, is driven by pheromones and instinct. I hope we get to see a further exploration into the relationship of ant DNA variation and pheromone response in our lifetimes. Only 2.5% of leaf cutter colonies founded by a new queen make it, selection is happening at a genetic level. Whack.

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