Activity for Pastychomperâ€
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Edit | Post #287831 | Initial revision | — | almost 2 years ago |
| Answer | — |
A: Do plants need ambient oxygen? Yes. All plants require free oxygen, and any (part of a) plant that is not actively photosynthesising has to obtain its oxygen from its environment. We owe our oxygen supply to the fact that, on average, plants produce more oxygen than they consume. Plants respire in much the same way as other ... (more) |
— | almost 2 years ago |
| Comment | Post #286180 |
Thanks, I've corrected it. (more) |
— | over 2 years ago |
| Edit | Post #286180 |
Post edited: Corrected vertices -> edges as per Jacob C's comment |
— | over 2 years ago |
| Edit | Post #286180 |
Post edited: Added eclipse |
— | over 2 years ago |
| Comment | Post #286180 |
Thanks, that's an excellent point. (more) |
— | over 2 years ago |
| Edit | Post #286180 | Initial revision | — | over 2 years ago |
| Answer | — |
A: If this earth were cube shaped would it be possible during Magellanic era using a float ship to figure out that the earth is cube shaped? The shape of the Earth is mostly a result of its gravity pulling its mass into the most efficient shape available. The oceans are also pulled towards the centre of mass, and collect on the lowest parts of the surface - covering a huge area to a depth of only a few miles because the planet is so smoo... (more) |
— | over 2 years ago |
| Comment | Post #286002 |
I don't have the equipment to "tr[y] the proposed solution" but find the answer entirely believable. Thanks. (more) |
— | almost 3 years ago |
| Comment | Post #285985 |
That's a very good point, not least because spacecraft designers would probably be able to choose non-flammable materials for most of the contents (although that hasn't always been done). Still I'd be interested to know if it would work in a less mass-constrained setting. (more) |
— | almost 3 years ago |
| Edit | Post #285985 | Initial revision | — | almost 3 years ago |
| Question | — |
Could a high-pressure, low oxygen atmosphere reduce fire risk while still being breathable? Years ago I read a letter in a magazine suggesting a method for reducing the fire risk in an enclosed environment such as a space shuttle. The idea was to reduce the oxygen concentration to the point where most common materials won't readily combust, and compensate by increasing the pressure so that... (more) |
— | almost 3 years ago |
| Comment | Post #283630 |
The "how" could be an interesting thread in itself. Possible methods I've heard of include sequestering greenhouse gases and covering huge areas of ocean in white material to reflect more sunlight. Both would need to be done on a vast scale, making them effectively sci-fi for now, but I wouldn't ru... (more) |
— | about 3 years ago |
| Comment | Post #282568 |
Thanks, I've added links to both. (more) |
— | about 3 years ago |
| Edit | Post #282568 |
Post edited: Adding the Dubai projects |
— | about 3 years ago |
| Comment | Post #284240 |
This probably won't help in the near future, but it looks like the light would last longer if you could slow it down as it bounces between the mirrored sides. Something like Bob Shaw's fictional "slow glass" would be ideal, but there have been some real-world experiments that slowed light to a few m... (more) |
— | over 3 years ago |
| Edit | Post #282568 | Initial revision | — | over 3 years ago |
| Answer | — |
A: Digging Depressions in seafloor to create artificial islands in nearby areas Small islands have been built in inland waters since prehistoric times, but using sea floor material to build an offshore island is a much larger project. As Peter Taylor and JBH have pointed out, it has been done) twice off the coast of Dubai. Both those projects have been monitored for erosion an... (more) |
— | over 3 years ago |
| Edit | Post #282199 |
Post edited: Fixing markup |
— | over 3 years ago |
| Edit | Post #282199 | Initial revision | — | over 3 years ago |
| Answer | — |
A: Creatine supplementation as enhancing the natural production of Carnosine and vice versa Possibly, but I think it's unlikely, except indirectly. Exercise increases natural carnosine levels, so someone who both takes extra creatine and uses the energy to increase their exercise level probably would have increased carnosine. I don't know if creatine production is also increased in re... (more) |
— | over 3 years ago |
| Edit | Post #281591 |
Post edited: |
— | over 3 years ago |
| Edit | Post #281591 | Initial revision | — | over 3 years ago |
| Answer | — |
A: Repetitive head-hair removal and lab-grown head-hair planting I assume proper hygiene to prevent post-implant infections, which would otherwise be the biggest risk. Presumably the lab-grown hair needed some hormone(s) to stimulate its growth. There's a chance that this will also increase the risk of a tumour forming in one of the new follicles. If the hormon... (more) |
— | over 3 years ago |
| Comment | Post #281056 |
The Aral sea (actually a lake) shrunk because the rivers that fed it were diverted for a Soviet irrigation project in the 1960s. This was an unusually large-scale project with an unusually drastic result. I gather from Wikipedia that water is extracted from rivers feeding the Caspian, but they have... (more) |
— | over 3 years ago |
| Comment | Post #281153 |
Formaldehyde is an ingredient in some nail treatments, it makes the nails harder by creating cross-links between strands of keratin. Since these "keratin treatments" also involve formaldehyde I suspect they do the same thing to the keratin in hair - the hot bar straightens the hair and the formaldeh... (more) |
— | over 3 years ago |
| Edit | Post #280412 |
Post edited: |
— | almost 4 years ago |
| Edit | Post #280412 | Initial revision | — | almost 4 years ago |
| Answer | — |
A: Plausibility of "multi-type transmissible animal cell tumor" to form more complex structures. For the cells to act exactly as described would require cooperation between different metastasising cell lines, both during infection and when growing structures in the new host. That implies a kind of control not usually found in a tumour. Even a simple tumour tends to grow into an amorphous mas... (more) |
— | almost 4 years ago |
| Comment | Post #280267 |
Good points. I don't think the problems I described stopped them being used for horses, either. (more) |
— | almost 4 years ago |
| Edit | Post #280376 | Initial revision | — | almost 4 years ago |
| Answer | — |
A: How do you establish identity when people can change their appearance at will? Short, easy-to-read gene tags. Since all modifications are reliably policed, you can require that every modification includes a short, non-coding DNA sequence containing the recipient's legal identity. For good measure they could add the date, the serial number of the clinic, and maybe a regulato... (more) |
— | almost 4 years ago |
| Comment | Post #280267 |
Years ago I was told there was a problem with rfid chips used in racehorses because it was easy to remove a chip from one horse and hide it in the mane of another to let the second horse temporarily impersonate (imequinate?) the first. It might be worth looking to that industry for pointers if you g... (more) |
— | almost 4 years ago |
| Comment | Post #276352 |
Chlorophyll is about 30% efficient at converting light energy to chemical energy, but only at certain wavelengths. The lower whole-plant efficiency figures that get quoted are due to that limitation compounded by things like limited CO2 and water availability, and the suboptimal collector orientati... (more) |
— | over 4 years ago |