Score
Title
378
AskScience Panel of Scientists XVII
78237
Help us fight for net neutrality!
11142
From my kid: Can you put a marshmallow on a stick out into space and roast it with the sun?
16
What would our world look like if the collision which ejected the material from which formed the Moon had not occurred? Would there be liquid water? What kind of atmosphere if any? Active geological processes? Life?
4
[physics] When I turn off my oven but leave the door closed how does the temperature cool?
3
How accurate is the usual picture of the atomic nucleus of a ball/mass of protons and neutrons? What's really happening in the centre of atoms?
42
On my bike: is it more efficient to pedal fast in a low gear or slower in a high gear?
3
How would the government broadcast an emergency message in today's world where a majority of people watch tv through a streaming service?
1
If the Earth is closer to the sun for a part of the year, why isn't that summer MUCH hotter?
1
How do you define the number of conduction electrons?
10
What makes it "impossible" as of now to detect the hypothetical Graviton particle?
9
How are Muscle Knots / Trigger Points Created at the Cellular Level?
2
Can Dark Matter be explained by scale Invariance of empty space?
17
Is deep-earth nuclear fission heating the Earth's interior?
4
How in the world could a particle have a 1/2 spin value?
3371
Hein et al (2017) have explored scenarios for sending a spacecraft to the recently confirmed interstellar asteroid "Oumuamua". What payloads and capabilities would we wish to prioritize on the exploration of this strange and peculiar object?
11
How are doctors able to determine genetic abnormality in a fetus, by testing the mother’s blood?
11
Are all prime numbers smaller than the biggest prime number discovered?
10
What exactly is the Van Allen radiation belt?
6
Why children with adenoditis fall behind in their neurophychiatric development and do they recover in that aspect after the inflammation is gone?
12
Can blue light cause cancer? What about UVA? Where is the threshold?
4
When there is a momentum transfer between two charged particles (via a virtual particle) is that transfer instantaneous?
10
Do cephalopods control their camouflage consciously, if yes how exactly can an animals thought's change it's cells?
15
How does restricting Internet work?
11
Why can't powerbanks charge while being charged?
9
Is it a coincidence that the moons rotation around its axis matches the duration for its revolution around the earth? Or is there some scientific explanation on how these aligned in such a fashion?
7
Ask Anything Wednesday - Engineering, Mathematics, Computer Science
2
Are there any advantages to Removing Net Neutrality that the consumer can enjoy and not ISPs?
4
How does your body heal cuts?
6
How do they know 'Oumuamua is elongated vs of assymetric albedo? (Bonus Question: Is the assumed rotation stable?)
1
What changes when you break the sound barrier?
10
How, or why, do refraction and dispersion occur?
2
Are electrostatic interactions photon-mediated?
2
How does Lebesgue integral put Riemann integral and discrete sums in the same theorical mold ?
25
Why are radio waves and microwaves more damaging to the human body than light waves?
14
In my Psychology textbook it says that cortisol (a result of stress) reduces telomerase activity, therefore speeding up the aging process, however, I know that exercise also releases cortisol, yet is known to combat aging - how?
2
I measured an imaginary component of Earth's magnetic field?
3
Why does water behave like a mirror?
6
Why don't electrons in a superconductor radiate away their energy?
1
Why does the index of refraction of water change with temperature?
14
Why do planets orbit in planes?
1830 Madenmann If you boil water, you'll kill most pathogens living in it. Dissolved chemicals or particulates will remain, so if you boil brown water it'll still be brown. If whatever is making the water brown happens to be a toxin drinking the boiled water is still inadvisable. However, you can use boiling the water to clean it. Catch the steam, let it condense and have some clean water. We don't do that generally because it's a rather arduous process and it consumes a lot of energy.
10285 organiker Boiling water doesn't "clean" it. It does, however, kill certain harmful bacteria, which results in water that is safer to ingest.
1418 audiyon No, boiling water only kills living pathogens that can cause diseases. Anything dissolved or suspended in the water, eg. micro-plastics, salt, lead, bleach, will not be removed and will be left behind in a higher concentration after boiling. Water has to be **distilled** for it to be cleaned of other contaminants. See also: [Boiling water for potability](https://en.wikipedia.org/wiki/Boiling#For_making_water_potable) [Distillation](https://en.wikipedia.org/wiki/Distillation)
43 UEMcGill In Pharmaceutical processing there's steam, and *sterile steam*. The two are not synonymous. You may have a processing system that is sanitized, generally free of microbial contamination and expected not to encourage growth to a reasonable limit. Things like shampoo, and lotion are made under sanitary conditions. Food is processed under a sanitary standard also. However, take that steam up to 130C and filter at .2 micron to remove solids and now you have *Sterile Steam*. This is generally assumed to be statistically free of pathogens, although there's a large and ugly formula with exponents to predict just how free something is. You can actually filter something to sterility also, and often this is the prefered method in pharmaceuticals. You may have a material that is heat sensitive, or not easily heat treated. You filter it through a 0.2 micron filter and it removes viruses, bacteria, and solid contaminants. So if your goal is to clean water, the easiest way is to filter it. This will take suspended contaminants out. If your goal is to sterilize it, you need to heat it to 130C for at least 23 minutes and for good measure filter it (0.2 micron)before you heat it. Purifying it is a different matter because different chemistry takes different steps. Things like RO and Ionic bed treatment will do most of it. But "pure" is a mater of specifying it also. There's a diffrence between 99.9% pure and 99.999%.
101 MadScienceDreams To be clear, boiling water doesn't clean it: it kills many disease causing bacteria. Their dead bacteria bodies are still in the water. In fact, a large number of bacteria survive the heat just fine. Some "sporify" - basically go dormant until conditions don't suck as bad. Any other contaminants will still be in the water. Heck, you'll probably add some from whatever container you used to boil the water. There are some really fancy filters that can filter things down to the molecular scale. And of course, there is distilling (turning the water to vapor and then condensing it back to water). Neither of these processes will give you 100 percent pure water though.
18 Iwantmyflag Boiling water will kill most bacteria, viruses, fungi and protozoa - but not all; Bacillus cereus is often found in dry rice but only in low concentrations, safe to consume. Cooking doesn't destroy it so once the rice is cooked it will start multiplying in the now wet warm rice. Boiling (in) water will destroy **some** toxins created for example by plants or bacteria but often it will **not**; Solanin found in potatoes that have been exposed to sunlight would be one example. (Many) Mycotoxins are another. Boiling will not remove heavy metals like Cadmium, Arsenic or Lead, industrial polutants like oil or microplastic, dioxins (thankfully not commonly found in water) or Trihalomethanes.
1828 0 Madenmann If you boil water, you'll kill most pathogens living in it. Dissolved chemicals or particulates will remain, so if you boil brown water it'll still be brown. If whatever is making the water brown happens to be a toxin drinking the boiled water is still inadvisable. However, you can use boiling the water to clean it. Catch the steam, let it condense and have some clean water. We don't do that generally because it's a rather arduous process and it consumes a lot of energy.
10288 0 organiker Boiling water doesn't "clean" it. It does, however, kill certain harmful bacteria, which results in water that is safer to ingest.
1420 0 audiyon No, boiling water only kills living pathogens that can cause diseases. Anything dissolved or suspended in the water, eg. micro-plastics, salt, lead, bleach, will not be removed and will be left behind in a higher concentration after boiling. Water has to be **distilled** for it to be cleaned of other contaminants. See also: [Boiling water for potability](https://en.wikipedia.org/wiki/Boiling#For_making_water_potable) [Distillation](https://en.wikipedia.org/wiki/Distillation)
40 0 UEMcGill In Pharmaceutical processing there's steam, and *sterile steam*. The two are not synonymous. You may have a processing system that is sanitized, generally free of microbial contamination and expected not to encourage growth to a reasonable limit. Things like shampoo, and lotion are made under sanitary conditions. Food is processed under a sanitary standard also. However, take that steam up to 130C and filter at .2 micron to remove solids and now you have *Sterile Steam*. This is generally assumed to be statistically free of pathogens, although there's a large and ugly formula with exponents to predict just how free something is. You can actually filter something to sterility also, and often this is the prefered method in pharmaceuticals. You may have a material that is heat sensitive, or not easily heat treated. You filter it through a 0.2 micron filter and it removes viruses, bacteria, and solid contaminants. So if your goal is to clean water, the easiest way is to filter it. This will take suspended contaminants out. If your goal is to sterilize it, you need to heat it to 130C for at least 23 minutes and for good measure filter it (0.2 micron)before you heat it. Purifying it is a different matter because different chemistry takes different steps. Things like RO and Ionic bed treatment will do most of it. But "pure" is a mater of specifying it also. There's a diffrence between 99.9% pure and 99.999%.
95 0 MadScienceDreams To be clear, boiling water doesn't clean it: it kills many disease causing bacteria. Their dead bacteria bodies are still in the water. In fact, a large number of bacteria survive the heat just fine. Some "sporify" - basically go dormant until conditions don't suck as bad. Any other contaminants will still be in the water. Heck, you'll probably add some from whatever container you used to boil the water. There are some really fancy filters that can filter things down to the molecular scale. And of course, there is distilling (turning the water to vapor and then condensing it back to water). Neither of these processes will give you 100 percent pure water though.
17 0 Iwantmyflag Boiling water will kill most bacteria, viruses, fungi and protozoa - but not all; Bacillus cereus is often found in dry rice but only in low concentrations, safe to consume. Cooking doesn't destroy it so once the rice is cooked it will start multiplying in the now wet warm rice. Boiling (in) water will destroy **some** toxins created for example by plants or bacteria but often it will **not**; Solanin found in potatoes that have been exposed to sunlight would be one example. (Many) Mycotoxins are another. Boiling will not remove heavy metals like Cadmium, Arsenic or Lead, industrial polutants like oil or microplastic, dioxins (thankfully not commonly found in water) or Trihalomethanes.