Jump to content


Senior Members
  • Content Count

  • Joined

  • Last visited

Posts posted by ScienceNostalgia101

  1. So firefighters, when they need to get to a lower floor in a hurry, slide down a pole. They let gravity to the work, rather than their legs.


    I'm kind of left wondering; wouldn't this be a good alternative means of transport, to locations of a lower elevation? Rather than having a bunch of asphalt-paved roads leading from something high-elevation (eg. an airport) to something low-elevation (eg. a seaport) why not have; instead of and/or in addition; a pole or large slide that lets gravity do the work?


    Here are my two proposals.


    1. A thick metal cylinder, that would be secured on each end, from which customers could put their arms and legs into sleeves attached to rings around the pipe. So long as the force of friction is less than the forward component of gravity pulling them along, would they not reach their destination without the aid of fossil fuels and/or electricity?


    2. A large ramp whose top surface is of reduced friction; and/or has a cart on which people can sit, as it too slides along the surface. Assume the second sentence from #1 still applies.


    Assume for the purposes of each of the above that safety precautions; such as guard rails for the latter, or spring-loaded protective clothing for either; are available.

  2. Question 1: Would the deliberate germ exposure lifestyle advocated by comedians like George Carlin have made people's immune systems better equipped to deal with diseases like this one? Why or why not?


    Question 2: Would a food-delivery equivalent of mass transit; such as, let's say, a large, moving trolley that does curbside delivery of food parcels with recipients' names on them (be it by mechanically tossing them or leaving people to walk by and pick them up) be more likely to spread disease, or less so?

  3. Technically a TV scene and not a movie scene, but in this Simpsons scene, an avalanche buries a cabin. Homer finds out by opening the door; only for the snow that formed around the cabin to fall inward.


    1. Would the snow, once it has buried the cabin, maintain its shape even if an open window or door gives it a new path downward? Or would gravity force the compressed snow to expand again into the cabin?


    2. Wouldn't the snow outside look dark from the inside, because of the snow's scattering of sunlight? Is there any formula for light intensity as a function of snow depth?

  4. Sorry to bump this again, but I have another question; what about waterwheels?


    If one lined every river in the USA with height-adjustable waterwheels, would that be a means to convert rivers' kinetic energy into electrical energy? Could they be mass-manufactured cheaply enough to supply the USA's energy needs if one were to put every unemployed American to work manufacturing them?

  5. There are a number of things for which "bacteria-laden, but not salty" water are still useful (farming, spraying on forest fires, etc...) and in some places, like California, far more of the state's clean, treated tapwater goes to such uses than to direct ingestion of said water.


    Conversely, I presume there are things for which saltwater could be useful (bathing, spraying oneself with it as an alternative to air conditioning) that bacteria-laden water would not.


    So what I'm wondering is... would it be practical to have 2 or 3 different sets of water infrastructure, for 2 or 3 distinct purposes, as an alternative to one single one?


    For instance, suppose you had a set of germ-water pipelines; a western equivalent of Chinese tapwater, if you will. Now, I don't know whether the energy Chinese people consume on boiling tapwater to kill pathogens outweighs the energy the west uses to purge it of pathogens, but suppose we had a separate set of pipelines for water that does not need to be germ-free, and only needs to be used for farm irrigation or forest fire extinguishing. Here's one proposal on how to go about that. To summarize, you have a concave-up ellipsoid over the intertropical convergence zone to capture rainwater, and create a pressure head from the accumulation of rain, such that the water doesn't need to be pumped vertically upward. The more specific caveat, for the purposes of this thread, is that the pipelines would be attached to sprinklers both in the forest and in the farms, such that they can be opened manually by farmers, or opened automatically by heat like building sprinklers. Is this practical and/or feasible?


    For another, suppose you had a set of saltwater pipelines, piping raw seawater vertically upward, and filtering it to keep animals out, before distributing it to the masses. Now, to be honest, I'm not sure how clean seawater is, or how small a filter you would need; or whether filtration would even be enough, whether for small animals or for microbes. I know people often swim in it, but I'm not sure whether this leaves people cleaner or less clean. Would it be feasible or practical to have a network of saltwater pipelines, whether filtered or unfiltered, for the purposes of bathing, and/or in spraying oneself to keep cool during warm weather? Would this be more energy-efficient than air conditioning, or less?

  6. I say "without a motor vehicle" because I know there's light aircraft you can get that would cost an amount comparable to a personal motor vehicle. But I'm discussing this; mostly as a thought experiment; as to whether or not there's wings you could attach to your arms and achieve lift by acquiring a high enough speed without a motor vehicle. (Let's say, rolling downhill in roller blades or a skateboard or something like that. Presumably also wearing protective body armor with springs in case anything goes wrong.)


    For instance, suppose you had encased your arms in wings designed in a similar shape to airplane wings. What would the scaling effects be? Would the most efficient shape at a small scale be the same shape as the most efficient one at a large scale?


    As well, what would the scaling effects be on speed required? Assuming the ratio of wing size to body size was the same as an airplane's wing size to fuselage size, would you need, let's say, only a tenth as much speed at a hundredth as much mass or something like that?

  7. So from my understanding, paper is mostly just wood pulp, with a few other chemicals added. If trees weren't cut down to make wood, they would die in nature. If they died in nature; they would at best give off carbon dioxide; at worst give off even worse greenhouse gases like methane. (I think it's typically both, with how much of each depending on what kind of decomposers get at it?)


    So what's the deal with paper recycling? Why are we even recycling paper at all, when burning it would at worst produce the same end-result as a tree's best-case scenario in nature, and at best could be used as a source of heat energy that reduces combustion of other, less renewable materials?


    Is the issue with the fumes from combustion of chemicals in paper? If so does it depend on the paper, and how does that compare to the fumes that would be given off from some recycling truck taking the paper all the way to... wherever it's recycled? And even if it is, why is electricity considered a more efficient way to head a home than, let's say, an old-fashioned wood-stove? Again, the choice is between that tree giving off CO2 in your stove vs. that plus worse gases in nature... why is the latter considered a preferable option?

  8. I'm not sure whether this belongs in the physics of movies thread or not, but I figure I should have a spearate thread for video games given the interactive nature of the medium.




    In one part of Kaizo Mario 3, Mario is temporarily in projectile motion, until his trajectory crosses paths with a waterfall. At this point, the viscosity of his surroundings is no longer negligible, and therefore, he can push his feet downward against the water to propel himself upward.


    I assume it's exaggerated, and that one couldn't possible propel oneself to THAT extent in real life. But at the same time, this leaves me wondering whether it's possible to "slightly" propel oneself this way, or not at all because it violates conservation of momentum. I know in horizontal motion, one can swim by pushing the water back and therefore propelling oneself forward; it's a matter of encountering less water resistance when putting your hands in front of you than when pushing the water behind you. Could the same thing work vertically? Does it depend on whether one positions oneself for it before entering the waterfall or after?

  9. On 1/24/2020 at 1:39 PM, CharonY said:

    It is one of the issues that are going to be increasingly difficult to contain due to increasing mobility of folks. Right now there are ca. 800 infections and the Chinese government has restricted travel in a possibly unprecedented scale. 


    It should be noted that this at bets highly speculative. Bats are a suspected reservoir, but nothing is certain yet. A  cooked soup is less likely to be the culprit than direct contact with one. But again, it is not sure whether the virus originated from bats in the first place. It just has similarities to some known to be found in bats.

    But is eating bat or snake meat safe so long as it's cooked long enough? Is there any virus or other pathogen that'll be present no matter the temperature to which it is heated or the duration for which it's heated to that temperature?


    While I'm at it, I know it's a distinct topic, but... does the same apply to human meat? I'm not considering trying it or anything, but I know a lot of people in desperate circumstances end up resorting to it, is that safe as long as it's heated enough or is there some other reason that's unsafe?

  10. Not sure whether this is better for here or Biology, but I'll put it here for now. I assume most of you have already heard of China's coronavirus outbreak, but in case you haven't, a little refresher...




    A. So does this suggest doing farming within the city limits of a major city is more likely to spread disease than relegating the farming tasks to small towns? Does it depend on whether it's meat farming or just vegetable farming? Either way, how come China often does their farming in major cities, while in the United States, farming's considered a "small town" thing?


    B. Within the idea of farming in cities in particular, is it safer to slaughter animals before bringing them to a market, or after? Does the former risk causing insects and/or microbes to get at them faster or something?


    C. Within the latter, is it safer to cook the meat before bringing it to the wet market, or to leave the customer to cook it? Would "cooked" meat have only the illusion of safety since in an open air market insects and/or microbes could get at it?


    D. Is there any animal that's dangerous to eat no matter how long you cook it for?

  11. Another question now (sorry to keep bumping this, but it's not letting me edit the previous post now) but I was wondering another thing.


    I mentioned before the question of a concave arrangement of various small mirrors, vs. one large concave mirror, in the context of solar collectors on land. It was pointed out that in that context, it's better to have a number of small mirrors than one large one. Does the same apply to thermal solar power at sea? If one were to mass-manufacture, and then arrange into a concave pattern, a series of small mirrors, could most of the thermal energy that would otherwise fall on the Atlantic Ocean instead be captured by these solar collectors, if they were made to float in the ocean? (Presumably tied to each other and the land, to prevent them from being swept away by the currents...)

  12. Looking at various chemical reactions, I used to see parallels in acidity and alkalinity to the energy concept. Acids and bases neutralize; sort of temperatures contrasting. Acids react with metals to form neutral hydrogen and salt; but those metals would if electrolyzed would've become alkaline, so it almost looks like the "alkalinity" equivalent of latent energy. And of course, if you burn plants, the ashes are alkaline, but the gases could be reacted with water to form acids. A divergence between alkalinity and acidity, if you will.


    But then I found this.




    This person forms a strong acid; hydrochloric acid; by reacting together two substances for which neither of them are strong acids. The other product of this reaction is not a strong base, so it's not a "divergent" reaction either. Is there some sort of "latent" alkalinity contained here? If so, could something like this be used to reverse the effects of acid rain by, let's say, reacting together substances that aren't strong bases to form a strong base, with the other product not being a strong acid, therefore increasing the pH of the bodies of water?

  13. On 1/17/2020 at 7:35 PM, Sensei said:

    I am using my balcony as refrigerator during true winter (hard to get one these days).. After shopping e.g. beers and meat land on my balcony (there is -5 C at the moment).

    Before refrigerator has been created people used ice houses


    which costed nothing to operate except a while of work to gather ice.

    ps. Typical house electronic and electric devices are not designed to operate in cold and/or humid environment..

    For the record I wasn't referring to using indoor appliances outdoors so much as whether or not there's some outdoor equivalent that'd still keep it cold on abnormally warm (as far as winter goes) days.


    In any case, I was surprised to learn they manage to store ice all year, let alone through the occasional warm day within winter. I guess anything well insulated enough with enough ice in it would prevent the temperature from going too far above freezing, if only by convection. (Though I'd be terrified of accidentally locking myself in one.)

  14. Can't edit prior post. Have a new energy-saver inquiry.


    Is it more energy-efficient, in the wintertime, to have an outdoor refrigerator/freezer, such that the temperature difference between the outdoor air and refrigerator/freezer is less than that between the indoor air and refrigerator/freezer, or less efficient because an indoor refrigerator/freezer releases heat into its surroundings anyway?


    Wasn't sure whether this belonged in physics or chemistry, but being that from my familiarity with physics, heat makes objects LESS conductive, I assume it's chemistry that explains this. (And/or gives us enough to go on as to whether or not it's a hoax.)


    Starting at 4 minutes and 13 seconds in, you can see a tree branch that fell on two power lines conduct smolder; presumably from conducting electricity between them. However, it takes more than a minute for any flames to become visible. Within seconds of the flame becoming visible, you can hear audible electrical arc sounds for a few seconds before the tree branch outright explodes, turning the smoke given off from grey to brown.


    So what's going on here? Does the electricity directly cause chemical reactions that produce compounds more electrically conductive than those of the tree branch itself? Or does the smoldering cause that? As well, why the abrupt shift from flame to explosion if it took more than a minute for flames to appear?

  16. On 1/11/2020 at 5:09 PM, Huckleberry of Yore said:

    A lot of low carb treats contain "sugar alcohols" which I gather don't metabolize as sugar does, at least for some of them.  Do these count as sugars?  I'd guess yes but they don't count as digestible carbs.  I've wondered if you ate enough would you get a buzz.  Might have to eat several pounds so it's a non issue.

    Apparently there's digestive problems from them as well.




    Not sure if it'd be worth it for the buzz.


    The issue with the corn syrup thing is that the federal government itself won't call it sugar. So why the impetus to refuse to in this context even though fructose is referred to as "a sugar" in biology classes?



  17. On 1/4/2020 at 5:01 PM, Sensei said:

    How about different approach: instead of searching for a way to increase power production, search for a way to reduce current power usage?

    I forgot to reply to this earlier. I'd like to take this opportunity to ask; should this be the same thread or a separate one?


    Because I can think of some things that blur the distinction between "increasing power production" and "reducing current power usage."


    For instance, suppose that instead of throwing paper waste away, one were to burn it for heat. There are two ways I can think of for this heat to be used:


    A) Put a metal tube above the fire that does not allow smoke to enter, but allows the heat energy to conduct through, so that enclosed air molecules can warm up from contact with this surface and enter any household to which this tube is connected, or...


    B) Just directly boil water above it and use it to cook food or brew coffee.


    Would either of these be more efficient; or less; than transporting everyone's paper waste to an incinerator that uses higher temperatures to generate electricity? (Efficiency of an engine; if I recall correctly, is a strictly monotonic function of difference in temperature between the hot reservoir and cold reservoir, correct?)

  18. So a lot of companies try to get around admitting to the sugar content of their products through special pleading. They'll refuse to count high fructose corn syrup as sugar, for instance, presumably by the fact that it's technically chemically distinct from sucrose.


    This raises a key question; how was sugar originally defined? Did the original definition include all things chemically counted as sugars, or just a narrower subset of them?

  19. Water is easily the most common oxide of hydrogen. Its two hydrogen atoms for every oxygen atom correspond to the 2- charge of oxygen and 1+ for hydrogen. I would think, if only for those reasons, "hydrogen oxide" would be the most appropriate name for it.


    To cap it off, other covalent hydrogen compounds seemed to be named that way. H2S, for instance, isn't called "dihydrogen monosulfide." 


    However, I always hear "dihydrogen monoxide" referred to as the name for water when people are using it to mock environmental scares. I see two explanations for this:


    A. They're actually that ignorant about this, which would make it seem rather hypocritical to then paint environmentalists that way, or...


    B. They're deliberately misrepresenting the way chemical names work to catch people off-guard, whether to make it sound scarier than water's actual chemical name would be, or to avoid allowing anyone an opportunity to think "hydrogen oxide, eh? Hmm... what is formed when hydrogen is burned in oxygen again?"


    Is there a legitimate reason H2S is more commonly referred to as hydrogen sulfide and H2O as dihydrogen monoxide, or am I onto something here?

  20. On 1/5/2020 at 3:52 PM, swansont said:

    You would need to know the magnification to know the angles. The angle between the two points is approximately the length of the island divided by the distance to it. (The exact equation would use the arc length)

    Magnification... as in camera magnification, or is there an equivalent for "field of view" in the context of eyesight?

  21. On 1/5/2020 at 1:07 AM, zapatos said:

    If you stop the fires, how will that impact that which is dependent on fire? Is the impact an acceptable tradeoff to the benefits of limiting fire?



    Again, a network of permanent firebreaks could isolate the fire to one grid square at a time (presuming it didn't spread) but that isn't denying them fire altogether. It's just having one grid square catch fire at a time. So they'd still replenish themselves with fire, just on a smaller (if more frequent) scale.

  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.