| How do eyelash microorganisms get to a newborn? Posted: 14 Feb 2022 07:50 AM PST All people have eyelash microorganisms, but I don't think they are born with them. How do they populate a newborn? Edit—I was referring to the mites that exist near eyelashes, but I'm also curious about other microorganisms as well! Thank you for all of these detailed and thoughtful responses. The human body is cool: submitted by /u/ablarimer [link] [comments] |
| Is there another pair of animals that reverse hunter and prey in their lifecycle? Posted: 13 Feb 2022 04:19 PM PST Question from my 4th grader. The dragonfly nymphs prey on tree frog tadpoles, but grown tree frogs can hunt dragonflies. Is there another pair of animals that reverses these roles? Thanks in advance. We were watching a video on National Geographic kids if you want to share this with your kids. submitted by /u/greg_d128 [link] [comments] |
| If you were to hold a strong magnet very close to your body. Would that magnet have an influence (if any) on our bodily functions over time? Posted: 13 Feb 2022 07:13 AM PST |
| How valuable is sterilization of a knife used to cut raw chicken? Posted: 14 Feb 2022 10:04 AM PST The guidelines for cleaning a knife after cutting raw chicken typically advise to sterilize with something like a chlorine bleach solution after washing with soap and water. Conversely, the guidelines for washing your hands after handling raw chicken are to thoroughly wash with soap and water for 20-30 seconds. If washing with soap and water is truly sufficient to ensure your hands are not a significant disease vector for something like salmonella, why does the same not hold true for a knife blade? submitted by /u/burf [link] [comments] |
| Why do lighter Olympic ski jumpers have longer jumps? Posted: 14 Feb 2022 11:24 AM PST In research for a presentation on the topic I came across this study which simulated jumps, keeping ALL factors (velocity at takeoff, drag and body size, angle of fall, air density, etc) constant, and changing ONLY body mass. They found a direct relationship between body mass and jump distance, with lighter simulated athletes attaining longer jump distances and more airtime. How is this possible? If you have two objects of the same size and drop them from the same height, they fall at the same speed. So why is it that when body size, air resistance, angle of flight, etc are all held the same, mass still influences jump distance? I know that the athlete's trajectory has a horizontal component as well as a vertical. So from my understanding, mass shouldn't affect the vertical component (acceleration due to gravity). How does it affect the horizontal component, when takeoff velocity (the forward acting force) and air resistance (the inhibiting force) are held the same? I'd really appreciate any help with this, I'm totally stumped-- but to be fair, my understanding of physics is pretty limited (I'm in health sciences). Thanks in advance! submitted by /u/forestfortuity [link] [comments] |
| How are natural instincts explained on a fundamental level? Where do they originate and how are they inheritable? Posted: 13 Feb 2022 07:12 AM PST How are instinctual behaviors inherited? Would they survive in an animal raised in isolation from others of its same species? I find complex behaviors like intricate web, hive, and nest creation particularly fascinating. submitted by /u/Artane_33 [link] [comments] |
| Why do some animals hop instead of walking? Posted: 13 Feb 2022 07:54 AM PST Some birds, rodents, marsupials etc hop rather than stride, but not all. What is it that makes it a better way to move for only certain members of the species. Why is it always one or the other and not some mix? Are there any examples of it being individual case by case rather than across the board for that animal? submitted by /u/cl0th0s [link] [comments] |
| Did Ice Stay At the Poles Year Round During Pangea When all the land was concentrated in the tropics, How Did That Affect the Weather? Posted: 13 Feb 2022 05:09 PM PST |
| What happens in a photon-photon colliding when each photon energy is 120 Mev? Posted: 13 Feb 2022 10:28 AM PST Hello, I am a 17 y.o stduent who is trying to fully understand photons colliding. We usually know that when two photons collide and each one's energy is 0.511 Mev they produce an electron and a postiron and this idea is the same for other particles. But what if two photons with an energy, which is not equivalent to any other particle, collide? What would they produce? Or would they even collide? Like for example 120 Mev. Thank you very much. submitted by /u/vizex9 [link] [comments] |
| Given the constant tectonic movement, will there someday be an 8th continent? Posted: 13 Feb 2022 08:55 AM PST |
| Does an acquired immune response (e.g. to a virus) get stronger when it is “used” to successfully defend against that virus in subsequent exposures? Posted: 13 Feb 2022 09:19 AM PST |
| What is the chemical and anatomical difference between the muscle tissue that makes up crustacean meats like crab & lobster vs. vertebrates including cattle, poultry, and fish? Posted: 12 Feb 2022 06:34 PM PST |
| Protocooperation and Facultative Mutualism difference? Posted: 13 Feb 2022 08:30 AM PST As the title suggests, can someone please explain the difference between these two positive relationships between organisms? As I understand both have the same meaning - a type of interaction where both parties benefit but isn't essential to their survival. submitted by /u/Hris22 [link] [comments] |
| Why is cerebrospinal fluid salty? Posted: 13 Feb 2022 02:13 AM PST I would've thought that the reduced Ψ outside of cells would've been damaging but I feel like I'm missing something extremely obvious, a bit of a mental block really. submitted by /u/detonater700 [link] [comments] |
| How is Sodium Polyacrylate able to absorb water? Posted: 13 Feb 2022 03:21 AM PST Through reading, I can see that it has something to do with the osmosis between the Sodium and the water and the cross-links between the chains to keep it all together. Is anyone here able to explain it to me in more depth or provide me with some high school friendly resources where I can understand more about this (maybe diagrams)? submitted by /u/Zombie_Chickenz [link] [comments] |
| Do Species of different genus mate? Posted: 13 Feb 2022 12:10 AM PST I'm not talking about closely related species like lions and tigers but things like fur seals and king penguins. It's so fucked up that its interesting submitted by /u/EstablishmentShoddy1 [link] [comments] |
| I was always taught that you get stronger when exercising because your muscles "tear" and they repair by adding new growth. Recently I learned that a certain muscle cell metastasizes, leaving one copy for future use and the other copy embeds into the muscle. What exactly happens for muscle growth? Posted: 12 Feb 2022 07:11 PM PST |
| Is there expansion in gravitationally bound space? Posted: 12 Feb 2022 06:09 PM PST I was just reading a layman's article about expansion, that it is observed in largely empty space but not in gravitationally bound areas like galaxies. Do scientists believe that there actually is no expansion in that bound space? Or do they believe that space does expand in those areas, that gravity holds the mass together while the new space expands out past it, and that as a result expansion is not observed? submitted by /u/movtga [link] [comments] |
| What was the Arctic Ocean like during the peak glaciation? Posted: 12 Feb 2022 07:46 PM PST The oceans were smaller when a lot of the water was locked away as ice on land, freeing up great expanses of continental shelf. But the deep ocean remained liquid. That much I understand. But some things are confusing to me:
I know there are undersea ridges similar to the mid-Atlantic Ridge in the Arctic Ocean. And I know the sea was saltier.
1) Was the sea ice thinner, because of the higher salinity? (Is the Arctic ice cap frozen salt water all the way, or is it mostly fresh water because fresh water freezes out of solution? Does new precipitation continuously added to the top make the ice cap basically fresh water anyway?) Or was it thicker, because the climate was colder?
2) Did the polar cap rest on the ocean floor? Was the ice cap grounded in places, like on the Langseth Ridge?
3) Did the lower sea level mean some of these undersea peaks were islands during the glacial periods? (For that matter, were there lots of islands, like Iceland today, along the Mid-Atlantic Ridge?) Thank you! submitted by /u/whyareyouwhining [link] [comments] |
| How does conservation of energy allow or prevent a spring system from regaining energy? Posted: 13 Feb 2022 03:29 AM PST I'm not sure if you are familiar with a safety lancet , basically its something like this https://m.youtube.com/watch?v=YwpJc6Ii8OM Just wondering if the safety lancet in the video could somehow : 1)be fired (by being pressed down onto someones skin) 2)compress itself back to a near fully compressed state after it reached its maxed extended state and started returning(>99%, almost no losses whatsoever like extremely extremely small) where the plastic hooks could hold it back in place (imagine the spring rebounding and the hooks being allowed to return to their original position because the user has stopped applying pressure to the persons skin thereby allowing the hooks to return to their original position therefore recapturing the spring in its original position)*** Best example i can think of is an automatic gun where the firing pin is ready to strike the primer of the bullet again without manually compressing the hammer like in a revolver , i know a gun uses the recoil from the cartridge explosion to reload just the closest thing i can think of All this without any other intervention , solely the device as it is. Maybe some sort of system with extremely low losses? So low that the spring is retracted to almost the same height as it started from. I know there would be a ton of calculations to get the spring to return just as the hooks were returning back ot their original position , just wondering if this is possible. In my head if the losses were extremely small to the point you could barely even see the losses this would be possible because the hooks would recapture the spring replacing the energy lost to friction and piercing of the skin , but i have minimal knowledge of physics & engineering and wanted to ask the experts. Not trying to design a reusable lancet. Just want to know if its possible. I know safety lancets are for the most part designed to be single use. I just feel that if the losses were extremely small it would be possible Apologies for the lengthy and long winded question just wanted an answer with explanation behind it rather than "nope" Thank you for any time spent answering the question submitted by /u/funkymonkey123444 [link] [comments] |
| How do we know that the brain stops developing at 25? Posted: 12 Feb 2022 04:54 PM PST |
| Where do great white sharks give birth? Posted: 12 Feb 2022 12:27 PM PST |
