| If the electrical conductivity of silver is higher than any other element, why do we use gold instead in most of our electronic circuits? Posted: 21 Nov 2021 03:12 AM PST |
| Why makes Endometriosis so hard to diagnose? Posted: 21 Nov 2021 10:55 AM PST According to Wikipedia, "Women suffering from endometriosis see an average of seven physicians before receiving a correct diagnosis, with an average delay of 6.7 years between the onset of symptoms and surgically-obtained biopsies, the gold standard for diagnosing the condition. This average delay places endometriosis at the extreme end of diagnostic inefficiency." (source) What makes Endometriosis so hard to diagnose? Is it purely social factors ("periods are supposed to hurt a little, get over it" etc.) or are there other factors involved that complicate diagnosis? submitted by /u/SCWthrowaway1095 [link] [comments] |
| What kind of data is transferred to your computer during an internet speed test? Posted: 21 Nov 2021 11:49 AM PST |
| How much of the smallpox fatality rate was due to poor healthcare, nutrition and limited disease knowledge vs. actual deadliness of the virus? Posted: 21 Nov 2021 06:59 AM PST Smallpox killed about 30% of those it infected and the numbers were even higher among populations with no exposure. If small pox returned, most of the population would have no exposure or vaccination history. But with more knowledge of viruses and better healthcare today, do we have a sense of how deadly it would actually be? submitted by /u/badlybarding [link] [comments] |
| Why can something such as Root(-1) be categorised as an entirely new, in this case imaginary, number while 1/0 is undefined? Posted: 21 Nov 2021 09:30 AM PST This is probably a very vague and poorly thought out question but I'm curious. Basically, from my limited understanding of complex and imaginary numbers. A number which has no real solution can be manipulated and exist within things that have ramifications in the real world. Despite having no "real" solutions. What separates something like root(-1) from something like 1/0. Where one can have its own inner working where one is completely unsolvable? Could something like 1/0, 2/0 ever be computed into its own classification like negative roots can? submitted by /u/NihongoThrow [link] [comments] |
| What makes you need less oxygen when your muscles are trained? Posted: 21 Nov 2021 10:39 AM PST When you start working out, in the beginning, you gasp for air like crazy after a very short training time. But when you keep doing it it gets much better and after a while, you don't even breathe harder than normal for twice the workout you did in the beginning even with more muscles (due to the training). So my question is, do your muscles get more efficient, or do your lungs get more volume? Or is it something else? submitted by /u/srirachaninja [link] [comments] |
| If anti-matter interacts with light the same as matter, how do we know that half the galaxies we see aren't made of anti-matter? Posted: 21 Nov 2021 12:38 PM PST |
| Why do Virologist use Vero(Monkey Kidney) cells to culture respiratory viruses and respiratory tract cells? Posted: 21 Nov 2021 02:14 PM PST |
| Re: Gauge blocks. Why is the exact mechanism for "wringing" unknown? Is is Van Der Waal forces? Is this too difficult to test? Posted: 21 Nov 2021 12:32 PM PST I'm hoping someone can help. I was reading about gauge blocks yesterday and I'm a complete novice in this area so please correct me if I'm wrong. This topic is absolutely fascinating. https://en.wikipedia.org/wiki/Gauge_block#cite_note-NIST2-5 Basically, gauge blocks which are hard and ultraflat have an attractive, binding property which can join together with considerable force. The blocks can be metallic or non-metallic, like ceramic, so the force isn't magnetic. The blocks need to be joined in a sliding process called "wringing", in order to squeeze the air out between the two pieces; just banging the two pieces together won't work. Gauge blocks also need a tiny film of oil to help with surface tension. Gauge blocks can work in a vacuum, so air pressure isn't considered to be a major but is a contributory factor? Most sources online agree the force is intermolecular, but don't specify which force exactly. Examples of Intermolecular forces can include Van der Waals force, London Dispersion force and hydrogen bond forces. Van der Waals forces are extremely short range. https://en.wikipedia.org/wiki/Optical_contact_bonding However this link says: "Intermolecular forces such as Van der Waals forces, hydrogen bonds, and dipole-dipole interactions are typically not sufficiently strong to hold two apparently conformal rigid bodies together, since the forces drop off rapidly with distance, and the actual area in contact between the two bodies is small due to surface roughness and minor imperfections. However, if the bodies are conformal to an accuracy of better than 10 angstroms (1 nanometer), then a sufficient surface area is in close enough contact for the intermolecular interactions to have an observable real world physical manifestation—that is, the two objects stick together. Such a condition requires a high degree of accuracy and surface smoothness." As an interesting side note: It's accepted that Van der Waals forces explain how geckos walk up walls. They splay out long hairs on their toes which increases surface area in order to stick to the wall. When they're ready to take the next step they unfurl their toes to break the force. " Gecko's hairs are 30-130 µm long that end with hundreds of even tinier hairs of radius 0.2-0.5 µm. Because of these hairs gecko is capable of holding it's weight with only one toe of one foot." Questions are: What is the actual gap measurement between two gauge blocks after wringing? Would intermolecular forces work within this distance? If not, which of the intermolecular forces would be a likely candidate? Why is the exact mechanism unknown? Have there been no studies on this phenomenon or would testing be too difficult? submitted by /u/LorenClay [link] [comments] |
| What makes Einsteins field equations symmetrical over the diagonal? Posted: 21 Nov 2021 12:02 PM PST I've watched a lot of videos lately where people point out that the 16 equations are really just 10 because the matrix is symmetrical, but I dont understand what "physical" property actually create this effect? submitted by /u/taracus [link] [comments] |
| Does the nerve pathways in the PNS myelinate the same way that they do in the CNS? Posted: 21 Nov 2021 04:11 PM PST My understanding is that brain plasticity comes from neural pathways becoming myelinated and de-myelinated. This is how we are able to reshape patterns and behavior. Does this same mechanism apply to the peripheral nervous system? submitted by /u/Peeeats--uh [link] [comments] |
| What's the purpose of citric acid in the prostatic fluid? Posted: 21 Nov 2021 04:21 AM PST I'm studying reproductive physiology and I'm a bit confused as to why the prostatic fluid contains citric acid. Isn't the prostatic fluid supposed to be basic in order to help neutralise the pH of the vagina, since sperm cells don't do too well in acidic pH? Based on my reading + what I could find online, I have two theories: citric acid may be part of the substances in semen that the mitochondria of sperm cells use to create energy. The citric acid could be converted into citrate, which would then participate in the citric acid cycle. Alternatively, the citric acid could be helping to clot the semen following ejaculation along with fibrin + prostatic clotting enzymes. I can't find any sources that clearly discuss what exactly the citric acid is for though. submitted by /u/Lithrops [link] [comments] |
| helicopters have rear rotors to control spin, why don't single prop planes need to control roll? Posted: 20 Nov 2021 04:56 PM PST I get that the rotational torque of a helicopter's main rotor needs to be offset to prevent it the body from spinning in place--and that is what the rear rotor is for, makes sense. But in the case of a single propeller plane, why doesn't it need some smaller prop/rotor at the wingtips to help with the rotational force that would make it roll? submitted by /u/Dimsby [link] [comments] |
| Why does uranium-235 split when hit by a neutron? Posted: 21 Nov 2021 10:19 AM PST I'm writing an essay on nuclear power vs. fossil fuels in an attempt to promote advocacy for nuclear power, and while I'm looking up information something started bugging me. What EXACTLY causes uranium-235 to release energy? Is it because the neutron destabilizes the atom so it ejects it? I'm no physics expert (although I intend to pursue a degree for it in two years) and would really like to know. This is all fascinating to learn. I feel like a kid again! submitted by /u/Jedifruitsnacks94 [link] [comments] |
| How do ophthalmic medicines enter systemic circulation? Posted: 21 Nov 2021 05:32 AM PST |
| Why is it that doctors mustn't shake pfizer vacine but its is in requirements of the Chinese vacine? Posted: 21 Nov 2021 02:56 AM PST I am interested why do doctors need to gently invert vial but not shake? If they shake the bottle the vacine is not usable. This is true for pfizer and moderna, however chinese vacine requuires shaking of the vacine? What is the science behind this? This is by no means an antivaxer post, I am vacinated 😊. submitted by /u/IvoAndric [link] [comments] |
| What is the average unique antibody count for a healthy human? Posted: 21 Nov 2021 12:23 PM PST I've been trying really hard to find out how many unique antibodies an 'average human' has. I get a lot of research about the potential number of combinations (up to a quintillion according to some sources). But what about just the average number we have? I am an overworked high school Biology teacher, trying to prepare some good information for my students about the immune system (and to allow them to better understand the place of the mRNA vaccines in the fight against infectious disease. I think that students will be even more accepting of the vaccine, once they realise that it only adds one extra antibody to the vast repertoire their body already has). Thanks for any help at all and have a nice day. submitted by /u/slackslackliner [link] [comments] |
| Could we splice together all the little chunks of Neanderthal DNA in European and West Asian peoples to clone %revive a Neanderthal? Posted: 20 Nov 2021 01:37 PM PST I hear some Europeans have up to 4% Neanderthal genes. How close could we get to resurrecting Neanderthals from splicing together these gene segments? submitted by /u/JamesKPolkerface [link] [comments] |
| Can you cold weld materials that have been case hardened with nitrogen? Posted: 21 Nov 2021 05:24 AM PST |
| Does Specific Heat/ Heat Capacity correlate with heat Conductivity? Posted: 20 Nov 2021 05:12 PM PST This whole topic takes a lot of wrapping my head around it and is super confusing so bear with me Basically, if you have an Object, like Water with a higher Specific heat than another Object of the same mass, let's say Iron, this means Water can hold more Heat Energy per 1 Kelvin right? How does this relate to the Amount of Energy both substances can conduct/ emit, so the time it takes to emit 1Joule of energy from said object to another given object? How exactly do this work and does a 50°C High Specific Heat Object feel hotter or Colder to the Touch than a Low specific Heat Object? Last, of all does this also apply to colors? A Black painted Object conducts and emits heat better than a bright object like a white or silver one. does this mean A black object take feels hotter to the touch as it emits more heat faster and does this also mean a black object can store less heat energy than a white object? Thanks for any takes on this in advance! submitted by /u/DerMax_HD [link] [comments] |
