| /r/Science X-Post: We are mental health professionals and researchers with expertise in Black mental health, racial identity, and race-based trauma. Let’s discuss! Posted: 05 Aug 2020 09:09 AM PDT |
| If space is expanding, are more units of space being made, or are they getting "bigger"? Posted: 05 Aug 2020 06:27 PM PDT My knowledge of quantum field theory is very tenuous and high-level - I have basically no clue about the underlying math here - but my rough understanding is: - the universe, particularly the empty bits, are expanding due to some unexplained force we call dark energy
- quantum field theory basically implies that if you drill down far enough there is some minimum quantum of space, and it has a sort of energy or potential energy (vacuum energy?) of its own
So if space is expanding, are more quanta of space being created? Or is existing space stretching in some way? IE - is the ratio of quanta of space to the size of the universe steady or changing? Either way, doesn't this mean that more energy is being created out of nothing? How does that work? Or am I off the mark with the space quanta thing? submitted by /u/sarapsys [link] [comments] |
| How is the yield of an explosion calculated after the fact? Posted: 06 Aug 2020 12:58 AM PDT Seeing reports of the Beirut explosion being multiple kilotonnes of TNT and just wondering how they figure that out? Is it just a formula given the crater and blast radius or what? submitted by /u/hugglesthemerciless [link] [comments] |
| (NSFW) Where do turtles hide their penises? Posted: 05 Aug 2020 10:20 AM PDT |
| What limits the minimum size and yield of Fission Bombs? How small can they theoretically be, and why no smaller? Posted: 06 Aug 2020 03:03 AM PDT |
| Are false negative rates on virus test random? Posted: 06 Aug 2020 12:41 AM PDT So I was reading about the false positive and false negative rates of the Covid test here in Australia, however my question isn't to discuss Covid specifically. My question though, is do we expect that each of the false results has an equal proportion of happening for each test (ie random), or are there factors that drive the results; ie if someone has one false negative result, are they more likely to return more false negatives? Is there a chance that whilst someone may carry a disease, that the sample draws from a non-infected portion of the test medium; ie is there a chance that the sample medium is non-homogenous, such that the taken sample, may have a significantly lower portion of the target than other parts - is this different for saliva vs nasal swabs vs blood etc? If these are factors, what controls are used to minimise the problem - either in test design or administration protocols? submitted by /u/ForumUser013 [link] [comments] |
| How can we be sure the universe is what we see? Posted: 06 Aug 2020 03:54 AM PDT Ok, the universe is expanding and it is accelerating (Hubble, Doppler effect, red shifting and so on). I understand all that. But, according to science, with time, the universe will be expanding faster than light (or something like that, due to dark energy, I guess). Galaxies will be getting away from other galaxies faster than light, so that whatever life form that exists in the future in our galaxy (which will become Milkdromeda) will have no way to know about anything outside the local group. The local group is bounded by gravity, but dark energy "wins" in the bigger picture. My question is: how do we know that hasn't already happened? How do we know the universe isn't way bigger than we imagine, but there is no way to detect those faraway galaxies and groups of galaxies? How do we know the obsarvable universe, which we estimate to be some 13.8 billion years old and 43 billion light-years in diameter (or more, who knows, I have just googled that number up), isn't like the local group that we except to have in the future? Because if that is so, than I think our calculations about the big bang, the age of the universe, the mass of the universe and everything else would be wrong. To sum it up, how do we know there aren't things we cannot even detect by any means in the universe already? Things that are in this very moment moving away from us faster than the speed of light light (due to dark energy, quantum fluctuations or something - i am not a physicist). And in the case the answer is "we know, but not with great certainty", wouldn't it be possible for the big bang calculations to be wrong? submitted by /u/pajavu [link] [comments] |
| Does "pi" (3,14...) contain all numbers? Posted: 06 Aug 2020 03:52 AM PDT In the past, I heart (or read) that decimals of number "pi" (3,14...) contain all possible finite numbers (all natural numbers, N). Is that true? Proven? Is that just believed? Does that apply to number "e" (Eulers number)? submitted by /u/placenta23 [link] [comments] |
| How big are modern nuclear bombs? Posted: 06 Aug 2020 03:12 AM PDT The RDS-220 hydrogen bomb known as "Tsar Bomba", is the biggest nuclear bomb to ever be detonated, with a blast yield of 50 megatons of TNT (210 PJ). That was back in 1961. How large are the biggest nuclear bombs in 2020 likley to be in comparison? Also, how would they be stored and what would happen if they were left alone for hundreds of years? Could they ever self-detonate? submitted by /u/MinorSpider [link] [comments] |
| Why does radiation stay in one place? It seems like it clings to humans and objects, and is obviously in the air, so why doesn't the wind blow the fallout all over the world? Posted: 05 Aug 2020 11:16 PM PDT |
| How do ants communicate with one another? Posted: 05 Aug 2020 05:20 PM PDT I saw an ant and it's far from its nest. I purposely dropped a few drops of water in its path. It drank for a while before another ant came by. They touched each other and it continued back on its way. After 10 minutes, a entire line of ants arrives at the water droplets. How do they all know? submitted by /u/Enceladuus [link] [comments] |
| If sand is being pulled out to sea and beaches are shrinking because of it, how are there still beaches left after millions of years? Posted: 05 Aug 2020 06:42 PM PDT |
| Climate change experts, why does an increase in temperature of 2 Degrees Celcius pose such a threat? Posted: 06 Aug 2020 02:51 AM PDT I'm not disputing that something that feels like a small change, in this case, 2 degrees Celcius, can have a large impact, I'm asking why. The one that pops out initially is the oceans melting and the sea levels increasing. But according to scientists, entire temperate regions will be turned into deserts, and why is that? 2 degrees shouldn't be enough to completely change the climate of a region, perhaps something to do with the ozone layers? submitted by /u/donekymann [link] [comments] |
| How can a modified adenovirus be effective against coronavirus? Posted: 06 Aug 2020 02:36 AM PDT I understand that the adenovirus is slightly modified to produce the coronavirus spike proteins, but if you already have the adenovirus antibodies, wouldn't the adenovirus vaccine be destroyed by those antibododies? What if you have a couple of vaccines based on the same adenovirus, wouldn't you also develop antibodies to the adenovirus itself, thus making the second and third vaccine less and less effective? submitted by /u/raducu123 [link] [comments] |
| Ammonium Nitrate, the chemical implicated in the Beirut explosion, is an oxidizer and not explosive. How does improper storage of oxidizers cause explosive mixtures to form spontaneously? Posted: 05 Aug 2020 09:35 AM PDT There are news reports today that yesterday's massive explosion in Beirut was caused by 2750 tons of ammonium nitrate (NH4NO3) that had been stored improperly. News reports often refer to NH4NO3 as an explosive, but if I remember my freshman chemistry this is inaccurate. My understanding is that NH4NO3 is an oxidizer and is not explosive on its own. In order for combustion to occur, the oxidizer needs to be combined with a fuel source. For example, ANFO, the explosive implicated in the Oklahoma City bombing, is a mixture of ammonium nitrate and fuel/heating oil. From what we know so far, the ammonium nitrate stockpile in Beirut was a hazard known to authorities for years and basic safety precautions were not followed in its storage. I'm wondering: what safety precautions need to be followed when storing large quantities of ammonium nitrate? What happens to cause ammonium nitrate to form explosive mixtures when stored improperly? I understand that the situation is Beirut was essentially a time bomb waiting to go off, but I am having trouble understanding on a chemical level how a pile of relatively pure nitrate salt can become explosive just by sitting around for a few years. submitted by /u/lstyls [link] [comments] |
| In an explosion, how are lethal blast zones calculated? Posted: 06 Aug 2020 01:23 AM PDT |
| Why are there so few fjords on Scotland's east coast, compared to the west coast? Posted: 05 Aug 2020 09:13 AM PDT Scotland has a lot of glacial landscapes, at one point cutting straight through the country from Inverness to Fort William. The Highlands and the Hebrides have fjords galore. But around Aberdeen, between Moray Firth and Firth of Forth (try saying that ten times), the coastline is comparatively "neat" and more similar to non-glacial coastlines. It doesn't even have the lake and island clusters you often get on coastlines in glacially formed lowlands, like in Sweden and Finland. Did the area simply not have as much ice coverage during the ice age, despite being at the same latitude and right next to areas in Scotland that did? If so, is there a known reason why? Or is there some other reason for why the area looks the way it does? submitted by /u/DrKlootzak [link] [comments] |
| As one slowly becomes more and more nearsighted over the years, are there any neurological changes occuring in the brain to compensate and better interpret the blurry image it receives? Posted: 05 Aug 2020 08:18 AM PDT Modern neural networks are capable of reducing blur in images by recognizing objects in parts of the image and replacing them with their normal, sharp looking versions that they've been trained on (I'm not sure if this really is how they work, but you get the idea). I was wondering if our brain is capable of something like that. submitted by /u/rjrl [link] [comments] |
| Can eating oxidized proteins cause the oxidized proteins to be inappropriately added (by t-RNA synthetases) to proteins? Posted: 05 Aug 2020 10:53 PM PDT |
| Do animals with longer lifespans have a slower rate of genome evolution? Posted: 05 Aug 2020 10:13 PM PDT |
| How does astronomical research pay dividends back to society? Posted: 05 Aug 2020 03:51 PM PDT [This may not be the right subreddit to post this, please direct me to a better one if that is the case] First of all, I want to state that I am a full supporter of science research, and am enrolled to begin a chem PhD in a month. I do not doubt how exciting astronomy research is. I consistently go out and look at the stars in my backyard, and if I have my binoculars, will find some deep sky objects. I have memorized the constellations that I can see from my latitude. I guess what I am trying to say is that I enjoy the stars more than a typical person. Which is why I spent time thinking about this. In almost every science field that I can think of, there is a benefit to society. Chemistry gives us new and fun materials, biology has led us to understand why we get sick, geology allows us to predict avalanches and earthquakes, etc. But I still wonder about astronomy. I understand how the ISS benefits society, as it fundamentally is a lab space to test how gravity effects systems. I can also get my head around sending probes to the other planets in our solar system, as in the future we will be probably be traveling to them. But how does understanding galaxy and star formation and evolution benefit society? We build huge telescopes (VLT, ELT, Hubble, Keck, JWST to name a few) to let us study these systems. But would spending the money that has been sunk into these telescopes be better spend on other fields of science or society? submitted by /u/deadflashlight [link] [comments] |
| What causes us to actually fall asleep? Posted: 05 Aug 2020 07:38 AM PDT So when you're laying down trying to sleep, you are usually conscious for quite a while depending on whether or not you're tired but what changes in the body that causes you to suddenly become unconscious, does something trigger in the body to switch you into an unconscious state or do you just progressively become less conscious while laying there? submitted by /u/iYadhveer57 [link] [comments] |
| How fast does solid matter move when one end of it is pushed? Posted: 05 Aug 2020 08:54 AM PDT If I have a steel bar and push against end A, end B seems at the same time, but if I had a bar a light-year long, would there be a delay between end A being pushed and end B moving? Would there be some kind of ripple? submitted by /u/Bryce_Trex [link] [comments] |
| Do caterpillars have sexual dimorphism? When, and by what mechanism, is sex set in Lepidoptera? Posted: 05 Aug 2020 09:37 AM PDT |
