Didn't the person who wrote world's first compiler have to, well, compile it somehow?Did he compile it at all, and if he did, how did he do that? |
- Didn't the person who wrote world's first compiler have to, well, compile it somehow?Did he compile it at all, and if he did, how did he do that?
- Can the Standard Quantum Limit for the repeated measurement of a free mass be broken in theory?
- How do biologists know when they've discovered a new species?
- Does the recent Vitamin D study published in the NEJM show significant results of reduction in risk of death from cancer?
- What prevents birds from reaching the sizes that pterosaurs did?
- What makes a plastic microwaveable or not?
- Where did the fish in volcanic crater lakes come from?
- How do companies that sell the GFP gene actually purify it nowadays?
- GPS requires microsecond clock accuracy in the satellites but the terrestrial receiver accuracy doesn't matter at all. Why is this?
- What is it about GR that causes the subtle changes in the Perihelion Precession of Mercury?
- If skills are not inheritable then how do cats and other hunters seem to just know how to hunt from a very young age?
- Why is it that people who suffer from a stammer/stutter in their speech mostly are unaffected by it when they sing?
- How do techniques like electric stimulation or vibrating boards actually train a muscle or your body? Or do they even?
- Does reflective radiator foil work?
- How does Bernoulli's principle (basically, saying that pressure and velocity of a fluid are inversely related) work in the case of a tube that enlarges with distance?
- Is the expansion of the universe isotropic?
- Does eating 5 fruit/veg daily actually help you stave off a cold and other diseases?
- Do planets expand when they're closer to the sun? And get smaller when they're distant from the heat?
- What are the recommended controls to be used when making transient transformant plants via agroinfiltration?
- If I inhaled pure oxygen, would I be able to hold my breath longer than if I was just breathing the air around me?
- Are there any anatomical changes in humans living in a poor air quality environment?
- If ulcers are caused by H. pylori, why isn't there a simple test, why are so many much more dangerous diseases misdiagnosed as ulcers?
- Why does the melting point of ice increases under more pressure ?
| Posted: 12 Nov 2018 07:26 AM PST |
| Can the Standard Quantum Limit for the repeated measurement of a free mass be broken in theory? Posted: 12 Nov 2018 04:10 AM PST Maybe I am cheating here, given that my not knowing the answer may come from my incomplete literature review. But I am getting confused by the claims of the contractive states breaking the limit, and yet a reinterpretation of definitions of precision and resolution seems to validate that repetitive measurements can never be broken due to the Heisenberg Uncertainty Relation between the Standard Deviations of the positions of the free mass at the first and the second measurements, which equals to the SQL. But the review paper I read itself said, after pointing the the HUP=SQL, that the SQL is not a fundamental limit. How? Does the Uncertainty relation mean that the SQL can never be broken? Shouldn't it? Does it mean no one's working on breaking it? All the above paragraph was from papers from before 2000s, so what's the consensus now? [link] [comments]  |
| How do biologists know when they've discovered a new species? Posted: 11 Nov 2018 06:47 PM PST I am in Ecuador and today I saw a striking hummingbird while hiking around 4300 meters. I didn't know hummingbirds could live that high up, so I did a bit of investigating and found this article about a species discovered only 6 weeks ago and the coloration, size, habitat and range all match perfectly to what I saw. Who knows if I actually saw this hummingbird or a more common species- i could not find any others that resembled my sighting- but that's neither here nor there. It got me thinking: suppose I did see this species, if I had seen it 6 months ago I apparently would've been the first person to ever see it. But at the same time, I would never have known that it was a new species. How do biologists make this determination? Is there a comprehensive list somewhere of every known hummingbird species? Do biologists just go down the list and if they can eliminate every known species then they know they've discovered a new one? How exactly does this sort of thing work? Here is the article in question, by the way- including a picture of the species in question. https://www.sciencenews.org/article/new-species-high-altitude-hummingbird-may-already-be-trouble [link] [comments]  |
| Posted: 12 Nov 2018 06:18 AM PST The recent study on Vitamin D Supplements and Prevention of Cancer and Cardiovascular Disease published in the NEJM didn't show a lower incidence of cancer than placebo. However, it did show a reduction in death from cancer, especially, as noted in the results of the study, when the first two years of the study are excluded. Are these significant results? Is there any additional context/interpretation of these results that could help a layperson make some useful inferences here? [link] [comments]  |
| What prevents birds from reaching the sizes that pterosaurs did? Posted: 12 Nov 2018 05:54 AM PST Title more or less. Reading up on how a doubling of bird weight requires 2.25 more muscle power and how wingbeat frequency decreasing as well gives a limit to bird size. Is just the difference in the morphology of the two groups responsible for the size difference? [link] [comments]  |
| What makes a plastic microwaveable or not? Posted: 11 Nov 2018 03:47 PM PST |
| Where did the fish in volcanic crater lakes come from? Posted: 12 Nov 2018 04:15 AM PST I've seen two volcanic crater lakes in Southeast Asia - Lake Toba and Lake Taal. Both have fish, but both are isolated and cut off from other bodies of water. Since they're volcanic crater lakes wouldn't the eruption would have killed all the fish? So where did the fish in the lakes come from? [link] [comments]  |
| How do companies that sell the GFP gene actually purify it nowadays? Posted: 12 Nov 2018 04:12 AM PST My friend and I were discussing this and read about the origins of discovering GFP - having the cut fluorescent rings off of a million jellyfishes, and squeezing them through gauze doesn't seem like a very efficient process, so we were wondering how companies nowadays would obtain their original sample of GFP. Sorry if it's a silly or basic question, but it's very interresting to think about :) [link] [comments]  |
| Posted: 12 Nov 2018 01:09 AM PST |
| What is it about GR that causes the subtle changes in the Perihelion Precession of Mercury? Posted: 12 Nov 2018 04:40 AM PST I create and present Planetarium shows at the local college. I've done show on Special and General Relativity, so I have a solid understanding of these effects, but the mechanism by which GR affects the orbit of nearby celstial bodies still eludes me. What I understand: Mercury's orbit varies ever so slightly from the orbit calculated with Newtonian physics. Apparently this variation is due to relativistic effects since it orbits so closely to the Sun (this is about as far as most internet sources will delve into it). In the last day or two, there are reports that the closely orbiting stars around Sgr A* (the supermassive black hole at the center of the Milky Way) also display variations in *their* orbits which confirm some effect of GR. Are these the same effects, just at different scales? Are their orbits slowing during their closest approach as compared to an external observer? What is it *actually* that's going on that modifies these orbits? Thanks in advance! [link] [comments]  |
| Posted: 12 Nov 2018 05:10 AM PST Im a third year junior cycle student and in science i learned that skills, interest and knowledge are not inheritable, so what makes cats and other hunters get hunting skills? When i asked this to my science teacher she told to just get on with my work and stop asking silly question (shes very petite) so i came here to ask. - learns science in school - has science question - asks reddit [link] [comments]  |
| Posted: 12 Nov 2018 03:30 AM PST |
| Posted: 12 Nov 2018 02:31 AM PST I dont know if this does quite fit in here, but couldnt figure a more suitable sub to post this question on. Some Background: I came across such training-techniques several times in my life and recently found out, how big of a business all that get in shape without actually working out stuff has become. I have always been sceptical about that topic, however I have also received such treatment once during physiotherapy, hence a medical procedure based on scientific methods. Also, I have been studying the mechanism of muscle metabolism in a side project of my last job a year ago and I simply cannot figure out, how such a technique is supposed to work. Electric stimulation: I have had some corrective knee-surgery back when I was 14 years old as my right knee suffered from frequent patella-luxations. During regen, I have had frequent physio-appointments which have basically been normal remobilisation techniques, muscle training and - at the end of each session - some electric stimulation with swell current for half an hour. I suppose you all know this kind of thing: Some electrodes stimulate with an electrical current and cause your muscle to flex. The same technique is fundamental to a huge part of teleshopping-articles, who claim to help you gain a Baywatch-Body while sitting on your sofa doing nothing. To my understanding, training is building on activating muscle metabolism, by forcing the processing of carbon-hydrates in an either aerobe, anaerobe lactacid or anaerobe alactacid way, based on what kind of exercise you do (peak-performance, long-time,...) and I actually cannot see electric stimulation to intiate any sort of processing of carbon-hydrates. Hence you will also never produce metabolic byproducts, that activate the second part of muscle-metabolism which relates to breathing. In other words: To my understanding, you have to get out of breath in order to actually use muscle-metabolism. Vibrationboards: I mainly came across that stuff, when I saw some "training"-studios opening up in my town where you can book some workout on such a plate. While this didnt really catch my interest to actually try it, I happened to receive one of these boards now, when my wife actually signed up for some product evaluation on the vibrashaper and we happened to get that thing for free. So long story short, I gave this a few tries and always ended up questioning what the actual benefit of that thing was. If I tried using it the way, that commercials present it, like stand on it daily, get comforatble and let the plate do its magic, and you will end up with your Baywatch-body in a few weeks, the effect was zero. Vibration was definitely not activating my metabolism and no effect was felt after a session. So I tried leveling it up and squated to a degree, similar to the casual pretend to be a downhill ski-racer-exercise. This obviously got my thigs heating up and I started breathing heavily, resulting in an active metabolism. However, comparing that workout to the exact same exercise but without a vibrating board, I actually felt the same. So what do you actually think of such techniques? Am I mistaken for measuring an active muscle-metabolism with whether I heat up and get out of breath? Or are there other aspects, that can actually achieve a training-effect even though you dont feel your body heating up? [link] [comments]  |
| Does reflective radiator foil work? Posted: 12 Nov 2018 02:12 AM PST Some hardware stores recommend putting tin foil behind radiators as it 'reflects' or 'bounces' heat back into the room, stopping it from being lost into wall. I'm pretty sure that's nonsense, heat doesn't work like that, otherwise people wouldn't bother insulated walls, they'd just use thin sheets of tin foil everywhere, which is also bonkers. To what extent does science support or disprove the use of reflective radiator foil? Have there been any studies? [link] [comments]  |
| Posted: 11 Nov 2018 09:10 PM PST College student here, just learning about fluid mechanics, ftp blah blah. So Bernoulli's equation says that pressure + (gravity*density*height) + 1/2(density*velocity squared) is the same throughout a fluid. If we take a fluid flowing through a tube that is horizontal (keeps the same height), we can eliminate the middle term, so pressure + 1/2(density*velocity squared) is constant. I'm just having an intuition problem here. This makes sense when we consider a tube that shrinks in radius; since flow rate Av is constant as well, the velocity is higher as the tube gets narrower. Then, when the tube is larger, the velocity is smaller, but there is more fluid pushing on the walls as the tube shrinks, like the bottleneck effect. This makes sense with Bernoulli's equation - when velocity is lower, pressure is higher, and vice versa. But how does this make sense if the tube widens over time? It just seems like a fluid coming from a narrow opening and losing velocity due to the greater area wouldn't expand enough to make any pressure on the walls of the tube, let alone more pressure than when it was in the narrow part. My professor used the example of a water fountain, or a hose, to illustrate the conservation of Av; as the water sprays out of the end, it slows down and the area expands. But at this point, there's even less pressure on the water than when it was inside the hose! So the pressure and velocity would both be decreasing (and even the height, if it falls). This seems like it doesn't follow Bernoulli's principle. Where am I going wrong here? [link] [comments]  |
| Is the expansion of the universe isotropic? Posted: 12 Nov 2018 03:40 AM PST Some physical theories, such as string theory, claim that there are more dimensions that the three we are used to. Supposedly, we have a hard time observing those extra dimensions because they are very thin. We know that the universe is expanding when we look at our three familiar dimensions, but i) is this expansion isotropic? ii) Could some dimensions expand while others (namely the extra ones) shrink? iii) Could the universe have a constant volume when taking into account "thin" dimensions? [link] [comments]  |
| Does eating 5 fruit/veg daily actually help you stave off a cold and other diseases? Posted: 12 Nov 2018 05:42 AM PST |
| Posted: 12 Nov 2018 01:30 AM PST I was studying phsycs and that I started wandering about this. But there's no information on Google. [link] [comments]  |
| Posted: 12 Nov 2018 04:31 AM PST I both want to overexpress and downregulate (VIGS) my gene of interest [link] [comments]  |
| Posted: 11 Nov 2018 09:41 PM PST |
| Are there any anatomical changes in humans living in a poor air quality environment? Posted: 12 Nov 2018 03:25 AM PST Do People living in polluted cities develop any anatomical change to adapt to the environment? [link] [comments]  |
| Posted: 11 Nov 2018 03:40 PM PST |
| Why does the melting point of ice increases under more pressure ? Posted: 12 Nov 2018 05:14 AM PST |
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