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Saturday, November 9, 2019

Why is PH scale 0-14 with 7 as neutral? Wouldn't it make more sense to have 0 as neutral?

Why is PH scale 0-14 with 7 as neutral? Wouldn't it make more sense to have 0 as neutral?


Why is PH scale 0-14 with 7 as neutral? Wouldn't it make more sense to have 0 as neutral?

Posted: 08 Nov 2019 11:12 AM PST

How much pain do small insects experience when they are smashed and killed by humans?

Posted: 08 Nov 2019 05:57 AM PST

I know pain is relative which is why i'd like if there is a comparison with a certain kind of pain humans experience.

submitted by /u/sergiogfs
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How thin is a bubble? Can someone explain the physics behind them?

Posted: 08 Nov 2019 10:24 AM PST

They seem impossibly thin and perfect.

submitted by /u/gautam_right
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What determines whether a city's train system runs on overhead wires or third rail? What are the advantages and disadvantages of each?

Posted: 08 Nov 2019 07:18 AM PST

How exactly is a nerve signal translated into muscle movement?

Posted: 08 Nov 2019 11:31 AM PST

What are the physical processes involved? How is the required energy generated?

How is the "speed" and "force" of the movement encoded in the nerve signal?

submitted by /u/GlaedrH
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Is the Sun a relatively old star compared other stars alive today?

Posted: 08 Nov 2019 10:29 AM PST

What does it mean for a 2+1 dimensional (quasi)particle to obey anyonic statistics, in concrete terms?

Posted: 08 Nov 2019 09:12 AM PST

Given Elon Musk's recent comments about finally being able to reuse rockets: Why is it so difficult to recover and reuse them?

Posted: 08 Nov 2019 02:42 AM PST

What is the Portuguese man o' war if it is not a jellyfish?

Posted: 08 Nov 2019 05:43 AM PST

I thought the Portuguese man o'war was a jellyfish but after more research I found out it is not. So what is it?

submitted by /u/pediepew
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Sources claim the petition by 11000 scientists re: climate change includes signatories like Mickey Mouse and Albus Dumbledore. Access to the list of signatories has now been blocked. How much does stuff like this undermine the credibility of the climate change movement?

Posted: 08 Nov 2019 10:32 PM PST

How do we know dogs are colourblind?

Posted: 07 Nov 2019 11:54 PM PST

Does your immune system get stronger the more you get sick?

Posted: 07 Nov 2019 09:33 PM PST

Friday, November 8, 2019

AskScience AMA Series: Hi! We're experts from the National Institutes of Health, the National Toxicology Program, and the American Botanical Council studying the quality, safety, and effectiveness of botanical dietary supplements and essential oils. Ask us anything!

AskScience AMA Series: Hi! We're experts from the National Institutes of Health, the National Toxicology Program, and the American Botanical Council studying the quality, safety, and effectiveness of botanical dietary supplements and essential oils. Ask us anything!


AskScience AMA Series: Hi! We're experts from the National Institutes of Health, the National Toxicology Program, and the American Botanical Council studying the quality, safety, and effectiveness of botanical dietary supplements and essential oils. Ask us anything!

Posted: 08 Nov 2019 04:00 AM PST

Botanical dietary supplements, sometimes called herbals or herbal dietary supplements, and essential oils are products made from plants, plant parts, or plant extracts. One study found that natural products, including botanical dietary supplements, are used by approximately 15% of adults and are widely available in the United States. In fact, according to the American Botanical Council, Americans spent a total of $8.8 billion on botanical dietary supplements in 2018.

But, just because a product is from a plant source and sold in stores or online, doesntt mean it's safe. The safety of a botanical or essential oil depends on many things, such as its chemical makeup, how it works in the body, how it is prepared, and the dose used.

The amount of scientific evidence available for various botanical supplement ingredients varies widely, in part, because product safety is not tested by FDA and federal law does not require dietary supplements be tested for effectiveness before they are marketed.

Studying the potential effects of botanical dietary supplements has several unique challenges. For example, all botanical dietary supplements contain a complex mixture of ingredients, making it difficult to identify and link active ingredients to health effects. Growing, harvesting, and processing conditions can also affect the chemical makeup of a botanical supplement, leading to challenges in manufacturing identical products batch after batch. Possible contaminants - either accidental or intentional via adulteration - in botanical dietary supplements (e.g. heavy metals, microbes, undeclared ingredients, or pesticides) needs to be determined as part of routine quality control since these can affect its safety.

Our hosts today are all experts on studying the quality, safety, and/or efficacy of botanical dietary supplements and essential oils to better understand how to use them more safely and effectively.

  • Stefan Gafner, Ph.D., is the Chief Science Officer at the American Botanical Council (ABC). He answers many of the inquiries from ABC members, in particular those relating to quality control and analytical methods. As technical director of the Botanical Adulterants Prevention Program (BAPP), he writes and/or edits the Botanical Adulterants Prevention Program publications and ensures the accuracy of the content published by the Program. Stefan grew up in Switzerland, and, on rare occasions, you may actually hear him yodel (or at least trying to).
  • D. Craig Hopp, Ph.D., is the Deputy Director of the Division of Extramural Research at the National Center for Complementary and Integrative Health (NCCIH), part of the National Institutes of Health (NIH). Here, he manages several large-scale projects such as research centers focused on drug-natural product interactions and centers focused on improved natural product technologies. He also provides scientific leadership in the NCCIH research portfolio on the biological activities of natural products, including studies in preclinical models for a wide variety of potential clinical indications. Craig is an avid DIY-er who has completed several major renovations around his home and handles all his own automotive repairs.
  • Adam Kuszak, Ph.D., is a Health Scientist Administrator in the Office of Dietary Supplements (ODS) at NIH and Director of the ODS Analytical Methods and Reference Materials Program (AMRM). Through AMRM, Dr. Kuszak works to support scientific resource development and promote biomedical research on the mechanisms and health effects of dietary supplements and natural products. In his free time, Adam has a passion for exploring the world through photography, and for world-building through modeling.
  • Tyler Ramsey, B.S., is a second-year medical school student at Campbell University School of Osteopathic Medicine and a former postbaccalaureate research fellow at the National Institute of Environmental Health Sciences (NIEHS), also part of NIH. His research looks at essential oil components and their potential link to breast growth in young boys and girls (i.e. prepubertal gynecomastia and premature thelarche). Tyler is the vice president of his medical school and enjoys spending his free time in the gym or taking a walk with his 3-year old golden retriever.
  • Cynthia Rider, Ph.D., is a toxicologist in the Toxicology Branch of the National Toxicology Program (NTP), headquartered at NIEHS. In this role, she leads an effort to characterize the effects of botanical dietary supplements studied in NTP's testing program. NTP conducts toxicology studies in animal models to understand what happens once the supplement enters the body. Cynthia spent her formative years on a tiny Pacific Island, Kwajalein in the Marshall Islands, which is currently threatened by global warming and rising sea levels.

We'll be on to answer questions at 1 pm ET (18 UT), ask us anything!

submitted by /u/AskScienceModerator
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Why is varicella more dangerous to get as you grow older?

Posted: 08 Nov 2019 06:19 AM PST

If dark matter has no electromagnetic interactions, does that mean it could move right through regular matter?

Posted: 08 Nov 2019 05:21 AM PST

My understanding is that the fact that I can't put my finger through a table is actually the result of electromagnetic interactions between the molecules of my finger and the molecules of the table. If dark matter has no electromagnetic interactions, does that mean it could "phase" through baryonic matter?

submitted by /u/Shotstopper
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How (by natural processes) are nutrients added and changes made in an area of soil over time to make it fertile?

Posted: 08 Nov 2019 04:10 AM PST

Just how dangerous is radiation in space?

Posted: 08 Nov 2019 03:27 AM PST

Space news websites often post new articles about the danger of space radiation to Mars astronauts, and often describe the radiation levels as completely prohibitive. NASA does that, too, but often in very vague terms, like "we need to know more" or "more research is needed".

On the other hand, people like Robert Zubrin, Elon Musk, etc., acknowledge the existence of an elevated background level, but completely dismisses the notion that it should preclude humans from traveling to Mars. These people often refer to actual studies, and never say that more research is needed. In fact, Robert Zubrin insists that no more research is needed.

So who's right?

submitted by /u/oz1sej
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How can the wave function of a s-orbital not vanish in a H-Atom?

Posted: 07 Nov 2019 05:04 PM PST

Hi guys, an electron in a s-orbital of a H Atom has a non vanishing wave function and probability to be at r =0. How can that be possible, if the coulomb potential diverges there? Thanks for your help!

submitted by /u/drrost
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Why does azurite turn dark/black when exposed to large amounts of sunlight?

Posted: 07 Nov 2019 10:58 PM PST

Also does it turn into anything toxic when it turns black? I like to hold it.

submitted by /u/CrystalCrackhead
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On the level of hardware, how do pointers work?

Posted: 07 Nov 2019 07:05 PM PST

So I understand that when I'm writing a linked list, and a node points to another node, it is the memory address where the first node is stored pointing to another. So like if you have a table of memory addresses, if the first node is stored at memory location n and the second node is stored at memory location k, you would just have to iterate (k-n) times through the table (from node n) to get to location k. However, I'd assume that in a real system, you may sometimes run into a problem where weirdly spaced blocks of this memory table have been allocated to other programs. More formally, if I have a memory demand of k memory units for some program x, and there is already an allocated block of memory for some program z starting at (address k minus some non-zero constant y) and ending at an address n s.t n>k; will my memory assignment program try to reallocate the memory for z or will it split the memory for program x into blocks 1:(0,k-y) and 2:(n,k)? If it is the latter then doesn't that present a routing problem? As in if my memory circuit is laid out in vertical rows where the height of each row is (length of memory address table/number of rows), and i have a large gap between blocks 1 and 2(one that may even span multiple rows), at some point,I hypothesize that it may become quicker to traverse the memory circuit horizontally rather than to iterate through the entire block of program z-s allocated memory. TL;DR: Can a memory circuit be visualized as a linked list? Does memory always reallocate? If it doesn't, does traversing the memory circuit linearly between referenced memory locations impose a demand on processing power? Why can't we (or do we) produce circuits where memory units are laid out in a "complete graph" configuration where every unit is connected to every other unit?

submitted by /u/moog500
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Do dog behaviours show cultural variation depending on geographic origin?

Posted: 07 Nov 2019 05:45 PM PST

We ran a shelter for Balkan street dogs. As I had little knowledge of dogs up to that point, I assumed what I learned from these dogs was 'how dogs were'. When we returned home, we brought two emotionally damaged dogs, as they had no alternative but death. This meant a lot of training, and work with a behaviourist, which is where the question comes from.

All the soft-eared dogs we sheltered carried their ears pressed back high on the skull, letting the tips fall loose, with the inside of the ear facing out, when relaxed. When angry or stressed, their ears would be lower and pressed straight back, with the inside facing inward to the skull -- a quite different placement.

The behaviourist insisted that any time a dog pressed its ears back it was unhappy/threatened. Despite any progress the dogs made, every visit consisted of her telling me how I was failing these dogs because they were so stressed. Eventually, I just stopped going.

It's a decade later. The dogs, now well adapted and trained, still carry their ears folded at all times unless they are specifically interested in something right ahead of them, or I am talking with them: then the ears are up and forward, like a collie. As they age, I am wondering whether or not I've given them the best I could, and those ears still puzzle and, I admit, upset me. Is it possible the street dogs of the Balkans simply have a different culture, one in which laid back ears can communicate different things depending on the way in which they are laid back? Is there research on dog postural communication that takes into account differing geographic/situational origins? All I have been able to find looks at North American or Western European dogs who come from generations of domestic canines, while these are Eastern Europeans who come from generations of semi-feral, often abused dogs.

I'd be grateful for any knowledge you can share.

submitted by /u/Mrs_Cosmopolite
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What do deaf people have as an internal voice if they have never heard language?

Posted: 07 Nov 2019 07:15 AM PST

Would a large sauropod die if it fell over? Wouldn’t its massive weight crush its ribs?

Posted: 07 Nov 2019 03:25 AM PST

What did the Earth look and feel like at the height of the Permian Extinction?

Posted: 07 Nov 2019 08:08 AM PST

I believe it killed some huge percent (like 80 to 90) of all life on earth and it took millions of years to begin to recover. I believe it was caused in part by a massive volcanic event which spewed so much methane and co2 into the atmosphere that it cause rapid global warming that life couldn't cope with.

Were there plants and land animals at this time in earths history? Were there forests? What did the continents look like?

Did the great dying cause most of the land to turn into desert? What was the average temp during this time? What about the oceans, were there fish or coral life yet?

I have so many questions about what youd see and feel if you could go back to the peak of the Permian extinction and just experience Earth in it's most disaster state.

submitted by /u/HailMePls
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What would the Voyager probes look like now?

Posted: 06 Nov 2019 08:00 PM PST

In the 40+ years since their launching, after traveling through the solar system and now beyond, what would the Voyager probes look like today if we could see them up close? Would they look any noticeably different, namely due to any damage from space travel (dust/debris/rays/etc)?

submitted by /u/Coldblackice
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How does a global shutter in a camera work?

Posted: 07 Nov 2019 03:32 AM PST

I understand how rolling shutters work, from an engeneering point of view, but how exactly do you expose the entire sensor at once?

submitted by /u/ChillDolphin
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You know how latex balloons have a distinct smell to them? What is it that you're smelling?

Posted: 06 Nov 2019 08:32 PM PST

Can defibrillators revive someone who has been pronounced legaly dead?

Posted: 06 Nov 2019 10:16 PM PST

I remember reading about how they cant when someone is flatlining, but this website, https://www.nhlbi.nih.gov/health-topics/defibrillators says:" Defibrillators can also restore the heart's beating if the heart suddenly stops". Is there truth to this? It's the only website I can find that says this.

submitted by /u/CmdrSpicyllama
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Thursday, November 7, 2019

What does it mean physically that the Weak force and electromagnetism become one force at a certain energy?

What does it mean physically that the Weak force and electromagnetism become one force at a certain energy?


What does it mean physically that the Weak force and electromagnetism become one force at a certain energy?

Posted: 06 Nov 2019 06:53 PM PST

If a black hole's singularity is infinitely dense, how can a black hole grow in size leagues bigger than it's singularity?

Posted: 07 Nov 2019 03:41 AM PST

Doesn't the additional mass go to the singularity? It's infinitely dense to begin with so why the growth?

submitted by /u/CyberMatrix888
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Voyager 2 has reveled that the interstellar medium near the heliopause has a temperature of around 30,000-50,000K (29,000-49,000C). How and why doesn't Voyager just melt with such tempatures?

Posted: 06 Nov 2019 05:44 PM PST

Is the vacuum of space the same temp or is it just the infrequent and tiny particles that are this temp? I thought space was rather cold when away from a star.

submitted by /u/PurpleSailor
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Why does orbital penetration reduce the energy of an orbital?

Posted: 07 Nov 2019 02:20 AM PST

I've read that by approaching the nucleus, the electrons lose energy. So i'm guessing that the 2s orbital is lower in energy than 2p since it is more penetrating, likewise for how 1s is lower energy than 2s. I would like to think this has something to do with Coulomb's Law but I'm not too sure why or how electrons lose energy near the nucleus?

submitted by /u/lurker4011
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How is detecting exoplanets via transit effective if some planets take decades or more to complete an orbit?

Posted: 07 Nov 2019 02:12 AM PST

Or is the transit method only practical for exoplanets with an orbit within a reasonable timeframe?

submitted by /u/Inverse_Square_Law
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Regarding transplanted organs, does the body eventually replace all the cells of the organ with "native cells" or are they still cells of the donor?

Posted: 06 Nov 2019 10:37 AM PST

As I understand it, all cells in the human body are replaced by in roughly 7 years time frame, and organ transplant recipients have to take medication to help the body not reject the organ. Do they have to continue taking the medication the rest of their life, or only for several years?

submitted by /u/Ignis33
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Does medicine actually expire? If so, how

Posted: 06 Nov 2019 10:42 AM PST

How does RNA polymerase know how to find the promoter regions on DNA?

Posted: 06 Nov 2019 01:23 PM PST

Is it just floating around and just so happens to run into a promoter site and start its process?

How does it know the xyz coordinates of where it needs to be to start this process? Is it making decisions????

submitted by /u/Captainbuttram
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How do our bodies make stomach acid?

Posted: 06 Nov 2019 12:12 PM PST

Frame-dragging effect and the Lense-Thirring metric. What exactly is happening to spacetime?

Posted: 06 Nov 2019 05:04 PM PST

Is spacetime moving? Is it a semistatic quality of spin around a massive rotating body?

submitted by /u/Xxx_M4D-R0n1n_xxX
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Why is the international date line crooked?

Posted: 06 Nov 2019 06:01 AM PST

Why aren't there any unedited/stitched photos/videos of Earth?

Posted: 06 Nov 2019 05:18 PM PST

To my knowledge we don't have any just straight photos or videos. There's definitely a reason (I'm not a flat earther or anything trying to poke holes or anything like that) and I wanna know. Thanks

submitted by /u/myhamsareburnin
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What do these number in front of hormone names mean?

Posted: 06 Nov 2019 07:29 AM PST

For example, 25-hydroxycholecalciferol or 7-dehydrocholesterol.

From a biology POV I understand what the hormone is and its role. But I've never understood what the numbers mean in front. Thank you for the help.

submitted by /u/HockeySlayer89
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Wednesday, November 6, 2019

Why isn't serotonin able to cross the blood-brain barrier when molecules like psilocin and DMT can, even though they're almost exactly the same molecule?

Why isn't serotonin able to cross the blood-brain barrier when molecules like psilocin and DMT can, even though they're almost exactly the same molecule?


Why isn't serotonin able to cross the blood-brain barrier when molecules like psilocin and DMT can, even though they're almost exactly the same molecule?

Posted: 05 Nov 2019 01:13 PM PST

Even LSD which is quite a bit larger than all the molecules I mentioned, is able to cross the blood-brain barrier with no problem, and serotonin can't.

submitted by /u/Deleizera
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Is constant light exposure beneficial to plants, or do they also require periods of low light?

Posted: 05 Nov 2019 12:45 PM PST

If experts can tell me I shouldn't leave my phone connected to the charger after it's charged, and my phone can detect and tell me when it's charged, why can't the phone just go ahead and turn off the charging when it's charged?

Posted: 05 Nov 2019 10:34 AM PST

I'm just not sure why it's down to me to unplug it. Can't it just flip a relay when it gets to 100 percent, or 80 percent, or what's considered healthy for the battery?

submitted by /u/Subduction
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How does a computer determine if a given number is larger than another number?

Posted: 06 Nov 2019 03:10 AM PST

Is something only warm to the touch, i.e I touch with my finger, if that object is warmer than my body temperature? Or at what temp does something become warm to touch, considering when run roughly 37 C/98.6F?

Posted: 06 Nov 2019 06:59 AM PST

How do Ampere's law and Faraday's law make sense conceptually? How does an electric field emerge from a changing magnetic field and how does a magnetic field emerge from a changing electric field?

Posted: 05 Nov 2019 10:56 PM PST

Ampere's law states that a changing electric field produces a magnetic field and Faraday's law states that a changing magnetic field produces an electric field. I can understand how they make sense mathematically (using the different vector theorems) but how do they make sense conceptually? How did Ampere come to the conclusion that a magnetic field is produced from a changing electric field and how did Faraday come up with the fact that an electric field is produced from a changing magnetic field? What made them realize and form these laws other than mathematics?

submitted by /u/trippy-mac-unicorn
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When two black holes merge, the new black hole has the angular momentum of both. Does this put a limit on the size of black holes? How fast can a black hole spin?

Posted: 06 Nov 2019 04:37 AM PST

Or am I misunderstanding how their angular momentum is combined? If so, does anything else limit the size of a black hole -- could one, in theory, eat everything in the universe?

submitted by /u/curiousscribbler
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In regards to ionic radius, how do you compare cations to anions of different elements that are not isoelectric?

Posted: 06 Nov 2019 07:33 AM PST

So I know the basics
A cation of a parent will be smaller and a anion of parent will be bigger
If the charges are the same the period trend for atomic radius applies
In an isoelectric series they can be arranged based on charge

But what if they are two different elements of different charge say

Br- and In+

submitted by /u/AtenderhistoryinrusT
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Ask Anything Wednesday - Economics, Political Science, Linguistics, Anthropology

Posted: 06 Nov 2019 07:08 AM PST

Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Economics, Political Science, Linguistics, Anthropology

Do you have a question within these topics you weren't sure was worth submitting? Is something a bit too speculative for a typical /r/AskScience post? No question is too big or small for AAW. In this thread you can ask any science-related question! Things like: "What would happen if...", "How will the future...", "If all the rules for 'X' were different...", "Why does my...".

Asking Questions:

Please post your question as a top-level response to this, and our team of panellists will be here to answer and discuss your questions.

The other topic areas will appear in future Ask Anything Wednesdays, so if you have other questions not covered by this weeks theme please either hold on to it until those topics come around, or go and post over in our sister subreddit /r/AskScienceDiscussion , where every day is Ask Anything Wednesday! Off-theme questions in this post will be removed to try and keep the thread a manageable size for both our readers and panellists.

Answering Questions:

Please only answer a posted question if you are an expert in the field. The full guidelines for posting responses in AskScience can be found here. In short, this is a moderated subreddit, and responses which do not meet our quality guidelines will be removed. Remember, peer reviewed sources are always appreciated, and anecdotes are absolutely not appropriate. In general if your answer begins with 'I think', or 'I've heard', then it's not suitable for /r/AskScience.

If you would like to become a member of the AskScience panel, please refer to the information provided here.

Past AskAnythingWednesday posts can be found here.

Ask away!

submitted by /u/AutoModerator
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Is it possible to (easily) calculate the private key of any modern encription technique if I know the exact content of one encripted file? If so, how long must that file be?

Posted: 06 Nov 2019 06:06 AM PST

Thanks.

submitted by /u/Rantamplan
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It's QWERTY measurably better for swipe typing than other layouts used for touch typing?

Posted: 06 Nov 2019 03:52 AM PST

QWERTY was designed to have the most common letters far apart to prevent typewriters from jamming. Most other keyboard layouts used for touch typing (Dvorak, Colemak, …) were designed to have the most common letters on the home row, so they are under the fingers.

If QWERTY has the most common letters apart, it may cause the paths of the finger to be spread more evenly over the keyboard and give more information so the prediction algorithm.

submitted by /u/matj1
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Does gasoline become "stale" when stored for a long period? If so, what is happening, chemically? Are additives sold to prevent this from happening effective?

Posted: 06 Nov 2019 12:34 AM PST

Why is the Heliopause directional as if all the galactic cosmic rays come from one location?

Posted: 05 Nov 2019 04:46 PM PST

Recently, reading articles about the Voyager spacecraft, illustrations all show the Heliosphere trailing off in one direction. I would expect cosmic rays to be coming from stars and galaxies all over the universe instead of from just from one location.

submitted by /u/kabloooie
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Hubble Ultra Deep Field galaxies: Are they named/studied?

Posted: 05 Nov 2019 03:20 PM PST

I've been looking at this HUDF picture: If I had questions about some specific galaxy in that picture, are any of them named and how much information should I expect to get from a given galaxy? How much can we learn about them based on just a photograph?

Also if anyone has any further information on the morphology of galaxies I'd appreciate the insight.

submitted by /u/Delukse
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How does a strong acid/base harm living cells?

Posted: 05 Nov 2019 12:56 PM PST

From humans to single-celled Archaea, how does very low pH harm cells? What is the chemical process?

submitted by /u/bigtittybumslut
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What does the search for an alternative chemical look like?

Posted: 05 Nov 2019 09:12 AM PST

The crux of the recent story about the UK engineer and his aluminum air battery was that such batteries have been known for a long time, but required a toxic corrosive electrolyte, so his breakthrough (that he spent two decades searching for) is an alternative electrolyte that works for the battery and is harmless enough to drink. My question is, **when any chemist is searching for a replacement chemical like this, what guides the search?** Is it things like number of valence electrons, molecular mass, bond length simulations, or what?

submitted by /u/ProfessorImprobable
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Is there a relation between wavelength of radiation absorbed by a surface and its surface roughness?

Posted: 05 Nov 2019 09:40 AM PST

Are all wavelengths equally absorbed by a surface, or is a specific wavelength more prominently absorbed depending on the surface roughness?

submitted by /u/theunknownKiran
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Is it possible for a solar system to have two planets of the same size within the habitable (Goldilocks) zone?

Posted: 05 Nov 2019 09:24 AM PST

I'm reading some science fiction where two earth-like planets of the same size are only slightly outside of each other's orbit, and have similar orbital periods. So similar life forms move back and forth between each planet.

I wasn't sure if this is possible. Would the two planets just collide?

submitted by /u/blackjack_oak
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How does kinetic energy make sense from different inertial systems?

Posted: 05 Nov 2019 01:53 PM PST

A friend and I have trouble making sense of a very basic fact of Newtonian Physics. Kinetic energy grows quadratically with velocity. This made sense to me until my friend suggested the following thought experiment: 3 bodies A, B and C rest next to each other not affected by any forces. A stays still while B and C accelerate to, say, 10 m/s, gaining an amount of kinetic energy x. In respect to each other, B and C are not moving. Now C accelerates to 20 m/s relative to A and 10 m/s relative to B. This increases C's kinetic energy to 4x. From B's perspective, this looks like an acceleration from 0 to 10 m/s but required 3x energy. It seems like A's perspective is "more correct" than B's, but why? If velocity is always measured relative to an inertial system, why is kinetic energy not? Where are my friend and I messing things up?

submitted by /u/LukkyLukke
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Why does most (if not all) life use phosphoanhydride bonds (ATP) as energy storage/currency when Phosphorous is limited in the environment?

Posted: 05 Nov 2019 06:43 AM PST

Is there any advantage to ATP and other phosphoanhydride bonds that seem to do most of the heavy lifting in the cells that other molecules just cannot do at all? It would seem that some other kind of energy currency would compete at all if there were comparable efficiencies and traits.

submitted by /u/PhillipsAsunder
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