| When sending robots to other planets, how do they make sure not to include Earth microorganisms? Posted: 29 Jan 2020 05:50 PM PST |
| When a virus has an R0 of >1, why does it not just grow exponentially until it has infected all of humanity? Posted: 30 Jan 2020 05:21 AM PST People are saying the Wuhan virus has an R0 of around 3. I've heard R0 explained as the average number of people and infected person infects. Thus, it would seem that as long as this number is >1, the disease would just spread exponentially ad infinitum until the entire population had been infected or enough had grown immune/been quarantined that the R0 fell below 1. In the case of Wuhan, the entire world population should be infected at around 21 iterations if the number of cases tripled each iteration (321 ≈ 10bil). However, given that basically every virus had R0 of >1 and not all of humanity has had every virus, this doesn't appear to be how it actually works. What am I missing here? submitted by /u/acvdk [link] [comments] |
| AskScience AMA Series: I'm Dr. BJ Fogg, founder and director of the Behavior Design Lab at Stanford University and the author of the New York Times bestselling book, Tiny Habits: The Small Changes that Change Everything, AMA! Posted: 30 Jan 2020 04:00 AM PST Hi, everyone, I'm leading habits expert Dr. BJ Fogg. I am a behavior scientist, with deep experience in innovation and teaching. I run the Behavior Design Lab at Stanford University, and I also teach my models and methods in graduate seminars. Over 25 years ago I was reading Aristotle's Rhetoric when I realized that someday computers would be designed to influence humans. Being a natural optimist, I imagined many benefits of combining persuasion and technology. I decided to explore this area scientifically. As a doctoral student at Stanford in the 1990s, I ran the first-ever series of experiments to discover how computers could change people's attitudes and behaviors. I named this new area "persuasive technology." My research won Stanford's Maccoby Prize and spawned an international academic conference, going on 10 years now. After graduation I started working in Silicon Valley, but I also devoted about half my time to Stanford. I founded a new Stanford lab in 1998. And each year since then, I've created a new course on a topic that interests me. I no longer do industry consulting. Instead, these days I focus on teaching innovators about human behavior--my models and methods in Behavior Design--so they can create products to help people be healthier and happier. The focus areas include health, financial wellbeing, learning, productivity, and more. My current projects include the Good Habit Project, out of my design lab at Stanford; designing for behavior change; and, of course, my new book, Tiny Habits: The Small Changes that Change Everything. It was an instant New York Times bestseller for a reason: it keeps its promise to change your life with actionable tools to transform your behavior quickly and easily. There's a reason resolutions, repetition, and willpower don't work when it comes to forming lasting habits. I'm here to share expertise gained from decades of my own original research and personal experience coaching thousands of others about what it takes to wire in a new habit, and what (tiny) steps you can take today to start your own life-changing transformation. My book cracks the code on a fundamental part of how human behavior works when it comes to forming new habits, framed in terms of my Fogg Behavior Model, which states that behavior happens when three elements come together at the same moment: motivation, ability, and a prompt. I write it like this: B = MAP. This model is easy to learn and apply to everyday life. When something is easy to do, we don't need much motivation to do it. There are no tricks here, no weird fads. It's basic science, and it can be applied to any behavior--so don't hesitate to ask me anything! I'm so looking forward to answering all of your habit questions with specific tools, recipes, and advice. See you at 3 (ET, 20 UT), AMA! submitted by /u/AskScienceModerator [link] [comments] |
| What caused the spanish flu outbreak in 1918 to be one of the deadliest outbreaks ever? What made this version of the flu so deadly vs other flus? Posted: 30 Jan 2020 12:33 AM PST |
| how do I assess if a 1072nm wavelength light emitting machine is actually emitting that light? Posted: 30 Jan 2020 03:44 AM PST How do I check (at home) if a machine emitting peak 1072nm wavelength is actually functioning? Doesn't seem to show up when using camera phone. submitted by /u/peripateticpeople [link] [comments] |
| How many times did the transition from water to land take place? Posted: 30 Jan 2020 03:21 AM PST When we talk about the evolutionary transition from water to land, we usually think of some lungfish giving rise to land living vertebrates, but surely that wasn't the first land living organism, right? When did Arthropods and Mollusca first walk on land? was that before vertebrates or after? When did plants and Fungi come into play? did they make the transition separately or did they evolve into existence after some ancestor made the transition? Did fungi come first or did plants come first? How did the first land based organism survive without organic material on land to feed on? An answer to my questions would really make my day. submitted by /u/R3c3n71yD3c3a53d [link] [comments] |
| What is the smallest number of cells in a multicellular organism found in nature? Posted: 29 Jan 2020 04:28 PM PST Basically, a nematode worm apparently has around 1000 cells. Are there any multicellular organisms with, say, 10 cells? submitted by /u/EPIKGUTS24 [link] [comments] |
| From what I understand, macrophages are constantly trying to break down ink in tattoos, so do tattoos cause chronic hyperinflammation? If so, isn't this a serious problem? Posted: 29 Jan 2020 09:39 PM PST I know that hyperinflammatory contexts are harmful, both in the CNS and periphery (with lots of crosstalk), so this seems like something that should be a concern. So what am I missing? submitted by /u/dtmtl [link] [comments] |
| Why do we need to run burns under water for 20+ mins when the heat is gone in seconds? Posted: 29 Jan 2020 11:30 PM PST |
| How does penecilin kill bacteria? Posted: 29 Jan 2020 05:32 PM PST The real question is how has bacteria became so antibiotic resistant, but I was hoping this would tie into it. submitted by /u/MasonNasty [link] [comments] |
| What Causes Some Ion Channels To Be Selectively Permeable To One Of Na or K, But Not The Other? Something about hydration shells? Posted: 29 Jan 2020 06:13 PM PST Kills me not being able to find specific, in-depth answers on physiological concepts like this. Only answers I've seen mention hydration shells, but never go into detail. Google has brought up nothing. submitted by /u/lift_fit [link] [comments] |
| How do Solar Flares Transmit through Space when Space is a Vacuum? Posted: 30 Jan 2020 02:31 AM PST |
| What causes the red color of rust (Fe2O3)? Posted: 30 Jan 2020 02:11 AM PST I was trying to understand why the material absorbs most wavelenghts except red on an atomic level. I know the PI electron-absorption of azo dyes can be calculated with the amounts of conjugated double bond next to the N=N, but I have no idea how we can deduce the colour of inorganic matter. submitted by /u/StonedHedgehog [link] [comments] |
| How do scientists accurately determine exactly when a species was introduced to a land outside its native distributional range? Posted: 30 Jan 2020 01:58 AM PST |
| How do scientists know two particles are actually entangled and not randomly reacting in sync? Posted: 29 Jan 2020 04:38 PM PST How does a scientist know that two particles are actually entangled? How do they know it's not random chance that the two particles seem to be reacting in sync? submitted by /u/xendaddy [link] [comments] |
| How can minocycline cause muscle pain? Posted: 29 Jan 2020 09:34 PM PST Hi everyone! I read in the package insert that minocycline can cause muscle pain. I'm curious – through which mechanism could it do that? Can it cause muscle pain directly, or would that muscle pain be a symptom of some other ailment it could cause? Thank you in advance! submitted by /u/Belaerys [link] [comments] |
| Where do opposite sex hormones come from? Posted: 29 Jan 2020 04:33 PM PST I know that both men and women have both estrogen and testosterone (in different amounts of coarse) I also know that estrogen is produced in the ovaries and that testosterone is produced in the testicles so my question is where do women get their testosterone and where do men get their estrogen? submitted by /u/Perfectclue [link] [comments] |
| Why does it take around 6 months to develop a new vaccine? Posted: 29 Jan 2020 10:37 AM PST I read from the WHO that it can take 5-6 months to get a new vaccine out, is this because of pushing it through human trials, funding issue or technological limitations etc? What are the main limiting factors at the moment? submitted by /u/seanmashitoshi [link] [comments] |
| Is it true that citron fruits stay on the tree for multiple years (and one other citron question)? Posted: 29 Jan 2020 11:30 AM PST The Talmud in Tractate Sukkah claims a few times that the etrog fruit (called citron in English) stays on the tree over multiple years and keeps growing, unlike most other fruits that fall off the tree once they've ripened the same year that they formed. Is this true in reality? Do citron fruits keep growing on the tree for multiple years? Do other citrus fruits do this? Do any other species of fruit do this? Furthermore, the medieval Talmudic commentator Rashi explains one passage in the Talmud by claiming that while most fruits' seeds are able to be planted and grow into a new tree before the fruit has fully matured and ripened, the etrog's seeds can only be planted and grow once the fruit has ripened. Is this true of citron seeds? Is it true of other citrus seeds? Is it true of other species of fruit seeds? submitted by /u/ScientificTalmudist [link] [comments] |
| Do pressure waves from explosions travel at the speed of sound? Posted: 29 Jan 2020 08:55 AM PST Or a more general question - do all pressure waves travel at the speed of sound? This doesn't sound right to me, but I don't know the relevant physics to prove why. submitted by /u/yeerth [link] [comments] |
| Why polymorphic form of crystal of API is used in the suspension meanwhile amorphous form is used in the solid dosage form? Posted: 29 Jan 2020 05:29 PM PST For BCS class II, posaconazole crystal form 1 was used in the delayed release tablet whereas crystal form I or IV was used in the suspensions! submitted by /u/Niloyrans [link] [comments] |
| How are fingerprints so stable throughout an individual’s life? Posted: 29 Jan 2020 12:17 PM PST I understand how every single human has their own fingerprint, because of how the skin forms and folds. But since this isn't DNA related (even homozygous twins have different fingerprints) how are fingerprints the same throughout an individual's life even if the whole epidermis is replaced very often (I think I read it is replaced something like once a month)? submitted by /u/DespicableMax [link] [comments] |
