Update: We’re all finished answering questions for the day. Thank you for all of the great questions and interest in our work! Thanks, The Dunn Lab. Microbes live everywhere, and are linked to everything we do. The Dunn lab aims to tell the stories of the small species – whether on our bodies, in our homes or our backyards – that humans interact with every day but tend to ignore. The ecology and evolution of these species has barely begun to be explored. We are tackling the unknown with the help of the public, through citizen science research. Here are some of our projects: The Sourdough Project: Humans have baked bread for over 10,000 years. All over the world, different cultures bake their own unique breads – and have for centuries. Yet we know almost nothing about the microbes that truly make a traditional sourdough bread. We have collected over 500 sourdough starters from 17 countries and are now engaging middle school students to grow and study their own starters, on a quest to understand the microbial zoos that transform flour and water into fluffy, nutritious, aromatic bread. The Crop Mutualist Project: Crop plants have many kinds of mutualists. Flies, bees, and wasps pollinate many crops and in many cases those relationships are specific. But others of the mutualists are smaller, they include the fungi and bacteria that aid plant roots in finding nutrients and also the fungi and bacteria that dwell in and on plant leaves and, in doing so, help to defend them against pathogens and, in some cases, against pests. It is these microscopic partners on which we will initially focus. The Great Pumpkin Project: We are documenting the insects and microbes that visit all cucurbit plants, including pumpkins (which are native to the Americas) and cucumbers (which are native to Asia). These plants are now grown and enjoyed throughout the world, yet we know very little about the microbes and insects that grow with them. The Wild Life of Our Homes: Human homes are often considered to be unique from the environments in which we evolved. Though we now spend most of our lives indoors, it has only been in recent years that we have started to fully explore the diversity of microbes which colonize and persist in these spaces. With the help of citizen scientists, our lab has studied the differences among interior surfaces within homes from North America (e.g., how microbial communities vary on pillows compared to toilet seats). We are now expanding this research to include differences in home design, as well as to consider how our species interactions may have changed throughout human history. We’re doing this AMA as part of the National Human Genome’s National DNA Day Reddit AMA series to celebrate how genomics is used in our everyday lives. Ask us anything about our work on microbial ecology in guts, crops, homes, sourdough, and other fermented foods! Your hosts today are: Dr. Rob Dunn, professor of applied ecology Dr. Erin McKenney, postdoctoral researcher studying microbial community dynamics and the relationship between taxonomy, function, and niche space in sourdough and guts. I’m interested in coupling research and education, and I am also a blacksmith. Dr. Anne A. Madden, postdoctoral researcher studying the bacteria and fungi of diverse environments (not limited to fermented foods and beverages, insects, and built environments) and developing human applications from these insights. Dr. Lori Shapiro, postdoctoral researcher studying how agricultural systems change selective pressures on plant-insect and plant-microbe interactions. I use cucurbits as model systems to investigate how landscape scale changes associated with agriculture affect crop mutualists. Megan Thoemmes, doctoral candidate studying the interface between the human body and the indoor environment. I am interested in how our species interactions have changed over time, as our homes have become more permanent and further removed from the natural world. Lauren Nichols, research technician studying how species adapt to their environment and how this affects inter-species interactions and evolutionary diversification, particularly in the context of anthropogenic environmental changes. Learn more about the Dunn lab: http://robdunnlab.com/ Learn more about our citizen science projects: http://studentsdiscover.org/ Ongoing work in the Dunn lab considers the role of wasps and ants in traditional vineyards, the biology of pants, the potential value of microbes in camel crickets to industrial waste remediation, and the biology of foods such as sourdough bread. In general, Dr. Dunn uses insights from basic ecology and evolution to make new discoveries but also to achieve applied goals.

We’re genetic counseling experts with the National Society of Genetic Counselors. Genetic counselors receive special training in two areas: genetics and counseling. We use our advanced training to guide and support patients seeking more information about how inherited diseases and conditions might affect them or their families, and to interpret genetic test results. The genetic counseling process integrates: Interpretation of family and medical histories to assess the chance of disease occurrence or recurrence. Education about inheritance, testing, management, prevention, resources and research. Counseling to promote informed choices and adaptation to the risk or condition. Helping patients and families prepare for or navigate at-home genetic test results. NSGC serves as an integral resource for patients, prospective students and healthcare providers interested in learning more about genetic counseling. We’re doing this AMA as part of the National Human Genome Research Institute’s National DNA Day Reddit AMA series! Ask us anything! Here’s a bit about those of us answering your questions today: Erica Ramos, MS, CGC: I am NSGC’s President and Personalized Medicine Expert. I can discuss next-generation DNA sequencing technologies such as whole genome and whole exome sequencing, and how these technologies are impacting healthcare and benefiting patients. Amy Sturm, MS, CGC, LGC: I am president-elect of NSGC and NSGC’s Cardiovascular Expert. I have more than 14 years of experience helping patients with a higher risk of genetic heart disease understand their familial risk and genetic testing results. I am a nationally recognized expert on familial hypercholesterolemia and can also discuss other hereditary forms of heart disease, including cardiomyopathies, arrhythmias, familial aneurysms and others. Joy Larsen Haidle, MS, CGC: I am a past president of NSGC and an NSGC Cancer Expert. I can discuss hereditary cancer syndromes such as Lynch syndrome and hereditary breast cancer. I am an active public policy advocate for genetic testing. Jason Flanagan, MS, CGC: I am NSGC’s Reproductive Health Expert. I can discuss preconception and prenatal genetics, such as how genetics affect infertility and miscarriage, as well as the process and ethics surrounding preimplantation genetic screening. Ana Morales, MS, LGC: I am NSGC’s Cardiovascular Genetics and Spanish-Language Expert. I specialize in genetics and heart conditions and I’m a nationally recognized expert on cardiomyopathy, a common condition in which the heart muscle’s ability to pump blood is diminished. I can also discuss how I’ve worked to expand access to genetic information in the Spanish-speaking community. Brianne Kirkpatrick, MS, LCGC: I am NSGC’s Ancestry Expert. I can discuss the use of genealogy and DNA testing for exploring family connections and genetic health risks. I can also discuss limitations and benefits of the popular at-home genetic tests. Blair Stevens, MS, CGC: I am NSGC’s Prenatal Expert. I have 10 years of experience counseling patients and their families about their risks to have a baby with a genetic condition as well as testing options for conditions such as Down syndrome, cystic fibrosis, sickle cell anemia and spina bifida. I have a passion for helping families who carry a pregnancy diagnosed with a genetic condition or developmental difference. Trish Brown, MS, LCGC: I am NSGC’s Policy and Nutrition Expert. I have more than 20 years of experience in clinical genetics and can discuss DNA testing for nutrition and fitness, at-home genetic tests, the study of pharmacogenetics, and policy issues. If you would like more information about genetic counselors and the role we can play in your healthcare, visit our website: aboutgeneticcounselors.com. Updated: Thank you all for participating in today’s AMA! We’ve enjoyed answering your questions. You can find more easy-to-understand genetics information on our website AboutGeneticCounselors.com. If you’re interested in genetics and infertility and have more questions on the topic, tune into a free webinar tonight at 7 p.m. CT. Sign up and see future webinar topics here: https://goo.gl/ZDFTrM Thank you, Reddit!

I will return at 12PM EDT to answer questions live. Please feel free to leave questions ahead of time! I am Clare Chambers, University Senior Lecturer in Philosophy at the University of Cambridge. I am a political philosopher specialising in contemporary feminist and liberal theory. I’ve been researching and teaching at Cambridge for twelve years. I was educated in the analytical tradition of political theory at the University of Oxford, where I did Politics, Philosophy, and Economics as an undergraduate. After a year spent as a civil servant I studied for an MSc in Political Theory at the London School of Economics. At the LSE I continued working on analytical approaches to political theory in contemporary liberalism, but I also engaged in a sustained way with feminist thought, and with the work of Michel Foucault. It seemed obvious that Foucault’s analysis of power and social construction was of profound relevance to liberal theory, but l had never read work that engaged both traditions. Wanting to work on this combination for my doctorate, I returned to Oxford to be supervised by Prof Lois McNay, who specialises in feminist and post-structural theory, together with Prof David Miller, who specialises in contemporary analytical thought. The result was a thesis that later became my first book: Sex, Culture, and Justice: The Limits of Choice (2008). Sex, Culture, and Justice argues that the fact of social construction undermines the liberal focus on choice. Liberals treat choice as what I call a “normative transformer”: something that changes a situation from unjust to just. If someone is disadvantaged liberals are likely to criticise that disadvantage as an unjust inequality, but will change that assessment if the disadvantage results from the individual’s choice. For example, women may choose to take low-paid jobs, or to prioritise family over career, or to follow religions that treat them unequally, or to engage in practices associated with gender inequality. However, our choices are affected by social construction. Our social context affects the options that are available to us. It affects whether those options are generally thought to appropriate for people like us. And it affects what we want to do. I argue that, if our choices are socially constructed in these ways, it doesn’t make sense to use them as the measure for whether our situation or our society is just. Instead we need to develop the normative resources for critically analysing choice. Most feminists understand this, and liberals should, too. Feminism is a movement that seeks to empower women, which in part means giving women choice, but it is also a movement that recognises the profound limitations on individual choice, and the way that power, inequality, and social norms shape our choices. My most recent book also combines feminist and liberal analysis and tackles a specific question of state regulation. Against Marriage: An Egalitarian Defence of the Marriage-Free State argues that the state should not recognise marriage. Even if state-recognised marriage is reformed to include same-sex marriage, as has happened in many states recently, it still violates freedom and equality. Traditionally, marriage entrenches sexism and heterosexism, and this traditional symbolic meaning has not been destroyed. And all state recognition of marriage treats married and unmarried people and their children unequally, elevating one way of life or relationship form above others. The fact that state recognition of marriage involves endorsing a particular way of life also means that it undermines liberty, especially as political liberals understand that idea. Instead of recognising marriage, the state should regulate relationship practices. Other areas that I work on include multiculturalism and religion, political liberalism and the work of John Rawls, beauty and cosmetic surgery, the concept of equality of opportunity, and varieties of feminism including liberal feminism and radical feminism. I am about to start a new project on the political philosophy of the unmodified body. Thank you for joining me here! (My proof has been verified by the moderators of /r/philosophy.) Some of My Work: “Marriage as a Violation of Equality” - the first chapter of Against Marriage (OUP 2017). You can purchase this book with a 30% discount by going to the OUP site and using promocode AAFLYG6 at checkout Podcast interview on “The State and Marriage” “The Marriage Free State” - podcast recording and paper draft “Sex, Culture and Justice” - interview at 3:AM Magazine Multiculturalism Bites podcast interview on when intervention in peoples’ lives is justified Thank you very much everyone! I really enjoyed your questions. I’m logging off now as the sun starts to set here in the UK. If you’d like to read more about me and follow my work you can find lots more on my website at www.clarechambers.com, which is regularly updated. Goodbye!

In 2016, Web of Science (WoS) was sold to private equity and incorporated into Clarivate Analytics. Our vision for WoS is both ambitious and long-term. When used responsibly scientometrics and bibliometrics offer vital measures of scientific and research output and impact. The Journal Impact Factor, derived from WoS data, is one metric that is particularly valued. But it is not, and should not, be the only measure. For years, these limitations have encouraged healthy debate among the academic community, which has spurred the development of additional ranking platforms that have varied in accuracy. I believe that our history, expertise, and—most importantly—publisher-neutral status perfectly positions WoS to advance the field of scientometrics. And that is exactly what we’re setting out to do. In February, we re-established the Institute for Scientific Information (ISI), which will act as a think-tank, to identify gaps in and explore new ways to enhance scientometrics. Today, Clarivate Analytics announced the acquisition of Kopernio, the definitive publisher-neutral platform for research workflow and analysis for scientific researchers, publishers and institutions worldwide. Kopernio’s vision is to legally provide one-click access to millions of journal articles and academic research papers across the globe, dramatically improving and facilitating access to scientific knowledge. Not only will it revolutionize how academics access research papers, it will also provide unprecedented insights for institutions and publishers into how academics consume this research. These kind of data could feed into article-level scientometric analysis that could, one day, produce a novel way to measure research impact. The path of scientific discovery is long, and every now and then this path is punctuated by a eureka moment. A breakthrough. Today, I’m excited because I believe we are at a new dawn for scientometrics… I’ll be back at 1 pm EDT (6 pm GMT) to answer questions. UPDATE I think our time is nearly up! Thanks everyone for your questions, they’ve been great! I’m happy to come back later and respond to anything I’ve missed. Where has the time gone? You can find out more about our Kopernio acquisition here: https://clarivate.com/blog/news/clarivate-analytics-acquires-research-startup-kopernio-accelerate-pace-scientific-innovation/

Hi Reddit, my name is Natalia Trayanova, and I’m a professor of biomedical engineering and medicine at Johns Hopkins University. My lab uses predictive computer simulations to generate personalized virtual hearts of patients that have life-threatening arrhythmias. These first-of-their-kind virtual hearts are already being used in the clinic to assess patient risk of sudden cardiac death and to guide personalized anti-arrhythmia interventions. Simulation-driven engineering has put rockets in space, and airplanes in the sky. We trust engineering advances with our lives, however, when it comes to our own health, things are quite different. Computer simulations are rarely used in medicine. Our vision is to change this – we aim to bring computer simulations to the clinic, to make precise decisions for treatments for heart disease. We believe implementing an engineering data-driven simulation approach will increase the efficacy of diagnostic and clinical procedures for heart rhythm disorders and democratize the delivery of cardiac healthcare. You can learn more about our virtual heart approach in a recent TEDx talk [https://www.youtube.com/watch?v=wSDMPxGGy3A], and in this video describing our pioneering approach [https://youtu.be/bX62KNOfdBs]. We hope our virtual hearts will become a routine tool in the clinic, improving patient outcomes, which would be an unprecedented merging of computational simulation and clinical medicine. It has been extraordinarily fulfilling to have transcended my role as scientist and engineer, to be working directly with physicians helping patients. This is an unexpected and an exhilarating place to be. I look forward to having you #AskMeAnything on April 2nd, 1 PM ET.

Just like last year, 2016 and 2015, we are not doing any April Fool’s day jokes, nor are we allowing them. Please do not submit anything like that. We are taking this opportunity to have a discussion with the community. What are we doing right or wrong? How could we make /r/science better? Ask us anything. Further, if you’ve completed a degree, consider getting flair in r/science through our Science Verified User Program /r/science has a a system of verifying accounts for commenting, enabling trained scientists, doctors and engineers to make credible comments in /r/science . The intent of this program is to enable the general public to distinguish between an educated opinion and a random comment without a background related to the topic. What flair is available? All of the standard science disciplines would be represented, matching those in the sidebar. However, to better inform the public, the level of education is displayed in the flair too. For example, a Professor of Biology is tagged as such (Professor | Biology), while a graduate student of biology is tagged as “Grad Student | Biology.” Nurses would be tagged differently than doctors, etc… We give flair for engineering, social sciences, natural sciences and even, on occasion, music. It’s your flair, if you finished a degree in something and you can offer some proof, we’ll consider it. The general format is: Level of education | Field | Speciality or Subfield (optional) When applying for a flair, please inform us on what you want it to say. How does one obtain flair? First, have a college degree or higher. Next, send an email with your information to [email protected] with information that establishes your claim, this can be a photo of your diploma or course registration, a business card, a verifiable email address, or some other identification. Please include the following information: Username: Flair text: Degree level | Degree area | Speciality Flair class: for example: Username: nate Flair text: PhD | Chemistry | Synthetic Organic Flair Class: chemistry Due to limitations of time (mods are volunteers) it may take a few days for you flair to be assigned, (we’re working on it!) This email address is restricted access, and only mods which actively assign user flair may log in. All information will be kept in confidence and not released to the public under any circumstances. Your email will then be deleted after verification, leaving no record. For added security, you may submit an imgur link and then delete it after verification. Remember, that within the proof, you must tie your account name to the information in the picture. What is expected of a verified account? We expect a higher level of conduct than a non-verified account, if another user makes inappropriate comments they should report them to the mods who will take appropriate action. Thanks for making /r/science a better place!

Hi! We’re Robert Katzschmann and Joseph DelPreto, researchers at MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) who work in the field of soft robotics. We just published a paper in Science Robotics on “SoFi” (pronounced Sophie), a soft robotic fish we created that can swim alongside real fish in the ocean. We’re hoping a platform like SoFi could enable nature filmmakers to better document marine life up-close, monitor ocean pollution, and someday even inspect underwater infrastructure like oil rigs and pipelines. We’ll be online today at 2pm EST to answer your questions. Feel free to ask us about SoFi, our other projects (including a soft gripper for robot hands, a dynamic soft manipulator arm, 3d printed soft robots, and robots corrected by brain signals), our academic backgrounds, and anything else you want to know about. Note: Access to full Science Robotics paper via our lab website, search for and click on link called “Paper: Official full text version formatted/edited by Science Robotics”. Requisite disclaimer: we are by no means speaking for MIT or CSAIL in any official capacity!

See the eLife flyer and this post for pictures! Daniel Himmelstein (@dhimmel on Reddit, Steem, and Twitter) – Hi Reddit! I’m a data scientist in Casey Greene’s lab at the University of Pennsylvania. Before this, I got my PhD in Biological & Medical Informatics at the University of California, San Francisco. One reason I took the job at Penn (watch me accept the job on YouTube) was because I wanted to continue advancing open science – the idea that science will progress most quickly if research is immediately open without barriers to reuse and collaboration. Sci-Hub is a website that brands itself as the first pirate website in the world to provide mass and public access to tens of millions of research papers. It is a controversial form of open science, because it infringes upon the copyright of publishers. However, it’s interesting because we think it will push scholarly publishing towards more open business models. Therefore, when Sci-Hub tweeted the list of every article in its database in March 2017, we began analyzing it openly on GitHub. Fast-forward almost a year and, after the publication of three preprint articles, we published our findings in the journal eLife with the title Sci-Hub provides access to nearly all scholarly literature. We also created a Stats Browser to help anyone explore the data. Casey Greene (@greenescientist on Reddit, Steem, and Twitter) – My research lab is in the Department of Systems Pharmacology and Translational Therapeutics at the University of Pennsylvania. Our primary focus is on developing machine learning methods to better understand human health and disease. I also run the Childhood Cancer Data Lab for Alex’s Lemonade Stand Foundation, which is focused on integrating large-scale data to accelerate the pace of discovery. In addition to our research, I have an interest in the process of scientific communication, including our work studying Sci-Hub, our efforts to write a review paper entirely in the open via GitHub, and our biOverlay effort to launch an overlay for the life sciences. We’re here to answer questions about our eLife paper, or our work more broadly. We’ll start answering questions at 2pm EDT. AMA!

Immersive modes, such as Augmented Reality and Mixed Reality headsets, have the power to revolutionize how we work, play, teach, learn and shop. Enterprise already offers solutions for specific AR tasks in engineering, manufacturing, design, health care, architecture, retail and gaming; return on investment is mainly cost avoidance (shorter learning cycles, less errors, better communication, productivity and yields, etc.). However, most actors involved in developing the AR ecosystem (from hardware to app development platform to apps and content) agree that it will take a long time for hardware to hit the consumer level comfort required for mass adoption (5 to 10 years). Some of the hardware issues to solve, specifically from an optical engineering point of view, are: • Higher FOV and higher resolution through active foveation • Vergence Accommodation Conflict (VAC) mitigation through varifocal, multifocal, light field or true holographic display • Pixel occlusion for HDR for more “realistic” holograms • Higher brightness over a decent eye box for external usage (lower power, higher brightness / contrast displays and high efficient optics) • More accurate, less power, more compact IR and visible sensors (sensor hardware fusion: Head tracking, eye tracking, gesture tracking, 3D scanning, multispectral) There are many other challenges for the ultimate consumer AR experience (such as overall CG, size and weight, battery life, head dissipation, 5G connectivity for cloud rendering, etc…) which we will not discuss today. If you would like more information outside of this AMA, I will be at SPIE Photonics Europe in Strasbourg, France next month for the Digital Optics for Immersive Displays conference. You can also take my free course “An Introduction to VR, AR, MR and Smart Eyewear: Market Expectations, Hardware Requirements and Investment Patterns” on the SPIE Digital Library. It was recorded live at SPIE Photonics West in January. Enjoy!

Hi Reddit, my name is Chris Ruff [https://www.hopkinsmedicine.org/profiles/results/directory/profile/0000031/christopher-ruff], and I’m an anatomist and biological anthropologist at the Johns Hopkins University School of Medicine. During my 35 years of teaching anatomy, I’ve seen many changes in how we introduce students to this subject. Anatomy forms the foundation for much of medicine, but can be difficult to learn, so finding the best ways to communicate that information is important. Dissection of cadavers has always been a key part of anatomical training, because of the realism and experience with the actual body that it involves. However, increasingly we also use computer software to reinforce or review anatomical structures or concepts. Recently, we have developed a new product that makes learning muscles and bones fun and interactive. It’s designed for both medical professionals and anatomy neophytes. [https://www.hopkinsmedicine.org/news/articles/anatomy-app-offers-interactive-learning-from-johns-hopkins-expert] I’ll be back at 1 pm ET today to answer your questions.

EDIT 4:35 pm ET: Thank you all for your excellent questions. It’s been a lot of fun sharing our science with you. We’re signing off now. We have just published a study detailing “Steve,” an aurora-related dancing purple light first spotted – and named! – by amateur photographers. This new information about Steve comes from analyzing satellite data, all-sky cameras and additional citizen-scientist photographs. Steve’s scientific name is now Strong Thermal Emission Velocity Enhancement (which can still be shortened to STEVE). STEVE appears as a faint purple ribbon of light in the sky and is often accompanied by a short-lived, green, picket fence structure. It looks much like an aurora but occurs at lower latitudes closer to the equator. After analyzing satellite data, we learned that STEVE is the visible side of something we were already familiar with: sub auroral ion drift (SAID), a fast moving stream of extremely hot particles. SAIDs appear in areas closer to the equator (like southern Canada) than where most auroras appear. Until now, we never knew SAIDs had a visual component! Studying STEVE can help us paint a better picture of how Earth’s magnetic fields function and interact with charged particles in space. You can help us learn more about STEVE by submitting your photographs and sightings of the phenomenon to a citizen science project called Aurorasaurus (online at aurorasaurus.org or on your device as iOS and Android apps). Check here for more details about how to spot STEVE. Answering your questions today are: Liz MacDonald, space scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and founder of Aurorasaurus Chris Ratzlaff, citizen scientist who first named Steve; runs the Alberta Aurora Chasers Facebook group Burcu Kosar, space scientist at NASA Goddard Matt Heavner, space scientist at the New Mexico Consortium, Los Alamos, New Mexico Bea Gallardo-Lacourt, space physicist at the University of Calgary, Canada Bill Archer, space scientist at the University of Saskatchewan, Saskatoon, Canada Megan Gillies, space scientist at the University of Calgary, Canada We are now live. @NASASun on Twitter

We regret to hear that Stephen Hawking died tonight at the age of 76 We are creating a megathread for discussion of this topic here. The typical /r/science comment rules will not apply and we will allow mature, open discussion. This post may be updated as we are able. A few relevant links: Stephen Hawking’s AMA on /r/science BBC’s Obituary for Stephen Hawking If you would like to make a donation in his memory, the Stephen Hawking Foundation has the Dignity Campaign to help buy adapted wheelchair equipment for people suffering from motor neuron diseases. You could also consider donating to the ALS Association to support research into finding a cure for ALS and to provide support to ALS patients.

Our current focus is to solve the data challenge to model diseases the way they actually happen – where multiple factors from genes to lifestyle (how much you drink and smoke) work in parallel to protect or harm. The challenge is to analyze both structured and unstructured data in parallel, from genetic sequences to MRI (or other clinical scans) and to do so across large populations of diseased patients plus healthy controls to inform treatment for an individual based on his/her own unique profile. The computational challenge is massive given the exponential number of data combinations that need to be analyzed. I’ve also been applying artificial intelligence & machine-learning to develop knowledge graphs and semantic search tools to enable automated discovery of related concepts versus the traditional approach of applying keywords to search queries. I have designed, built and brought to market a number of innovative and commercially successful products to support drug discovery and clinical informatics. I am a serial entrepreneur with numerous patents and occasional angel investor specializing in informatics with a strong track record of building world-class companies, teams and products. I’d welcome your question on any of these topics above or to simply lend my experience and best practices for your professional development. AMA! My technical expertise is in: Hyper-combinatorial Multi-omics analytics Bioinformatics and Computational Biology Precision Medicine Semantic Search and Knowledge Graphs Artificial intelligence (AI) and Data Science Software-as-a-Service (SaaS) Internet of Things (IoT)

Hello Reddit! We invited your burning questions about non-Newtonian fluids in Part 1 of our lab’s AMA series last year, promising to test the most interesting ideas with real experiments. The time has come for us to release our results to these popular questions! 1) Can oobleck (shear thickening fluid) be used for the best kind of speed bumps? (Credit: /u/slp50) ANSWER: Yes! Turns out /u/slp50 had the best idea all along. Experiment: We drove a remote controlled car over two different types of oobleck speed bumps at different speeds. The resultant video itself not the most interesting, but we analyzed the vertical acceleration of the car in slow-mo, and the analysis shows some really exciting results! When we compared our data with people driving their cars over all kinds of road speed bumps in 1973 (source: G. R. Watts, Transport and Road Research Lab Report, 1973), we find that non-Newtonian speed bumps are actually MORE COMFORTABLE AT LOW SPEEDS! And on the flip side, they are really uncomfortable if the car exceeds a certain critical speed! So, this idea is a winner. 2) What happens if you shoot ultra-strong sound waves into oobleck? (Credit: /u/ittimjones) ANSWER: The water inside the oobleck ends up quickly separates from the solid particles, and the entire non-Newtonian fluid expands. See our experimental video here. 3) What happens if you inject oobleck onto oobleck, or drop other non-Newtonian fluids onto themselves? (Credit: /u/bangbangIshotmyself) ANSWER: This one was really hard to do experimentally, so we changed it just a bit: we injected colored water into a normal liquid, a transparent gel that flows kind of like ketchup (yield stress fluid), and oobleck (shear thickening fluid). The gels lock the injected fluid in place, while oobleck “spits out”, or phase separates, the injected fluid. Check out our experiment here. 4) What if we drop a ball in these fluids? (Credit: /u/Croanius) ANSWER: We tried two types of non-Newtonian fluids: a liquid gel made of clay, and our cornstarch oobleck. Balls get stuck in the gel, and balls bounce on oobleck. Did you know that the army uses gels to test the effect of ballistics on humans, because no matter how much we work out, our bodies are basically jello? You can check out our results of dropping a ball into non-Newtonian fluids here. 5) Is full fat mozzarella cheese really necessary for the best kind of pizza (where the cheese is stretchy)? (Credit: /u/voilsb) ANSWER: For pizza connoiseurs: Yes, you must use full-fat mozzarella cheese if you want to reproduce that stretchy cheese phenomenon found in Pizza Hut commercials. We tested full-fat and skim-milk mozzarella, and the full-fat moz stretches extremely well above 80°C (175°F). See our experiment here. 6) Are cats non-Newtonian fluids? (Credit: Dr. Goulu) ANSWER: YES! But it depends on the situation and mood of the cat. Hear it from the IgNobel Physics prize winner! Tell us what you think about these experiments, non-Newtonian fluids, or just science life in general. Our lab members will be here to answer your questions all day.

As director of the Center for Western Weather and Water Extremes at Scripps Institution of Oceanography at UC San Diego, I lead a team of researchers focused on understanding the physical processes that create extremes in precipitation, ranging from flood to drought. We are also focused on advancing extreme weather monitoring, predictions, climate projections, and decision support tools. The core of my research is to better understand atmospheric rivers, bands of moisture in the sky that can carry more water (as vapor) in them than any terrestrial river in the world (as liquid). These bands can deliver as much as half of California’s water supply in a handful of precipitation events every year. This winter, I’m leading a field effort with the National Weather Service using NOAA’s Gulfstream IV and two Air Force WC-130J Super Hercules planes, manned by Air Force Hurricane Hunter crews, to study any atmospheric rivers that form over the Pacific Ocean and hit the West Coast. The planes will be stationed in Hawaii, Seattle, and Northern California, and when the conditions are right, we’ll fly through atmospheric rivers, dropping instrument-laden, parachute-tethered dropsondes across the width of the storms to collect data. Our ultimate goal is to provide research and information to the National Weather Service and California Department of Water Resources to help improve atmospheric river forecasts. The effort is related to a study exploring the potential of using atmospheric river forecasts in reservoir operations on Lake Mendocino in northern California to support water supply management, flood mitigation and recovery of endangered salmon, supporting the U.S. Army Corps of Engineers. Ask me anything about atmospheric rivers or other western US extreme weather and water events!

I’m Debra Satz, the Marta Sutton Weeks Professor of Philosophy at Stanford University and co-host of the Philosophy Talk radio program. I grew up in the Bronx, and was the first of my family to go to college. From there, I graduated from City College of New York and received my PhD from M.I.T. where – after toying with the idea of writing on the philosophy of logic – I wrote a dissertation focusing on Marx’s theory of social progress. Although I have traveled far from where I began, my experiences growing up in the Bronx continue to influence my work and thought. My philosophical work has been broadly concerned with the economic preconditions for a democratic society of equals. But rather than approaching this question at a very high level of abstraction, I have focused on the ethics behind the creation and operation of particular markets. Markets in the abstract are models of freedom and equality. Freedom because each has the choice to enter into, or refrain from entering, any particular exchange. Moreover, because each of us is linked through countless others, no one is under the thumb of any particular person. This latter point also underwrites our equality. In theory, neither is dependent on the other and each has the right to refuse a deal which we view as unfair. But, in reality, many markets depart very far from that theory. Some markets involve agents who are asymmetrically situated: One person desperately needs a good that only the other has (think of credit markets in the developing world); or, one person has relevant knowledge that another person lacks (think of the market for used cars). Moreover, some markets involve risks that fall on others besides the transacting agent (think of exchanges that generate pollution); or markets where others are transacting on our behalf (think of child labor markets where parents transact on behalf of their children, or governments where dictators transact debt on behalf of their populations). My book, Why Some Things Should Not be For Sale: The Moral Limits of Markets develops a theory that distinguishes between ordinary markets that resemble abstract markets and what I call noxious markets. Noxious markets are characterized along four parameters: weak agency, background vulnerability and inequality of the transacting agents, harms to individuals, and harms to society. My book examines markets in body parts, commercial surrogacy, child labor and prostitution. Importantly, I argue that the fact that a market is noxious does not entail the conclusion that we should ban it. It may be possible to increase agency (by giving parties better information) or address third party harms through regulation. But a message of my work, which resonates with a long tradition of political economy (where figures such as Adam Smith, David Ricardo, Karl Marx and RH Tawney are central) is that not all markets are the same. I also have interests in the distribution of educational opportunities, where I have argued that the sharp divide policy makers and philosophers draw between adequacy approaches and equality approaches is overdrawn. A theory of distributing educational opportunity that is adequate for a democratic society will have strong egalitarian elements. In addition to pursuing my interests in education (which was my path out of poverty), I am writing a paper which examines the role of the state’s distribution of in kind goods (such as health care) for a democratic society of equals. I look forward to discussing my work with you on reddit! Links of Interest: My book: Why Some Things Should Not be For Sale: The Moral Limits of Markets. Thanks to OUP can purchase it 30% off from their site with promocode AAFLYG6. A newer co-authored book dealing with the relations between ethics and economics: Economic Analysis, Moral Philosophy and Public Policy, Third Edition My Stanford Encyclopedia Article on Feminist Perspectives on Reproduction and the Family My Ethics article “Equality, Adequacy and Education for Citizenship” My class day speech at Stanford University on the Moral Limits of Markets The Philosophy Talk radio program which I co-host

Hi Reddit, my name is Albert Lau, and I’m a biophysics professor and computational and structural biologist at Johns Hopkins University School of Medicine. I am interested in studying how biologically relevant molecules interact and change shape in order to carry out their physiological functions. My lab has focused on studying proteins called glutamate receptors that help neurons in the brain communicate with each other and are necessary for learning and memory. We’ve been examining the details of how neurotransmitters, specifically glutamate, manage to bind to these receptors and what the energetic and dynamic consequences of this binding are. My team and I recently published a paper in Neuron that shows, in part using molecular mechanics simulations carried out on supercomputers, that flexible protein elements on the surface of the receptor accelerate the process of glutamate binding by grabbing glutamate and helping to guide it into its recessed binding pocket [http://dx.doi.org/10.1016/j.neuron.2017.11.024]. This discovery might assist the development of new therapies for neurological disorders and diseases associated with glutamate receptors, such as epilepsy, depression, and Alzheimer’s disease. Over the course of my training, I have been lucky to interact with and learn from extraordinary scientists in the fields of structural biology, computational biophysics, and neuroscience, and they have all influenced the research I pursue. I look forward to answering your questions at 1pm ET.

Hello, we are Professor Tim Lenton and Dr Damien Mansell, climate scientists from the University of Exeter. Together, our research looks into the science of Climate Change. We’re also passionate educators and have, for the last 5 years, produced free online courses that look at the Challenges and Solutions of climate change. It can be easy to feel disillusioned by climate change and as if there is nothing we can do, but that’s not true and there are many ways we can take action into our own hands. Tim: My research has looked at the evolution of the Earth System and, in particular, tipping points in the climate system. I’ve recently begun focussing on detecting early warning signals for these tipping points. If we are able to detect when a system is close to tipping, we can better assess the solutions that can prevent catastrophic climate change or reduce the impacts. Damien: I study the contemporary cryosphere (the world’s ice) and how this is changing with recent climate warming. My research uses satellite data and the development of new remote sensing techniques to study cryosphere instabilities. I’m also interested in the use of technology in teaching and education, from developing virtual field trips to these online courses. Our new course ‘Climate Change: Solutions’ discusses and applies the theme of Climate Action to the UN Sustainable Development Goals. We look at a range of solutions, from changing the way we produce energy to the way we farm, and explore where different options might be viable around the world. In particular, we’ll be focussing on the SDGs of Life below Water, Life on Land and Sustainable Cities and Communities. In this AMA, we will be joined by our facilitator team from the University of Exeter to help answer your burning questions about all things solutions! Ask us anything! We’ll be back at 11:00 am ET to answer your questions, Ask us anything!