Questions in the Science & Nature category.
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A simple mechanism made of two identical gears can be used to reverse the direction of rotation without changing the speed of rotation. Is there a simple planar linkage (e.g. 5-bar or 6-bar) with only rotary joints and rigid links that can do the same thing? [more inside]
Could a tadpole remain a tadpole, and never metamorphose, for a long time, years even? The internet implies that captivity, water temperature, or available nutrients could have an effect on prolonging a polliwog's larval state. But could this state, given the right conditions, persist for years? [more inside]
I'm doing some work for an engineering company that certifies modifications to cars. One of the tests that they perform is a lane change manoeuvre test. This test simulates an emergency lane change and back to the original lane to prove the stability of the vehicle. Given testing is relatively expensive (as it involves hiring a suitable facility), and involves some risk to the test driver, they have asked me to come up with a spreadsheet or similar that they can use to have a high level of confidence that the test will be safe before they leave the workshop. i don't know how to do that. [more inside]
Please help me understand electricity and electronics. I have read the water analogy numerous times but I still can't quite grok it. Like "Ummm, Where does the water go and does it evaporate?" I have started tinkering with a Raspberry Pi and would love to build more complicated circuits with capacitors and transistors. [more inside]
I have been told to lead a nature walk & workshop for a Girl Scout event that has a "magic" theme. This will be in the Pacific Northwest in a coniferous-riparian setting, and these are 7-17 year old girls. Yeah, I know. that's a broad range of ages. That's why I need your help. I'm a botanist. EVERYTHING sciency and outside is magical to me, so I'm hoping to make a list of very quick (<5 minute) demos with things found outside that have a big impact or are somehow surprising to a non-science audience. I'd like to avoid the pointing-and-telling kind of nature activity - I want these concepts to show themselves off somehow. Apparently I'll be doing this multiple times throughout the year so seasonality doesn't matter. [more inside]
I have a computer science background, but never got much formal training in statistics. I'm working more with data from psychological experiments and am interested in neural networks to model human behavior. I'm looking for two books (or maybe more): an intermediate book on statistics focused on applications in psychology and a basic book in modern neural networks. [more inside]
Is there a place I can compare the historical accuracy of different weather forecast websites? I'm interested in which source is best for my location, and which source is best overall. We had a previous question on this, and I've seen this website - but I am looking for multi-source comparison. Thanks!
I'm a musician, working on someone's project where the sound needs to be very accurate to the recording techniques and sound of a specific time period in the early 80s. There are many steps in the recording process, but the sound of old tape is one of the more difficult ones to get right. Even if no one here has an answer, I would love to be in touch with someone who knows what happens chemically to analog tape as it ages (under normal storage conditions), and whether it's possible to mimic that process chemically with a new reel of tape. Thanks!
Please tell me the funniest statistics-related joke or jokes that you know. I give talks and run workshops about statistical concepts - broadly defined - to mixed audiences. Jokes will be used as ice-breakers. The ideal joke will be funny to everybody, and doubly funny to statisticians. [more inside]
A friend has moved to a new townhome in Atlanta, GA and has asked for help identifying this tree. All of my searches have come up short. [more inside]
Can you help me come up with some bird-related experiments or projects for six-year-olds that teach a simple version of the scientific method? [more inside]
I am looking for nonfiction books that deal with stories of people who have lost (or gained) their sight/hearing/sense of smell, etc. Also books about people who have dealt with memory loss or other neurological problems. [more inside]
I somewhat understand Trudeau and I somewhat understand quantum computing but I don't understand either well enough to parse this video. And so I turn to you Metafilter. Please make sense of this of this for me or explain why it is just not so? [more inside]
A while ago, I saw a video where a woman speaker discussed some of the puzzles in biology about why sexual reproduction evolved and continues to happen. It covers "the cost of males" and other major drawbacks, then discusses how only models that incorporate a finite population show sex evolving and persisting. [more inside]
I'm looking for a positive ID on this bug before I get rid of it. I think it is some type of assassin bug. I live in south Georgia. [more inside]
Where can I learn about the physics of spaceflight if I don't know calculus? What books, movies, video games, websites, etc., would you recommend? [more inside]
While hiking on the Point Reyes peninsula (Marin County, California, USA), we kept smelling an almond smell. We poked and prodded various trees and plants but could not find the source of the smell. What would commonly grow in a costal fir forest that would smell like almonds? It was a strong "so where's the cookies" almond extract-y almond smell, though slightly more herby and piercing than that cheap bakery cookie smell. [more inside]
An idle curiousity question for the Green's resident chemistry boffins: is there a chemical that could break caffeine down into safe and inactive (from the body's perspective) components? [more inside]
I am struggling with explaining the origin of life, evolution and natural selection in a tangible way to my kids 4 & 5. Informing myself better has helped in the explaining, but I hope you can direct me towards videos aimed at young children which do a better job. Those I have found online are great for adults and slightly older kids, but level of detail is off-putting for them e.g. From the big bang to me, great video, but slightly too advanced.