AskScience AMA Series: My name is Pascal Lee, and I am a planetary scientist at the SETI Institute and director of the NASA Haughton-Mars Project (HMP) at NASA Ames Research Center. AMA! |
- AskScience AMA Series: My name is Pascal Lee, and I am a planetary scientist at the SETI Institute and director of the NASA Haughton-Mars Project (HMP) at NASA Ames Research Center. AMA!
- Was the Spanish flu pandemic a large enough selection pressure to cause a change in the human genome detectable in some populations today?
- How does a sponge "suck up" liquid? The liquid is moving against gravity, but it doesn't seem like any energy is being spent to do this
- Why was the solid rocket boosters of the Challenger designed in four segments requiring o'rings instead of just one piece?
- What happens to eyelashes that get stuck somewhere in the back of the eye?
- Why does infrared radiation make things hotter than visible light?
- HID Lamp ionization time - why doesn't it extinguish on AC?
- Do behavior of children solely depends on the way they’re raised or it also depends on the child itself?
- Are Quasars essentially a larger, slower Gamma Ray Burst?
- If the magnetic north pole is moving at faster rate and shifting places shouldn't the magnetic south pole also be doing that and in the opposite direction?
- Why don't countries use random sample testing to determine the prevalence of COVID-19 in the population?
- How do transistors amplify current and voltage if the law of conservation of energy states that you can't create energy?
- Is a Super Nova explosion bigger than the earth?
- What would a plasma-based rocket engine liftoff look like for spaceships?
- What factors affect the shape and terrain of continents?
- How do biological molecules bind time-efficiently?
- Is it coincidence that the geographic north and south poles are very close to the magnetic north and south poles, or is there a reason for it?
- Converting thermal energy into elecric energy?
- Why do Cooper pair electrons have to have opposite momentum?
- How do calculators/computers figure out how to display e or pi or the square root of 2? When you push the pi button on your calculator, what is it doing?
| Posted: 12 May 2020 04:00 AM PDT I am a planetary scientist at the SETI Institute and director of the NASA Haughton-Mars Project (HMP) at NASA Ames Research Center. I also co-founded and now chair the Mars Institute. I have an ME in geology and geophysics from the University of Paris, and a PhD in astronomy and space sciences from Cornell University. I was privileged to be Joe Veverka's last graduate student, and Carl Sagan's last T.A.. My research focuses on the history of water on Mars, ice and caves on the Moon and Mars, the origin of Mars' moons, and the future human exploration of the Moon and Mars. I do fieldwork at Moon and Mars analog sites, mostly on Devon Island in the Arctic where we go every summer for the HMP (https://www.marsinstitute.no/hmp), but also in Antarctica where I once wintered over for 402-days. I'm still thawing from that. I also work on surface exploration systems for future Moon and Mars exploration: drones, hoppers, rovers, spacesuits, and habitats. I was lucky to serve as scientist-pilot for NASA's first field test of the LER (Lunar Exploration Rover) SPR (small pressurized rover) concept. I also led the Northwest Passage Drive Expedition, a record-setting vehicular traverse on sea-ice along the fabled Northwest Passage - now that was a bad idea - and the subject of the documentary film Passage To Mars (2016). I currently lead the HMP's Astronaut Smart Glove project and JPL's GlobeTrotter planetary hopper concept study. I am also interested in SETI - the actual Search for Extra-Terrestrial Intelligence. I've argued that there are likely very few advanced civilizations per galaxy, and we might be the only one in ours at this time. As you might imagine, it's not the most popular view at the SETI Institute. In my free time, I enjoy being walked by my 1-year old Australian cattle dog, Apollo. I also love to fly and paint, although not at the same time. I am an FAA-certified helicopter commercial pilot and flight instructor, and an artist member of the IAAA (International Association of Astronomical Artists). I post some of my drawings and paintings on Instagram @spacetimeartist. I also wrote a children's book: Mission: Mars, published by Scholastic: link If you have nothing better to do, follow me on Facebook (https://www.facebook.com/PascalLeeOfficial/) or Twitter @pascalleetweets. I do post some interesting stuff, I have to say. AMA. Looking forward to chatting at 10am (PT, 1 PM ET, 17 UT). Username: setiinstitute [link] [comments]  |
| Posted: 12 May 2020 05:41 AM PDT I've recently finished Adam Rutherford's 'a brief history of everyone who's ever lived'. He talked about how the black death and the bubonic plague caused greater variation in the human genome amongst particular populations. I was wondering whether the spanish flu would have caused a large enough selection pressure to cause detectable changes in the human genome still noticeable today. [link] [comments]  |
| Posted: 12 May 2020 06:25 AM PDT |
| Posted: 11 May 2020 09:33 PM PDT |
| What happens to eyelashes that get stuck somewhere in the back of the eye? Posted: 12 May 2020 06:57 AM PDT I got an eyelash stuck vertically in my eye. After moistening it with some drops and rubbing the eye I noticed the eyelash was nowhere to be seen, neither inside or outside, so I guess it went behind the eyeball. This made me wonder if the intruder will in some way be dissolved or if I've got a potential nasty collection of eyelashes behind my eyes. [link] [comments]  |
| Why does infrared radiation make things hotter than visible light? Posted: 12 May 2020 04:05 AM PDT Basically the title. Also why does this occur despite the fact that visible light caries more energy per photon? [link] [comments]  |
| HID Lamp ionization time - why doesn't it extinguish on AC? Posted: 12 May 2020 06:24 AM PDT I've been researching HID lamps and their drive electronics, and information is surprisingly sparse, so if anyone can point me to something more interesting than usual datasheets I'd appreciate that. The question itself - how long does the arc last in the lamp? How long of a pause in voltage/current is allowed so the lamp doesn't has to be restriked? There are plenty of transformer/inductor ballasts are out there, driven by mains AC, and the current/voltage goes through zero, but not always at the same time due to inductance. [link] [comments]  |
| Posted: 11 May 2020 01:05 PM PDT |
| Are Quasars essentially a larger, slower Gamma Ray Burst? Posted: 11 May 2020 11:03 PM PDT |
| Posted: 11 May 2020 10:43 PM PDT |
| Posted: 11 May 2020 08:34 PM PDT So there has been a lot of talk in the media about the efficacy of the US government's re-opening guidelines. One of the major concerns has been the fact that there still isn't adequate testing available. Vox recently wrote an article about how the US needs millions of tests available per day. If the end goal of the quarantine is to bring the R-naught value below one until a vaccine has been approved, and the amount of testing available is limited, why don't states use random sample tests to derive the overall rate of infections in the population, and use those estimates to determine the overall R-naught value? I'm nature sure about the accuracy of the currently available test, but even if they were only 95% accurate, we could get a pretty good model with only 16,000 or so tests a day in the United States? I apologize if the question is sophomoric, I only have a rudimentary understanding of how virus modeling works. [link] [comments]  |
| Posted: 12 May 2020 02:23 AM PDT |
| Is a Super Nova explosion bigger than the earth? Posted: 12 May 2020 12:36 AM PDT Also about how often do they happen? I'm just curious. [link] [comments]  |
| What would a plasma-based rocket engine liftoff look like for spaceships? Posted: 11 May 2020 06:20 PM PDT I recently was fascinated by the VASIMR (Variable Specific Impulse Magnetoplasma Rocket), but I'm trying to envision what one might look like taking off in the atmosphere. Color, plume, sound, etc. I was just curious if anybody had any ideas or thoughts! [link] [comments]  |
| What factors affect the shape and terrain of continents? Posted: 11 May 2020 04:06 PM PDT With COVID-19 I've had plenty of time on my hands and got to wondering about how continents come to be as well as the terrain on them. Obviously in the distant past all the continents were originally one Pangaea and have since drifted apart, and various landmasses themselves are still being formed by volcano eruptions and suchlike. But what other factors are significant in shaping terrain, how much of an impact do they have, and how regularly do they have such an impact? Things I considered were sea level, volcanoes, extreme weather, tsunamis, earthquakes, and man-made interventions (e.g. nuclear weapons). What predictions are there concerning how our planet will look in 50 years, 100, 1000, 5000 and 20000 years? Is that a significant timescale for planetary reshaping? And how big an impact can humans have on what terrain looks like, the shape of the continents, and subsequent impacts on ecosystems and weather patterns? Apologies if this is a little too broad, but the topic feels really big. In summary, I suppose my questions are 1) What affects the shape/terrain of continents, 2) How big an impact do humans have on those factors and on their timescale, and 3) Are there any predictions or reasonable assumptions we can make about how the planet will look differently 50/100/1000/5000/20000 years from now, based on both natural and human activity? [link] [comments]  |
| How do biological molecules bind time-efficiently? Posted: 11 May 2020 09:52 AM PDT I'm trying to understand how binding in cellular activities even happens in reasonable time scales they do. For example how is it that once the right transcription factors bind to a region of DNA it becomes so kinetically favorable for the parts of RNA polymerase to bind that they bind to the correct spot within moments? Are the densities (of bases, parts of polymerase...) just kept very high and due to rapid enough random motion it ends up working? I was thinking you could model the densities of all the reactants in random motion at each step and once they reach a critical density it becomes very likely for reactions to happen as fast as we observe, [link] [comments]  |
| Posted: 11 May 2020 09:14 PM PDT I know the naming of the poles of a magnet are arbitrary, as long as we understand they are opposite, so I'm sure we named them to match the geographic poles. But, is there a reason (like the rotation of the earth) that causes them to be where they are relative to the geographic poles? Thanks! [link] [comments]  |
| Converting thermal energy into elecric energy? Posted: 11 May 2020 06:27 PM PDT Today I took something out of my fridge and thought that the concept of a fridge was pretty stupid since it uses electric energy to get rid of the (thermal) energy that the objects you put in have. Is there a way or will it be possible in the future to cool things down and while doing so converting the thermal energy into electric energy? Sorry if the question is stupid but my 17 year old mind just had this idea and I really hope you can help me out. [link] [comments]  |
| Why do Cooper pair electrons have to have opposite momentum? Posted: 11 May 2020 11:49 AM PDT Basically what the title says - I get they have to have opposite spin because the singlet state is lower and more favourable in energy and it's symmetric, but don't understand why they have to have opposite momentum as well! [link] [comments]  |
| Posted: 11 May 2020 10:21 AM PDT |
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