AskScience AMA Series: My name is Matija Ćuk, and I am a research scientist at the SETI Institute specializing in the orbital dynamics of solar system bodies. AMA! |
- AskScience AMA Series: My name is Matija Ćuk, and I am a research scientist at the SETI Institute specializing in the orbital dynamics of solar system bodies. AMA!
- Black Lives Matter
- What negative side-effects can vaccines have that need to be eliminated before it is allowed to be distributed?
- Do spiders take over webs?
- If global warming causes the oceans to rise and oceans absorb CO2, is it a considerable negative feedback loop?
- Where does the mass in a proton come from ?
- How is a mosquito's snout able to pick up and transmit diseases such as Malaria, but not HIV/AIDS, a blood trasmittable pathogen?
- Does the Monty Hall Problem apply here?
- How does the ancient eruption of Krakatoa compare to our most recent volcanic eruptions and atomic bombs?
- Why does the Jet stream converge and diverge?
- Would a constant acceleration from unlimited energy produce an observation of a non-linear acceleration from a different reference point?
- how do benign growths happen? And why do they grow a certain amount and stop?
- What are the chances this and younger generations will have significant hearing loss as we age?
- Are there any birds which produce a blue pigment?
- How do stem cells get to the axillary meristem?
- Today it's hot out. Just now I opened my sliding door and ran out, then a minute later, back in. Which action puts more burden on my AC system - running in (bringing hot air inside) or running out (losing cooled air)?
- Why do some very expensive CPUs use lots of slow cores vs. fewer very fast cores?
- What is the relationship between insulin and hGH?
- What is the difference between a continent and an island?
- Is it possible to distinguish a deterministic pseudorandom generator from a true random generator?
| Posted: 03 Jun 2020 04:00 AM PDT I earned my undergrad degree in astrophysics in at the University of Belgrade, Serbia, in 1999, and then I did my PhD in astronomy at Cornell University in 2005. I specialize in the orbital dynamics of solar system bodies, using their present orbit to figure out their past history. I usually use computer simulations, and my job involves quite a bit of programming. Back in graduate school I discovered the BYORP effect, which is driven by solar radiation and which changes the orbits of small binary asteroids very quickly (astronomically speaking). In 2012, Sarah Stewart and I had a paper in Science where we proposed that Earth was spinning very fast when the moon-forming collision happened, which made it possible to make the moon from Earth's material. My part was to show how Earth could lose excess spin afterwards through complex interactions between the Sun and the Moon. In 2016, I revisited this issue and found that early Earth was probably not only spinning super fast but also had a large axial tilt. I have also worked on the dynamics of Saturn's moons, and I proposed in 2016 that Saturn's inner moons and rings are probably only about 100 million years old. Cassini spacecraft results later suggested this is indeed the case, at least for the rings. My latest paper is on the past orbits of Martian moons Phobos and Deimos, and how the orbit of Deimos makes sense only if Mars had a large ring about 3 billion years ago. I will be on at 11am PDT (2 PM ET, 18 UT), AMA! Username: setiinstitute [link] [comments]  |
| Posted: 02 Jun 2020 10:57 AM PDT Black lives matter. The moderation team at AskScience wants to express our outrage and sadness at the systemic racism and disproportionate violence experienced by the black community. This has gone on for too long, and it's time for lasting change. When 1 out of every 1,000 black men and boys in the United States can expect to be killed by the police, police violence is a public health crisis. Black men are about 2.5 times more likely to be killed by police than white men. In 2019, 1,099 people were killed by police in the US; 24% of those were black, even though only 13% of the population is black. When black Americans make up a disproportionate number of COVID-19 deaths, healthcare disparity is another public health crisis. In Michigan, black people make up 14% of the population and 40% of COVID-19 deaths. In Louisiana, black people are 33% of the population but account for 70% of COVID-19 deaths. Black Americans are more likely to work in essential jobs, with 38% of black workers employed in these industries compared with 29% of white workers. They are less likely to have access to health insurance and more likely to lack continuity in medical care. These disparities, these crises, are not coincidental. They are the result of systemic racism, economic inequality, and oppression. Change requires us to look inward, too. For over a decade, AskScience has been a forum where redditors can discuss scientific topics with scientists. Our panel includes hundreds of STEM professionals who volunteer their time, and we are proud to be an interface between scientists and non-scientists. We are fully committed to making science more accessible, and we hope it inspires people to consider careers in STEM. However, we must acknowledge that STEM suffers from a marked lack of diversity. In the US, black workers comprise 11% of the US workforce, but hold just 7% of STEM jobs that require a bachelor's degree or higher. Only 4% of medical doctors are black. Hispanic workers make up 16% of the US workforce, 6% of STEM jobs that require a bachelor's degree or higher, and 4.4% of medical doctors. Women make up 47% of the US workforce but 41% of STEM professionals with professional or doctoral degrees. And while we know around 3.5% of the US workforce identifies as LGBTQ+, their representation in STEM fields is largely unknown. These numbers become even more dismal in certain disciplines. For example, as of 2019, less than 4% of tenured or tenure-track geoscience positions are held by people of color, and fewer than 100 black women in the US have received PhDs in physics. This lack of diversity is unacceptable and actively harmful, both to people who are not afforded opportunities they deserve and to the STEM community as a whole. We cannot truly say we have cultivated the best and brightest in our respective fields when we are missing the voices of talented, brilliant people who are held back by widespread racism, sexism, and homophobia. It is up to us to confront these systemic injustices directly. We must all stand together against police violence, racism, and economic, social, and environmental inequality. STEM professional need to make sure underrepresented voices are heard, to listen, and to offer support. We must be the change. Sources:
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| Posted: 03 Jun 2020 01:41 AM PDT |
| Posted: 02 Jun 2020 09:45 AM PDT Do spiders ever stumble upon another spiders web and occupy it? Or do they always have to build their own? [link] [comments]  |
| Posted: 03 Jun 2020 05:04 AM PDT I am aware that there are a huge number of factors at play; I'm just wondering if the effect is considerable and worth taking into account in models. [link] [comments]  |
| Where does the mass in a proton come from ? Posted: 03 Jun 2020 01:13 AM PDT I know a proton is made of two quarks up and one quark down and gluons have no (or very little mass) and when you add their mass up you don't get the mass of the proton, so where does the mass in a proton come from ? [link] [comments]  |
| Posted: 02 Jun 2020 08:31 PM PDT From a mere standpoint a mosquito's snout appears to be a miniature extendable jagged surgical needle. Despite the seemingly lack of scientific evidence available, there have been incidences such as this, though the CDC supports that Zika is already a mosquito-borne illness whilst HIV is not. Then my question is: What constitutes as a blood-borne and non-mosquito-borne illness? [link] [comments]  |
| Does the Monty Hall Problem apply here? Posted: 02 Jun 2020 09:38 AM PDT Does the Monty Hall apply in the following situation? If not, how is it different from the classic Monty Hall problem? Let's say 3 runners of equal ability are going to race. They are called Alvin, Simon, and Theodore. At the beginning of the race, I bet on Alvin. 6 miles into the race, a bear appears on the track and eats Simon. The betting office announces the chance for me to change my bet at this stage. Should I switch my bet to Theodore? [link] [comments]  |
| Posted: 02 Jun 2020 12:57 PM PDT I actually asked this in r/homeworkhelp not too long ago, but I am genuinely still curious about this. Do we even have estimates of how devastating Krakatoa's damage is? What are they, and how do they compare to the damage of some of the most recent volcanic eruptions and atom-bomb blasts? [link] [comments]  |
| Why does the Jet stream converge and diverge? Posted: 02 Jun 2020 04:26 PM PDT From what i've understood about meteorology; low and high pressure happens when e.g. the jet stream converges or diverges. I understand the basics of how this causes low and high pressure, and how the jet streams works, but not why it converge and diverge. What causes the convergence and divergence in the first place? Has it something to do with the temperature gradient? if so, what causes the temperature to vary that much, so close together? [link] [comments]  |
| Posted: 02 Jun 2020 10:33 PM PDT I am by no means very studied in physics or general relativity. If my very basic understanding of a factor of general relativity is correct, the faster an object moves compared to another object, the slower time appears to move for that object. Since velocity is a function of time, and time in affected by relative velocities, would an object under constant acceleration appear to an observer to non accelerate in a linear fashion? As the object moves faster and faster, would the time dilation produce an effect where the object, moving in its own relative field, experiences the same acceleration, but from out outside perspective, due to a comparitively slower time dilation, see the object as accelerating faster and faster, in a third derivative of position sense. To perhaps clarify. If Velocity is related to time, and time is related to velocity, would not an accelerating object eventually appear to an outside observer as having infinite acceleration and velocity due to having no time? A division by zero scenario? [link] [comments]  |
| how do benign growths happen? And why do they grow a certain amount and stop? Posted: 02 Jun 2020 12:58 PM PDT Comparing cancerous growths to benign. I understand that cancerous cells replicate to cause cancerous growths but how do benign growths come to be and why do they stop growing? [link] [comments]  |
| What are the chances this and younger generations will have significant hearing loss as we age? Posted: 02 Jun 2020 04:04 AM PDT Is there any evidence that the popularization of earphones will lead to significant hearing loss as we get older? [link] [comments]  |
| Are there any birds which produce a blue pigment? Posted: 02 Jun 2020 06:01 AM PDT I've seen statements to the effect of "no bird species can make blue from pigments" (example), but I've also seen many sources saying that blue is only "typically" the result of structural color (example 1, example 2). But I can't find any specific mentions of a particular bird species which manufacture a blue pigment, so I'm left wondering if any actually exist or if all of the sources saying it's "typically" the result of structural color are just hedging in case there's one they didn't know about. Do we know of even a single bird species which has non-structural blue color? [link] [comments]  |
| How do stem cells get to the axillary meristem? Posted: 02 Jun 2020 09:34 AM PDT I am wondering, as the shoot apical meristem begins to grow do some stem cells migrate over to the axillary meristem that originally existed in the SAM. Alternatively since some plant cells are totipotent, do normal cells convert back to stem cells in order to generate the axillary meristem? [link] [comments]  |
| Posted: 02 Jun 2020 12:58 PM PDT Wherever I go, I'm going to be sweeping a bunch of air along with me. So which transfer is more impactful on being bad for the A/C? [link] [comments]  |
| Why do some very expensive CPUs use lots of slow cores vs. fewer very fast cores? Posted: 02 Jun 2020 12:23 AM PDT Basically my question as an amateur computer builder and IT curious person with not a ton of in depth knowledge of computer engineering is this: Server grade processors, which have MSRPs that at the highest price point are $20,000+US, seem to utilize tons of cores running in the mid 2.5 GHz range per core. High end enthusiast processors run significantly less in the $500 - $1000 range and have core speeds that are now pushing past the 5 GHz range per core. What are the limitations or engineering reasons why you don't see at this moment, Intel or AMD releasing CPUs with massive core counts and also massive clock speeds? Wouldn't it theoretically be an advantage to have a ton of super fast cores? Are the reasons economic or due to engineering or technological limitation? A more minor follow up would be is this something that the future of CPU design has in store or is it less practical as high core counts and programs meant to utilize multi-core systems become more common and standard? [link] [comments]  |
| What is the relationship between insulin and hGH? Posted: 02 Jun 2020 01:50 AM PDT Hello everyone! I am a last year med student I was reading my physiology textbook(Guyton's) and something confused me. In the book in some chapter it says different thing about insulin secretion and insulin resistance mechanism of hGH also Insulin like Growth Hormone. I can understand some of them true but I think there is a problem I couldn't get it. From clinic I know hGH cause insulin resistance. In book it says different things. hGH secreted in lack of insulin In other chapter it says hGH necessary for insulin action and also insulin and hGH synergetic. I googled and in many places it says different things Like in wiki says insulin induce growth hormone secretion. Also at beginning in book glucagon inhibit insulin secretion later it promotes it. What am I missing? Thanks. [link] [comments]  |
| What is the difference between a continent and an island? Posted: 02 Jun 2020 01:00 AM PDT As far as I know, continents are basically just huge islands, so how is the difference between an island and a continent decided? [link] [comments]  |
| Is it possible to distinguish a deterministic pseudorandom generator from a true random generator? Posted: 02 Jun 2020 12:37 AM PDT Follow up: If we are living in a simulation, can we test it by testing the randomness of quantum particles? [link] [comments]  |
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