npts2020

Been reading some interesting stuff about Jupiter's moon Io and nobody has posted here in a while so, here goes. Only a little bigger than Earth's moon, Io is the densest object, not actually a planet (Earth is densest), in the solar system. It is also the most volcanically active and has the least water of any bodies in our neighborhood. Surface temperature is about -130C but lava flows have been measured to over 1200C and may exceed 1700C (about 3 times the hottest temps on Mercury). The gravities of Jupiter and sister moons Ganymede and Europa can cause "tides" of over 100m. Since there is no water, those tides are of rock! The magnetic field of Jupiter can generate lightening discharges of 400,000 volts and 3,000,000 amps, discharging from the moon into the upper atmosphere of the planet. (is this the reason the moon glows when eclipsed by Jupiter?) The magnetic field of Jupiter ionizes and pulls about a ton of material from Io into space every second, creating a plasma torus around the moon, fueling auroras on the planet, and doubling the size one would expect Jupiter's magnetosphere to be. (IMO) Conditions there will be a survival challenge for any organisms, even the most radical extremophiles from Earth so it is unlikely humans will ever get anything other than raw materials from there and certainly not anytime soon

It seems like they are using single sheets of paper, so it may come down to how fast you can accelerate the plane without collapsing or severely vibrating the wings, creating drag. OTOH if you are going for MTA (maximum time aloft), my money is on the glider. I know for discs, there is a big difference between ones thrown for distance (WR just over 1100 ft ~336 m) and ones thrown for MTA (WR 16.72 seconds). Even if the golf disc thrown for a distance WR was legal for MTA (and you could run it down and catch it without breaking your hand), it wouldn't hover like a fastback (looks like the cheap frisbees they give away with advertising on them) or regular frisbee (IIRC WR frisbee distance is still under 500' 152m)

In the US, that is only true in the lowest courts, any appeals (if heard. Generally they aren't but when "property rights" are involved, you never know) are decided by a panel of judges, all the way up to the Supremist Court. It is usually at least 2 appeals before it reaches the Supreme Court

Damn!! And I always thought the courts were a branch of the government. How did I ever pass civics class?

Well, if I was dictator of the universe and in charge of solving the homeless problem, the first thing I would do is "slap some people up side the head" and tell them to have some regard for their fellow human beings. After that, I would see that those committing crimes like assault, bullying and theft are jailed (would need due process but since I am dictator off the universe, it is not necessary) and all others have a safe, clean place to get food, sleep and interact with staff running the facilities. That staff, at least some of it, should be qualified to determine the kind of help needed (psychological, medical, education, day care, change of venue, job, etc) by individuals and encourage them to seek out that help. Food service would be cafeteria style and housing would be simple (converted shipping containers, micro houses, or something else relatively cheap). Once somebody's problems have been addressed and progress toward their resolution has been made, they may move on to integrating into an actual neighborhood, hopefully, becoming a productive member of society. Of course, there are some few who will never get beyond the "soup kitchen" stage and even a few who will refuse any help but I would think it less expensive and better for all to just house those people rather than pay to incarcerate them for stealing food, peeing on the sidewalk or doing any of the myriad of other things homeless people do that we might try to criminalize. I realize the above is very simplistic but also believe it is the gist of what ought to be done. In the US of A we have something called "eminent domain". If it was considered vital enough, the government could confiscate any land/property it wants and give the owner "fair market value" (spoiler alert, I don't see that happening in the US anytime soon). Fair market value happens to be whatever the gov says it is so it wouldn't necessarily be that expensive.

AFAIK The biggest obstacle to Habitat building and remodeling more is funding so they may possibly be able to build enough to solve the housing problem in those cities but even if they (likely) can't, I was only pointing out there ARE other options for going about things. (If you agree that Habitat is neither a developer or arm of the government)

I'm confused, is "Habitat for Humanity" an arm of the government or a developer? I heard they once built a dwelling or 30 million or so.

A leadership PAC is just another PAC but is usually connected to a party or elected (or wannabe) official.. In general, it seems like non connected committees (the majority of PACs) is what is being referred to in this discussion. These PACs may only give $5000 to any given candidate and receive a like amount from each donor in a given year. SuperPACs may receive unlimited amounts of money and spend as much as they want. The difference is SuperPACs are not allowed to give directly to candidates or coordinate advertising with them. If you still have questions, I highly recommend the FECwebsite https://www.fec.gov/help-candidates-and-committees/registering-pac/understanding-nonconnected-pacs/ . There are lots of links to define terms being used and comparisons made. It is a shame more people aren't interested in understanding how their political process works.

The main purpose of PAC's is that you can give money to a candidate then give money to a PAC that will give it to "a" (wink, wink) candidate. Saddest part is that both Republicans and Democrats have been in control of all the branches of government since "Citizens United" but neither party seems much interested in changing this.

Without knowing things like the scale of the park, product being manufactured, and manufacturing method being used, it is hard to give an accurate answer. This site https://www.energy.gov/eere/amo/manufacturing-energy-and-carbon-footprints-2010-mecs gives the metrics the feds use when assessing the carbon footprint of such projects.

Was more idle musing than serious inquiry but I have known more than one person who grew their own "weed" and could see tobacco smokers doing the same if they don't want to roll up chewing tobacco (not banned if I read a correct interpretation of the law).

What if you just grow your own? I wonder if it is as easy to grow tobacco in your closet as it is cannabis?...

The biggest problem with commercialization of fusion is that it has been "a decade away" for at least the 50+ years I have followed the subject. The catch is figuring out a substitute for the gravity well of a star.

If you can get a (relatively) low pressure water pump to get anywhere near 10 PSI with air, you are doing quite well, IMO. In general, water pumps don't make very good air pumps but air pumps *may* make fine water pumps (if you don't mind a bit of leakage and can keep from burning the pump out). In a closed system, air pumps are made primarily for compression of fluid (air) whereas water pumps are primarily for transport of fluid (water). Pumps made to do both air and water compromise a bit either way and are not as efficient as one or the other but are apparently efficient enough for certain uses.

Seems like it would be easier to strap rounded pieces of wood to the stone and just roll it to wherever you wanted to take it.

Sounds like a birthday to me. I hear some people celebrate those, for some reason.

Lots of good points made in this discussion. Here is my $.02; near as I can tell there is no scientific reason for claiming an embryo is more "alive" than the sperm and egg were a short time before the egg first divided, or that a fetus is more "alive" than an embryo, or a newborn more than the fetus a few hours or days before. The problem is a line (if one is to be drawn anywhere) has to demarcate when one becomes a "person" worthy of curtailing another person's (the mother) right and freedom to pursue happiness etc. Since that seems to be more of an ethical/moral question than a scientific one the debate gets pushed (wrongly IMO) to viability. What happens when scientists figure out (and they get nearer and nearer all the time) how to make a human being from just a sperm or egg? Will females then be required to attempt pregnancy every time they ovulate? Will it be a capital offense for a male to ejaculate anywhere other than a fertile womb? The whole point being, there ought to be other considerations than "viability" in who gets to decide the issue. That's where personal choice for the mother comes in and when should the state curtail their options. IMO, the state has no compelling interest in stopping abortions at any stage regardless to how abhorrent you, I or anyone else finds them. Also, I find the Catholic Church to be one of the most hypocritical entities in this whole debate. For most of the history of the church one was not even considered to be alive until you were baptized. This was such a strong belief that many historical figures have unknown birthdays, only baptismal dates, presumably days or weeks after being born.

Firstly, without giving away top secret information, I can assure everyone all US nuclear powered carriers are propelled by steam turning a turbine which, through a system of reduction gears, turns the propeller, no electricity required. When cruising at even a fairly slow speed, those props use more steam than the electrical generators and all of the other steam systems aboard combined. Lastly, smart grid technology should help keep major sudden transients within manageable limits for most reactors. (I don't think we should be building more, though)

Where does the power to turn the propeller for full speed ahead come from, then? The point is, the reactor I worked at aboard a carrier never seemed to have much problem with pretty wide power transitions in short periods of time.

How, then, does a nuclear powered aircraft carrier go from all stop to full speed ahead in a short period of time?

A typical method is to heat water in an insulated tank, then circulate the water through spaces where heating is desired. This can even be done with a passive solar system (you would definitely want back-up heating with that, tho)

Four men are in a bar drinking and bragging about their families. As they come to discuss their sons, one has to use the bathroom and leaves the table. The other three continue the discussion, the first puffing his chest out with pride and telling how his son worked at an automaker and how he had gotten a bunch of patents to improve cars. He says, "In fact, he has made so much money off of his inventions that he bought his best friend a top of the line Mercedes for his birthday." The second man says, "Well, my son is also an engineer and works in the aerospace industry. He has made improvements to airplanes and spaceships and has earned so much money he gave his best friend a new Lear jet and is teaching him to fly it." The third man thought those were pretty impressive but begins to tell about his son being a real estate agent. He says, "My son is probably the best real estate agent in America and has made so much money that he gave his best friend a 30,000 square foot hacienda on the beach for his birthday." About this time the fourth man comes back to the table and is asked about his son. He says, "My son is a stripper at a gay nightclub. The other men are stunned and don't quite know what to say and begin to offer him condolences but he says, "No, he is my son and I love him nonetheless. Besides, he has a LOT of really good friends. Why just last week for his birthday one gave him a top of the line Mercedes, another gave him a Lear jet and is teaching him to fly it and still another gave him a 30,000 square foot hacienda on the beach." The conversation quickly turned to other subjects.

My favorite 70's band nobody ever heard of, Klaatu. The guitar work in this song is pretty amazing.

Gotta love Tree Lobsters

Welcome all, it is always good to have new people interested enough in science to bother signing up to participate at this site. Learning about and teaching science is what this site is all about and I don't think it is too much of a stretch to say that everyone who is here for long does some of each.