Jump to content
Science Forums


  • Content Count

  • Joined

  • Last visited

  • Days Won


Everything posted by CraigD

  1. But the small generator you’ve built isn’t charging the coil– changing the number or arrangement of charged particles – it’s inducing a current in it. That’s what electric generators fundamentally do – convert mechanical work into electric current. In science and engineering, it’s important to use terms like “charge” and “current” correctly. Cool video, though I think some spoken explanation would improve it. Cool gadget, in any case. :thumbs_up As others have noted, the output of your direct current motor-driven generator (lacking as it appears to brushes or electronic switches) is lik
  2. Assuming all the particles to be filtered have similar densities, you can make a sort of filter that doesn’t truly refuse, but slows, passage of the smaller particles, by having them fall or rise through a container of gas or liquid of lesser or greater density than the particles. For example, drop an aggregate of small and large stones into a pool of water, and the large stones reach the bottom first. The drawback to such a filtering (or sorting) scheme is that you’d have to work fast to remove the big stones from the bottom of the pool before the small ones caught up, and the aggregate wa
  3. Welcome to hypography, George. :) Do you have a link to that article? Though used primarily as an anesthetic and a post-operative or chronic pain-killer, Ketamine has been used to treat major and bi-polar depression, as best I can tell, since around 2000. From what I gather from a quick read of a few references, it’s efficacy in long-term depression treatment is low, it’s best psychiatric use being short-term, emergency use, as an alternative to the more traditional benzodiazepines. Ketamine’s benefits vs. similar drugs include very low risk of accidental lethal overdose and low-to-
  4. I though I’d read most of Greg Bear’s novels, since I got interested in him after reading his mind-blowing Eon in or not long after 1985, but when I failed to find a Wikipedia page for the War Dogs series (a good Wikipedia editing project for you, sanctus – Wikipedia’s only as good as we its editors make it) and went to his “all my books” page, I see he’d been writing a novel or 2 a year for the past nearly 40 years! I’ve barely scratched the surface of the goodness that is the writing of Greg Bear. :) I finished a foray into the weird, mostly ineptly written, and occasionally disturbing sex
  5. Some of my favorited jokes are like this one "What did the big chimney say to the little chimney? "Nothing, chimneys can't talk." which the nbcnews article gave as an example of a “bad joke”. I like these kind of jokes. Their humor comes from making, then rejecting, a silly assertion – in the example case, “chimneys can talk”. My favorite joke of this kind is A physicist, a rabbi, and a dog walk into a bar. The dog says, “bartender, gimme a beer.” The bartender says “holy *[email protected]#, a talking dog! This joke sets up then knocks down the assertion that dogs can talk, then sets it back up
  6. I’m fairly sure you’re mistaken about this, A-wal. See if you can find a source to back it up. JMJones asks the same thing, less gently. ;) Though models of the complicated details of how the fusion energy in their cores gets to their surfaces, and how stars’ size and mass vary as they age, especially during interesting explode-y and semi-explode-y phases continue to be evolve, the basics of how that energy is produces, and the balance of it vs self-gravity that determines stars’ rough densities has been well-understood since the late 1950s. See the Wikipedia articles Nuclear fusion, Stel
  7. If for every star, there must be a black hole, we’d need a lot more black holes than are thought to exist. Because the only known way black holes are formed is by the collapse of large stars, and because only about 1 in every 1,000 stars is massive enough to form a black hole at the end of the shiny phase of its life, there are about 1,000 times more stars than black holes. (source: HubbleSite.org’s “how many black holes are there?”) I have childhood memories of astronomers speculating in the late 1960s through mid 1970s that blackholes were connected via wormholes to “white holes” as an
  8. There’s a neat exercise you can do to show yourself that the idea that the force exerted by heavenly bodies is too small to support the claim that their position during our conception, gestation, birth and life significantly influences our character. It’s one I was shown as a child in school, and I wish every child was shown. Calculate the relative gravitational force on yourself caused by: the Moon; the Sun; the planets; another person standing nearby. I encourage you to do this, current. Learning by doing is, in my experience, stronger than being told what is and isn’t true, or argu
  9. Welcome to hypography, pandabear! :) Please feel free to start a topic in the introductions forum to tell us something about yourself. As A-wal notes, all psychologically normal people are empaths to some degree, in that we experience the emotions of others. When we see other people being hurt or frightened, we instinctively feel hurt or frightened ourselves. When we see people behaving happily, we feel happy. Unconsciously, we tend to imitate one another, smiling when we see someone smile, frowning when we see them frown. The experience of empathy can be indirectly caused – for example, we
  10. I’m guessing you mean black hole – something so massive light can’t escape from it – rather than gravitational singularity, a point where the gravitational force is infinite. A few answers come quickly to mind if the inside of an atom, or just the nucleus of an atom, was within a black hole, we wouldn’t be able to get information out of it, so couldn’t discover its internal structure in the ways we have, such as using Deep inelastic scattering.since the force is between charged particles is carried by virtual photons, which like observed photons, can’t escape from a black hole, atoms or nucl
  11. You seem to be moving from the question of “are we being kept in a zoo by an advances alien species?” to “are we in a computer simulation.” Both are worthwhile questions, but I think it’s better to discuss one of them at a time. We’ve had some discussion (but, surprisingly since the idea has been so well-known as to be practically main-stream for night-on 15 years) in these threads, going back more than 10 years: Infinite recursive Simulated Realities and it's implications for the GUT; What Would Be Proof Of A God Or Gods Running The Universe?; Reality Vs Illusion; and What If We're Simulants.
  12. Zubrin’s suggestions include the SpaceX Interplanetary Transport System should have 3, rather than the proposed 2, stages. This would allow the 2nd stage, with its massive engines, which are much larger than needed for launching from Mars to return to Earth, to quickly return to Earth orbit. The Interplanetary Spacecraft part of the ITS, which is currently its 2nd stage, but with Zubrin’s change, would be a 3rd, would have much less massive engines, so much more – he suggests 10 times – passenger and cargo payload.Rather than the current single-piece vehicle, the large, passenger and cargo-car
  13. Arsoles are aromatic. Add a CH to an arsole and it becomes arsinine. :D I don’t think any comedic creativity is involved, though, as these funny names come from just applying standard nomenclature rules when adding a bit of arsenic to a benzene ring.
  14. Maybe the WWW wasn’t made out of anything unusual, but had a freaky immune disorder manifesting as fantastically severe aquagenic urticaria (we had a short, strange discussion of this last year in this thread). If you want to read a lot about the witches of Oz and their various fantastical powers and afflictions, read the Wicked books. A detail that’s stuck in my mind from them is that the Witch of the West (Elphaba, Elphie for short) has to cover herself with special oils to avoid burns from such things as physical contact with another human being. And her mom was a promiscuous munchkin. :)
  15. Current, in your own words, how would you summarize Simpson’s criticism of Druker’s, Altered Genes, Twisted Truth It can be just as or even more important to read critical reviews of books than to read the books themselves, especially if you are not well-educated in the books’ subjects. Since many books present only the author’s claims, it’s easy for the non-expert to be convinced of claims that aren’t true. Have you read Druker’s book? Do you agree or disagree with Simpson’s criticism that “Druker’s tryptophan story is incorrect”? Why?
  16. JAXA has actually flown some prototypes of a “magnetic space junk cather”, such as the Space Tethered Autonomous Robotic Satelite-2, with talk of a full-scale one flying as early as next year The scheme doesn’t just use magnetics to attract and catch debris, but to maneuver and, when it’s collected lots of junk, deorbit itself. It’s an electrodynamic tether propelled spaceship. Sources: https://www.newscientist.com/article/mg22129534-800-japans-huge-magnetic-net-will-trawl-for-space-junk, http://www.bbc.com/news/world-asia-38265676, http://www.cbsnews.com/news/japan-launches-net-into-spac
  17. I haven’t, and because of reviews like MD Terry Simpson’s Steven Druker's book: Not worth reading, I don’t plan to. From this biographical summary, lawyer Steven Druker sound like a well-intentioned, dedicated person, with a good humanities education, but from reviews like Simpson’s, it sounds like he’s written a book with naïve and unsound science. It’s unfortunate he didn’t collaborate with an expert in microbiology, since IMHO, there are sound scientific reasons to be concerned about the large-scale use of GM crop plants. Raising objections that have been scientifically discredited distra
  18. Archeological anthropology tells us, I think. We have pretty unambiguous evidence that our intellects are greater than those of our ancestor species, like Homo erectus about 1,800,000 years ago: our brains are bigger, and we make much more impressive artifacts. If secretive ETs are trying to keep us from being too smart, they either haven’t been at it until recently (the past 50,000 years or so, when anthropologist think Homo Sapiens Sapiens became pretty much intellectually like we are now), or they don’t mind us being about as smart as we are. As we’re becoming increasingly good at usi
  19. I think you’ve misused a couple of words here, petrushkagoogol: Postulate is term usually used in mathematics to mean something taken to be true without proof, or intention to prove, it true. Common postulates are “the integer 1 exists” and “every integer has a successor”. I think what you mean, rather than postulate, is hypothesis. In science, a hypothesis is something you tentatively propose is true, then attempt to support with the outcomes of experiments. Instead of “simulated pain”, I think you mean “self-inflicted pain”, or “pain inflicted with the person’s consent”. A simulation i
  20. Of course, nobody doubts that you can store information for a long time using H2O in a solid state – just write on it with an ice chisel, like this: It’s when people don’t distinguish solids from liquids that things get weird and confused. The fact that homeopathy is still the underlying explanation for a big, profitable family of businesses, even after the discovery of atoms pretty much completely discredited it as a scientific theory, doesn’t help.
  21. I think everyone has done a good job of explaining that you and I are not the descendent of a one man and one woman, or a one single celled organism. :thumbs_up I’d like to take a shot at this question Since every living human has different genes, and even slightly different numbers of genes, we have to agree on what we mean by the “form” of the human genome. One way is to define it as the number and rough size of its chromosomes, which describes the physical structure of the genome. The latest major change in the human chromosome was the fusing of 2 chromosomes into the single human c
  22. The psychiatric term for “mental illness marked by periods of great excitement, euphoria, delusions, and overactivity” is mania. I can’t recall on that applies only to inappropriate feelings of euphoria. In psychiatry, mania is a description of behavior and mental state, not a diagnosis of a disorder causing it. The most commonly diagnosed disorders involving mania are bipolar disorder and schizophrenia. When neither diagnosis fits well, a diagnosis of Schizoaffective disorder is sometimes used. As DrKrettin noted, manic periods are not always euphoric. Mania is mostly about excessive exc
  23. Welcome to hypography, formad! :) Please feel free to start a topic in the introductions forum to tell us something about yourself. EEG is an abbreviation of ElectroEncephaloGraphy. “Electro” means “using electricity”, “Encephalo” means “head”, and “graphy” means “to make a picture”. So EEG means “making a picture of the head using electicity”. The part of the head EEG is interested in is mostly the brain. EMG is an abbreviation of ElectroMyoGraphy. “Myo” means “muscle”, so EMG means “making a picture of muscles using electicity”. EMG can be used to measure the activity of practically a
  24. Have you looked into battery heated glove or glove liners, like these? I imagine similar products can warm your toes, too. Von Neuman dream of weather control may have been slammed by Lorentz’s chaos discoveries, but be damned, one technology that’s really done well is long-lasting, high energy and power batteries. They’re not just good for flying ‘copter drones and putting a 1980s super computer equivalent in our pockets – they can keep our fingers nice and toasty, too. :)
  25. The practical moral to this story is that, if you find yourself facing imminent murder in the presence of an Amazon echo, or an phone with a voice-command application like Apple Siri or Hey Google Assistant, you should shout its activation word (eg: “Alexa”, “Siri”, or “OK Google”) then identify the person about to kill you and give other damning evidence. Though the program won’t do anything to help you (for odd reason, none of these systems is allowed to place 911 or other emergency calls), at least for a little while, a recording of what you say will be stored on one of these companies’ ser
  • Create New...