Jump to content

Leaderboard

Popular Content

Showing content with the highest reputation since 04/06/21 in all areas

  1. A marketable skill for sure in the looming post-crash economy.
    4 points
  2. Economists have successfully predicted 10 of the last 4 market crashes
    3 points
  3. The period over which tidal locking would occur is highly sensitive to the distance between the bodies, and varies by the distance to the power of 6. It is less dependent on the mass of the primary. The relationship ( assuming all else is equal) is T = a^6/M^2 So, if we take a very luminous red dwarf like Lacaille 8760 with a mass of 0.6 that of the Sun, and a Earth equivalent position in the habitable zone of 0.268AU, you get a time period for tidal locking of roughly 1/1000 of the the time it would take for the Earth to tidal lock to the Sun. For a smaller star like Proxima Cen
    3 points
  4. Every number (except 0) has two square roots. Using the convention (ignore negative root) leads to these kinds of problems. l
    2 points
  5. Don't expect too much from me... Ethics never was a main topic for me. I would say, as any sensible person, just the risk of giving capital punishment to an innocent should be reason enough to refrain from it. And AFAIK deterrence seldom works. So I think incarceration might be the best solution, in the first place simply because we put somebody away who has proven to be dangerous, in the second place we, i.e. society must attach consequences to people who do not want to play by the rules. However, if a society does not take the chance to rehabilitate the offender, it is not much us
    2 points
  6. I think a distinction can be drawn between religion and pseudoscience. Astrology and crystal healing are pseudoscience, in that they make claims about observable physical phenomena, based on theories for which there is no evidence and which conflict with science. Attacking pseudoscience is fair enough, I would say, for anyone with a scientific education. Religion, at least in its more reasonable manifestations, is something different from pseudoscience. It is mainly a guide for living one's life, inspired by stories and ideas that don't make testable physical claims. However one can cer
    2 points
  7. Beautiful little shark babies have been hatched out of eggs laid at the aquarium.
    2 points
  8. Not hours; minutes. But many. Why? For all crackpots out there: https://www.gapingvoidart.com/
    2 points
  9. I would like to defer discussion of hydrogen bonding to another thread as it is taking us further and further off topic. The weakest standard bond my copy of Lange's Chemistry Handbook lists is the lithium - Lithium bond at 11 kcal/mol and the strongest hydrogen bond this modern article lists is the formic acid - flouride ion one at 48 kcal/mol (on page 22) https://www.tdx.cat/bitstream/handle/10803/7945/tdhg.pdf?sequence=3Girona But the important point I wanted to make was not the strength if the individual bond but the collective strength of many bonds applied to large mo
    2 points
  10. OK so here is some more Chemistry which I hope will also be useful to Oneworld. As I have mentioned before, homegeny depends upon the scale you are working at. So starting inside the atom things are definitely not homogenous. There is a massive nucleus surrounded by a lot of empty space containing some electrons. Uniformity is represented by saying that every atom of a particular type is the same as every other atom of that type. For example all hydrogen atoms are the same. (for those who know about isotopes I am ignoring them) If we use those atoms to build molecul
    2 points
  11. I assume it was still April 1st in your time zone when you posted this. Happy Easter.
    2 points
  12. When will WHAT happen? The title of this thread is "Will America EVER achieve immortality?" which really doesn't make sense because America is either a continent or a country, and immortality really applies to neither one. The context of your post implies you are asking if humanity will ever achieve immortality; it's really short-sighted to think only one country would work on or achieve this. Appeal to conspiracy doesn't advance your argument This is a science site and you insist on discussing science fiction, and seemingly have no interest in learning or discussing
    1 point
  13. It is good it worked out well, but it was not a reliable action to take - not that I'm sure there can be any guarantees, whatever course is taken. Even constant supervision comes with downsides. But it could also have had a bad ending. The potential for an "ordinary" fist-fight to result in serious injury or death is always there - usually without any such intent. Fighting on or around concrete surfaces for example raises the risks greatly. Achieving some kind of just outcome also depends on whether the aggrieved party can win the fight - which is always far from certain. Legal repercussi
    1 point
  14. I find that a proportional response to violence is often the best course of action. I alway told my children to walk away if possible but they should not stand for being abused by another. It's always going to be a judgement call, and things can turn out badly, but unfortunately the world is not a fair place and it is important that we look out for our own best interests.
    1 point
  15. I gave iNow a tick of approval. But I do have a situation to relate that I believe to be relevant. When my young bloke was about 3 or 4 years old, we had just moved into the house we now still own and live in. Three houses down was another family who had been there for a few years who had another little boy about the same age, who had two older brothers around 13 or 14 years old. My Son and Andrew [the other little bloke] generally got on well together and played with each other as kids do. Except for the occasions his two older brothers would egg him on to hit my young bloke. This happen
    1 point
  16. Yes, and there’s a way to calculate the effects (which is not just flinging crap at the wall to see if anything sticks) It’s also electromagnetic, not gravitational, so you wouldn’t have the right boundary condition to make a Casimir-type interaction. Inefficiency is one thing, but conservation of properties is quite another; they involve symmetries and you have to show the symmetry being broken
    1 point
  17. Alternatively if you want to use brackets to write the square root as the power 1/2 then you must use [math]{\left( {{{\left( { - 2} \right)}^{10}}} \right)^{\frac{1}{2}}} = {\left( {1024} \right)^{\frac{1}{2}}} = 32[/math] Again you must work from the inside out, working out the value of the innermost bracket before applying the out one.
    1 point
  18. I've never heard of this incident Stringy. The Lightning was a 'rocket with a saddle', and while it had a rather cramped 'office' by American standards, it did use the excellent Martin-Baker Mk.4 ejection seat. I have heard of a vertical ejection where the pilot broke his legs on landing. Take a look at the picture ... The dramatic story of a nose-diving plane as pilot escaped death by seconds in Hatfield - HertsLive (hertfordshiremercury.co.uk)
    1 point
  19. Wars without human casualties tend to go on as long as money/resources last. My opinion on the matter was formed by an episode of Star Trek:TOS, 'A Taste of Armageddon'. Read the plot here A Taste of Armageddon - Wikipedia And I think it is the wrong direction to be heading. As for battleships, they have evolved. A small aircraft carrier can be as short as 600 ft, with a displacement of 15000 t, and in addition to cannon/missile armament, can field 8-12 L-M F-35B off a ski-ramp deck, for self defense. So who needs a battleship ? Here is a typical example Italian
    1 point
  20. Seems like it was yesterday. Promise of jobs for physicists, a new era of almost limitless energy, and what not. The goose that laid the golden eggs died without a bang, and after months-long whimpers. And the world never recovered from it. Or did it? We lost a lot of our former innocence anyway. I did. Very interesting Nature article on it: Lessons from cold fusion, 30 years on https://www.nature.com/articles/d41586-019-01673-x Reflections welcome. Sorry that the topic is a bit old. It's not the anniversary that I'm interested in.
    1 point
  21. If you jump in and recreate the experiment, like a few dozen labs did, you either confirm or refute the experiment, and your reputation isn't really on the line. I don't think anyone remembers any names other than Pons and Fleischmann. Similar with theory. There were people who leapt in with theoretical explanations of superluminal neutrinos (which may be a good example to contrast with cold fusion). Did they suffer any harm to their reputation? Probably not, because they didn't go public with their results, they went through the proper channels. I think perhaps being wrong isn't punished
    1 point
  22. And the next phase begins: Mars Helicopter Ingenuity runs/spins rotor blades motors for the first time On April 9, 2021 NASA’s Perseverance Mars Rover sent images of Ingenuity Helicopter’s rotor blades spin up within motor test. Ingenuity is ready to make First Fly on Mars on April 11-12. Rotor blades spinned up and are unlocked and helicopter is going to make high-rpm test. So next milestone is to spin up rotor blades full-speed for the first time on Mars (to the planned flight speed of ~2400 RPM) while still on the surface. When Ingenuity is flying, it uses a lot of power-
    1 point
  23. You cannot have a CPU "just connected to the power", and not connected to anything else. It is the most basic rule of logic circuitry that all connections (inputs, outputs, control terminals) must be conncted to something. If you do not do so then the conditions at the terminals will be indeterminate (not much use in a logic circuit) and may lead to damaging electrical runaway conditons. In fact a CPU has several power supplies, and the power supply itself which provides these is a sophisticated system that brings the power up gradually in the correct order, and after the already m
    1 point
  24. What the article does not touch on is that cold fusion has spawned a "zombie science" that continues to this day. If you google LENR (for low energy nuclear reaction), you will get pages of references to groups, self-published papers and even conferences that continue to tend the flame of Fleischmann and Pons, in the hope of limitless cheap energy. It seems impossible to kill this off - and I suppose we should not worry too much. Time will eventually do that if, as seems certain, there is nothing in the idea. But I find myself wondering if it was always like this with dead ends in science
    1 point
  25. Question for researchers. Do you jump to conclusions, and possibly ruin your reputation ? Or do you wait for independent confirmation, get 'scooped', and never get a reputation ?
    1 point
  26. Everything I've read suggests the mining waste would only be marginally radioactive, so I'm more concerned about the phosphate than radioactivity. We already have frequent algae bloom problems. Biscayne Bay National Park is right there too.
    1 point
  27. 1 point
  28. An attempt at humor since your profile photo displays your glasses on top of your head, every time I see ya.
    1 point
  29. Agreed. In the US people are referring to their Rights guaranteed under the Constitution. The claim is frequently made by the same people who discuss their Right to bear arms. "Freedom of Speech" is a direct quote, and people in the US know the phrase from the Constitution. It is taught beginning in early elementary school. There are certainly other legitimate uses of the phrase, but if asking how it is generally used in the US, the answer is as a violation of a Constitutional Right.
    1 point
  30. It's a recession, not The Omega Man or Soylent Green ( I liked Charlton Heston before he became involved with the NRA ). And there won't be any zombies either ...
    1 point
  31. Agreed, neither capital punishment nor life imprisonment serves as a deterrent to the first offence. However they certainly put a damper on the ability to re-offend ...
    1 point
  32. Much of the instability is already priced into the market anyway. The traders tend to make money on both the upside and the downside and it’s only massive unanticipated system shocks that cause huge crashes.
    1 point
  33. Yes. Very definitely. And they may continue for some time.
    1 point
  34. But that’s not the sole goal of the justice system. Protecting society, rehabilitation and impacts on the aggrieved (i.e. “closure”) are factors, too.
    1 point
  35. Am I the only one who's wiped his arse with a dockleaf?
    1 point
  36. Beyond this, it gets rather more complicated when we consider them indoctrinating their children or legislating and putting laws in place motivated by said beliefs. Some might consider it “parenting” and instilling values, while others might see it as a form of abuse and harmful to our collective future.
    1 point
  37. the matter/antimatter asymmetry is the issue of why we have matter and not antimatter around. The amounts are not equal, or symmetric g-2 refers to the muon magnetic moment experiment, in the nature link I added to my previous post I come from atomic physics, which gave us "optical molasses" and "Bose-nova" (both, I think, from the Wieman and/or Cornell research groups) so don't look to me for help.
    1 point
  38. Yes I don't think there are many fridges or freezers on the market without this system +1 You got there before me, but I'll just add my diagram anyway, which shows the back of the device. Most of these have the drip collection and evaporation tray mounted directly on top of the motor to use the small amount of heat the motor generates. The drip tube coming out of the cold compartment is a frequent source of blockage and water collecting inside the device. But the important point here is the word evaporation. I already mentioned that water vapour is invisible in
    1 point
  39. I will never understand this need people have, to 'label' other people. We label them according to perceived aptitudes; those with athletic aptitude are 'jocks', those with technical aptitude are 'nerds'. We label them accordng to the government they need; 'liberals' need a government that takes care of people, 'conservatives' want a government that gets out of their way. We label them according to their roles in society; 'enablers' allow bad stuff to happen, 'complainers' bitch about bad stuff happening. We label them according to their station in life; successful people are seen as '
    1 point
  40. In static world there is no change. No progress. 1) decay of radioactive isotope of Carbon C-14. Carbon is part of DNA/RNA. Affected molecule is fatally damaged. Surrounding molecules can be damaged too by highly accelerated electron. https://en.m.wikipedia.org/wiki/Carbon-14 2) decay of radioactive isotope of Potassium K-40. Potassium is not part of DNA/RNA, but is present in blood and cells. It has a long half-life but has much larger abundance % than C-14 to C-12. https://en.m.wikipedia.org/wiki/Potassium-40 3) cosmic radiation from the Universe. 4) UV radia
    1 point
  41. ! Moderator Note "Read the attachment" is not compliant with rule 2.7. However, I did read it and it falls well short of the level of rigor we require (which you acknowledge when you admit you don't have a theory) A better approach might be to learn the physics by asking questions, in order to propose an actual model.
    1 point
  42. The truth of the matter is that reality would not be that tight a tissue. It does not hesitate until you take the most shocking phenomena or dismiss our own imagination's most possible figures. Perception isn't a science; it's not an act, it's not an intentional takeover; it's the context from which all actions come and are meant to emerge. Hhhmm ??
    1 point
  43. As per Scottish philosopher David Hume, nothing we envision is totally unlikely. We will describe the skills required to bring these images to life—to allow them as technologies—once we have the capacity to shape images in our minds. Our imagination produces only representations of hope based on our observations of the world surrounding us. It's true that anything that is unlikely is often unthinkable.
    1 point
  44. Two books I found very very useful in the past and still contain useful stuff. They are good because they both contain much practical info and examples eg breadboarding interface circuits and so on. I don't know where you are in the world, but if you can get hold of an old Open University Hektor trainer you would be laughing. I built one and learned machine code and assembler on one. Also you can get some pretty sophistic 'logic trainer breadboards' second hand these days. These can be adapted for use with micros.
    1 point
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.