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Sensei

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Everything posted by Sensei

  1. Sensei replied to studiot's topic in The Sandbox
    No. What I posted was not MathML. I simulated MathML functionality using superscript button. Web forum editors usually filter HTML tags, as this is a potential security vulnerability if the user can enter any tag.
  2. Sensei replied to studiot's topic in The Sandbox
    You can use only what is supported. Or make screen-shot of MathML online editor, clip to small size, and add here image in the reply.
  3. Sensei replied to studiot's topic in The Sandbox
    This forum software supports LaTeX.
  4. Sensei replied to studiot's topic in The Sandbox
    d3nxd3npρ(x,p) How did I do it? I copied and pasted your mathML into online MathML editor, and noticed 3n are superscript, selected them in pressed x2 button in tool box. For such simple formula as you used, it was enough without bothering about LaTeX..
  5. Sensei replied to Brainee's topic in Quantum Theory
    "Full battery" has charges (electrons) with a certain amount of energy.. "Empty battery" has charges (electrons) that released this energy.. Connect the plus electrode with the minus electrode and you will have fire or so.. because of the extensive release of energy in a short period of time..
  6. Sensei replied to Brainee's topic in Quantum Theory
    What does this change? The charge is just a property of the particles that participated in the whole action.. Q=Ne In the end, the charge is const.
  7. I wrote on-topic material i.e.: ..then expanded my answer to include other things that I thought were important.. OP thought they are interesting:
  8. My concerns were not primarily about space radiation shielding. I was on the subject because his structure would/could not work.. What is wrong with you today? You cannot have two objects with just vacuum inside - they would collide each other after acceleration of any of them.. ps. Have too much time on vacations from work for government? Buy a 3D printer.. The structural integrity between the outer surface and the inner surface is none, because there is a vacuum between them and nothing else.... This should be obvious to any physicist (or former physicist)..
  9. If you have a larger sphere with an inner smaller sphere and a vacuum between them, and the inner sphere will be accelerated, they won't fly together until the inner sphere hits the body of the outer sphere, so you would have to have some structure/mechanism to separate them and accelerate them together. At the moment, human use water as layer of protection against harmful cosmic rays. https://www.google.com/search?q=human+water+layer+protection+cosmic+rays "Currently, NASA and other space agencies plan on using water as a shield against radiation since it is already necessary for human missions. Water has been tested thoroughly and has been proven to be effective." https://en.wikipedia.org/wiki/Health_threat_from_cosmic_rays
  10. The annihilation of positrons with electrons is an important source of energy emitted by the Sun. ~ 7.8% of the all emitted by the Sun, at the moment. More than ordinary Hydrogen-1 fusion (0.42 MeV per reaction, in which part (half) of energy is took away by neutrino). https://www.scienceforums.net/topic/85656-solar-fusion-neutrinos-and-age-of-solar-system/ Electrons can be captured by the nucleus. https://en.wikipedia.org/wiki/Electron_capture Eventually, even rarer, double electron capture: https://en.wikipedia.org/wiki/Double_electron_capture Electron and positron can be transformed into electron neutrino and antineutrino. Instead of the usual annihilation into gamma photons.
  11. Old CRT television (century age technology) use a beam of electrons that is emitted from an electron gun toward a fluorescent screen. When the electrons hit the screen, they are decelerated and photons are emitted, which can be seen as an image on the screen. When photons hit atoms in your eye, the atoms are excited and converted into electrical impulses.
  12. ..which does not mean that the rainforests should be cut down, destroyed, erased, from the Earth.. it would have other tragic consequences apart from climate warming.. Some European countries have gone down this road and now have problems.
  13. Seagrass is better scalable. The Amazon rainforest is limited in area by the size of the country and continent.
  14. Mafia Inc. .... Depends on what you do with the money. 1) Consumption? Holidays (e.g. Christmas)? Vacations? No, you should not take credit for any of these activities.. even if you can.. 2) Investments? Possible. Depends on the details of what you want to invest in..
  15. Symptoms sound like "post-COVID-19 brain fog".. https://www.google.com/search?q=post-covid-19+brain+fog ^^^ this is common in people who have had COVID-19, even undiagnosed..
  16. Sensei replied to erik's topic in The Lounge
    Add the English dictionary and spell-checker extension to your web browser, enable it in the text area (RMB), and the web browser will highlight (with red underline) incorrect words for you.
  17. Can you use multi-threading? Can you use MMX/SSE/AVX? https://www.google.com/search?q=sse+array+sum https://www.google.com/search?q=avx+array+sum Can you use GPU? What do you know about these numbers, i.e., are they only positive ("unsigned"), or positive and negative too ("signed")? What is resolution of these numbers? i.e. 8, 16, 32, 64 bits, or more? What do you know about the array, i.e., is it sorted or not? f.e. if you know that they are all positives, you can stop counting as soon as 100 is exceeded.. f.e. if you know that they are all positives, and array is sorted, you can stop as soon as counting from last to first exceeds 100. Notice that summing 1000 numbers with 32-bit signed/unsigned resolution will require a 64-bit accumulator.. // This is the wrong code! int data[ 1000 ] = { ... initialized... }; int accumulator = 0; for( int i = 0; i < 1000; i++ ) { accumulator += data[ i ]; } By mistake, the resolution of the accumulator can be easily exceeded (overflow, easy to handle in assembler, hard to handle in higher level languages).
  18. The main problem with food & people is lack of moderation in eating.. Even healthy food that is overused will have unhealthy consequences (too many Calories, too few of other required ingredients, etc.)
  19. Sensei replied to geordief's topic in Biology
    Write the code? https://en.wikipedia.org/wiki/Conway's_Game_of_Life Author makes it in Python:
  20. Funny... The poor ancients couldn't buy a "PET bottle of mountain water". My posts had nothing about the alcohol part - they were all about the regular water source. Wine is juice. Beer is boiled water (so the microbes died). ps. Obviously ancients had no idea about it. Do you think drinking dirty water is healthier than drinking alcohol?
  21. You picked up the wrong part of my claim - I claimed that their "fresh river water is polluted" because people living slightly above them in the river dump all the garbage, shit and piss into it, making it polluted. Wine does not have river water inside - thus more healthier. That's why the Romans started making aqueducts.. to deliver "fresher" water to the city.. (but they used lead).. The Romans were only part of the ancient world, the rest used (and use now) water from rivers (because they have no choice). River water without a wastewater treatment plant is contaminated.
  22. Then, according to your claim, their "alcoholic orgies" are a myth, since there were no drunken.. ? and battles between X and Y, with one being poisoned by alcohol, are also myths.. ? The Romans made pipes using lead, which is a poison. Wine has no lead (because it is squeezed fruits) unless it is added to sweeten.. Just don't use "fresh water from lead pipes" and you're healthier.. Just don't use "fresh water from polluted river" (see Ganges now, that's how ancient river looked in the past prior invention of sewage treatment plants) and you're healthier..
  23. The worst part is the lack of restraint.. No. What matters is the amount per unit of time. Ancient people who drank alcohol were healthier than poor non-alcohol drinkers, i.e. to make beer you have to boil it ( >= "fresh" water from a polluted river, boiling kills some microbes), wine is just fermented juice (>= fresh water from a polluted river).
  24. Right. They usually shoot each other with guns, which Republicans promote to buy for everybody.. "PUBLISHED DATE: December 02, 2022 Total Number of GV Deaths - ALL Causes 40,739 Homicide/Murder/Unintentional/DGU 18,563 Suicide 22,176" Nonsense. People are dumber because they are stuck in their unhealthy social media interest bubbles. As we can see from your example - conspiracy theories. Right. Then why aren't you using your own advice?
  25. Sensei replied to sologuitar's topic in Homework Help
    a^1, a^2, a^3 are easy - anybody can do such calc even in memory. But mathematicians want to have universal functions, in this case pow(a,x). So, take piece of paper and make graph of f(x)=a^x, with a couple well-known x (a is constant and can be used any integer >= 2). Then use x=0.5, 0.25, 0.2, 0.125, 0.1, 0.01 etc. and you should see curve goes closer and closer to 1. Then draw line between them. With a=2, and default x in range -2 to +2, you will get such curve: https://www.wolframalpha.com/input?i=f(x)%3D2^x If you want to change range, use f.e. https://www.wolframalpha.com/input?i=f(x)%3D2^x%2C+x+range+-10+to+10 (Wolfram Alpha, and Excel/Spreadsheet are must-have for mathematicians these days) (you can draw such graph in Excel/Spreadsheet too)

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