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Sensei

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Everything posted by Sensei

  1. Human could not swim upwards, against the waterfall. The body is too weak for such a task. But some fishes do it at least once in their lives e.g. salmon must return from the sea to the river in which it was born. And they must to swim upstream waterfalls. Search net for keywords salmon and waterfall for videos how they do it.
  2. ..I am asking this question almost every day seeing what stupid politicians, or ordinary people, did that day...
  3. ..at the same time, they had slaves in their farms and mansions... So apparently they did not really think the above words..
  4. I think the main problem of universities is cheating students plagiarizing articles and diploma theses etc... Each university and college require completely different educational software. Uniform app could be for e.g. tests and quizzes, where teacher is entering custom questions, good and bad answes. Later app sends link to each student to fill them and brings results back to teacher. It could be made really hard to cheat by making database of questions and personalization (randomization of questions and answers) for every student independently. Such software (website?) needs databases of teachers, students, tests/quizzes, answers given by students. Teachers from different universities could exchange or reuse questions already entered by other teachers in the past, from the same discipline.
  5. 100% refund of the purchase and installation of solar panels on the roofs of ordinary people's homes. >= 50% refund of the purchase and installation of solar panels on company roofs. Tax reduction for everybody joining in to even further encourage people? Establishment of state-owned solar panel making companies across the country (otherwise government money would go to countries with the lowest solar panel price that would increase national debt). In other words, what the government will spend on solar panels, would end up as income of hundreds thousands of people working in these companies and installations. Current methods ("carbon tax") are not constructive. Electricity making companies will pass the all costs to their customers and they will be, as always, victims of the regulation made by government. Current methods rely on private companies to do everything (to earn money). Investors interested in renewable energy sources are starting from ground level and what they will earn one year will invest in the next year which drastically limits the growth rate. State-owned solar panels making companies can start from hundreds production factories across the entire country without bothering about cost of such giant investment since day zero (establishment of such company). If government would not pay for Apollo program, private business sector would not ever do in, as it is impossible to make money on it! Private business mostly do everything the easiest ways to earn money. It is unlikely that SpaceX would make rockets if they would not have possibility to make deal with NASA for delivery of stuff to ISS. Where would these rockets fly? Such company would be infinite hole sucking in the all investors moneys and would not ever return investment in any predictable time span. It would remain toy of billionaire or never being established.
  6. Conservation of momentum is even visible at quantum level. During decay of unstable particle, newly created particles are ejected in opposite directions with velocities which depend on difference between rest-masses of particles. In Cloud Chamber it is visible by naked eye.
  7. Person with mass 60 kg has ~ 2100 decays of radioactive isotope of Carbon C-14 and ~ 7600 decays of Potassium K 40. Per second. It is hundred millions per day. There are apps to calculate this. It happens inside of the body. If Carbon C-14 is part of cell-to-divide, especially part of DNA, there can happen mutation. DNA is randomly damaged or destroyed. It is possible to limit radioactive Carbon isotope percentage in human body and therefore risk of getting mutation, and cancers this way, by changing entire farming of plants and farm animals. Plants must grow in hermetic buildings (better farm skyscrapers to limit space) and disallowed unfiltered air with CO2 to get inside. Instead use CO2 from e.g. burning fossil fuels (after proper filtration other toxic chemicals). It has almost no radioactive isotope (half-life of Carbon C-14 is ~ 5700 years). Very expensive idea. It is unlikely that your child mutation happened due to exposure of your wife in the hospital. The more probable is exposure to e.g. cigarette smoke (it is carcinogenic), unhealthy contaminated air, carcinogenic food etc. Burning fossil fuels and release of smoke to atmosphere causes toxic chemicals (eg not fully burn byproducts with unpaired electrons) be also released and inhaled by people and farm or wild animals (which will get to humans as source of food).
  8. You are talking about the most primitive implementation from C. Array of characters. In C++ and other OOP string is blackbox object which you can read and modify only by calling object method.
  9. On each continent, several LIGO observation sites are needed. Burst of heavy, electrical neutral, particles or a "gravitational wave" would have come to Earth and would have been detected with a delay between observation sites. From the delays in the measurements, the propagation speed can be deduced.
  10. https://www.universetoday.com/144622/a-mysterious-burst-of-gravitational-waves-came-from-a-region-near-betelgeuse-but-theres-probably-no-connection/ "A Mysterious Burst of Gravitational Waves Came From a Region Near Betelgeuse. But There’s Probably No Connection"
  11. Bollocks. Anyone can use calorimeter to measure amount of energy required to melt piece of ice..
  12. Ice is an exception to this rule. Water in solid state has smaller density than in liquid state. Sorry, could not resist..
  13. Photons are emited by matter and eventually absorbed by matter, reflected or diffused, or refracted. There are other types of interactions at higher energies.. Blackbody radiation depends on temperature of body. Not always, but usually. There are also rare up conversions. https://en.m.wikipedia.org/wiki/Photon_upconversion https://en.m.wikipedia.org/wiki/Two-photon_absorption It is simply a matter of probability. To upconvert there are needed two or more photons with lower energies to be absorbed in very short window of time, in the right moment.. To downconvert there is needed just one photon and it is spontaneous process. Throw a dice to get 1 of 6, versus throw two dices to get 1 and 1 in single shot. There is 6 x 6 = 36 combinations.
  14. Mass is physical property. Sum of masses of the all particles added together. Volume is physical property. Space used by particles by themselves and space between them. One can use weight to measure mass. Then calculate or measure volume. Divide them both to get average density. If you have volume and know average density (e.g. from tables) you can calculate mass. It is often used tool. If you have mass, and know molar mass, you can tell quantity of particles or molecules (in uniform substance like distilled water). Is it not the basics that you should learn on physics and chemistry lessons?
  15. I am using my balcony as refrigerator during true winter (hard to get one these days).. After shopping e.g. beers and meat land on my balcony (there is -5 C at the moment). Before refrigerator has been created people used ice houses https://en.m.wikipedia.org/wiki/Ice_house_(building) which costed nothing to operate except a while of work to gather ice. ps. Typical house electronic and electric devices are not designed to operate in cold and/or humid environment..
  16. Consequences of global warming will be massive starvation, wars for water and food, increase of food and water prices, massive emigration of billions of people living on lands affected by increased temperatures to more moderate temperature regions (Europe, North America and North East Asia). Death of sea wild fishes and sea living organisms (plankton does not like higher temperatures and it is primary food source of the all sea living higher level organisms). Oxygen dissolves less efficiently at higher temperatures of water. Sea living organisms have no time to adjust for lower concentration of Oxygen, so many species will extinct. People relying on sea living organisms will be starving or will have to switch to other food sources even further increasing their prices. And so on, so on..
  17. This is timelapse video made from photos taken by satellites for forty years. Snow and ice, white surface generally , is reflecting sun light. Water absorbs light and gets hotter. So the less snow during winter on poles and land (mostly Northern Hemisphere) the higher increase of temperatures and the Sun is start adding its brick to human made global warming.. There is many such correlations accelerating global warming. ..sounds like you don't want to ask questions and learn..
  18. Did you see video from my previous post? Global warming means change of global maxima as well as global minima from moderate to more extremes. For example in the case of United Kingdom temperature will drop and UK will have colder winters than now. Don't be fooled that it's sign against global warming! It will be result of global warming.
  19. They are made to fool people and earn money on ads..
  20. In classical physics there is not boundary where force is literally reaching absolute zero. Equations just follow inverse-square law, or inverse-cubic law, etc. and vice versa in the other direction. That is often pointed out argument, by some people on this forum ("antiscience crackpots"), against quantum physics i.e. "why electron does not fall to nucleus". Energy is property of particle. Kinetic energy of particle or molecule, rotational energy of particle or molecule, is "lost" during collision with other particles. "lost" means that other particles will be created, which will carry on that energy away of place where collision happened. i.e. accelerated electron by electron gun, toward e.g. phosphorescent screen, will lose its kinetic energy after collision with the screen, and new photon(s) will be created which will carry on that energy away. Feature which was used in early CRT old TVs. Essential potential energy of particle ("mass-energy") is converted to kinetic energy of newly made particles during annihilation with antimatter (electron and positron). In the case of other particle-antiparticle pair annihilation is much more complicated (part of energy converts to rest-mass of newly created particles e.g. meson PI). Part of mass-energy of nuclei (or nucleus) is converted to kinetic energy of newly made particles during fusion, fission and radioactive decay.
  21. Concrete does not trap much of water *). But in urban areas it causes water to quickly flow to rivers disallowing to be absorbed by soil. Accelerated rate of flow of water might cause flooding even in places hundred kilometers away, as river water level is unnaturally raised up. Simply saying water is too quickly finding path to rivers. In older times the rivers used to meander. But it was taking large of areas of countries, so people started "straightening" rivers, to gain fertile areas around rivers, which used to be muds and swamps, for agricultural production. https://www.google.com/search?q=straightening+rivers "This straightening causes the streams to flow more rapidly, which can, in some instances, vastly increase soil erosion. It can also increase flooding" https://en.wikipedia.org/wiki/River_engineering Read instruction of making concrete (there is mentioned how much of water you have to add to cement), and multiply by worldwide concrete production (search net for both information). https://en.wikipedia.org/wiki/Water–cement_ratio *) ~35% according to the above article.
  22. "Weather satellites have been available to infer sea surface temperature (SST) information since 1967, with the first global composites occurring during 1970.[9] Since 1982,[10] satellites have been increasingly utilized to measure SST and have allowed its spatial and temporal variation to be viewed more fully." https://en.wikipedia.org/wiki/Satellite_temperature_measurements Comparison of temperatures collected from satellites and ground monitoring stations: There is no need for specialized weather satellites to capture photography of Arctic, Greenland, Antarctic etc. etc. and to make timelapse video from forty years: ...or measure the amount of land that has turned into a desert during the last forty years... ... or measure the number of forest fires (and area) during the last forty years.. etc. etc.
  23. @BorisBoris Multimeters, oscilloscopes and electronic/electric devices used by electricians are typically measuring frequency of alternating current (AC) or pulsing DC. This formula tells how much single photon has energy.
  24. Media journalists abuse words like "crisis" to have catchy title for an article, so people will visit and read their article. It is similar to the words "professional", and "intelligent" in advertising materials. Just yet another clickbait. https://en.wikipedia.org/wiki/Clickbait
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