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Sensei

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Everything posted by Sensei

  1. Tunnel effect or quantum tunneling? https://en.wikipedia.org/wiki/Tunnel_effect https://en.wikipedia.org/wiki/Quantum_tunnelling
  2. ...the science forum warped colors after analyzing your thread...
  3. Keywords for the search engine: binary search, binary tree, quad tree, octree, kd-tree, bsp-tree, hash map/hash table. Read Wikipedia of these space-partitioning algorithms. They work with 1D and/or 2D and/or 3D.
  4. There are ~ 3131 isotopes of 118 elements. The vast majority unstable or extremely unstable. Which one do you want to know? You need to be specific. The vast majority of these isotopes have not been isolated in sufficient quantity to properly test their physical and chemical differences from the most abundant stable isotopes of the element. The differences between the isotopes are used to isolate them. The most noticeable differences are only apparent at the quantum level, i.e., to isolate a single isotope or element, a mass spectrometer can be used. Isotopes/elements with different m/e deflect differently in a strong magnetic field and accelerate differently (due to mass difference) in an electric field. Mass vary significantly from isotope to isotope, from element to element. In the case of Hydrogen-Deuterium-Tritium it is +100% / +200%. In the case of Uranium-235 vs U-238 it is just +1%...
  5. ..these fines are generally senseless.. It is procedure "how to produce domestic terrorists" | "how to produce criminals".. etc. etc. ..restaurants can sell on-line (and should! as long as they are not luxury restaurants they can operate pretty fine with on-line sales, if people can't go any restaurant nor shop, and there is a reliable delivery system) but there are businesses which completely rely on client coming in physically, and 1) unable to freely operate and 2) have to pay debts, office rents, fines (?) and 3) get fined if they are open... An endless loop... Not possible to pay fine, if you don't operate, and can't operate unless breaking the law which prohibits being open.. Complete madness.. Mutually exclusive..
  6. The stupidest action that was done was the evacuation of tourists, businessmen, citizens, to the homeland.... https://en.wikipedia.org/wiki/Evacuations_related_to_the_COVID-19_pandemic Which was basically importing the disease into the country.. What tourists do when they return home after a week or two of vacation? They go to the store or mall to buy food, where they spread disease to the local population (hard/impossible to track).. Then they meet family, friends, colleagues, neighbors (possible to track, if people are honest) and the disease spreads..
  7. Bizarre you listed some (pretty sci-fi) reasons for war in Asia with China, or even initiated by China, and "forgot", omitted the most obvious reason.. (and obviously I did not mean COVID-19..) The modern design of nuclear power plants is designed to reduce the possibility of an explosion whether it is attacked or affected by a natural disaster. Fukushima Daiichi Nuclear Power Plant was even older design than Chernobyl Nuclear Power Plant (~50 years ATM).
  8. Searching net for "online three body calculator" e.g. https://www.google.com/search?q=online+three+body+calculator gives this: https://www.desmos.com/calculator/icaqw49qeq where icaqw49qeq is data about initial condition.
  9. No. Pangea is part of the Earth. The Moon is a non-artificial satellite of the Earth.... No. It was the protoplanet Theia: https://en.wikipedia.org/wiki/Theia_(planet) The collision of the protoplanet Earth with the protoplanet Theia formed the present Earth and the present Moon from their debris. Scientists use simulations to confirm or deny such a hypothesis. Learn programming, create an algorithm, run the simulation with some input parameters, and observe the results. Change the parameters to observe something else. Repeat millions of times...
  10. ..did you mean Steven Frayne.... ?? https://en.wikipedia.org/wiki/Dynamo_(magician)
  11. Can I mock from your mockery? The God Jesus..
  12. Journalists like such click-bait, eye-catchy, subjects.. I would ask "for how long?" the hottest place.. If e.g. a proton hits an antiproton, either in a particle collider or as a result of cosmic radiation, at close to the speed of light, the temperature in that case is so high that it is counted in GeV or TeV, not K... https://en.wikipedia.org/wiki/Electronvolt#Temperature
  13. It should be ☰ in the first place. W3Schools has nice example how to make animated hamburger menu icon: https://www.w3schools.com/howto/tryit.asp?filename=tryhow_css_menu_icon_js Non-animated version: https://www.w3schools.com/howto/tryit.asp?filename=tryhow_css_menu_icon
  14. If you smell something, your nose has picked up atoms of something, such as the smell of skin...
  15. @Wilfred Thompson I checked your source code. It will work better if you replace line: document.getElementById("navdrop").style.width = "100"; by document.getElementById("navdrop").style.width = "100%"; More info about units in HTML/CSS: https://www.w3schools.com/cssref/css_units.asp If you want to test this thoroughly, open your page in a separate window and change the width (several different widths) of the window (and play with UI). There are other problems evident if you start changing the width of the window...
  16. Hello! What HTML, CSS, JS tutorial sites do you use? I think one of the best is https://www.w3schools.com There is a sample dropdown code there: https://www.w3schools.com/css/css_dropdowns.asp Curtain Menu example: https://www.w3schools.com/howto/howto_js_curtain_menu.asp Best Regards!
  17. Sensei

    Units?

    In adding (or subtracting) a physical quantity to another physical quantity, the scalars are added together and the units must match. e.g. 1 m + 10 m = 11 m If they do not match, even if they both represent e.g. length, they cannot be added or subtracted. e.g. 1m + 1 inch Inches must be first converted to meters, or meters must be converted to inches, so the two units match to add them together. In multiplying (or dividing) physical quantities, the units need not match. A scalar is multiplied by a scalar, a unit is multiplied by a unit. e.g. 3m * 10m = 30m^2 e.g. 10 m / 5 s = ( 10/5 ) [m/s] = 2 m/s e.g. 10 N * 5 m = 50 J Dividing a physical quantity by physical quantity with the same units yields a dimensionless/unitless scalar. e.g. 100 s / 50 s = 2 100 m/s * 10s = 1000 m (Unit cancellation)
  18. Trabants were made of bad quality plastics (recycled wastes).. ??? 4th paragraph on Wiki "The Trabant's build quality was poor,[13] reliability was terrible,[10][11][14] and it was loud, slow, and poorly designed.[3]"
  19. Scientists don't make up their formulas.. You need source data, and from that you derive formula in the area of interest. e.g. velocity is derived from analyzing the change in position of an object e.g. x0 at time t0, x1 at time t1, dx = x1-x0, dt = t1-t0, so v=dx/dt.
  20. Didn't you have dimensional analysis on physics lessons in your elementary school ? https://en.wikipedia.org/wiki/Dimensional_analysis h*f has unit J = kg * m^2 * s^-2 F has unit N = kg * m * s^-2 c has unit m/s If you divide J/N the result will have a unit in meters.. so it will dismatch with m/s.. so the simple answer to your question is, no it's not correct..
  21. If you know formula, you can use Excel or Open Office Spreadsheet.. If you don't know formula, but know website which is giving correct results, press ctrl-u to show HTML and JavaScript source code, and then find it, and copy it to Spreadsheet.
  22. Charge Q (in Coulombs, C unit) is integer multiply of e (elementary charge) (also in C). https://en.wikipedia.org/wiki/Elementary_charge Q/V would have unit C/m^3
  23. To get this effect, all it takes is for an EV to collide with someone else on the road.. "Do you have any evidence to support this claim"? Petrol fuels burn when there is ready access to Oxygen (and it's limiting speed of fire), and only vapors.. EV has no such requirements.. Reread my post, I said about catching fire after accident (aka "car crash" when things disintegrate). Not when everything works smoothly.. It's not even about capacity of energy. But speed in which that energy can be released. ICE car fuel tank burning speed is limited by access to Oxygen.. To have potential fire with accumulator, you just need to plug + to - with plain wire (i.e. "metal piece which accidentally joined them in a crash").. Don't misinterpret my words, by mistake, or premeditation.. I am fan of EV, unlike ICE.. ..which is irrelevant to our current position.. I always thought, you're reasonable member of this forum.. Lost confidence about you, after your today comment.. There are even airplanes which were destroyed by laptop batteries: https://www.google.com/search?q=airplane+destroyed+by+laptop+battery http://www.forfyre.com/the-lithium-safe-battery-bag-for-the-fire-protection-of-lithium-ion-batteries-that-catches-fire-due-to-thermal-runaway/?lang=en "A total of 171 incidents between 1991 and 2016 was recorded involving batterys carried as baggage or cargo on airplanes. (recorded by the US Federal Aviation Administration)" (without any crash, or damage)
  24. The urban driving speed in my country is currently 50 km/h, which is only +5 km/h more than 30 miles/hour. Who uses an electric car for longer trips when when you can't easily find plugs/unsure they are in place where you want to go.. ? ps. Many such speed regulations make no sense and have no real impact on road safety.. They are pushed by politicians who have no idea what they are doing, to pretend that they are doing something.. Electric cars, thanks to the energy stored in their batteries (which is good, if everything is OK), burn like they are "made of paper" after even a basic accident..
  25. Couple generic thoughts: The original must have been a JPEG, but you included a PNG. Do you have the original? Archive it and attach it again. Drag'n'drop of your image to Yandex Images (https://yandex.com/images/ ) did not give anything useful. It even misidentified it as a resistor. You can try: search by file name, search by file size (if you have the original, otherwise it won't work). Internet archives could gather older websites, as long as they were still online at the day webarchive started working.. even with greater chance than now.. because there was less websites to scan, and there was little JavaScript used, which dynamically generates website when user visits it. You can't archive FB, Twitter, Instagram, etc. just by using wget/curl etc. tools.. They are behind user logging wall (some media, behind paywall) and are dynamically generated by JavaScript at the time of visit and are context (user) dependent. Therefor in XXV+ century nobody will truly know what happened in XXI, as there will be no records.. A site must be linked by many other sites in order to be visited by search engines, web archive engine and other bots. A page that is not linked to from other, higher ranking pages, may never be visited, backed up or analyzed by a search engine. ps. What you have on the photo looks like stirring blades.
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