Comments by "Mikko Rantalainen" (@MikkoRantalainen) on "Two Bit da Vinci" channel.

  1. It was literally 200 m from wreck of Titanic and it was known that the sub was trying to go to the Titanic. Finding it there was probably the easiest task ever in trying to find a lost sub. If it had lost propulsion and floated within the currents for 50 km and then imploded, finding the remains would be next to impossible.
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  2. 6:15 In case of water, the "stays flat for a while" is a really long while at 100 °C. Heating 1 kg of water from 0 °C to 100 °C takes about 418 kJ. Boiling 1 kg of water from 100 °C to 101 °C takes about 2247 kJ (or 5 times more than getting it from zero to hundred).
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  3. Small correction to video: both copper and aluminium fail to work on induction stoves. You want something that reacts to magnets and the stronger a magnet sticks to your cookware, the better it will work with the induction stove. Stainless steel and cast iron are the best. I prefer stainless steel for most purposes because you can throw the cookware to dishwasher and it will take care of itself. Cast iron frying pan is still the best for cooking but real pain to keep clean if it gets dirty.
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  4. We have an induction stove with 3.5 kW per cooking position and I'd like to have even more power.
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  5. Definitely interesting news! However, I fail to understand how the cells could at the same time last 200K cycles with 500 C and have potential dentrite formation? Typically dentrite formation destroys the cell in 50–200 cycles which would be a bit shy of 200K cycles, right?
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  6. I'd love this research to be correct but I'm not holding my breath. Even if nothing could be done to increase the current, this should still result in interesting new CPU designs which have super low power use. Combined with SRAM instead of SDRAM, you could create super low electricity consumtion computers.
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  7. Not all induction stoves whine. It's called coil whine and it's caused by coils vibrating in the in magnetic field. Some manufacturers do the extra work required to stabilize the coils to avoid the audible noise. And amount of coil whine depends on your individual unit. If manufacturer doesn't consider coil whine for the QA, units from that manufacturer may or may not have audible coil whine depending on your luck.
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  8. 7:30 Note that "100%" and "0%" are just political decisions when it comes to battery cell chemistry. The actual chemistry works in voltage but difference manufacturers set "100%" to somewhere between 4.10 and 4.35 volts. The cell lifespan degrades the higher you charge the cells and the cells of manufacturer which sets "100%" to 4.10 volts doesn't seem to degrade at all compared to the manufacturers that set "100%" to 4.35. When it comes to smartphones, Samsung was known for setting "100%" to 4.35 V. This resulted in great battery performance in short tests with new handsets but the battery degraded really fast if you charged the phone to 100% daily.
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  9. 14:50 Induction stove doesn't actually need contact at all. You can try putting a piece of paper or even a newspaper between the stove and the cookware and it will still work. The longer distance will reduce efficiency of the system, though, similar to wireless charging in smartphones.
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  10. Carbon fiber is a poor material for subs because carbon fiber structures have high strength against tension but behave poorly under compression. In case of pressurized airplanes, the body is in tension and carbon fiber makes lots of sense. For a sub, the body is pretty much always under compression which makes carbon fiber really problematic material for building subs.
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  11. Unfortunately, EU was too fast to standardize and mandate CCS so every manufacturer is going to be forced to install CCS charging port to all cars that will be sold within EU area. As an European, I'm hoping that EU will reconsider and swith to NACS now that it can be used without licensing fees. And I totally agree that NACS is way superior connector. The only problem is that NACS cannot accept 3-phase 400 V AC power sources pretty commonly available in individual houses within EU area, which CCS port does support. You can obviously install quick charger that takes 3-phase 400 V AC from the grid and outputs DC to the car but that will be pretty expensive charger.
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  12.  @BillMitchell-lm8dg  I agree, you just need at least double amount of cells in a battery pack. However, that means that even smartphone class devices would need BMS and cell balancing implementation which would increase costs for the end user device. If the final battery pack can take even 500C charge and dischager speeds, that would be insanely great tech nonetheless. With 500C charging power, you could basically regen brake EVs in all situations.
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  13. 4:30 I guess the unit should be "Wh/kg" instead of "watts/kg". And the same for imperial units, too.
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  14.  @TwoBitDaVinci  Hard to tell. Some people seem to not mind the coil whine. I hate it. People also have different preferences for stove interfaces. I like physical knobs as the interface but I want digitally accurate control with those knobs. Touch screens on stove are really bad in my experience because even a tiny amount of oil or water in your fingers cause the touch detection to get really flakey in practice. My biggest gripe with our current induction stove is that it has stupid delay built-in. For some reason, whenever I turn the know, the firmware waits for maybe half a second, makes "beep" sound and then adjusts the power. I know this because when you have small amoutn of water boiling, you can see when the power gets applied and when the power is cut down. The LCD display rendering the current power reacts instantly to the knobs but the power to the stove doesn't. I assume the designers of the stove thought that this was good for some purpose but for me, that's the worst part of the stove. And the biggest missing feature is temperature control instead of power control. My perfect stove would have both. For many purposes I would want temperature control combined with max power to get to the selected temperature. Kind of like high quality soldering irons work: you can increase requested temperature from e.g. 150 to 320 °C and the target temperature is achieved in seconds but it will not overshoot.
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  15. I think this should be described as superior thermal mass instead of proper insulation. Insulation is something you need when outdoors is 40 °C less than indoors for 4 weeks. If you try to do that with thermal mass, the amount of material needed would be insane. If you want good insulation, try PU thermal insulation with aluminium laminate surface. High quality stuff will have interlocking tongue and groove between individual panels to avoid air leaks between the panels.
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  16. Natural gas cooking would be hideously expensive here in Finland because we don't have already built infrastructure for it. Instead we have high quality electric grid with 3x400 V connection to most houses (3 phase, you can get the typical 240 V voltage used here between the phases). In practice, even a modern 11 kW electric stove will only need 11000 W / 3 / 400 V = 9.2 A wiring which should make it obvious why this system is superior to the US grid setup.
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