Recent content by Nik_2213

  1. Nik_2213

    Why does a fan cool you in a sealed room if it adds heat?

    Perhaps check out 'Wet Bulb' vs 'Dry Bulb' temperatures in addition to 'Wind Chill' ? FWIW, during thankfully rare UK heat-waves that coincided with Saharan dust incursions and dire pollen-count 'Spikes', only desk and wall-hung fans, plus big 'Air Mover' stirring stair-well, kept my wife and I...
  2. Nik_2213

    Modelling the voltage measured across a dc motor

    IMHO, there is a further issue: Is this a 'brushed' DC motor ?? Such are notoriously 'Noisy' tech. Been a while since I did hobby robotics, but brushed motors were the domestic equivalent of 'Spark Gap' transmitters. They needed close-coupled, over-rated, back-to-back Zeners, warily-rated...
  3. Nik_2213

    Reality Check: Rogue Planet Flyby Scenarios and Survival Feasibility

    FWIW, there is a wandering inter-stellar population of genuine 'Rogue Planets'. IIRC, some were probably tossed 'wild & wide' when their host star 'evolved' off main-sequence. Some probably came via the 'Brown Dwarf' route, perhaps not accreting to full size. Almost certainly, some were ejected...
  4. Nik_2213

    Reality Check: Rogue Planet Flyby Scenarios and Survival Feasibility

    Wiki, YMMV, has... https://en.wikipedia.org/wiki/List_of_nearest_stars This includes prior and pending passes... https://en.wikipedia.org/wiki/Scholz%27s_Star This mini-binary came close enough ~70ky ago to disturb Sol's Oort cloud. But, IIRC, such objects need another million years or so to...
  5. Nik_2213

    Plausible Physics for a biblical Ark

    Um, this *is* the tamper-trapped 'Covenant' Ark, with historical provenance, rather than the 'Noachian' absurdity ? The latter mega-hyped from Gilgamesh river-flood reportage ?? Two thoughts: If you dig into the electro-chemistry, you'll find it is as easy to use a primitive battery to...
  6. Nik_2213

    Plausible Physics for a biblical Ark

    If the 'Baghdad Battery' was used for electrolytic acceleration of acid-leaching, comparable to the Incas' acidic Andes streams, rather than a gold-plating system, then a 'Voltaic Pile' might follow. Given the 'Angelic Ark' was claimed to be a hefty whatsit, it could readily accommodate enough...
  7. Nik_2213

    Molds in Front Loading Washing Machine

    I suspect it correlates with majority of cycles now being cool 'eco-washes'.. IIRC, everything except 'fragile' used to run on a 'hot' wash. Such attrition seemed to keep the dreaded bio-film at bay. Now, 30ºC eco-wash is routine --And effective !!-- with 'hot' washes reserved for 'Heavy Soil'...
  8. Nik_2213

    Molds in Front Loading Washing Machine

    I had an extended battle with black mould both in and behind our front-loader's detergent / softener tray. Unfortunately, a family member kept banging knee on drum's ajar door, would slam it shut.. And, without that minimal air circulation, mould set in..... There is usually a covert latch or...
  9. Nik_2213

    Do old CRT and O-scopes degrade to emit harmful X Rays?

    Please DO NOT dispose of that lead-doped glass such that recycling *might* mix it with food-grade feedstock. Yes, yes, considerable dilution should occur, but the popularity of 'flat screens' means fragmented 'legacy' lead-fronted 'Bottles' may be over-looked...
  10. Nik_2213

    I am writing a SciFi story but I don't like Rayguns

    Not necessarily. Don't forget some 'big' guns use 'bagged' charges. Technically, case-less... A magazine may include a small can of 'coolant' to better flush breech. Barrel heating is a bane of repeated firing, but a limited 'kick-charge' would mitigate that... Also see...
  11. Nik_2213

    I am writing a SciFi story but I don't like Rayguns

    I gave ' Expansionist Imperial' antagonists in a story-arc 'Hybrid Rocket Guns'. Down-side of 'trad' rocket guns is slow exit from barrel. The 'Gyrojet' lacked lethality at short range. And, when it 'got going', was sub-optimally accurate due aiming / spin issues. Reloading required external...
  12. Nik_2213

    The Short Story Thread: Post Yours Here

    Life World Most galactic species call the Terrans 'Death Worlders', for the myriad ways their home planet will kill you. A few, wiser, call that planet a 'Life World' {Spit_!!}, and shun Sol System as if about to go 'nova'. Consider how Terrans' mites, ants and roaches seem immune to most...
  13. Nik_2213

    Using a copper pipe in an aluminum tank?

    I'll not say 'DO NOT !!' but, IMHO, putting such electro-dissimilar metals into proximity is a very poor idea. IIRC, there are stiff-ish 'potable' grade polymer laminate pipe types which would side-step issues..
  14. Nik_2213

    What is this metal insert for in a desk?

    Note metal Cam lock dowels may even be double-ended, for joining panels end-on. A range of lengths available... Discovered such when needed to 'Frankenstein' two flat-pack kitchen units as '50' + '40' cm, when range did not include a '90' cm and '100' cm would be 'Just Too Long'... Yes...
  15. Nik_2213

    Mono-isotopic silica melting points?

    Sorry, my Google-Fu cannot find any' reference... Silicon has stable isotopes '28' ~92%, '29' ~5% and '30' ~3%. Oxygen has stable isotope '16' at >99 %, so effectively mono-isotopic. Do the three Si isotopes have significant effect on melting point etc of their silica SiO2 ?? For a...