Knowledge Database

 

The Superheating Mechanism Explained Superheating occurs when a liquid (like water) is heated above its normal boiling point (100°C/212°F at sea level) without actually boiling or forming visible bubbles. This creates a metastable (unstable) state —the water is hotter than it "should" be for a liquid, but it stays calm until disturbed. Why It Happens More Often in Microwaves Normal boiling (e.g., on a stove): Heat comes from the bottom, creating convection currents (hot water rises, cooler sinks). This agitation, plus scratches/impurities in pots, provides nucleation sites —tiny air pockets, scratches, or particles where steam bubbles can easily form and grow. Microwave heating : Microwaves excite water molecules directly and uniformly throughout the liquid (volumetric heating). There's little convection, and if the container is very smooth (e.g., a clean glass cup) and the water is pure/distilled: No nucleation sites → No easy places for bubbles to start. Water...

Below is a clear, evidence-based ranking of common animal cooking fats from healthiest to least healthy when used in moderation as part of a normal diet. Rank Fat/oil Why it ranks where it does Main concerns (if any) Best uses in practice 1 Fatty fish oil (used as supplement or from cooking salmon, mackerel, sardines) Extremely high in omega-3 EPA/DHA → proven to lower triglycerides, reduce inflammation, protect heart & brain. Almost none if from clean fish Eating the fish itself or supplements 2 Goose fat ≈60–65 % monounsaturated (same as olive oil), decent stearic acid (neutral), low PUFA. Very stable when heated. High calories, but excellent fatty-acid profile Roast potatoes, vegetables 3 Duck fat Almost identical profile to goose fat (60 %+ MUFA), high oleic acid, very heat-stab...

Clarifying "Two Different Kinds" of British Passports and the "6 Valid Passports" Based on your follow-up, it seems you're referring to the distinction between two main kinds of British passports (standard passports for British citizens vs. variant passports for other forms of British nationality) and the UK government's recognition of 6 valid types of British passports overall. This is accurate according to official HM Passport Office (HMPO) guidance. I'll break it down below, drawing from the latest UK government publications (updated as of August 2024). To recap briefly from our previous discussion: Yes, individuals can hold multiple valid British passports concurrently (up to two in most cases, with rare exceptions), but this is separate from the types of passports. Multiple passports are usually of the same type (e.g., two standard British citizen passports for frequent travelers). However, people with dual British nationality statuses (e.g., a ...

Here’s the real reason why most airplane headphones still have two pins (dual-prong) instead of the usual single 3.5 mm jack: 1. Historical safety rule (the original reason)    Back in the 1960s–1980s, aviation regulators (mainly the FAA) were worried that passengers wearing high-quality noise-canceling or tightly sealed headphones might not hear emergency announcements or crew instructions during evacuation.      So they required in-flight entertainment systems to use a non-standard dual-pin plug. Regular consumer headphones with a single pin simply couldn’t be plugged in, forcing people to use the cheap airline-supplied ones (which were usually low-quality and had almost no noise isolation). That way you’d still hear the crew yelling “Unfasten your seatbelts and get out!” 2. Two separate pins = left & right channel redundancy      One pin carries the left channel, the other the right. If one pin or wire breaks, you still get mono s...

Here’s a clear, up-to-date (2025) English summary of everything you need to know about HIV itself, PEP, and PrEP – all in one place. 1. HIV Basics in 2025 Topic Current Facts What is HIV? A virus that attacks CD4 immune cells. Without treatment → AIDS in ~8–10 years. Is HIV curable? Not yet curable, but 100% treatable . One pill a day → normal lifespan + cannot transmit. U=U (Undetectable = Untransmittable) If someone with HIV takes medicine and viral load <200 copies/mL for ≥6 months → zero risk of sexual transmission. Officially recognised by WHO/CDC since 2016. Transmission routes Only four body fluids can transmit: blood, semen (incl. pre-cum), vaginal/rectal fluids, breast milk. No transmission through kissing, saliva, sweat, mosquito, toilet seat, etc. Global/Taiwan numbers 2025 ~39 million people living with HIV worldwide....