Sources

Mass, radius, rotation period and orbital speed used as the baseline Earth.

Sidereal day used to set Earth's present angular velocity.

Equatorial radius used for surface speed and centrifugal terms.

gn = 9.80665 m/s², the conventional standard gravity (also ISO 80000-3).

Lunar mass and mean Earth–Moon distance for tidal comparisons.

Solar mass and the scale of sunlight at 1 AU.

Lunar and solar tide-raising, spring and neap cycles.

The astronomical unit is exact: 149 597 870 700 m.

Solar mass and the scale of sunlight at 1 AU.

Mass, radius, rotation period and orbital speed used as the baseline Earth.

The astronomical unit is exact: 149 597 870 700 m.

gn = 9.80665 m/s², the conventional standard gravity (also ISO 80000-3).

Mass, radius, rotation period and orbital speed used as the baseline Earth.

Lunar mass and mean Earth–Moon distance for tidal comparisons.

Mass, radius, rotation period and orbital speed used as the baseline Earth.

Lunar and solar tide-raising, spring and neap cycles.

Mass, radius, rotation period and orbital speed used as the baseline Earth.

gn = 9.80665 m/s², the conventional standard gravity (also ISO 80000-3).

Estimates the world population at 8.2 billion in 2024.

Mass, radius, rotation period and orbital speed used as the baseline Earth.

Structure and role of Earth's atmosphere.

gn = 9.80665 m/s², the conventional standard gravity (also ISO 80000-3).

Sidereal day used to set Earth's present angular velocity.

Equatorial radius used for surface speed and centrifugal terms.

gn = 9.80665 m/s², the conventional standard gravity (also ISO 80000-3).

Mass, radius, rotation period and orbital speed used as the baseline Earth.

Mass, radius, rotation period and orbital speed used as the baseline Earth.

Background on atmosphere and climate as human emissions stop.

Mass, radius, rotation period and orbital speed used as the baseline Earth.

gn = 9.80665 m/s², the conventional standard gravity (also ISO 80000-3).

Equatorial radius used for surface speed and centrifugal terms.

Pressure rises about one atmosphere every 10 m; about 200 atmospheres at 2,000 m; animals without air spaces are less affected.

Oxygen solubility by temperature and salinity: about 9.1 mg per litre in fresh water and 7.4 mg in seawater at 20 °C.

The Benson and Krause equations behind the solubility figures, and 1.429 mg of oxygen per ml.

Dry air is 20.95% oxygen by volume.

One MET, the oxygen cost of sitting quietly, is 3.5 ml per kg per minute.

Breathing air under pressure dissolves extra nitrogen into tissues, which can form bubbles on ascent.

Nitrogen narcosis below about 35 m (120 ft) and Boyle’s law squeeze on air spaces.

Dives to 2,992 m lasting up to 137.5 minutes, mammal records.

Mice survived breathing an oxygenated fluorocarbon liquid.

A study of 13 premature babies with severe breathing problems.

Boiling point of oxygen: −182.962 °C.

Most adults need between 7 and 9 hours of sleep a night.

Regular poor sleep is linked to serious health problems, including obesity, heart disease and diabetes.

Randy Gardner’s 264 hours in 1964, the 453-hour claim in 1986, microsleeps, and why the record stopped being monitored in 1997.

Two natural short sleepers with a DEC2 mutation averaged 6.25 hours a night against 8.06 hours for relatives without it.

Plain-English summary of the 2009 short-sleeper study.

Fatal familial insomnia causes progressive insomnia; prion diseases usually cause death within months to a few years.

The brain is active during sleep, and what sleep is thought to do.

Wien’s law (peak wavelength × temperature = a constant), used to turn a cutoff wavelength into a peak temperature.

c is exact in the SI: 299 792 458 m/s.

Infrared as a band, from near-IR to thermal.

gn = 9.80665 m/s².

Tropopause height and the idea of a standard atmosphere.

Earth mass and radius for orbital and gravity-train numbers.

Channel crossing on 12 June 1979: 36.2 km in 2 h 49 min; wingspan 28.6 m; take-off weight 97.5 kg.

NASA flight tests of the backup aircraft and why its low power need mattered.

Tropopause height and the idea of a standard atmosphere.

In real air, temperature is what changes the speed of sound; here the speed is simply multiplied.

c is exact in the SI: 299 792 458 m/s.

AU is exact: 149 597 870 700 m.

Earth mass and radius for orbital and gravity-train numbers.

gn = 9.80665 m/s².

Earth mass and radius for orbital and gravity-train numbers.

AU is exact: 149 597 870 700 m.

gn = 9.80665 m/s².

Earth mass and radius for orbital and gravity-train numbers.

Earth's equatorial figure; the train formula uses the IUGG mean radius.

c is exact in the SI: 299 792 458 m/s.

The second is defined by a caesium transition — time in physics is not a pause button.

Clocks 33 cm apart in height tick at measurably different rates.

Tropopause height and the idea of a standard atmosphere.

Earth's equatorial figure; the train formula uses the IUGG mean radius.

Earth mass and radius for orbital and gravity-train numbers.

Why a supersonic aircraft drags a continuous boom carpet behind it.

The first piloted supersonic flight, 14 October 1947.

Concorde cruised at Mach 2 at about 60,000 ft.

Practical UK guidance on sleep habits. Used as context for a typical adult night, not as a prescription.

States that adults need different amounts and gives an average band of about 7 to 9 hours. The default 7.5 hours sits inside that band.

Official estimates of how UK adults divide a day, including sleep and rest as the largest single block.

Regular poor sleep is linked to serious health problems, including obesity, heart disease and diabetes.

Period life expectancy at birth in the UK was 78.8 years for males and 82.8 years for females.

Recommended sleep by age, showing children need more sleep than adults.

Sets statutory paid leave at 5.6 weeks for most workers, which is the default holiday slider.

The 48-hour average weekly limit under the Working Time Regulations, and the opt-out.

Explains what usually counts as working time, including that a regular commute generally does not.

How paid work sits alongside unpaid work, travel and leisure in an average UK day.

The State Pension age rises from 66 to 67 between April 2026 and April 2028.

Period life expectancy at birth in the UK was 78.8 years for males and 82.8 years for females.

Average commuting trip of 31.5 minutes and 9.2 miles in England in 2025, with 112 commuting trips per person.

Tables NTS0403 (trip time and length by purpose, 2002 onwards), NTS0412 (commuting by employment status) and NTS0413 (commuting by region, including 43.5 minutes for London).

How people travelled to work on Census Day, including the large working-from-home share in 2021.

Average daily time spent travelling, as a separate activity from paid work.

Used for the default 5.6 holiday weeks, which also remove commuting days in this model.

Regular commuting to a fixed workplace is usually not working time.

Travel between home and work is likely to count as working time for workers with no fixed place of work.

Includes time using a computer or digital device as a measured daily activity for UK adults.

Underlying tables for average daily minutes on work, leisure, travel and media.

Notes screens as part of an evening routine. Cited for context only; this experiment does not give sleep advice.

Shows television and other media taking up more free time than sport or hobbies for a typical adult.

UK adults spent 4 hours 20 minutes a day online in May 2024, 3 hours 15 minutes of it on smartphones.

How to see your daily screen time on an Android phone.

Shows how an average UK day is already fully allocated, so an extra hour has to come from some existing block.

Daily and weekly rest entitlements, relevant if the extra hour is imagined as coming out of the working day.

A reminder that shaving the hour from sleep is a different experiment. This page does not recommend that.

What counts as working time, which helps decide whether a lost hour belongs to work or to you.

Period life expectancy at birth and at older ages. Cited so 100 is understood as a what-if, not a typical span.

The tables behind the bulletin, by age and sex, for anyone who wants the official figures rather than a round target.

How an ordinary week is spent, if you want to imagine what remaining weeks contain.

The official list of bank holidays in England, Wales, Scotland and Northern Ireland.

Employers can include bank holidays inside the 5.6-week statutory leave total.

Weekly rest of 24 hours in seven days, or 48 hours in 14, which is the legal skeleton under a weekend.

Official dates for England and Wales, Scotland and Northern Ireland, including substitute days.

Guidance on building a regular saving habit and checking that a rate still makes sense over time.

A way to check how much is really free to save each month.

Suggests a buffer of three to six months of essential costs, kept somewhere you can reach.

Why an illustrated rate is not a product, and why real rates move.

The 2% inflation target, and why a total in today’s pounds may buy less later.

You can save up to £20,000 a year across ISAs without paying tax on the interest.

Savings are protected up to £120,000 per eligible person, per authorised firm, from 1 December 2025.

The practical place to see which lines of a UK household budget can actually move.

Official picture of how spending is split, as context for a percentage trim.

If the cut becomes saving, independent guidance on what to do next.

Independent guidance on starting a savings habit now.

Why extra years of compounding are sensitive to a rate that is not guaranteed.

A related official conversation about contributing more from today, without rewriting the past.

A 3% yearly bump is in the same conversation as rising prices, not a claim that it matches them.

Why a flat contribution loses buying power even if the account balance rises.

Reviewing a regular amount, rather than setting it once and walking away.

If the drinks budget is redirected to saving, this is the independent how-to.

Tea and coffee can count toward daily fluid. A reminder that drinks count towards daily fluid, not only cost.

Cafe prices move. A fixed £3.20 on the slider is a model, not a high street.

Leisure, drinks and takeaways sit in a full budget, which is fairer context than a single habit.

How UK households split spending on food at home, restaurants and takeaways.

Official statistics on how often people in England travel, by mode and purpose, including short trips and time spent travelling.

Places walking and wheeling above private car use for short journeys, and notes that most UK trips are under five miles.

Tracks how fuel, insurance, tax and maintenance move over time, useful context for a simplified cost-per-km slider.

Walking was 29% of trips in 2023, 81% of trips under a mile were walked and the average walking trip was 0.7 miles.

Approved mileage rate for cars and vans: 55p a mile for the first 10,000 business miles.

Official material on vehicle tax, which often continues unless a vehicle is sold or declared off road.

Regular UK pump-price and duty context for the fuel line of a motoring budget.

Breakdown of fuel, tax, insurance and maintenance as separate parts of the cost of running a car.

Approved mileage rates show how HMRC bundles running and standing costs; useful contrast with a fuel-only saving.

Statutory paid leave is described as 5.6 weeks for most workers, with a 28-day cap and notes on bank holidays.

Official series on hours actually worked, used here only as context for a typical full-time day length.

How paid work sits alongside unpaid work and leisure in an average day — a reminder that “free” time has a shape.

61 companies and about 2,900 workers, June to December 2022; 56 continued and 18 made it permanent.

Employees can request flexible working from their first day in a job.

Commuting remains one of the longer-distance trip purposes; average travel time in England was about 58 minutes a day in 2023.

Shows how commute length varies, and why a single default time is a poor substitute for the minutes you actually spend.

Context for drivers who treat fuel and related costs as the office-day bundle.

Advice on thermostats, programmers and typical comfort bands. Figures there are examples, not applied automatically here.

Typical Domestic Consumption Values, used to explain bills nationally — a backdrop, not your meter.

Quarterly unit rates and standing charges for default tariffs in Great Britain.

Home charging versus petrol fuel cost, with the caveat that public charging and purchase costs change the picture.

Electricity unit rates used as context for the default pence-per-kWh slider.

Official weekly and monthly UK pump prices for petrol and diesel.

HMRC’s pence-per-mile fuel rates, derived from typical mpg and DESNZ prices — a cross-check on petrol cost per mile.

Household expenditure including food at home and restaurants, cafés and hotels — context for how eating-out sits in a budget.

Cooking energy is real but usually small next to the ingredient-versus-takeaway gap; included as a reminder to put it in home cost if you care.

Approved mileage rates for cars: 55p for the first 10,000 business miles from the 2026 to 2027 tax year (45p from 2011 to 2026), then 25p.

Fuel-only rates per mile from 1 September 2026: 14p to 27p for petrol and 15p to 22p for diesel, by engine size, with the mean mpg figures used here.

UK average pump prices: petrol 175.28p and diesel 200.04p a litre for the week of 12 October 2026, against 134.81p and 142.99p a year earlier.

Mileage tax relief does not cover travel to and from your regular workplace.

Average commuting trip of 31.5 minutes and 9.2 miles in England (table NTS0403); rail and car commute distances for full-time workers (NTS0412); 1.13 people per commuting car and 89% lone drivers (NTS0905).

Fares across Great Britain unchanged on average in 2026, against a 4.1% rise in RPI; regulated fares down 0.1%.

Regulated fares in England, including season tickets, frozen from March 2026.

Any 8 days of travel in 28, with at least a 20% discount on an equivalent monthly season ticket; most railcards not accepted.

Milton Keynes Central to London Euston season tickets: weekly £170.90, monthly £656.30, annual £6,836.

£18 a day if paid on the day or in advance.

Timetables and fares for Great Britain’s railway; use a real quote in the ticket slider.

How energy labels work and what they quote for annual consumption.

Cold appliances and wet appliances as a large share of household electricity after heating.

Context for the default 24p/kWh electricity unit rate.

UK research on when repair and resale actually displace a new purchase, rather than sitting on top of one.

Reuse as a practical systems change, not only a household virtue — useful framing for replacement cycles.

Household resource use sits alongside energy; this page stays on the cash cycle rather than a carbon factor.