Part A · the number scale — feel the gaps between orders of magnitude
From 1 to 1 trillion — with real anchors at every step
Each row is 1,000× the one above it. That gap never gets smaller.
1
one
1,000
one thousand
1 million
11.5 days in seconds
1 billion
31.7 years in seconds
1 trillion
31,700 years in seconds — before end of Ice Age
Thousand (10³)
~1,000 people
A village. Fits in a small theatre.
Million (10⁶)
~1M people
A medium city (e.g. Birmingham, Prague).
Billion (10⁹)
~1B people
China or India. ~⅛ of humanity.
Part B · the cosmic time scale
How old is everything? (years ago)
Compressed to a single bar. Human history is invisible at this scale.
Big Bang
13.8 billion years ago
Earth formed
4.5 billion years ago
First life on Earth
~3.8 billion years ago
Dinosaurs extinct
66M yrs
First humans (Homo sapiens)
300K yrs
First writing / cities
5,000 yrs
If Earth's entire history = 1 year, humans appeared on December 31st at 11:48pm. All of recorded history — Egypt, Rome, the Renaissance, everything — fits in the last 10 seconds of that year.
Part C · human time — from seconds to a lifetime
Key time conversions to feel, not just calculate
1 minute
60 sec
1 hour
3,600 sec
1 day
86,400 sec
1 week
604,800 sec
1 year
~31.5 million seconds
1 human lifetime (~80 yr)
~2.5 billion seconds
A human lifetime ≈ 2.5 billion seconds. A billionaire's wealth in dollars roughly matches the number of seconds in many lifetimes. Elon Musk's $220 billion ≈ 88 human lifetimes' worth of seconds.
Part D · interactive number sense — compare anything
How big is a number? Enter any number and see it in context.
Part E · cross-module connections — putting it all together
Weight + money
Apple earns ~$97B profit per year. At $1 per gram, that would weigh 97,000 tonnes — roughly the steel in the Golden Gate Bridge (83,000 t). Apple earns a Golden Gate Bridge's weight in profit every year.
Population + infrastructure
The world adds ~80 million people per year. That's roughly 3 million new homes needed annually. At $300,000 per home, that's $900 billion in housing per year — more than Germany's entire GDP ($4.1T) every 4.5 years, just to house new arrivals.
Distance + time + wealth
Light travels 300,000 km per second. In the time it takes you to blink (~150ms), light travels 45,000 km — more than Earth's circumference. In that same blink, Apple earns about $460 in profit.
Hair + lifetime
Your 100,000 hairs grow 1.25 cm/month each. Total hair growth across your whole head: 1,250 metres per month, or 15 km per year. Over an 80-year lifetime: ~1,200 km of hair grown — roughly the distance from Paris to Madrid.
Births + cargo
385,000 babies are born per day. Each weighs ~3.3 kg. That's 1,270 tonnes of new humans per day — roughly 49 fully loaded trucks, or a small cargo ship, arriving daily in human mass alone.
Part F · the master anchor list — everything in one place
Seconds
1M sec = 11.5 days · 1B sec = 31.7 years · 1T sec = 31,700 years
Weight
1L water = 1 kg · human = 70 kg · car = 1,400 kg · HGV load = 26 t · ship = 200,000 t
Distance
1,000 km ≈ 1 hr flight · Earth circumference = 40,000 km · Moon = 384,000 km
Money
$1M = 20 yrs saving · $1B = 20,000 yrs · Apple profit = ~$97B/yr · richest person ~$220B
Human lifetime ≈ 2.5B seconds · Earth = 4.5B years · universe = 13.8B years
Part G · final test yourself — mixed questions from all modules
1. Someone says "I've been alive for about a billion seconds." How old are they?
About 31.7 years old. 1 billion seconds ÷ 31,536,000 seconds per year ≈ 31.7 years. This is a great party trick — you hit your "billion second birthday" around age 31 years and 8 months. Most people in their 30s have lived almost exactly 1 billion seconds.
2. The universe is 13.8 billion years old. Humans have existed for 300,000 years. What percentage of cosmic time have we been here?
About 0.0022%. 300,000 ÷ 13,800,000,000 = 0.0000217 = 0.00217%. Rounded: roughly 2 thousandths of a percent. All of human existence — every war, every civilization, every person who ever lived — occupies less than 1/45,000th of cosmic time. And recorded history (5,000 years) is just 1/360th of even that tiny slice.
3. A news story says a government spent "$2 trillion on infrastructure over 10 years." How does that compare to what you now know?
$200B per year. To calibrate: that's roughly twice Apple's annual profit, about 7% of US GDP, and enough to build ~130 Golden Gate Bridges per year, or fund the entire French government for about 6 months. It sounds enormous — and it is — but spread over 10 years across a large country's entire infrastructure, it's actually a moderate commitment. The USA spends roughly $500B/year on its military alone for comparison.
4. Your friend says "I walked 10,000 steps today." How far is that in km, and how long did it take roughly?
About 7–8 km, taking roughly 1.5 hours. One step ≈ 0.75 m, so 10,000 steps ≈ 7.5 km. Walking speed is ~5 km/h, so 7.5 km ÷ 5 = 1.5 hours. This is a useful anchor: 10,000 steps ≈ 7.5 km ≈ 90 minutes of walking. It also burns roughly 300–400 calories — about the same as a Mars bar.
5. Final challenge: Apple has a market cap of ~$3 trillion. The world's population is 8.2 billion. If Apple's value were divided equally among all humans, how much would each person get?
About $365 each. $3,000,000,000,000 ÷ 8,200,000,000 ≈ $366. One year's worth of Apple's entire market value, spread across every human alive, gives each person roughly enough to buy a mid-range phone — ironically, perhaps an iPhone. This illustrates how concentrated wealth is: the entire value of the world's most valuable company amounts to about one modest purchase per person on Earth.