The universe · scale, oddities, big questions

Sixty-two powers of ten, and we’re in the middle.

From the smallest length physics can talk about to the edge of what we can see spans about 10⁶² times. Humans sit near the middle of that range. Zoom through it, squeeze 13.8 billion years into a calendar, and meet the objects that break intuition.

Demo 1 · scale

Powers of ten

Each step of the slider multiplies the view by ten. Every circle is drawn to scale. Inspired by Charles and Ray Eames’s 1977 film Powers of Ten.

Light takes this long to cross the view
Demo 2 · time

The cosmic calendar

Squeeze the universe’s 13.8 billion years into one calendar year, as Carl Sagan did in The Dragons of Eden (1977). The Big Bang is midnight on 1 January. Today is the last stroke of midnight on 31 December. Each day is about 38 million years; each second, about 440 years.

31 December, zoomed in: last 3 hours
Demo 3 · gravity

How small would you have to squeeze it?

Anything becomes a black hole if it’s compressed inside its Schwarzschild radius, r = 2GM/c². That radius grows in direct proportion to mass, about 3 km for every Sun’s worth.

Mass
Event horizon radius
Demo 4 · cosmology

Space is expanding, and there’s no centre

In 1929 Edwin Hubble found that distant galaxies recede faster the farther away they are. It isn’t an explosion from one spot: space itself stretches, so every galaxy sees all the others moving away. Tap any galaxy to stand on it.

Hubble’s lawSpeed = H₀ × distance. Every arrow is proportional to its galaxy’s distance from you, wherever “you” are. Today H₀ is about 70 km/s for every megaparsec (3.26 million light-years).
The Hubble tensionMeasurements from the early universe’s afterglow give about 67 km/s/Mpc; measurements of nearby supernovae give about 73. The gap has survived years of checking, and may point to new physics.
Bestiary

The weirdest things out there

Real objects, observed or measured, that sound like science fiction.

Big questions

What we know, and what we don’t