Powers of ten, not a poster fly-through.NASA / ESO, public domain or CCWhy this matters
A night walk from Greenwich is still Earth underfoot. A dark sky over Yosemite is still the same jump: one planet, then a star, then a gap you cannot draw honestly on a poster. Leeds does not sit next to Hawaii in kilometres the way a wallchart parks them. Scale is a skill. Wonder without a fake fly-through. The Kola borehole is a 12 km scratch on a 6371 km radius — even crust is thin — and that is still stop one. Stop two is the solar system in AU. Stop three is neighbouring stars in light years. Stop four would be a cartoon. UK GCSE diagrams and US planetarium posters both hide the jump. Your job is to say so. If Earth is a pea, the Sun is a much larger ball a good walk away. This lab still exaggerates. The next stars are not just beyond Neptune on the same table. That sentence is the whole point.
A second photograph for the projector script — not the lab cover.Wikimedia Commons / NASA / USGSThe mechanism
Input is the Scale jump slider: 0 Earth, 1 solar system, 2 local stars. What moves: the camera’s hop, the unit on the readout, which objects are allowed to exist on screen. What does not: the fact of nested scales, the order of the hops, the honesty that each jump hides a factor. What is conserved: powers of ten as a way of thinking, not a tape measure. Stop 1: Earth in kilometres, Moon drawn close so you can see it — real gap is about 30 Earth-diameters. Stop 2: 1 AU is about 150 million km; planets at true size would be dust. Stop 3: neighbouring stars; units are light years; planets have no right to remain as dots you could name. The lie the model tells is every poster’s lie: one frame, several scales. We stop before a galaxy tour because one more jump and the screen is decoration. Keep it short. Order of magnitude, not a ruler. Greenwich underfoot is still stop one. If the class asks for the whole universe, the answer is no, not on this glass.
How to drive the model
Drag Scale jump from 0 to 2. Pause at each stop. Ask what vanished before you scrub on. Space does little here; the slider is the drive. Arrows still nudge time if anything is turning. L labels. R reset. P projector. No explode, no slice. Reset view if the hop has left the class in empty black. Name the unit at each stop: km, AU, light years. Then stop. No cartoon universe tour. The slider is labelled Scale jump. Do not skip a stop.
If the model will not spin
If the hop will not run, keep three sentences. Earth is a sphere you can name, units in kilometres. The solar system is a jump to AU; planets would be dust at true size. Neighbouring stars are another jump; they are not just beyond Neptune. Every poster hides a jump. This lab refuses a galaxy fly-through because that would be a fourth lie. Powers of ten are the skill. Wonder stays. The tape measure does not pretend. Without the 3D view, a student should still refuse a cartoon galaxy tour and still name which unit belongs to which stop.
Film
How Does the Earth Move? Crash Course Geography #5. Crash Course Geography. About 11 min. Crash Course / Complexly on YouTube. Standard YouTube licence. Educational embed, autoplay off. Autoplay off.
Misconceptions
Space pictures are a single scale.
Every poster hides a jump.
The next stars sit just beyond Neptune on the same poster.
That is a jump of scale that makes planets vanish. Light years, not AU.
If Earth is a pea, the Sun is another pea beside it.
The Sun is a much larger ball a good walk away. This lab still exaggerates.
Astronomical unit
Earth–Sun distance, about 150 million km. Stop 2’s unit.
astronomical unit in the universe-scale lab — a TERMS crop, not the glossary plate and not the lab cover. A TERMS crop, not the glossary plate and not the lab cover. Source: Wikimedia Commons / NASA / USGS / NOAA, public domain or CC.Wikimedia Commons / NASA / USGS / NOAA, public domain or CCLight year
Distance light travels in one year. Stop 3’s unit. Not a time.
light year in the universe-scale lab — a TERMS crop, not the glossary plate and not the lab cover. A TERMS crop, not the glossary plate and not the lab cover. Source: Wikimedia Commons / NASA / USGS / NOAA, public domain or CC.Wikimedia Commons / NASA / USGS / NOAA, public domain or CCPower of ten
A jump of scale by ×10, or many tens. The skill is naming the jump, not pretending one picture holds them all.
power of ten in the universe-scale lab — a TERMS crop, not the glossary plate and not the lab cover. A TERMS crop, not the glossary plate and not the lab cover. Source: Wikimedia Commons / NASA / USGS / NOAA, public domain or CC.Wikimedia Commons / NASA / USGS / NOAA, public domain or CCOrder of magnitude
A rough size class. If Earth is a pea, the Sun is not another pea. Exact millimetres are not the point.
order of magnitude in the universe-scale lab — a TERMS crop, not the glossary plate and not the lab cover. A TERMS crop, not the glossary plate and not the lab cover. Source: Wikimedia Commons / NASA / USGS / NOAA, public domain or CC.Wikimedia Commons / NASA / USGS / NOAA, public domain or CCScale jump
This lab’s slider: Earth, then solar system, then local stars. Each hop hides a factor.
scale jump in the universe-scale lab — a TERMS crop, not the glossary plate and not the lab cover. A TERMS crop, not the glossary plate and not the lab cover. Source: Wikimedia Commons / NASA / USGS / NOAA, public domain or CC.Wikimedia Commons / NASA / USGS / NOAA, public domain or CCParsec
About 3.26 light years. An exam unit for stellar distance. Not used as a stop here, but it is the same idea.
parsec in the universe-scale lab — a TERMS crop, not the glossary plate and not the lab cover. A TERMS crop, not the glossary plate and not the lab cover. Source: Wikimedia Commons / NASA / USGS / NOAA, public domain or CC.Wikimedia Commons / NASA / USGS / NOAA, public domain or CCLocal stars
The neighbouring suns, not a galaxy tour. This lab stops there on purpose.
local stars in the universe-scale lab — a TERMS crop, not the glossary plate and not the lab cover. A TERMS crop, not the glossary plate and not the lab cover. Source: Wikimedia Commons / NASA / USGS / NOAA, public domain or CC.Wikimedia Commons / NASA / USGS / NOAA, public domain or CC