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Rubina Hashmi

One ruler, 40 videos

How big is everything? From a molecule to a galaxy

Every video measures something. Here they sit on one ruler, each step ten times bigger than the one before, and the gaps are part of the picture.

Rubina and children's hands doing an experiment on a balcony
  1. 10-9 mMoleculesToo small to see, but not too small to measure.
  2. 10-8 mNothing at 10^-8
  3. 10-7 mNothing at 10^-7
  4. 10-6 mNothing at 10^-6
  5. 10-5 mDustWhat floats in a sunbeam.
  6. 10-4 mA hair and a grain of saltThe smallest things I can see with a drop of water.
  7. 10-3 mGrains and coinsA few millimetres across.
  8. 10-2 mNothing at 10^-2
  9. 10-1 mA plateWhat fits in your hand.
  10. 100 mNothing at 10^0
  11. 101 mA treeTaller than you, but a shadow can reach it.
  12. 102 mA streetA walk of a hundred steps.
  13. 103 mNothing at 10^3
  14. 104 mNothing at 10^4
  15. 105 mNothing at 10^5
  16. 106 mNothing at 10^6
  17. 107 mThe EarthThirteen thousand kilometres across.
  18. 108 mThe moonFar, but only just.
  19. 109 mNothing at 10^9
  20. 1010 mNothing at 10^10
  21. 1011 mThe sunA hundred and fifty million kilometres away.
  22. 1012 mNothing at 10^12
  23. 1013 mNothing at 10^13
  24. 1014 mNothing at 10^14
  25. 1015 mNothing at 10^15
  26. 1016 mThe starsThe next sun is a very long way off.
  27. 1017 mNothing at 10^17
  28. 1018 mNothing at 10^18
  29. 1019 mNothing at 10^19
  30. 1020 mA galaxyA hundred thousand years of light across.

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Latest videos

A new video every Sunday from the kitchen table and the balcony: one thing, measured.

Rubina and children's hands doing an experiment on a balcony

12 min

How far away is the moon? A ball and a walnut

A ball the width of a hand and a walnut three metres apart show how far away the moon really is.

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Downloads arrive by email. Merch is printed to order and shipped by Printful.

A Number a Week

A short letter every Sunday with one number from the week's video, how I found it and how you can find it too.

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About

About me

I have always liked asking how big things are. How thick is a hair? How far is the moon? How many grains of rice are in that jar? When the people I teach started asking the same questions, I began filming the answers on the kitchen table, and then on the balcony when the table was not big enough.

Every video is short and every video measures something. I use jars, spoons, a torch, a tape measure and a phone on a stand. I show you what I did and what I got, and where I was not sure. You do not need a laboratory, only a table and a bit of patience.

I sell what I use to teach: sheets to print for each size of thing, a wall chart and a notebook, and two video courses. I do not sell lessons or kits here. I teach you to measure well on your own, or with whoever is at your table.