Posts Tagged ‘light’


Isaac Newton, The Great Plague and how he filled in his Time!

March 18, 2020

I am grateful to Jeff Jacoby and his column, Arguable, in the Boston Globe for reminding me of how Isaac Newton filled in his time when he went into self-isolation during The Great Plague of London in 1665-1666.

He spent time thinking and the results were astounding!!!!!



9. A single match or candle will light a room the size of a football stadium.

November 21, 2018


This is the rework of a previous post.

Action heroes such as Indiana Jones or even film kids like Tom Sawyer or The Goonies who go into a cave, anabandoned house, a crypt or a catacomb light the entire place with one match, one candle, a lighter or a cellphoneIndiana jones 1tm sawyer.

Is this real?


Now mathspigs, if you are interested in a career in stage/film lighting or even architecture you will need this maths.light globe_tns


60Watt light globe tells us how much power it uses. But some 60W globes are brighter than others. Light is measured with weird units.

candle_tnsUSA uses Foot-candles. Can you imagine the pickup line ‘You brighten up my world like a footcandle’? A foot-candle is the brightness of a candle 1 foot away. Now think of a bubble around the candle. Brightness is mostly measured using one square foot or one square metre of that bubble:

1 LUMEN = 1 Footcandle/ft squared

1 LUX = 1 footcandle/m squared

Don’t get too hassled by these units.  As a rough rule:

1 candle = 1 LUX

candle 1 Correction

candle 2 Correction

candle 3 Correction

From graph you can see by 3m a Birthday Cake is not very bright even in a haunted house or crypt.

Challenge: Draw a graph of the brightness of your own Birthday Cake!

Big Challenge:Draw a graph of your Teacher’s Birthday Cake!!!!!! Ahhhh!!!!

We know:

1 candle = 1 LUX

Now compare the brightness of 1 candle to the brightness of other sources of light:

If you want sufficient light to live your everyday life you’d need:

80 candles just to go to the toilet!!!!!!


Square Root. It’s a Tree!

May 20, 2018

Just found this on Twitter! Had to share it.

If an IMAGINARY NUMBER screams alone in a forest can you imagine that you can hear it? Ha!