2. The size of things
            Powers of 10
            Distance, time, temperature, mass, put them on a line

2. The size of things
Plot the range of values of  temperature, mass, length along a line.

Start with Temperature: plot temperatures on a line. Make a line of geshes lined up according to hand temperature.
Human perception of whether something is hot or cold can be imprecise so we have to create an instrument, a thermometer.
Explore the history of thermometers.
Look at the definition of temperature.
There is a zero temperature. Most everyday temperatures can be plotted along a line with linear spacing. Most temperatures fall in the range between absolute zero and the temperature of the surface of the sun, 5800 K. Temperatures can have much higher values.
Look at the history of the definition of temperature: from human hands, through thermometers, to thermodynamics.

Mass: what is mass? Mass (actually rest mass) ranges from 0 for massless particles to the mass of the universe. The plot must use powers of 10 because for objects with non-zero mass since it stretches over 80 orders of magnitude.

A side trip tells the story of Napier and the invention of logarithms.

Space: plot the diameter of things and also the distance between things. The shortest size is the planck length at which space itself becomes quantized. The greatest size is the diameter of the visible universe. The size of the universe The distance between two points in the vacuum of  space is changed when viewed while the observer is in motion or when measured near a mass.

Time: Time is what is measured by clocks. Plot events in the history of the universe by the time since the big bang. Examine time intervals as well. The shortest time interval is the planck time. The measurement of the passage of time is changed when a clock is moving or when a clock is near a mass. The uses of modern atomic clocks

Keynote lectures Cosmology 101

Scientific Explorations with Paul Doherty

© 2011

18 October 2011