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Challenge: Problem 3

Very high temperature readings are usually made through the medium of the thermal radiation of the system. Look carefully at the items of the RESPONSE ARRAY, and decide which of them indicate something which you could use in order to set up a measurement system. There are (the author thinks) three possible methods. When you have sorted out what these are, put them in order of preference according to the combined criteria of accuracy and convenience.

1
the number of antinodes in the range v to v + dv is ( ( 8 v2 ) / c3 ) dv 		2
radiation pressure p = 1/3 u where u is the energy density		 3
E = T 4 (a form of the Stefan-Boltzmann law)		 4
max T = constant (Wien's displacement law)		 5
fluctuations of energy
6
the energy distribution of radiation is not a function of temperature alone		 7
characteristic vibrational frequency of a material particle's energy state		 8
exchanges of energy in discrete amounts		 9
spectrum of ionized gas		 10
continuum of energy changes
11
one-way emission of radiation		 12
av < 1 (absorbtivity less than one)		 13
a coloured surface often emits its complementary colour when heated		 14
characteristic radiation pattern of a surface for a given temperature		 15
as T decreases below a certain value for a solid, so does its specific heat
16
monochromatic radiation, as obtained by using a filter		 17
= ( hv / ( e ( h v / k T ) - 1 ) )		 18
= n 0		 19
= hv		 20
= kT