global warming the problem of scale. the imperceptible and the vast (1) as human beings we can...
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Global Warming
The problem of scale
The imperceptible and the vast (1)
As human beings we can judge:• temperatures
• close to ‘normal’
• weights• in the range a few grammes to a hundred kilogrammes
• distances.• from a few kilometres to less than a millimetre
• times• from a fraction of a second to periods of a few years.
The imperceptible and the vast (2)
As human beings we cannot judge:• temperatures
• more a few degrees away from ‘normal’• weights
• beyond a few tonnes or less than a gramme
• distances• beyond a few kilometres or much less than a millimetre.
• times.• much less than a second or greater than a fraction of a lifetime
The imperceptible and the vast (3)
Quantities and qualities that extend beyond our range of familiarity seem either:
imperceptible or
vast• It is important to retain an ability to quantitatively assess
quantities we perceive as imperceptible or vast• Becoming familiar is an important part of understanding• But then we can become too familiar!
Diameter:
12,800 km
Deepest hole: 10 km
Atmosphere:
Scale Height 8.4 km
The Planet Earth
The Sun
Diameter: 1,390,800 km
Earth
Powers of Ten
Very Very Small
Very Very
Large
1
1000103
106
109
1012
1015
1000000
0.00110-3
10-60.000001 1018 1024 1030 1036
1021 1027 103310-15 10-9
10-18 10-12
100
Powers of Ten
Very Very Small
Very Very
Large
1 metre
103
106
109
1012
101510-3
10-6 1018 1024 1030 1036
1021 1027 103310-15 10-9
10-18 10-12 1012
1000000000000 m
0.000000000001 m
Powers of Ten (Global Warming)Length scale in metres
Very Very Small
Very Very
Large
100
103
106
109
1012
101510-3
10-6 1018 1024 1030 1036
1021 1027 103310-15 10-9
10-18 10-12
Human Relationships
Diameter of the Earth
Distance to the Sun
Tallest Mountain
Deepest Trench
Atoms & Molecules
Microbes
The phenomenon of global warming involves physical
processes with length scales spanning 20 powers of 10!
Powers of Ten (time)Time scale in seconds
Very Very short
Very Very Long
100
103
106
109
1012
101510-3
10-6 1018 1024
102110-15 10-9
10-18 10-12
1 second
1 Year the Earth
moves once around the Sun
Milankovitch Cycles
A human lifetime
Time for a molecule to
jiggle
Typical survival time of a civilisation
Age of the Earth
End of last ice ageElectoral Cycle
Deep Ocean Current Circulation time
The phenomenon of global warming involves physical processes with time
scales spanning 25 powers of 10!