Figure 9.5 illustrates the Miller spark chamber. The water in the flask is boiling. The
atmosphere above the water and in the spark chamber is controlled. In this example,
hydrogen, methane and ammonia are introduced. The electrode is charged to a very high
voltage, and it creates an electric spark. This spark is an energy source. It allows the
chemicals in the chamber to react and form new chemicals. The condenser removes the
chemicals from the spark chamber, and they accumulate in the trap. Life uses 20 amino
acids. Miller’s chamber can create between 0 and 10 of the 20 ( the number created
depends on the gases used in the atmosphere).
The chamber also creates many other chemicals. Other scientists have repeated
this experiment with alternative energy sources like UV light and heat. These experiments
demonstrate that many amino acids are easy to create. Miller’s chamber is a
non-equilibrium system cleverly designed and optimized to create nonvolatile organic
compounds like amino acids.
Whether or not this experiment is representative of the conditions on the
early earth is questionable. Many scientists today do not believe that ammonia, hydrogen
and methane were present in the earth’s early atmosphere, and without at least one of
these, no amino acids are produced by the spark chamber. Despite these concerns, Miller's
experiment remains to this day the greatest accomplishment in origins research.
Figure 9.5: Miller’s Chamber
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