Home ] Up ]


Against PST

Recreating the Miller/Urey Experiment

    Amino acids are the building blocks of proteins, which are the building block of life. In some of the origin of life theories, the amino acids are thought to have come from the chemicals and gases present on the primitive earth, if there was a primitive earth. Evidence have suggested that the gases and compounds Miller and Urey used in their famous experiment were not the real ones that existed on the so-called primitive earth. The purpose of this experiment is to see what will be produced from the latest ideas of what existed on “primitive earth” and compare it with the Miller/Urey experiment. Therefore, the question would be what will be produced from the mixture of chemicals in the “real primitive earth” and some energy source, if there was ever a primitive earth. The implications of this experiment may be that life did not come from non-living matter present on earth.

    Miller and Urey used gases present in the atmosphere of primitive earth, but the gases they used are no longer thought to be present. I will recreate the Miller/Urey experiment as the control and compare the results with the mixture of the latest ideas of what was probably on primitive earth to see if amino acids were produced and if its sufficient for proteins. My hypothesis is that the new experiment with the new gases will not produce the building blocks necessary for life. Even if there were amino acids, there is a huge difference between amino acids building blocks and the assembled protein. There is a 10130 combination of 20 amino acids (if 20 can be produced spontaneously) to form one protein.

    To recreate the Urey/Miller experiment, I will mix methane (CH4), hydrogen (H2), ammonia (NH3), and water vapor (H2O) in a flask just like what they did. They excluded oxygen because oxygen is believed to be from photosynthesis and were not present on the primitive earth’s atmosphere. The setup is shown in the picture, with two tubes connecting to another flask, which is connected a power supply, simulating energy in the form of electricity (lightning). This process is supposed to happen in the earth’s atmosphere. The flask with all the compounds will be heated to boiling temperature because of the heat present on primitive earth. Because of the heat, the liquid solution will evaporate into clouds. The lightning will then strike the clouds, which would then condense and form into liquid again (the primordial soup raining onto earth). The process will go on for a week, as Miller and Urey did. The result will be what has become of the solution. (In the Miller/Urey experiment, amino acids and other complex organic molecules were produced in a week)

    There were several problems with the Miller/Urey experiment. First scientists now believe methane and ammonia were not present in the primitive earth’s atmosphere. Hydrogen would also have escaped because of its lightness. The best guess is that earth’s primitive atmosphere contained nitrogen (N2), Carbon dioxide (CO2), water vapor (H2O), and maybe some carbon monoxide (CO). Miller and Urey also used all reducing gases, opposite of oxidizing. It is now believed that the atmosphere was neutral, neither reducing nor oxidizing. The above-mentioned gases are neutral. I will do the same with these gases and compounds. They will be placed in a boiling flask with tubes connecting it to the energy source, as shown in the picture. There will be two experiments going on at the same time for one week. After one week, the solution will be thoroughly examined to see what has become of them. They will be compared and a conclusion will be made.