Miller (1953)

How do you make organics from simple materials? What begins the process? In a primitive universe of hydrogen and helium we know how we can get to the heavier elements, but how to get to compounds from there?

As we move away from strictly organic chemistry and into biochemistry we should answer the question of where do all these useful starting materials come from.

You should read the wikipedia page and also the original paper (links below).

https://en.wikipedia.org/wiki/Miller%E2%80%93Urey_experiment

http://web.archive.org/web/20090205194803/http://www.issol.org/miller/miller1953.pdf

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8 Responses to “Miller (1953)”

  1. Josh Ellsworth Says:

    I found it interesting that Miller’s success continued to blossom after his death with improved analytical techniques, and that he and his student had the foresight to set aside samples for fifty some-odd years. Also that HCN seems to be a crucial intermediate at the beginning of the process, but kills most all of the current results of the global experiment.

    The Wikipedia article mentions later experiments that Miller conducted, wherein he simulated a volcanic input to the system. It makes sense that these conditions produced a high diversity of organic molecules, did Miller ever repeat his experiment using UV light as an energy source?

    For that matter, although the later experiments mentioned in the Wikipedia article confirm Miller’s findings even when accounting for differences in atmospheric makeup, have there been more complex versions of this experiment performed, accounting for different models of atmospheric content, mineral influence, volcanic influence, as well as both UV light and lightning? Is the matter considered settled enough to table any debate?

    It also seems possible that Miller’s conditions (and early atmospheric conditions) stacked the deck in favor of organic molecule formation. Have experiments been conducted attempting to simulate conditions on the surface of a comet? Perhaps hard UV radiation is “effective” enough to enable these reactions to occur at incredibly low temperatures and pressure.

  2. Hunter Burgin Says:

    You know you’re scientific experiment is a pretty big deal when it has its own wikipedia page. The Miller-Urey experiment is in fact a hugely significant discovery in the world of biochemistry because it explicitly shows how amino acids most likely formed in the earth’s primitive atmosphere. The paper explains how they developed an apparatus which mirrored the conditions present in the primitive earth’s atmosphere and how they successfully synthesized several amino acids. In the paper Miller lists the several amino acids he synthesized using his apparatus: Glycine, a-alanine, b- alanine, and aspartic acid. Does this process used by Miller where he replicated the earth’s atmosphere successfully account for the synthesis of all 20+ amino acids and their enantiomers?

  3. Adam Settimo Says:

    Looking into the authors of the paper leads to some interesting places. I specifically found it interesting to see that Urey received the Nobel Prize in 1934 for his discovery of Deuterium, helped develop the method of separating uranium isotopes for the creation of the atomic bomb, and had G.N. Lewis as his doctoral adviser when he was working on his PhD. Fascinating characters for sure.

    I am curious about the chemistry section on the Wikipedia page, it seems to jump straight to reactions with CO2 and doesn’t really show where they obtained it. Since the only source of carbon is from the methane and the only source of oxygen is from the water added, there would be the metathesis reaction missing from from the section right? or is this chemistry done from another set of reaction conditions like the one discussed in the first paragraph?

    I was also wondering about the issue of using the a UV light source vs the electrode. Why not use both? I would assume that the conditions during that time would be subject to both lightning storms and radiation from the sun, so why not do both?

    Finally, this isn’t really a question so much as something I found and thought I’d share. I was curious about what “new” method they were using to analyze the samples found in Millers office after he died, and found the article with the results. It turns out they used HPLC and LC-MS, which makes sense, but then why hadn’t this been done earlier? These techniques aren’t new, HPLC is from the 1960’s and LC-MS started in 1974, so why haven’t they done this before? Also, the samples they found were “residues,” where did the water go? If it evaporated, where did it go? If it left the sample container, then there’s some kind of exchange between the sample and the outside environment and therefore it is contaminated. So how can analysis for these samples be helpful or insightful?

  4. Daniel Begay Says:

    I’ve always thought of this paper as a big step in the field of biochemistry. After looking at the Wikipedia page, it amazes me to see how many scientist have been inspired by this discovery. It also makes me wonder how many others were on the brink of making this same discovery, as it said that others were doing similar ‘Early Earth’ experiments. It’s interesting to see even Miller did not see the extent of his discovery as well. Not knowing that there were more organic compounds besides the ones he listed. I did not know they found trace amounts of sugars (ribose) in the apparatus. My question revolves around the use of the said apparatus. It’s stated that the circulation of the gases was slow, but it played an important role in the experiment, because once they accelerated the circulation, the was a smaller yield of products. I’d expect the yield to be higher of they were to ‘mimic’ the conditions of an Early Earth, which I think would be harsher conditions (stronger winds and such). Also, is there any mention of having slightly different products when the circulation is accelerated?

  5. Porter Marsh Says:

    If colloidal silica from the glass found its way into the solution can caused the turbidity, how can they be that sure that other pollutants didn’t find their way in? We’ve seen that even nanopure water can have up to 20 ppb of palladium. Is it possible that some of the products they found were caused in part by unknown impurities from the reagents of the glassware?

  6. Tony Says:

    Sorry for being skeptical about an experiment so widely accepted in the scientific community but are they really sure they devoid the container of all life. The mercury is used to kill anything there but wouldn’t dead life contaminate there experiment by spilling its constituents?

  7. Kevin Greenwood Says:

    It’s interesting to learn that this is an evolving experiment, with further refinements adding more data. I like that less than ten years ago, a successful new version of this experiment was carried out to test Miller’s failed variation from 1983.

    In the troposphere, methane is oxidized by the hydroxyl radical, which could easily have been formed with the electric arc. This regenerates water and a methyl radical, which could combine with a hydroxyl radical to get methanol. In Miller’s apparatus, the methanol condensed and ended up in the water. Once back in the boiling water, it would go into the gas phase and once again be subject to free-radical reactions with the simulated atmosphere. To oxidize methane all the way up to carbon monoxide for it then to combine with ammonia to form hydrogen cyanide seems like it would take a while. It took a day for the mixture to turn pink, showing that organics were present in the soup. It obviously occurred, it just happened so quickly!

    This brings up the problem of absence of other compounds that could be formed under these conditions. To form amino acids with such speed, there must have been side reactions. Where are the amides, formamides, carbamic acid and their derivatives? The simplest of these, formamide, has a boiling point of 210 C, so it would have been trapped in the water and if formed, should be present to some degree. It was never mentioned that these were present, though they would not show up using ninhydrin as a TLC visualizing agent. Is there a reason these would not be present?

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