The Smell of Rain

The Smell of Rain
When I was in graduate school, there were many times that I needed a break from working at the bench.  The guy that worked across from my lab bench one day walked in the lab from outdoors with a scoopful of soil in a test tube.  It seemed like the strangest thing ever.  I later watched him put that soil on a petri dish and I began to think that he must have been desperately trying to find something fun to do on the side.  It turned out that he was beginning a project that would later get him working in a lab at Harvard Medical School.  After the germs grew on the petri dish, I asked him what he was growing and he brought me closer to see his petri dish.  On the petri dish were many different bacteria colonies and I noticed they had a peculiar smell.  Almost everything in a microbiology lab has a peculiar smell, but this smell was a pleasant one and I did not mind it.  In fact, I was surprised because it smelled like rain on the petri dish.  That’s when I began to learn that the smell of rain wasn’t rain at all.
Rain Doesn’t Actually Smell
The next time it rains, try collecting a handful of rain and smell it.  When you smell the actual rain that fell from the sky that you collected in your hands, it will smell like regular water—not rain.  Rain doesn’t actually smell like rain.  The actual smell of rain doesn’t come from rain, but from a bacteria living in the soil called Streptomyces coelicolor.  Streptomyces are soil bacteria famous for producing many antibiotics we use today as well as producing the smell of rain.  Before it rains outside, the Streptomyces in the soil dry out and turn into spores that lay dormant in the soil.  When the rain comes, the spores are reactivated and begin growing again.  As spores resume growth, they produce a chemical called geosmin, which is the chemical known as the smell of rain.  The geosmin becomes airborne as the rains pass by and the geosmin is carried away by the wind in front of the weather pattern.  We can then smell the geosmin coming ahead of the rain and mistakenly think it is the smell of the coming rain.  What we actually smell is the secreted product from the soil microbes (i.e., the geosmin) carried on the wind.
Did They Smell Judgment Coming
We know that it smells like rain everywhere on the face of the planet whenever it rains.  The smell of rain on the face of the planet tells us that these bacteria are present everywhere.  It is tempting to say that the Streptomyces are present everywhere because of the global Flood.[1]
In this scenario, the Streptomyces were present in a small area before the Flood.  When the Flood came, Scripture plainly teaches that the great fountains of the deep were opened and rain came from the sky (it was not just that it rained, but it also was a great cataclysmic event involving catastrophic plate tectonics).
In the six hundredth year of Noah’s life, in the second month, the seventeenth day of the month, the same day were all the fountains of the great deep broken up, and the windows of heaven were opened. – Genesis 7:11 (emphasis added)
As the water began to cover the earth, Scripture teaches that all the high hills under the heaven were covered by the water.
And the waters prevailed exceedingly upon the earth; and all the high hills, that were under the whole heaven, were covered. – Genesis 7:19 (emphasis added)
The earth’s surface was covered in water and it essentially turned into a large mixing bowl.  The Streptomyces in one area of the earth before the Flood would get mixed evenly because of the Flood waters, before they settled down evenly across earth’s surface, as the floodwaters receded.  As a result, there would be a global smell of rain after the Flood, but not a global smell of rain before the Flood (before the Flood, it would’ve been a local smell of rain).
There is a slim chance that other mechanisms could explain the global smell of rain today.  One possibility is that the bacteria could be caught up as entire cells or spores during evaporation and make their way to the clouds before coming down over a new area.  The problem with this known mechanism to explain the smell of rain everywhere is that evaporation is slow and the number of bacteria in the air is extremely low compared to all the bacteria living in the soil.  If evaporation was responsible for carrying bacteria from the soil to the extreme parts of the world, then two things would have to be true: winds would move extremely fast across the earth regularly and that there would be significantly more than just the Streptomyces from the soil in the air particulates.  Furthermore, it doesn’t smell like rain when you are flying high in the air.
Our current understanding of rainfall and weather patterns could slightly allow the Streptomyces to get spread by the wind; however, the wind would have to be extremely fast because the earth is large.  The reason that the wind needs to be fast is because the earth is only 6000 years old and there was only 1500 years from the original creation to the time of the Flood.  There doesn’t seem to be enough time for the Streptomyces to get the uniform distribution across the entire soil of the landmass prior to the Flood in this scenario.  After the spores would be spread, they would also have to fall to the earth at a constant rate, which is equally unlikely to occur.  Another issue is that there would have to be more than just the Streptomyces present in the evaporation droplets.  Indeed, there are many diverse soil bacteria present in the water droplets of the rain.  But the problem with bacteria present in the upper atmosphere is that they are not so abundant that they could include sufficient numbers of the Streptomyces to cover the entire landmass leading up to the Flood.[2]
While it is sufficient to think people before the Flood did not smell the rain coming, there is a modest ongoing biblical debate whether it rained before the Flood.  The important thing to note is that Scripture is silent on the opening chapters of Genesis about whether it rained before the Flood.  What we know is that a mist went up out of the garden responsible for watering the vegetation life.  If there were no rain before the Flood, then there would be no real mechanism in place for the people to have smelled the rain coming because there would’ve been no rain.  However, there are some other biblical scholars that have no problem saying that there was rain before the Flood.  According to these scholars, it is possible that it didn’t rain frequently because rain isn’t mentioned in Scripture.  In summary, we simply do not know whether there was rain before the Flood and, as a result, it seems likely that there is biblical evidence that the people in the pre-Flood world did not smell rain before it came.
“Like the Fragrance After the Rain”
There is strong biblical and scientific evidence to support the idea that no one before the Flood smelled the rain before it came.  The same evidence can be used to support the idea of the Flood being a great mixing pot for soil microbes to distribute themselves evenly across the surface of the planet.  There is ultimately no way to know with certainty whether anyone smelled the rain before the Flood because none of us were there—we’ll have to wait until we get to heaven and find out from God Himself.  In the meantime, we can be reminded with every rainfall of two things: the smell of rain and the rainbow.  Both the smell of rain and the rainbow are physical signs that we have today that God judged the world once using water.  The reason that the world was judged was because man’s wickedness was deserving of judgment.  While we have the reminder of the rainbow after the Flood comes, it’s as if we have the current reminders before the rain comes that we can smell it and know that judgment of man’s wickedness happened once before.  We also have the same reminder that man’s wickedness will be judged again in the future—this time, the judgment will be by fire.  Part of what we stand for at Reasons for Hope is to let people know that we don’t have to face the coming judgment without Hope.  The Hope we have is in the person of Jesus Christ and we can know Hope for sure today and we can enjoy the fragrance of the rain.  The old hymn said it well that “Jesus’ name is the sweetest name I know” and compared it to the “fragrance after the rain.”
FOOTNOTES
[1] We tend not to find Streptomyces in water environments.  They also do not live in association with living things.  These are the largest two places where we do not find the Streptomyces living.  They literally cover the earth’s surface.
[2] The irony with this alternative explanation to the global distribution of Streptomyces is that it also includes water just like the Flood explanation uses water.  Therefore, we know that water has distributed the Streptomyces across earth’s surface regardless of the exact explanation.