What is the Smell of Rain?

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A discussion of physical rain implies the same in the spiritual realm.

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The science aspect:

Credit:

EARTHSKY // EARTH, HUMAN WORLD, SCIENCE WIRE

http://earthsky.org/earth/whats-that-smell-in-the-air-when-its-about-to-rain?utm_source=EarthSky+News&utm_campaign=9ee7cc05c8-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-9ee7cc05c8-394204433

Excerpt:

The word is “petrichor,” and it’s used to describe the distinct scent of rain in the air. Or, to be more precise, it’s the name of an oil that’s released from the Earth into the air before rain begins to fall.

This heady smell of oncoming wet weather is something most people are familiar with – in fact, some scientists now suggest that humans inherited an affection for the smell from ancestors who relied on rainy weather for their survival.-

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Origins

Even the word itself has ancient origins. It’s derived from the Greek “petra” (stone) and “ichor” which, in Greek mythology, is the ethereal blood of the gods.

But the story behind its scientific discovery is a lesser known tale. So, how is it that we came to find this heavenly blood in the stone?

Nature of Argillaceous Odour might be a mouthful, but this was the name of the paper published in the Nature journal of March 7, 1964, by CSIRO scientists Isabel (Joy) Bear and Richard Thomas, that first described petrichor.

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Thomas had for years been trying to identify the cause for what was a long-known and widespread phenomena. As the paper opened:

That many natural dry clays and soils evolve a peculiar and characteristic odor when breathed on, or moistened with water, is recognized by all the earlier text books of mineralogy.

The odor was particularly prevalent in arid regions and was widely recognized and associated with the first rains after a period of drought. The paper went on to say:

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There is some evidence that drought-stricken cattle respond in a restless matter to this “smell of rain.”

The smell had actually been described already by a small perfumery industry operating out of India, which had successfully captured and absorbed the scent in sandalwood oil.

They called it “matti ka attar” or “Earth perfume”. But its source was still unknown to science.

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Joy and Richard, working at what was then our Division of Mineral Chemistry in Melbourne, were determined to identify and describe its origin.

By steam distilling rocks that had been exposed to warm, dry conditions in the open, they discovered a yellowish oil – trapped in rocks and soil but released by moisture – that was responsible for the smell.

The diverse nature of the host materials has led us to propose the name “petrichor” for this apparently unique odor which can be regarded as an “ichor” or “tenuous essence” derived from rock or stone.

The oil itself was thus named petrichor – the blood of the stone.

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Bring on the humidity

The smell itself comes about when increased humidity – a pre-cursor to rain – fills the pores of stones (rocks, soil, etc) with tiny amounts of water.

While it’s only a minuscule amount, it is enough to flush the oil from the stone and release petrichor into the air.

This is further accelerated when actual rain arrives and makes contact with the Earth, spreading the scent into the wind.

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According to the Nature Paper:

In general, materials in which silica or various metallic silicates predominated were outstanding in their capacity to yield the odor.

It was also noted that the odor could be obtained from freshly ignited materials rich in iron oxide, with or without silica.

It’s a beautiful sequence of events, but one that may be hard to visualize.

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Thankfully, in a testament to the ongoing scientific fascination with this finding, a team of scientists at the Massachusetts Institute of Technology have just this year released a super slow motion video of the petrichor process in motion.

https://youtu.be/Waqmq_GTyjA

Using high-speed cameras, the researchers observed that when a raindrop hits a porous surface, it traps tiny air bubbles at the point of contact.

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As in a glass of champagne, the bubbles then shoot upward, ultimately bursting from the drop in a fizz of aerosols.

The team was also able to predict the amount of aerosols released, based on the velocity of the raindrop and the permeability of the contact surface which may explain how certain soil-based diseases spread.

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Spiritual aspect:

What impressed me was the comment that the stones have oil in them, and the rain beating down on the stones release this oil into the air.

This is what happens in a true worship experience where the person, who is the porous stone, and filled with the aromatic oil of the Holy Spirit, is rained upon by the presence of God.

As the presence of God comes down, the perfume of worship goes up.

And as the oil of worship goes up, the presence of God comes down.

One elicits the other.

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And we are living stones which receive both the oil and the rain, and as we receive, we give back to God.

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So to me, nature reflects heaven.

And it inspires me to think of us as creation, with heavenly blood in our stones.

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