Fictional Gas

3.7 Ga photosynthesis?

Cosmos: A Spacetime Odyssey, episode 7, "The Clean Room" takes note of the biogenic origin of oxygen on Earth. How can we know when our planet made the transition to an oxygen-rich atmosphere?

Geological studies of ancient sediments in Greenland have suggested that bacteria with oxygenic photosynthesis might have existed from about 3.8 billion years ago and continued generating oxygen for a period of about 1.5 billion years before atmospheric oxygen levels finally began to climb significantly.

In the Exode Trilogy, I've been imagining a role for the pek in keeping the atmosphere of Earth optimized for the development of a species that might strive to follow in the evolutionary footsteps of the Huaoshy.

Measuring the age of ancient rocks (C. C. Patterson).

The balance between atmospheric oxygen and carbon dioxide levels during Earth's history is an active topic of scientific investigation. For Exode, I imagine that the Huaoshy first visited Earth at about the time of the last "snowball Earth" event. Uranium-lead dating is a useful method for determining the age of ancient rocks such as those in Greenland as well as sediments that have been interpreted as resulting from the last planetary "snowball" event.

Cosmos went beyond discussion of the scientific utility of uranium-lead dating and right on into our love/hate relationship with toxic metals. Lead toxicity might account for as much as one percent of all human illness in the world today.

Lead emissions (source)

An important source of environmental lead was from the use of lead as an additive in gasoline. When government regulations forced leaded gas to be phased out, the levels of lead in people declined:

One of the influences on atmospheric carbon monoxide levels since the arrival of the pek on Earth was the evolution of plants that could store carbon in forms that were difficult to biodegrade. It has been suggested that large coal deposits formed during the Carboniferous period because conditions were favorable for trapping plant-derived carbon polymers in sediments. High carbon dioxide levels may have helped end the snowball Earth phenomenon while periods of lower atmospheric carbon dioxide have been suggested to correlate with higher levels of atmospheric oxygen than what we experience today.

For Exode, I imagine that coal was particularly important for carbon dioxide levels in the Ekcolir Reality. Even here in the Buld Reality, coal burning remains as one of the major sources of environmental toxins including metals like lead.

Sisters of the Sun
In Episode 8, we are shown some of the history of how Humanity learned the composition of "star stuff", work that led to full appreciation of the fact that we (at least our heavier atoms) are composed of star stuff - atomic nuclei that were cooked up inside stars.

astronomy in an alternate Reality

Spectroscopy has allowed recognition of the atomic constituents of stars and growing understanding of the life cycles of stars. This episode mentions the work of people like
Annie Jump Cannon and Cecilia Payne.

Is Earth far enough out from the crowded center of our galaxy that we have been able to avoid having our planet zapped by radiation from a nearby hypernova? In episode 8, Eta Carinae was discussed as a "nearby" large star that provides an example of the dangers posed  by stellar explosions.

In the Exode Trilogy, I imagine that worlds of the Galactic Core such as Hemmal have all been exposed to the "sterilizing" effects of gamma radiation, thus they have not had a chance to evolve complex land-dwelling life forms like we humans.

Thus, worlds of the Galactic Core provide convenient "workshops" for the pek and their attempts to craft a primate  variant that can transcend its physical existence and join with the Huaoshy in the Sedronic Domain.

The Lost Worlds of Planet Earth

Another world: Earth of the Past

In Episode 9, another major cosmic challenge to the survival of life on Earth is mentioned. Our world was formed by the merging of planetoids and asteroids and we are still at risk of large impacts from comets and asteroids.

For Exode, I imagine that the pek have intentionally bombarded Earth with large asteroids.

More Gases
Episode 9 starts with an account of high oxygen levels during the Carboniferous. The animators had fun tormenting Tyson with images of the kinds of giant bugs that were supposedly able to exist due to the high oxygen levels. It has been proposed that some of the sulfur stored in coal deposits during that time was later catastrophically released and cooked up by flood basalts.

For Exode, I imagine that with the assistance of nanites, the Prelands are able to breath through their skin.

Marie Tharp

Marie Tharp was introduced and her mapping of the ocean floors described. An image from the animated sequence showing how she first recognized the mid-Atlantic ridge is shown to the right.

It seemed like this episode suffered from a last minute edit session that left the discussion of hydrogen sulfide seeming contradictory. The gas H₂S was first mentioned for its role as a poison during the late Permian. Then H₂S was described as the basis for deep sea life in locations like the volcanic vents of the mid-Atlantic ridge. It would have been nice if this episode had the time to mention the roles of H₂S in human physiology.

Faraday in the Cosmos animation.

The Electric Boy
Episode 10 features Michael Faraday, one of the explorers who brought us into the modern era of human civilization. A unified scientific understanding of electric fields, magnetic fields and light provides a solid foundation for many technologies that we now take for granted.

For the Exode Trilogy, I pretend that the ancient Huaoshy long ago understood dark matter and found many additional fundamental particles and a few more forces.

The fictional particles include hierions and sedrons, particles that are able to exist in dimensions beyond those that we experience as hadronic life forms.

The Huaoshy long ago transcended their biological nature and became artificial life forms residing in the Sedronic Domain of the universe. Their mastery of sedronic matter gave them the ability to travel through space a faster-than-light speeds.

In Exode, I imagine that the alien pek reached Earth millions of years ago and they created we humans by domesticating and redesigning some early primates.

Magnetic Fields
There have been many time in the past when Earth's magnetic field shifted or weakened. What would happen to our technological society if we lost our planetary magnetic shield and we were exposed to the full force of solar radiation?
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Cosmos:
episodes 11-13
 episodes 3-6
episodes 1 and 2