On this page, observations of various kinds appear that are related to big history.

 

 

 

November 27, 2022

 

 

Surely there could be nothing wrong with terms such as 'sunrise' and 'sunset.' In every language known to me (admittedly a small fraction of all languages spoken on this planet) such terms occur. Yet here it will be argued that if we want to understand ourselves well as inhabitants of planet Earth living within the very thin shell on its outside known as the biosphere, those terms are outdated, and, in fact, not helpful at all.

 

Let me explain. Seen from a modern scientific point of view, the Sun does neither rise nor set. It is the Earth turning around its axis that causes this apparent effect to those who live on its surface. In other words, 'sunrise' and 'sunset' are apparent effects, but they are not very good descriptions of reality as understood by modern science ever since the Polish monk Nicolaus Copernicus revived the idea earlier expressed by the ancient Greek astronomer Aristarchos of Samos that the Earth orbits the Sun, and not the other way around.

 

So, how could we change those common terms to make them better express reality, and which effects might that have? Because a sunrise is caused by our portion of the planetary surface turning toward the Sun, instead of a “beautiful sunrise” we could say something like: “that is a beautiful turn toward the Sun.” And a “most gorgeous sunset” could become: “What a gorgeous turn away from the Sun.”

 

This may sound like annoying nitpicking. But before saying such things, I would advise you to observe all of that with a clear view on the horizon, while letting the meaning of those novel terms sink in.

 

My experience of doing so is that it produces a sudden awareness of standing on the surface of a large but finite, slowly-spinning, globe, while the portion of its surface where we happen to be is turning either toward, or away, from our brightly-shining central star. Quite an unnerving cosmic feeling! Furthermore, doing so makes me suddenly aware of the thin layer of air, soil, and water that all of us inhabit, known as the biosphere, on which all of us depend.

 

For mountaineers or mountain-dwelling people, that latter experience is not entirely new. Even at moderate elevations above sea level, let’s say at 2500 meters altitude, the thinner air becomes quite noticeable, while ascending higher such effects rapidly increase, to the extent that at elevations higher than 5000 meters above sea level hardly anybody lives there anymore other than mountain climbers during temporary visits.

 

Five kilometers (3.5 miles) is not a lot. Just think of how far that is if one travels across Earth’s surface: about an hour’s walk, a short car drive, or an easy bike ride, so, nothing spectacular. Yet going down five kilometers into Earth’s interior is also quite a challenge. No one lives there permanently, either.

 

The views from such altitudes show our biosphere and its limits more clearly, much like the views from commercial jet airplanes, which usually fly at an altitude of about ten kilometers (30,000 feet) above sea level.

 

Such elementary considerations immediately show how thin the planetary layer is that we inhabit. It is, in fact, thinner than the skin of an apple. That is the area we call home within the extraordinary large expanse of the mostly, if not entirely, uninhabitable cosmos.

 

If we want to consider the ecological and social issues that we are facing today, it seems important to foster such a view, so that we can understand those issues a little better. Terms such as 'sunrise' or 'sunset' are not helpful in that respect. To the contrary, they continue to foster outdated views of the Earth and of our existence on it, which do not offer a good perspective for understanding our current global situation.

 

I therefore invite all of you to take a look at the Sun with well-protected eyes as we turn toward, or away from, it, and let all those consequences sink in, both cognitively and emotionally. Surely, better terms for those phenomena might be found. I therefore also invite all readers to come up with suggestions that better express those aspects of our reality as understood by modern science.

 

The same could be done while watching the Moon, the stars, the planets and the Milky Way. With the Moon, there is one difference: it does orbit the Earth, about once a month. But during one single night, the Moon’s apparent movement backward across the sky caused by its rotation around our planet is too slow to make it clearly noticeable to a casual observer. To observe it, careful and precise measurements need to be performed.

 

Considering all of this may make us more aware of not only the biosphere, our one and only common cosmic home, but also of the importance of better understanding it including its history. My most recent views –I think, perhaps immodestly, currently the best available views– of this subject can be found in my recent book How the Biosphere Works: Fresh Views Discovered While Growing Peppers (2022, CRC Press).

 

POSTSCRIPT

 

August 12, 2025

 

Today, after again watching Carl Sagan’s excellent lecture of 1994 The Age of Exploration I realized that in that presentation he argued along very similar lines, including suggesting that the terms 'sunrise' and 'sunset' still showed a pre-Copernican world view, yet that terms representing the Copernican world view were rather cumbersome. While writing the above I had completely forgotten that. Clearly, the late US astronomer, planetary scientist, and science communicator Carl Sagan (1934-1996) deserves full credit for those ideas.

 

Yet he did not mention that by using such new terms one becomes far more aware of the fact that all of us are living on the outside of a slowly spinning globe that is moving through an enormously large and mostly inhospitable universe. I am sure he would have agreed with that.