Making a TOC, esp. one that expands to a second level, with links to main text below

In Word:

Create the TOC

Create the links to the text below

(Last time I tried it I had only Appendix pages to link to, with URLs, not bookmarks)

(If I put all the body text with it, does it all become ineditable?! Try it)

Move it all to WordPress

In WordPress:

Insert the TOC and all the text that follows it, with links in the TOC to text parts

Highlight the 2nd-level TOC entries;

Click on Collapse-Hide in the editing ribbon

Check the box that says this shortcode should be nested in another shortcode

Now highlight all of the TOC

Click on Collapse-Hide


Here’s a test: First, the Word text, with links (nonsense links)

Habitability of the Earth – and can we keep it? Extinctions; current hazards, mitigations, ameliorations

Grand conclusion: I do think we are alone in a very big space

Still hoping? The search for exoplanets – who, what, when, why, where… and SETI

Will we colonize other planets, why, how, where? And deal-breakers abound (This link is to a webpage)

About the author

Appendices and Sidebars

   Appendix. Blackbodies and blackbody radiation (under construction)

   Appendix. Calculating_planet_temperature

   Appendix. Energy balance of an organism

   Appendix. The exponential_function



Regular text

Let’s face the facts. On Earth, large vertebrate species such as ours have a lifetime of about 2 million years. For mammals in the “modern” or Cenozoic era, that lifetime has been about 1 million years on average. We big vertebrates go extinct for a variety of reasons.- competitors (e.g., we modern humans vs. archaic Homo species), predation (esp. by humans now– the dodo by European hunters, and probably the North American megafauna by Paleo-Indians), habitat shrinkage from climate change (a good part of the cause of five mass extinction events), exotic species invasion (bird malaria in Hawaii introduced by humans; extinction of South American marsupial species by North American mammals after Isthmus of Panama emerged close to 3 million years ago), overspecialization on food sources (watch out, koalas and pandas), natural emergence of novel diseases (transmissible facial cancer threatening the Tasmanian Devil), and, surely a mix of several causes. Larger species are more likely to go extinct fast; they are, among other things, slower-breeding.       Once a population shrinks very much in what’s termed a population bottleneck, the remaining individuals represent low genetic diversity for adaptive responses to new threats (climate plus other species). Extinction probability rises – a worry of ours for cheetahs. There have been studies, mostly genetic analyses that show we humans also have low genetic diversity for a species with such an enormous population. These studies have been interpreted as evidence that humans went through a population bottleneck – say, 70,000 years ago during the eruption of the Toba supervolcano in Indonesia. More recent analyses say that our genetic diversity has an explicable pattern and, moreover, that this pattern is not what derives from a population bottleneck. Most of the causative agents of extinction are other biological species, and some are climatic.       In an isolated Mars colony one expects very few other species and fewer active agents of extinction, but the very simplicity of the ecosystem gives little recovery potential from crop failures or emerging diseases. Lethal failure of life-support technologies is a more likely cause. In any event, it is supremely unlikely that humans could survive more than a handful of millions of years. I dismiss the idea as specious that humans can become a near-eternal multi-planetary species. Besides, who wants to live forever on one more planet. Recall how bored was the character Bowerick Wowbagger in the hilarious social commentary trilogy, the Hitchhiker’s Guide to the Galaxy. Having become immortal by an industrial accident, he spent his time traveling to insult every other being. The Dyson Sphere of a long-lived civilization (look it up) sounds just as terminally boring.

Colonizing other planets is forgoing a lot of our luck in the Universe on a wild bet that we’ll fill in a lot of bad luck that makes those other planets barren. It’s a tech tour de force and predictably a short-lived one.

      Conclusion: It’s enormously easier and enormously safer and enormously more enjoyable to live on Earth than on Mars. As astronomer Lucianne Walkowicz said, “…for anyone to tell you that Mars will be there to back up humanity is like the captain of the Titanic telling you that the real party is happening later on the lifeboats.” Keep this great Earth going!

We live in a remarkable Universe that we are just beginning to comprehend. Go back to the origin of the stars and planets. The simplest chemical element fills the Universe, accompanied by a little helium and lithium. Almost preposterously it condenses from great dilution to an extreme density where it self-ignites in a fusion reaction nearly forbidden by the need for the truly weak force. The stars light up, yet, restrained by the weak force, last a long time on our human scale. They later make the panoply of chemical elements in our biosphere by the startling r-process. Our Earth came about around a star with remnants of a chemically enriching catastrophe of previous stars, favorably single rather than binary, at the right distance from the star, and at the right size of its own to keep water and gas, not too much of either, in a planetary system that had the help of Jupiter and asteroids… but, again, not too many asteroids. Einstein once said, “The most incomprehensible thing about the universe is that it is comprehensible.” Earth’s beauty may lie in part in the eye of the beholder; nonetheless, it is an extreme rarity among planets. William Butler Yeats once penned, in essence, that beauty is uninhabitable. I beg to differ, for the Earth in its span. He also wrote that “There is another world, but it is in this one.”

       About the author

This is an outreach activity of the Las Cruces Academy ( The LCA is a non-profit private school in Mesilla, NM, serving students from early kindergarten through 8th grade with strong academics, including 3 languages (English, Spanish, and Chinese every day), Singapore Math, much science, social studies, even cursive writing. Author Vince Gutschick is the Board Chair and a teacher of science, computer programming, and (pre-COVID-19)tennis there. He retired from a career in research and teaching, spanning positions at the University of Notre Dame (B.S., Chemistry), Caltech (Chemistry w/joint research in Chemical Engineering, basically chemical physics), the University of California, Berkeley (NSF Postdoctoral Fellow), Yale University (J. W. Gibbs Instructor), Los Alamos Scientific Laboratory (before renaming to National Laboratory; in Theoretical Biology and Environmental Science), and New Mexico State University (Biology), with postings at Georg-August Universität, Göttingen (Forestry), CSIRO Canberra (Plant Industry), LaTrobe University, Melbourne, the Australian National University (Ecosystem Dynamics), the Carnegie Institute of Washington at Stanford (Plant Biology), the US National Science Foundation (Program Officer, Functional and Physiological Ecology and cluster leader, Integrative Biology), INRA/ Laboratoire d’Ecophysiologie des Plantes sur Stress Environnementaux, Montpellier, France. Vince has over 60 peer-reviewed publications in 23 international journals in physics, chemistry, ecology, plant physiology, meteorology, radiative transfer, remote sensing, and agronomy (i.e., he has a pretty short attention span in any one field!). He and his wife, Dr. Lou Ellen Kay (City University of New York, Biology) also ran a small scientific consulting company, the Global Change Consulting Consortium, which had, alas, a similarly small number of contracts in the US and the UK. He had a radio program on a small community radio station in Las Cruces, NM, KTAL-FM, after which he moved to weekly spots on KRWG-FM, the area NPR station ( He maintains the website with analyses and commentaries on science, technology, and social ramifications, as well as interesting (he hopes) demos and experiments. Lou Ellen is his lifelong partner in science and education, as well as a partner in travel to 41 countries; their son, David, has traveled to most of those countries with them, and now David’s wife, Yi, is a great traveler with us. We bring world culture to the Las Cruces Academy in presentations and as interjections in many classes.