News

Putting More Truth in the First Great Lesson August 18 2024, 0 Comments

Storytelling is a vital skill for the guiding adult in a Montessori classroom. The heart of cosmic education is the five Great Lessons/Great Stories that teachers give at the beginning of the school year. Teachers are charged with being storytellers of the truth – giving children accurate information in an inspiring way.

Truth is a slippery concept. In science or in stories that have science content, we deal with truth with a small “t”; the pursuit of Truth with a capital “T” is beyond our lessons. Scientific truth is based on evidence that scientists have gathered by observing and measuring phenomena. Scientists are able to gather more evidence as they invent newer instruments and techniques; as a result, the truth changes. Mostly, the changes are small, but that doesn’t mean they are unimportant. Note also that we cannot discount the present state of knowledge because it might change.

Recently, I received a version of the first Great Lesson, The Coming of the Universe. Below, I’m going to quote some statements from that lesson and then give my ideas on how to make them more truthful. I am referring back to this example when I write “the lesson.”

Referring to the beginning of time, the lesson says “…it was very cold…” You cannot truthfully say anything about the conditions that existed before the Big Bang. It could have been hot, cold, or something in between, but we have no evidence, so we cannot make any definitive statements. Neither can we say if it was dark or light.

The example lesson tells of tiny particles coming together to create the Big Bang. This is not how we understand the first event in the universe. I like the way the book, The Stardust that Made Us* tells it: “In the beginning, there were no elements at all. Our universe exploded into a sea of energy…” At first, there was only energy. The universe quickly expanded and cooled, and within a fraction of a second, some of the energy was converted into particles. Within minutes, the particles came together to form atomic nuclei. It was too hot and energetic for atoms to form. (An atom is an atomic nucleus with a cloud of electrons swarming close around it.) The high energy kept the electrons from the nuclei. Atoms didn’t form for nearly 400,000 years. At that time, the universe had expanded and cooled enough that atomic nuclei could capture and hold their electrons.

The lesson says, “Although this explosion occurred over 13 million years ago, our universe continues to expand.” Yes, this is a good truth for the story. After the Great Lesson, children may wish to learn more about how astronomers learned that the universe is expanding. Look for the story of Edwin Hubble’s observations of galaxies.

The lesson goes on – “Within a few minutes of this explosion, all the matter in the universe was formed.” Not quite – energy can be transformed to matter, although we are more familiar with the opposite. Our Sun and all stars convert matter to energy, which is what keeps them from collapsing under the force of gravity. All of the matter AND energy of the universe came into being then.

The lesson implies that all the early matter was in the form of a gas. This is not true. At those temperatures, matter is in the plasma state. It is a sea of bare atomic nuclei, free electrons, and various other particles. It is important to get this right. Here’s a better version.

In the beginning, the first atomic nucleus to form was hydrogen. In the very hot, dense, and energetic conditions, some hydrogen nuclei collided and formed helium. There were also teeny tiny traces of lithium and possibly just a few other elements – all of which were less than one-billionth of all matter. Almost all the matter was hydrogen and helium. That’s what scientists observe today when they look at the stars – they are mostly hydrogen and helium. After this, the universe was too cool for atomic nuclei to smash together and form new elements. It would take special conditions found only in a very special place to make other elements.

The lesson says that as the universe cooled, the particles came together and formed stars, planets, moons, asteroids, etc. There is more to the story, and it is not too complicated for children to understand.

There is only one thing that can be made from hydrogen and helium alone, and that’s a star. Stars are made of enormously huge amounts of atoms. Gravity pulls the atoms together until the star’s center is very hot and dense. Astronomers think that it took an extra huge amount of hydrogen and helium to make the first stars. These giant stars burned their hydrogen and helium fuel quickly. Gravity pulled their matter together very compactly, and that made their centers very, very hot. These conditions squeezed the atomic nuclei together and formed larger elements. Some of the matter converted to energy, like it still does in stars. Now you know the special place where elements other than hydrogen and helium form. It is the amazing furnace inside the stars that gave us the elements that form planets and life.

As the first stars died, they spread new elements into space, and this helped further star formation. With some different kinds of atoms mixed with the hydrogen and helium, smaller stars that lasted longer could form. Our Sun is likely a third-generation star. It has a bit less than 2% of its mass as elements other than hydrogen and helium as compared to less than a billionth in the first stars.  

One of my favorite children’s science books, The Horse and the Iron Ball** explains the origin of elements very well. It is a bit outdated, as astronomers now know of other cosmic events that produce heavy elements. The basic story is still good and still inspiring.

I will write more about the formation of our Sun, the Earth, and the Moon another time. This is a big enough bite for now. Please feel free to add your questions and comments.

* The Stardust that Made Us: A Visual Exploration of Chemistry, Atoms, Elements, and the Universe. Written by Colin Stuart, illustrated by Ximo Abadia, published in 2024 by Big Picture Press (no relation to Big Picture Science.)

**The Horse and the Iron Ball: A Journey Through Time, Space, and Technology. Written by Jerry and Georgiana Allan, illustrated by Jerry Allan, published in 2000 by Lerner Publications Company.


What’s New in the Third Edition of Kingdoms of Life Connected? January 12 2023, 1 Comment

Last fall, I completed the third edition of my book, Kingdoms of Life Connected: A Teachers’ Guide to the Tree of Life. This came only six years after the second edition, which in turn came eight years after the first edition. “Why all this change?” you may ask.

I found that updates were needed because of changes in biologists’ view of the diversity of life. The data about how organisms are related continue to pour in, and because of this, the details of lineages and relationships change. You may be tempted to wait until the field stabilizes and stick with older ideas. Children, however, need a useful view of the diversity of life, even if it will be somewhat amended later. They cannot build on a foundation that is clearly obsolete. Specifically, it is no longer useful to present children with Five or Six Kingdoms, and those charts need to go in your history-of-science file.  

I updated Kingdoms of Life Connected from cover to cover. I redid the lists of learning resources – books and websites; I purged links that no longer worked and added new ones. Publishers and authors have brought forth valuable new books in recent years, and I added titles to the lists while retaining older but useful books. I revised all the text, including the activities and lesson suggestions. I fact-checked the information to make sure it was as up to date as I could make it.

There is one especially important addition, a new lesson for introducing to the Tree of Life chart to beginning elementary children. This lesson gives older children important concepts as well, particularly if they have not yet had this overview. The introductory lesson leads children to the idea that all life shared a common ancestor and is connected. It shows them the relationships between the major branches of life. For example, they learn that the animals and fungi are sister lineages and that plants are only distantly related to fungi.

I’ll give a brief summary of some of the changes below. For more information, see the book, which is available at https://big-picture-science.myshopify.com/collections/biology/products/kingdoms-of-life-connected-third-edition (printed version). The ebook (pdf) is at https://big-picture-science.myshopify.com/collections/biology/products/kingdoms-of-life-connected-third-edition-ebook.

There are no big changes in the prokaryotes. I have kept a very basic approach because it takes extensive knowledge of biochemistry to understand the many branches of bacteria and archaea. Introductory college biology texts present a few basic lineages, and I felt that this approach would be good for children as well.  

In the protists, I rearranged the Excavata lineage on the Tree of Life chart. Now, the euglenazoa and kinetoplastids are sister lineages and the metamonads are the first branch. I expect that Excavata will be split apart and redone in the future. It probably won’t be a eukaryotic supergroup, but studies continue to confirm the other supergroups – Archaeplastida, SAR, and Amorphea.

Scientific terminology evolves, and I was happy to see a complicated name go away. The branch of the stramenopiles and alveolates was previously called Chromalveolata, but that term has fallen out of favor. It originally described a lineage that included two branches I didn’t show, the cryptophytes and haptophytes; these are now placed elsewhere on the Tree of Life. The branch of the stramenopiles and alveolates may get a new name, but it seems best to leave that branch blank for now.  

The fungi were the major branch that changed the most. The former Zygomycota lineage is now divided into two main lineages, the Mucoromycota and the Zoopagomycota. On my Tree of Life chart, I show the larger one, Murcoromycota. Its branches include the pin molds or Mucoromycotina (black bread mold, for example) and the arbuscular mycorrhiza fungi or Glomeromycotina (AM fungi). The AM fungi were previously placed on their own branch, but they have been added back to Mucoromycota. I didn’t add the Zoopagomycota to the Tree of Life chart, but if you have children who are interested in learning more, Fungarium by Katie Scott and Ester Gaya, is a good book for launching their explorations.

In the animal kingdom, studies have clarified some relationships in the protostome branch. You can give children the term “Spiralia” for the lineage previously called Lophotrochozoa. The whole branch is called Spiralia; “Lophotrochozoa” still refers to the mollusks and annelids. It is another of the situations where it is useful to know an older and newer term. “Lophotrochozoa” has been used for the Spiralia branch for about 20 years, and it appears in a number of websites. I recommend looking to the future and using “Spiralia” primarily. It is certainly easier to say and spell.

In the plant kingdom, studies have resolved several questions about the bryophytes. They are a single branch of life, a monophyletic lineage. The first branch was recently determined to be the hornworts. The mosses and liverworts are sister lineages. The older story was that the liverworts were the first branch because they do not have stomata. It appears that their ancestors lost their stomata rather than never having them.

The virus chapter now has suggestions for making a model of a coronavirus. I published this chapter as a stand-alone pdf in 2020. Note that if you have the third edition of Kingdoms of Life Connected, you already have the content of “What Is a Virus?”.

It is easy to become overwhelmed by all the names and branches of life. I recommend that you concentrate on the larger branches on the Tree of Life and continue to other branches as children (and you) learn about these and are interested in pursuing more. For in-depth studies at the elementary level, I recommend the digging further into the animal and plant kingdoms.

Start with the big overview of the Tree of Life. After that, my learning material, Sorting Branches on the Tree of Life: Vertebrates and Plants, is a good place to go. It is available as a pdf that you can print https://big-picture-science.myshopify.com/collections/biology/products/sorting-branches-on-the-tree-of-life-vertebrates-and-plants or as a printed material https://big-picture-science.myshopify.com/collections/biology/products/copy-of-sorting-branches-on-the-tree-of-life-vertebrates-and-plants-file-for-printing.  

Enjoy your explorations of the Tree of Life!  


Why Montessorians need a new biology album July 28 2021, 0 Comments

Why does the Montessori world need a new biology album? Basically, there are two reasons...

It's time to take out the teleology March 03 2021, 3 Comments

It is imperative that we inspire children with scientifically valid ideas.

Why are updates so hard? October 28 2019, 0 Comments

Maria Montessori didn’t give guidance on updates. Why would she see the need to do this? The biology taught in her lifetime hardly changed.