From 5162ba45131b59745c663aca84c750498f2c7c0b Mon Sep 17 00:00:00 2001 From: Andrew Cady Date: Sat, 1 Oct 2022 12:17:31 -0400 Subject: new file: life-on-earth-celebration.md --- Makefile | 3 ++ life-on-earth-celebration.md | 76 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 79 insertions(+) create mode 100644 life-on-earth-celebration.md diff --git a/Makefile b/Makefile index 1303b5e..0ac7a36 100644 --- a/Makefile +++ b/Makefile @@ -31,3 +31,6 @@ else endif endif endif + +%.html: %.md + pandoc -f markdown -t html -o $@ $^ diff --git a/life-on-earth-celebration.md b/life-on-earth-celebration.md new file mode 100644 index 0000000..b4e580e --- /dev/null +++ b/life-on-earth-celebration.md @@ -0,0 +1,76 @@ +# Life on Earth Celebration + +A water-balloon fight to celebrate the anniversary of the first life on Earth. + +## The first life on Earth + +### The Cosmic Calendar + +The Cosmic Calendar is made by pretending that the universe is exactly one year +old. + +The universe was born on January 1st, at midnight, the beginning of this year; +and it will reach its present age on midnight, December 31st, at the end of this +year. + +Since the universe is actually 14 billion years old: + +* One month on the Cosmic Calendar is 1.1 billion years. + +* One day on the Cosmic Calendar is 38 million years. + + and + +* One second on the Cosmic Calendar is 437 years. + +#### Today, on October 1st, the universe becomes 10 months old. + +That means today we commemorate the time when the universe was 10.3 billion +years old. Or, about three and a half billion years ago. That was a very special +time, because it was then that life first formed on Earth. + +In fact, life probably began around September 23rd -- 3.8 billion years ago. We +chose this day to celebrate because of the weekend and the nice weather. + +But the earliest fossils which prove to a certainty that life existed date from +exactly tomorrow -- October 2nd -- 3.4 billion years ago. So today's date works +out pretty well either way. + +## Why water balloons? + +When Rory was four years old, Ella left her alone with me one night to go to a +Mom's night out. We were looking at photographs of the desert and at some point +I told her that humans are mostly made out of water -- and she did _not_ believe +me! How can humans be made of water? Why doesn't the water spill out? I went to +the kitchen and filled up six zip lock bags with water and stacked them up on +the table. Humans are made up of little _bags_ of water called cells. All life +is made up of cells, except for viruses which can only live inside the cells of +other life forms. This is why the water balloon is a symbol of all life. + +The water balloon is also fun to play with. It is fun because it is unstable -- +it is easily broken -- and when that happens, the water _does_ all spill out! +Today we are going to get wet, or at least those of us who are kids are going to +get wet. And then we will dry off and warm up by the fire. + +It's a bit late in the year for water balloon fights but it's a nice day today, +just nice enough. It's may be the last day of the year when we can get wet and +still have fun. Soon it will be cold. + +This is also fitting the theme of the first life on Earth, because on the cosmic +calendar, life is a phenomenon of fall and the winter. + +In the history of the Earth, life is also connected closely with cooling down. +Just three weeks ago, on September 6th -- Rory's Birthday -- the planet Theia +collided with Earth, forming the Moon. The Moon was not formed from the mass of +Theia, though; Theia and Earth were thoroughly mixed together. The two planets +became one exploding mass, and the remnants of the explosion became the Moon. +Those remnants were so hot that they were made out of vaporized rock. Not liquid +lava, but liquid lava turned into vapor. _Thankfully_, things have cooled down +since then. In just about 100 years of real time, the doughnut-shaped cloud of +rock vapor cooled down enough to become the Moon. And in a short 600 million +years, or 17 cosmic days, the Earth itself cooled down enough to allow for life +to begin. + +So as the days get cooler and become cold, or if you happen to get cold and wet +today, remember to be thankful. + -- cgit v1.2.3