Saturday, December 17, 2022

Week #17 Wrap ....

 Week #17 wrap up

  • Life on Earth diversified into the complex animal phylum we see today in a relatively short period of time, about a half billion years ago. It’s called the Cambrian Explosion. It was probably triggered by the buildup of oxygen in Earth’s atmosphere from photosynthesizing bacteria and the forerunners of plants.
  • About a third of a billion years ago (300 million years ago) vast tropical forests were repeatedly buried which would lead to the coal, oil, and gas deposits upon which economies depend today.
  • Current Events:  The FUSION breakthrough, announced in the news this week, is an important leap forward in meeting our power demands. Coal, oil, and gas are FOSSIL FUELS - which means the supply is finite.
  • “October Sky” (“The Rocket Boys”) by Homer Hickam not only shows the scientific method in action but also illustrated the problems with fossil fuels. West Virginia has polluted half of its rivers through its coal mining practices.  “Flat Topping” of mountains has destroyed much of the ecosystem as the landscape is opened to expose ancient coal seams. 
  • Burning coal, oil, and gas adds CARBON to Earth’s atmosphere, speeding climate change by trapping more SOLAR RADIATION. 
  • FOSSILS give us insight into EVOLUTION through the Law of Superposition. Thanks to the ROCK CYCLE there are three, main, types of rock - Sedimentary, Igneous, and Metamorphic. Sedimentary rock, usually, has older layers below younger layers. By studying the FOSSILS found in each layer we can put together a timeline of how life has changed and diversified over the last half a billion years.
  • Winter Solstice - Wednesday, at 1:48 pm - The sun begins its return to the Northern Hemisphere! (Whoo hooo!) - It’s the first day of Winter and the shortest day of the year :-)

Wednesday, November 16, 2022

Friday, November 11, 2022

Friday recap ... Quiz reminder.

 Hi Scientists;

Our science guest speakers guided students through experiments on conduction and heat transfer on Thursday.
Convection currents and heat transfer touch on everything from the rock cycle and atmosphere to the endothermic photosynthesis reaction and the exothermic reactions of respiration and fermentation.
The Week #13 quiz lis live and the Week #12 quiz is still open (both through Sunday.)
Board pics and notes attached ... Have a great weekend! SF

Wednesday, November 9, 2022

Week #13 Quiz

 Quiz link:

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Week #13 recap (so far)

 November 9th - Wednesday - Week #13 - 

     Hi Scientists;

     I made a very exciting 14 minute video, yesterday, as a recap. When it was done, it would have been posted but - for some technical reason beyond the scope of an old science teacher - there was no sound.

     Which was, probably, just as well. Fourteen minutes is too long for a recap. Heck, my own teenagers wouldn’t listen to me for more than five minutes. So … the notes are posted and here’s a bullet-point recap for the last three days. The important things we’ve been trying to teach and the tidbits that are snuck in so students remember this for high school, and beyond.

  • Earth was formed, about, 4.5 billion years ago and life arose about 3.6 billion years ago. The vast history of life on Earth has been one-celled organisms. 
  • The oxygen content of our atmosphere didn’t build up to a level high enough to sustain respiration until photosynthesizing bacteria had been around for, about, two billion years. In other words; if you had a time machine with a “random” button and you wanted to go back in time to see ancient life; most of the time you’d step out of your machine to see nothing more than green, slimy rocks. (Stromatolites.)
  • When life finally did inhabit land it diversified into the six Kingdoms we now recognize. (Although, the Protist kingdom will be subdivided soon.) Bacteria has no specialized organelles, while animals, plants, and fungi do have nuclei and specialized organelles.
  • Our job, this week, has been to identify the structure and function of organelles. Text books love to compare cells to factories. (I suppose that comes from the industrial revolution and the view that everyone knows how factories work?) We use that analogy as it is in our text and in various handouts. The product of these factories is proteins; built up from smaller parts called Amino Acids.
  • There are three, important, chemical reactions we should know going forward - photosynthesis, respiration, and fermentation. We introduced fermentation this week by making wine (yes, wine) and using that as a vehicle to discuss the things that come together to make the geology, ecosystem, and geography of California possible and how water, plants, fermentation, and the physical laws we studied in weeks one through eleven - combine to make the California we know today.
  • The quiz, this week, will focus on the organelles and kingdoms of life.

Notes - Week #13 -