Teaching Science

In Our Time: The Evolution of Teeth

In Our Time is a wonderful series on BBC Radio 4.

Melvyn Bragg and guests discuss theories about the origins of teeth in vertebrates, and what we can learn from sharks in particular and their ancestors. Great white sharks can produce up to 100,000 teeth in their lifetimes. For humans, it is closer to a mere 50 and most of those have to last from childhood. Looking back half a billion years, though, the ancestors of sharks and humans had no teeth in their mouths at all, nor jaws. They were armoured fish, sucking in their food. The theory is that either their tooth-like scales began to appear in mouths as teeth, or some of their taste buds became harder. If we knew more about that, and why sharks can regenerate their teeth, then we might learn how humans could grow new teeth in later lives.

Linked in the grade 11 biology page.

In Our Time: Kinetic Theory

In Our Time is a wonderful series on BBC Radio 4.

Melvyn Bragg and guests discuss how scientists sought to understand the properties of gases and the relationship between pressure and volume, and what that search unlocked. Newton theorised that there were static particles in gases that pushed against each other all the harder when volume decreased, hence the increase in pressure. Those who argued that molecules moved, and hit each other, were discredited until James Maxwell and Ludwig Boltzmann used statistics to support this kinetic theory. Ideas about atoms developed in tandem with this, and it came as a surprise to scientists in C20th that the molecules underpinning the theory actually existed and were not simply thought experiments.

Linked in the grade 11 chemistry page.

The Game of Floods

The "Game of Floods" was developed by the County of Marin as a public education activity on sea level rise adaptation, including traditional flood protection measures such as levees and seawalls; green infrastructure approaches including horizontal levees, wetland restorations, and beach nourishment; and policy/zoning changes. The Game of Floods is a small group activity, with 4-6 participants tasked with developing a vision for ‘Marin Island 2050,’ a hypothetical landscape that highlights the conditions that will be experienced in Marin in coming years with sea level rise and increased storm impacts causing the loss or deterioration of homes, community facilities, roads, agricultural land, beaches, wetlands, lagoons, and other resources.

To start the game, participants are given a lesson with an adaptation strategy reference sheet, including the effectiveness, environmental impacts/benefits, and cost estimates. Integral to the activity is the introduction and consideration of green infrastructure as an alternative to traditional levees and sea walls, with habitat and water quality benefits of such concepts articulated. Seated around the game board, participants take turns championing assets they value and proposing strategies to protect these sites from sea level rise and storm impacts. The game creates a lively interaction between participants, heightening awareness of the challenges of planning for sea level rise. The game concludes with group discussion to obtain consensus for a vision which protects critical assets, while maximizing ecosystems benefits through wetland restoration and other living shoreline approaches.

I haven't had a chance to try this yet, so I'm not certain how well it would work in the classroom. The website mentions it has been used in high schools, so I imagine it won’t need many tweaks to fit it into a lesson on adaptation.

Canada’s Changing Climate Report

Canadians are experiencing the costs of climate-related extremes first hand, from devastating wildfires and flooding to heatwaves and droughts. As the planet warms, extreme weather events will become increasingly common. The knowledge provided by our scientists has helped us understand that climate change is real and driven by human activity. The Government of Canada will continue to work with Canadian scientists, by listening to their expertise and evidence-based advice to help us continue to take ambitious action to reduce emissions and fight climate change.

Just released,
Canada’s Changing Climate Report provides the first in-depth, stand-alone assessment of how and why Canada’s climate has changed, and what changes are projected for the future. Undertaken by some of Canada’s finest scientists, this report provides an independent analysis and evaluation of the scientific confidence based on the scientists’ expert judgement. The assessment was led by Environment and Climate Change Canada, with contributions from Fisheries and Ocean Canada, Natural Resources Canada and university experts.

The assessment confirms that Canada’s climate has warmed in response to global emissions of carbon dioxide from human activity. The effects of widespread warming are already evident in many parts of Canada and are projected to intensify in the near future. A warmer climate will affect the frequency and intensity of forest fires, the extent and duration of snow and ice cover, precipitation, permafrost temperatures, and other extremes of weather and climate, as well as freshwater availability, rising of sea level, and other properties of the oceans surrounding Canada.

This is the first report completed as part of the
National Assessment Canada in a Changing Climate: Advancing our Knowledge for Action, led by Natural Resources Canada. It provides the climate science foundation for the forthcoming reports by addressing the impacts of climate change on our communities, environment, and economy, as well as how we are adapting to reduce risk.

This report may be a bit of a stretch for our students. On the other hand, they probably know more about the climate than most adults (having just studied it) and the language isn't much harder than a senior textbook. The information is fresh — and certainly relevant to them.

Linked in the grade 10 climate unit.

Discovery: Donna Strickland and extremely powerful lasers

Discovery is a BBC Radio 4 programme that explores today's most significant scientific discoveries and talks to the scientists behind them.

Donna Strickland tells Jim Al-Khalili why she wanted to work with lasers and what it feels like to be the first woman to win a Nobel Prize for Physics in 55 years. When the first laser was built in 1960, it was an invention looking for an application. Science fiction found uses for these phenomenally powerful beams of light long before real world applications were developed. Think Star Wars light sabres and people being sliced in half. Today lasers are used for everything from hair removal to state of the art weapons. Working with her supervisor Gerard Mourou in the 1980s, the Canadian physicist, Donna Strickland found a way to make laser pulses that were thousands of times more powerful than anything that had been made before. These rapid bursts of intense light energy have revolutionised laser eye surgery and, it's hoped, could open the doors to an exciting range of new applications from pushing old satellites out of earth's orbit to treatments for deep brain tumours.

Linked in the grade 12 physics light unit.