Key Stage 3 or 4 (11–17 year olds)
Clips from Lecture 2 of 3: Life in orbit
CHRISTMAS LECTURES 2015 – How to Survive in Space
The CHRISTMAS LECTURES at the Royal Institution were started by Michael Faraday in 1825, and are now broadcast on national television every year. They are the UK's flagship science series and the CHRISTMAS LECTURES 2015, presented by Dr Kevin Fong, will be accompanied by a series of secondary school teaching resources. Kevin Fong is a medical doctor with a special interest in space medicine and extreme environments, particularly the medical and physiological challenges of long duration human space missions. He holds degrees in Astrophysics and Medicine from University College London, a degree in Astronautics and Space Engineering from Cranfield University and has completed space medical training rotations at Johnson Space Center, Houston and Kennedy Space Center, Cape Canaveral.
Use a clip from the 2015 CHRISTMAS LECTURES to enhance biology lessons on the skeleton, physics lessons on structural strength, or chemistry lessons on calcium. There are accompanying ideas, information, and worksheets for short, medium, or long activities.
Lecture 2 https://www.youtube.com/watch?v=OHDW1B6hQNo
Long activity (60+ minutes) – Soft Bones
Explore calcium, the element that gives bones their strength, by turning chicken bones and eggs rubbery. This activity must take place over the course of at least two days to allow time for the reaction to take place. Consider beginning the activity before a weekend.
2 clean chicken bones, cooked similarly
2 chicken eggs, hard boiled
4 glass jars with lids
Vinegar, approximately 1L
Ask the class if they know what bones are made of. Bones are mostly composed of a collagen matrix (a long, strong, flexible protein) and calcium carbonate to provide hardness and rigidity
The body knows how much calcium to put on bones based on the amount of stress is regularly placed on the bones.
To simulate spaceflight, put one bone in a jar and fill with vinegar until the bone is covered. Seal the jar tightly
Place a hard-boiled egg (with shell on) in another jar and cover it with vinegar. Seal the jar tightly.
Put the extra egg and bone into their own separate jars and cover with water as a control. Seal the jar tightly.
Ask the students to hypothesise about what will happen to the bone and egg over time in the vinegar.
After at least one day (but up to several weeks), remove the eggs and bones.
Compare the students’ original hypotheses to the properties of the bones and eggs
The bone and egg soaked in vinegar should have become rubbery and easily bent.
For additional guidance, refer to this NASA activity
Ask the students what they believe happened. The calcium in the bone was dissolved by the acidic vinegar. Discuss the chemical reaction that took place (CaCO3 + 2CH3COOH Ca(CH3COO)2 + CO2 + H2O)
Compare this process to the degradation of bone calcium during spaceflight, but also as a result of aging.
Brainstorm ways to stop this kind of degradation from happening. Compare this to real strategies on board the ISS.
Connect this experiment to ocean acidification. An increasingly acidic ocean will dissolve the calcium carbonate that shellfish use to build shells.
Extend the experiment over a period of weeks, measuring the angle of bend of the bone using a protractor. Ask the students to infer the rate at which the vinegar makes the bones bendy (degrees per day). You can also try the experiment with stronger and weaker acids.