Physics and a position, always both

Two things at once, always

This kind of response has an unusual structure: it does two things at once — physics, and a position built on that physics. Missing either one sinks the work, however strong the other is.

The physics half	The response half
Explain the key physics ideas relating to the issue	Present a personal position and propose action(s) at a personal and/or societal level, using relevant physics
Explain how or why the physics ideas relate to the issue	Justify the position using physics — say why this position and these actions were chosen
Link the physics ideas together into a coherent picture	Analyse and prioritise the physics knowledge to justify the response

Each row goes deeper than the one above it, and the two halves have to move together — a coherent physics picture attached to an unjustified position is still an unjustified position.

What "analyse and prioritise" means

This is the most demanding phrase in the whole task, and there are three things it can include.

• Comparing the significance of the implications for individuals and for society. The same issue often affects the two differently, and saying which matters more, and why, is analysis.
• Considering the likely effectiveness of the actions you proposed. An action that sounds good but cannot work at the scale of the problem should be identified as such — by you, before the reader gets there.
• Commenting on your sources: their validity (how recent, whether peer reviewed, whether scientifically accepted) and their bias (the attitudes, values and interests of whoever produced them), and how different groups use the same science differently.

Prioritising means saying which pieces of physics matter most to the decision, and why the others matter less. A response that treats every fact as equally important has not prioritised.

What counts as a socio-scientific issue

There are three requirements. Check your issue against all three before you start.

• It involves physics — real mechanisms and real numbers, not just a technology that happens to exist.
• It has social implications, which may be economic, ethical or environmental.
• It is one on which people hold different opinions. If everyone agrees, there is no position to take.

Issues that work well in a New Zealand context

Issue	The physics in it
Whether New Zealand should build utility-scale solar farms on productive farmland	solar irradiance, efficiency limits, energy density, intermittency and storage
Whether 5G transmitters near homes pose a health risk	photon energy $E = hf$, ionising versus non-ionising radiation, inverse-square law, power density
Whether New Zealand should allow nuclear-powered vessels into its ports	fission, mass–energy, half-life and containment, radiation dose
Whether to expand geothermal generation in the Taupō Volcanic Zone	thermal energy transfer, efficiency limits of heat engines, energy per unit mass of steam
Whether household solar with batteries should be subsidised	energy storage, efficiency, power versus energy, payback in kWh
Whether to build more wind farms in the Cook Strait region	$P \propto Av^3$, swept area, capacity factor, intermittency

The one restriction to plan around

• The physics used here must be different from the physics used in your applied-context report. Choose the two together at the start of the year: if your context report is on medical imaging, your issue should not be another wave-based topic.