Quick questions on Limitations of scientific technology: HSC Investigating Science Module 6

The smallest detail an instrument can detect. A light microscope cannot resolve objects smaller than about 200 nm because of the wavelength of visible light. Atoms (about 0.1 nm) and viruses (10 to 100 nm) require electron microscopy.

The lowest signal an instrument can detect. Detecting a single molecule of a hormone in blood requires extremely sensitive mass spectrometry or radioimmunoassay.

How fast measurements can be made. Sanger DNA sequencing (1977) reads 800 base pairs per day. Next-generation sequencing reads billions per day.

Many instruments cost millions to billions of AUD. The Australian Synchrotron cost about 220 million AUD to build. The James Webb Space Telescope cost 10 billion USD.

Even when instruments exist, access can be limited. Synchrotron beam time is allocated by peer-reviewed proposal, with success rates of about 30 per cent.

Sanger sequencing reads about 800 base pairs per reaction. Sequencing the 3 billion base-pair human genome required millions of reactions in parallel.

Ground-based optical telescopes could resolve features about 1 arc-second across, limited by atmospheric turbulence. Infrared astronomy was nearly impossible from the ground because water vapour absorbs infrared.

Explain how the cost of an instrument constrains which scientific questions can be answered. [3 marks]

A team proposes mapping the entire NSW koala genome population to study chlamydia resistance. State two technological limitations they must overcome, and outline one mitigation. [4 marks]

A school astronomy club uses a 200 mm reflector and a CMOS camera to image Jupiter. (a) State one limitation of their instrument. (b) State one secondary data source they could use to supplement their primary images.