In Summary

  • Analysis for The Conversation by Professor Matthew Bailes, Swinburne University of Technology

Today I awoke to the news that Germany has announced its intention to withdraw from the Square Kilometre Array (SKA) project. The SKA is an ambitious project that plans to build a radio telescope with a square kilometre of collecting area by an international consortium of ten countries. These include host nations Australia and South Africa, leading scientific nations in Europe such as the UK and Germany and emerging science powerhouse China. India is an associate member. The project is currently in the planning stages, but will ultimately cost well in excess of one billion Euros.

The SKA and the Germans have both been quick to point out that Germany’s withdrawal is not due to any lack of confidence in the project itself, but just one forced by competing scientific priorities for Germany in challenging economic times.

 Animator’s impression of some of the dishes that will form part of the Square Kilometre Array. The SKA is an ambitious project to build the world’s largest radio telescope with unprecedented resolution and sensitivity at cm wavelengths. SKA Organisation

Unfortunately for the project, this is a major hit. It is often the case in international projects that member countries contribute on the basis of their GDP, and losing Germany will mean that the other nations will either have to stump up their share of Germany’s cash contribution or “de-scope” the telescope project.

A back-of-the-envelope calculation would suggest that the SKA just got 20% more expensive for the remaining partners unless new partners sign on. This is not what any of the remaining governments wanted to hear. The big danger for the SKA will be if Germany’s exit triggers a “run” for the door. After all, no country wants to be the first to say the science isn’t worth it, but it is much easier for a government to save face if they can claim that it just got too expensive due to the departure of others.

For the SKA there are of course other options, one of which is just to omit one (or more) of the subsections of the telescope that will allow it to observe in different frequency bands. The SKA is currently planning to build a dish array, a dipole array and a survey telescope in “stage one”. Chopping one of these options might make the telescope economically viable, but would leave a hole in the science case, making the whole project vulnerable. Another option is to try and replace Germany with other member countries, but this won’t be easy. The Germans are both skilled in radio astronomy and a large economy.

The SKA, the ultimate radio telescope?

The amount of science a telescope can complete in a given time is a strong function of its collecting area. To achieve a science outcome usually means obtaining a satisfactory signal-to-noise ratio. If a telescope has twice the diameter it has four times the collecting area and can achieve the same signal-to-noise ratio in just one sixteenth of the time.

If the “true” SKA was ever built, then it could have done its science 10,000 times faster than existing 100m class telescopes. Since radio telescopes can now have their signals combined relatively cheaply it makes a lot of sense for the world to combine their efforts in radio astronomy into a few instruments, not continue to work in isolation.

But the SKA’s scope is unprecedented in radio astronomy and its cost is still being defined. South Africa and Australia both bid aggressively for the project and the final split-site decision attempted to capitalise on the investment in both sites and was reluctant to say no to any of the constituent arrays too early. The rate at which the full SKA could deliver science was going to be astounding, but at what cost?

Although the development of the technology behind the SKA is bleeding edge and may well find its way into industry, once the telescope is in operation the research conducted by it will be mainly performing “pure science”, where the payback in economic terms is much fuzzier. Germany has obviously decided that the cost of continuing with the SKA is too great.

The benefits of pure science vs the cost

Germany’s exit from the SKA begs the question of what is an appropriate amount of money to spend on pure science for a given economy? It is a question I am often forced to ponder as I sit in judgement of research proposals or write my own.

There is absolutely no doubt that scientists' pursuit of pure knowledge has been pivotal in both our understanding of the Universe and the driver of technological innovation that has led to phenomenal economic growth and improvements in our health and quality of life.

But will this always be the case? Is there a finite amount to learn about some aspects of physics? At what point are all the fundamentals understood and we just start trying to understand Nature’s infinite complexity by reapplying the same equations?

If it costs A$2 billion to build a telescope capable of testing General Relativity around our Galaxy’s supermassive black hole is that a bargain or a luxury we can’t afford?

Unfortunately we don’t know the answer. History has shown that research into the unknown often surprises us and leads to unexpected breakthroughs that filter into our everyday lives. In the late 1800s it was thought that most of the fundamentals of physics were understood with just a few loose ends to be tied up. Then physics was rocked by the implications of special and general relativity and then quantum theory. The technological innovations these theories sparked have been unparalleled in human history.

The right amount to invest in pure science must be a function of a country’s population, GDP and economic circumstances. The SKA community is meeting this week in Italy to discuss how the telescope will advance science. For the remaining SKA partners the loss of Germany’s expertise and financial backing means that there are difficult decisions ahead.

The ConversationWritten by Matthew Bailes, Pro-Vice Chancellor (Research) , Swinburne University of Technology. This article was originally published on The Conversation. Read the original article.