Construction activity, like everything else, responds to demand. It has been driven in large part for many years by high annual population growth of 400,000 including immigration at 240,000 people a year. COVID-19 has stopped that immigration. Nobody knows if or when it will ever resume.

Those earning a living in construction may soon experience shrinking demand. There'll be too many land and property developers, project managers, architects, engineers, surveyors, builders, tradesmen, real estate agents, conveyancers, and suppliers of materials and appliances.

Is COVID-19 forcing upon Australia an ultimate inevitability, the end to impossible, unlimited growth in human numbers?

Before COVID-19 arrived the weather was already messaging us; more frequent droughts and water supply crises in the Murray Darling Basin - evidence we were exceeding our environmental limits. Only economists and madmen would deny that and seek a return to it.

Steve Evans's homily to the Boeing 747 in his uplifting article "Diary of an Optimist: Ingenuity from jumbos to vaccines" (July 20, p6) reminds me of a memorable meeting in 1972 while I was working on my PhD thesis at the University of Melbourne.

My girlfriend introduced me to her father, a Qantas pilot. He told me that he flew international routes as the captain of a Boeing 747.

I asked him what it was like to fly. His enthusiastic response was that it flew like a dream, more like a Learjet than a Jumbo, and was remarkably easy to land.

I've had many memorable flights in 747s and have never felt safer in an aircraft. I had a jumbo lump in my throat when the last Qantas 747 flew over Canberra last Saturday.

If we could ever dream of a world free of nuclear weapons that moved a step closer to reality when Vladimir Putin called for Hagia Sophia to become a world symbol of peace.

With Turkey's President Recep Erdogan wanting to revert this historic sixth century Christian cathedral back into being a Muslim mosque, he is rebuffing Ataturk's secularist attempt at bringing together Islamic and western civilisation.

But this sacred shrine also stands at the dividing line between Eastern and Western Christendom.

On one side we have Eastern Orthodox Christianity, and on the other is Western Protestant and Catholic Christianity.

Given that the world's two great nuclear powers, Russia and the US, stand on opposite sides of this dividing line, we can only hope that Hagia Sophia will help further the cause of peace and bring an end to the nightmare of a nuclear Armageddon.

It is likely a surge of coronavirus infections will hit Canberra before a vaccine or fully effective treatment is found. Given the very old are most at risk, the ACT government should review preventive measures in Canberra's residential aged care facilities.

Germany has kept its COVID-19 mortality rate much lower than many of its European neighbours largely by limiting the spread of the virus into aged care facilities. Comparing the recommendations issued by its national Robert Koch Institute with those in our corresponding national guidelines shows Germany places more emphasis on proactive checking of aged care staff and residents. This includes daily detailed assessments, including temperature, kept in a central record. By comparison, our guidelines are reactive and less prescriptive, and downplay the checking of staff.

The ACT government should be encouraging and assisting Canberra's residential care facilities to implement checking procedures following the German model. It is inevitable the daily checking of residential care employees will result in staff shortages, as those staff showing danger signs are identified and given leave. The Chief Minister and Minister Stephen-Smith should be looking towards filling these temporary vacancies by taking up the federal government's offer of ADF personnel.

The argument that aged care is a federal responsibility should not be raised as an excuse for non-involvement by the ACT government.

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