How can we expect students to continue with or be attracted to STEM studies if they do not have teachers who have a good understanding of the subjects needed.

After more than 30 years of teaching the physical sciences, I believe that a teacher needs two years of university study in the subject they are teaching and themselves have had a good teacher at school.

When the ACT college system was set up teachers were required to have a major in their degree in the subject they taught. It worked so well.

Why have we gone backwards when this area of study is so important to Australia? Can we please start a discussion that will lead to change?

Lyn Moss, Flynn

Further to my earlier note about Belconnen's decaying Lake Ginninderra foreshore (Letters, December 15) I feel I should issue an update.

Some work has taken place to remove weeds around the trees adjacent to the skate park. This has merely revealed that four of the trees no longer exist. However, the most serious problem remains. It is now impossible for the "wetland area" to be viewed from either the college or the skate park due to the wall of thistles and weeds.

It would appear that, during the costly and bungled construction of the "wetlands", no thought was ever given as to how the area could be maintained later. Oh well, it was the ACT government wasn't it?

Murray Upton, Belconnen

Margot Sirr makes sensible observations about the useful capabilities of deciduous trees (Letters, January 25).

James Allan seems to be criticising a letter she did not write.

It is true that many deciduous trees are good at sweetening degraded soils. Having arrived in Australia without hundreds of pests from their homelands they can free more energy to hunt for and unlock nutrients deep in the soil. Their leaf fall decays to humus and holds these precious nutrients in topsoil.

Many deciduous trees have a strategy of pumping lots of carbon-based sugars into the soil to encourage microbial life.

Lots are heat ablative and a comfort to have as shelter in a firestorm. As for wildlife , many insectivorous birds don't care what species of tree supports the thrips and aphids they live on.

Many migratory birds love acorns (they eat them in Siberia and Korea before they fly here) and the limiting factor for many species is nesting or perching space, provided quickly and well by many deciduous trees.

Mr Allan assumes deciduous trees come from temperate landscapes quite unlike our arid places. Wrong , oaks and poplars from arid Mexico, Arizona, Iran and China are perfectly preadapted to live here and extremely useful for land repair. This should not be an argument about natives versus exotics. Land managers need every tool in the box if we are to fix our broken lands, before it is too late.

P.A. Marshall, Braidwood

These are two excerpts from speeches by two world leaders:

"As part of our defence, we must modernise and rebuild our nuclear arsenal, hopefully never having to use it, but making it so strong and powerful that it will deter any acts of aggression. Perhaps someday in the future there will be a magical moment when the countries of the world will get together to eliminate their nuclear weapons. Unfortunately, we are not there yet." (Donald Trump, State of the Union Address 2018).

"Then or now, there is no change in the geopolitical position of the nation, but the small and weak nation of yesterday – which had been mercilessly trampled upon at each festival scene of the powers – has today changed into a dignified political and military power and our people are displaying dignity as independent people who can never be toyed with by anybody". (Kim Jong-un, Kim Il-sung Square in Pyongyang, 2012).

Difficult for me to spot the difference.

Greg Simmons, Lyons

Without doubt, Roger Federer is one of the greatest tennis champions that graced courts around the world. A true gentleman, his conduct always exemplary on and off the court, Federer has now won his sixth Australian Open and 20th tennis major overall, but not his 20th grand slam.

TV and radio commentators and sports writers wax lyrical about Federer and other current tennis greats winning x number of grand slams, when they should be referring to winning tennis majors, like the Australian Open. A tennis grand slam is winning all four "majors" in singles competition during a calendar year.

That is, the Australian Open, the French Open, the Wimbledon Championship and the US Open. The last time such a feat was achieved by a man was in 1969, by Rod Laver. Laver also achieved this in 1962 during the amateur era.

The last time a woman won the grand slam was in 1988, by Steffi Graf. Graf also won the gold medal in women singles at the 1988 Seoul Olympics. Yet our sport "experts" – almost mantra-like – keep crediting many current tennis players with the grand slam title.

Describing any of the current players as grand slam winners, including the peerless Federer, takes away from the exceptional achievement of the very few who managed to do so.

R. S. Baczynski, Isaacs

Patrick O'Hara (Letters, January 27) falls into the trap of touching on an apparently elitist membership model of the Liberal Party, in support of Labor recruiting methods.

Estimates are that for some years now the Liberals may be a nose in front of Labor in rank and file members, extraordinary when you consider the ratio of workers to executives.

My concerns lie with the 85per cent of workers who do not currently benefit from union membership and why this number is so high. It's not simply that unions have crumpled under sustained attack from industry groups, although anti-union tactics are probably the major cause.

Workers who have been separated from the pack and are now out in the wilderness, are generally known as casuals. The Labor side of politics needs to work a lot harder to support them.

It is not surprising suicide rates are high among low-paid workers, with so many obstacles facing them in what has become a stratified workplace, full-time workers now the blue and white-striped bourgeois.

Matt Ford, Crookwell, NSW

On four occasions in the last month I have observed cyclists riding against a red signal.

On one of these occasions the cyclist was making an unauthorised left turn on red. However he did stop first and there was no conflicting traffic so the move did not cause any danger.

On each of the other three occasions the cyclist riding against the red light moved into the path of an oncoming vehicle making a legitimate green signalled manoeuvre.

For the new regulations permitting cyclists to ride on pedestrian crossings to work safely it is essential that all road users behave in a responsible and considerate manner.

With risk takers like those just described at large on the roads this is clearly not going to happen.

I therefore stand by my original claim that this regulation is fundamentally flawed, and if it is implemented it will be only a matter of time before there is an ugly accident – caused by a cyclist but blamed on the motorist.

Roger Quarterman, Campbell

Two of the basic foundations of a flourishing, democratic society are being undermined through privatisation by stealth – education and health.

On January 30, the article "Appeal to cut over-funding for schools" was not referring to public schools, but to the over-funding of private schools (31.3 per cent) and Catholic schools ( 38.3 per cent).

How can the Commonwealth and ACT governments justify over-funding of elite schools such as Canberra Grammar (124 per cent) and Radford College (53 per cent)? If families want to send their children to private or religious schools, taxpayers should not be forced to subsidise their choices.

Quality public education for all is a requirement for a dynamic democracy.

On January 31 an article on page 3 of The Canberra Times, noted that the ACT has the lowest rate of bulk billing of GP services in the country at 62.1 per cent compared to a national average of 86 per cent.

Private corporations such as Ochre are taking over medical services that previously bulk-billed, undermining access to health care.

We need to support and defend quality education and health care for all and oppose privatisation.

Pamela Collett, Narrabundah

It is quite easy to work out who is responsible for the cabinet documents going astray ("Urgent probe launched into accidental sale of classified documents", canberratimes.com.au, January 31).

The senior security advisers who have crafted those new government security laws clearly foresaw the inevitably of something like this happening.

"Look", they say, "we're never going to stop classified documents going astray, I mean who hasn't left the odd accountable document or two behind in some filing cabinet and thrown away the key" (guilty laughter all around).

How about we just put in something along the lines that "anyone who communicates or deals with protected government information could be jailed for up to 20 years".

The added irony is that some of the documents found also point fingers at the AFP for being unable to account for their holdings of "nearly 400 national security files".

The very same agency is now apparently being tasked to investigate this latest farce.

Only the Hollowmen scriptwriters could have come up with something more humorous in these times of fear and insecurity.

Michael Crowe, Hawker

Australia is a successful multi-cultural nation.

The ancestors of Australians of Aboriginal descent may have inhabited this land as a nation before white colonisation, but just because there was no formal settlement treaty signed between them and the first white settlers does not mean that they are still a separate nation or culture.

Other Australians of multi-cultural descent cannot and should not regard themselves as separate nations or cultures.

Australia was not invaded by white settlers. Invasion is what happened during the First and Second World Wars, and during the Korean and Vietnamese wars, when countries were over-run by invading armies with lethal weapons and force.

Australia has given so much financial, social, and medical aid to Australians of Aboriginal descent, that they should not have to feel guilty about wrongs committed against Aborigines during white colonisation.

There should have been a formal settlement treaty signed between the Aborigines and the first white settlers (such as the one signed between the NZ Maoris and the white NZ settlers), the date of which would have been a perfect Australia Day, but there have been so many generations of Australians of Aboriginal descent born into multi-cultural Australia since white settlement that a formal settlement treaty would be impossible to draw up, unless Australians of Aboriginal descent wanted to become a separate self-governing nation with their own separate state and culture.

Claude Wiltshire, Queanbeyan, NSW

Contributions by John L Smith (Letters, January 24) and Kevin Cox (Letters, January 28) around electricity network costs are incomplete and wobbly.

While Cox correctly argues that local photo-voltaic and battery is "best", his claim that the "greedy" network owners should contribute to battery "subsidies" is not reasonable.

The networks were sold by governments to the incumbent owners, and they act like businesses do to stay in business. However they are also heavily regulated by the Australian Energy Regulator, and it recently lost in the Federal Court when it tried to limit proposed charge increases.

What Cox calls "greed" is really the networks complying with high standards set by government and the need to replace ageing infrastructure.

Smith on the other hand reckons that subsidised battery owners are privileged and that they should help offset network costs. His case starts on the poor assumption battery subsidies were offered for no value in return, and his proposition requires the contract implied in the subsidies arrangement to be broken.

This is not acceptable in a country that operates under "rule of law".

Trevor McPherson, Aranda

NUMBER CRUNCHING

In this decimal age, 3.8 is an unusual number.

So is the $3.8b, precisely, earmarked to boost our "defence" industry merely the sum of past, or future, political donations? An astute investment perhaps?

Adrian Gibbs, Yarralumla

HOUSING PAIN

From Martin North: Digital Finance Analytics has released the January 2018 mortgage stress and default analysis update.

Across Australia, more than 924,000 households are estimated to be now in mortgage stress.

This equates to 29.8 per cent of households.

In addition, more than 20,000 of these are in severe stress.

Ken Morehouse, Wangaratta, VIC

OBVIOUS SOLUTION

By my rough calculations there are about one to two hundred people sleeping rough in Canberra every night.

There are about one to two thousand vacant dwellings.

The solution seems obvious to me.

Over to you "progressive" Labor/Greens government.

John Passant, Kambah

SPITTING THE DUMMY

Perhaps the reason, C. J. Johnston (Letters, January 31), that "mature men" call their teammates "boys" is because they regularly throw tantrums if things do not go their way.

Ken McPhan, Spence

AM I MISSING SOMETHING?

The recent debate over whether or not Australia Day should be renamed/moved or simply ignored has me confused.

Would someone please explain to me, given that we have been informed in these pages that the 1967 referendum had nothing to do with Aboriginals being recognised as citizens (because they already were) or getting the vote (because they already had it), what exactly was the referendum about?

Penny Bowen, Chisholm

PAINFUL

Peter Sesterka, ouch. (Letters, January 31).

Kenneth Griffiths, O'Connor

CBA NEEDS CLEAN OUT

The whole board, including its chair, Christine Livingstone, needs to be replaced at CBA.

They have obviously learnt nothing from the various fiascos in appointing Matt Comyn as CEO. He will not shake the tree vigorously to get rid of other rotten apples as it would impact negatively on the bank's share price.

As a shareholder myself, I am willing to absorb such a loss simply to feel that I have some confidence in the CBA acting ethically in the future.

The support for Comyn by various ex-bankers and finance commentators does not wash with me.

Ric Hingee, Duffy

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