Trams would be useful if their dedicated line resulted in very fast speeds between major destinations but they don't. The Gungahlin to Civic journey will take much the same time as the current bus service.

Continuing developments in solar and hydrogen-powered vehicles, improved batteries and self-drive/shared vehicles are likely, within the next decade, to make light rail look like the old technology it is. Mass transit could take the form of bus-like trains that run on rubber wheels on ordinary roads that can be used by other vehicles and that generate electricity when the engine is not driving the wheels, such as running downhill or slowing.

Trams support a 19th-century lifestyle. Halfway through the second decade of the 21st century, why are we looking backwards instead of forwards? We have major problems that need to be addressed in a serious, well-substantiated way, not with a supposed solution that is really all about increasing revenue from property development along the route.

Robyn Coghlan, Hawker

The right to protest is fundamental in Western democracies, whether it be environmentalists chaining themselves to old trees, or Greenpeace pursuing whalers at great personal risk on the high seas.

Not long ago we were shocked by the Four Corners investigation into live-baiting in the greyhound industry: trainers were filmed using live rabbits, piglets and possums to instil the blood lust in dogs in order to improve their chasing/racing skills. There was an avalanche of anger directed towards those who pursued cruelty in order to benefit financially – and justifiably so.

Similarly, there was an almighty howl of protest concerning the executions of drug traffickers Andrew Chan and Myuran Sukumaran – and justifiably so. Life is sacred, even the lives of drug traffickers.

Perhaps one day the mainstream media and the public might dare to pursue, also with moral courage, the plight of the unborn; tens of thousands of whom disappear without trace each year, some of whom are beyond four months in gestation; not to mention the targeting of those with Down Syndrome and other disabilities.

Surely, Minister Rattenbury ("Move to ban protests at abortion clinic", July 20, p1), people not only have a right to discomfit us on behalf of trees and animals and assorted other progressive causes, but also on behalf of our voiceless young?

Peter Day, Queanbeyan, NSW

Technological advances in the past 50 years have permitted the human population to double, and resources consumption to increase even more quickly. Human actions now determine the future of our species and that of the natural world. The Anthropocene has arrived. (See Wikipedia.) With power comes responsibility. Humanity's collective ability to alter the world's climate by the emission of greenhouse gases means we now have the responsibility to choose a future that favours the survival of our species, or one with a risk of not doing so.

There are also crucial choices at national, regional and local levels. For example, should the Liverpool Plains in NSW continue to produce food for the foreseeable future, or should we risk compromising their capacity to do so by mining coal? (See "Massive mines close in on Liverpool Plains" by Mike Foley, Peter Austin and others in "The Land", July 16). We have technological progress. But we have failed to develop decision-making processes that give sufficient weight to options that lessen the risk of future catastrophe. We need to learn that, if the risks of a development are unclear, the best course may well be to shelve such development until we have the requisite knowledge to properly assess the risks.

David Teather, Reid

Several of your contributors, most recently Herman Riet (Letters, July 21), have called for action to stop the sale of the SupaBarn stores to one of the major supermarket chains.

My parents ran a small suburban grocery store in Adelaide some years ago. The hours were long, seven days a week, with early morning visits to the markets and late evenings doing the books. As kids we helped out after school and on weekends. Holidays were non-existent. When the opportunity arose, my parents were able to sell up and take advantage of their hard work.

It's my understanding that SupaBarn is a similar (albeit larger) private family business, built up over many years of hard work. People opposing the sale are denying the owners the right to make commercial decisions in their own interests. They are effectively saying SupaBarn is obligated to keep providing a service which they demand, and the owners have to keep working to serve them. That is extremely selfish and inconsiderate.

If Mr Riet is so concerned about the ready availability of products he wants, why doesn't he put his own money at risk and commit to working 60-70 hours a week by opening his own store? What right does he have to demand that the sale be stopped and that the SupaBarn folks stay put to meet his personal expectations?

Competition is great, but as a community we have no right to require the SupaBarn owners to stay in business longer than they want to.

Kym MacMillan, O'Malley

I agree with Herman Riet (Letters, July 21) who outlines so many of the advantages of shopping at Supabarn.

The staff have regular training about customer relations, efficiency, polite responses and, yes, Herman, the quality of their fresh food is excellent. Their rewards scheme is encouraging and beneficial for frequent shoppers.

How can we ordinary citizens "stop" this sale? Perhaps by contacting the managing director and telling him how much we appreciate their efforts. Surely if enough of the shoppers we meet there protest we will have some effect on keeping our preferred store.

Carlene Bott, Fisher

The deficit could be obliterated in one fell swoop if Tony Abbott and co acted to stop or at least curb unconscionable tax evasion by national and international companies; reined in middle and upper class welfare including negative gearing/CGT, superannuation and trust concessions; sought proper recompense for our natural resources; cleaned up the black economy; and put a price on carbon pollution.

But, as is usual whenever a government is bereft of ideas, guts, and goodwill to its citizens, politicians inevitably look for the easy way out – and in Tony Abbott's case, someone else to do the hard yards and cop voter flak. And so it is that once again the hoary old chestnut about the need to raise the GST is being run up the flagpole. The politics of sloth and pusillanimity are alive and well in the capital.

Jon Stirzaker, Latham

Jessica Irvine's article on the GST ("Push to lift rate of GST to 15 per cent", July 20, p1) refers to recommendations by the Chartered Accountants of Australia and New Zealand which calls for an increase in the GST to 15 per cent.

We should, of course, take its advice – it would be an unbiased report by the architects of the tax-avoidance industry. I bet it didn't mention cutting tax concessions on super, although it would achieve the same outcome and has been called for by most economic commentators.

Max Jensen, Chifley

If the state of the budget is so dire that the government is looking for new taxes, why not bring back the carbon tax which was doing so well in reducing pollution and putting money into the budget, instead of taking money out of the budget to pay the polluters?

G. Hammer, Narrabundah

Perhaps the "radical right" isn't so radical after all, C.Lathbury (Letters, July 20), as evidenced by polls that show at least 37per cent of those polled (up from a truly pathetic 15per cent a couple of years ago) support a better GST, together with the excruciatingly middle-of-the-road Mike Baird and old lefty Jay Wetherill join forces and come on board for a fair dinkum GST. Even the allegedly not so well-off will benefit from a better run economy, plus the free use of all that common infrastructure they use and haven't contributed to. Soon, C. Lathbury will be reduced to seeking support from the likes of Jacquie Lambie and Sarah Hanson-Young.

Christopher Smith, Braddon

Flights of fancy

As you well know, Canberra Times, media outlet for ALP propaganda, the Bronwyn Bishop affair is quite different to that of former speaker Mr Slipper. Mr Slipper was convicted of deliberately falsifying cab charge dockets to suggest a number of smaller charges – all for a private "jolly" to Canberra wineries. He was not invited to any public function.

Ms Bishop was late returning from another function to which she had been invited. Ms Bishop is invited because she is the Speaker of the House of representatives. Her staff, not Ms Bishop, booked a helicopter to get her to the function quicker than the hour on the Geelong Freeway. As you also well know, a politician attending a function in his or her official capacity, regardless of whether it is a party function, is always on duty in that capacity. So her travel, while the mistake of her staff, was clearly within the rules.

Before you comment, Canberra Times, about the "speck in Ms Bishop's eye", you should pay attention to the "moat" on yours: running dead on the Bill Shorten debacle.

R.C. Warn, Weston

The egregious selfishness of Bronwyn Bishop's misuse of public money is why she is in trouble now, with few defenders, even in her own party. A while ago Liberal Party members were apparently issued with prototypes of a Troy Buswell-designed "aromatic sensitivity meter". Joe Hockey obviously used his before announcing that Bronwyn Bishop's helicopter flight, at $5227, didn't smell right. Tony Abbott should have used his before making yet another disastrous "captain's call" to appoint her as speaker.

I won't get into the argument about her fairness in this role. Let's just say her impartiality has highly directional anisotropy. Far more important is her disdain for keeping a close control on her publicly funded expenditure.

Hockey got it right when he said we need "lifters", not "leaners", in this country, but if ever there was a leaner it is a person who charges the public $5227 for a short helicopter flight to enable her grandiose entry to a Liberal Party fundraising event. She could have made the journey in an equally short time by going to Bunnings and buying a good new broom for $40 or so. For $50 she could have got one with a long handle and taken, say, Sophie Mirabella, as well, for extra power on take-off.

Robin Connaughton, Aranda

Bryden Spurling's article about the reasons why our scientists leave their country ("Taxing issue of how to keep our best scientists" Times2, July 20, p5) took me back to my years at a British university.

I confess I did not come across a single scientist, including a couple of Australians, who had made the move for any other reason than to gain greater experience and success in their field. To them, recognition by their international peers was of paramount importance.

That said, the cartoon that accompanied the said article – depicting the scientist as money-grabbing as well as odd-looking – is unlikely to thwart the attempts of these dedicated people from seeking new horizons.

Sam Nona, Burradoo, NSW

Justin Said (Letters, July 21) says "erasing Israel off the map" by Iran "is non-negotiable". This is an often repeated claim by supporters of Israel, though we have yet to see any evidence. Meanwhile, the Israeli government is systematically and illegally stealing more and more Palestinian land, so Palestinians are now squeezed into bits and pieces of the country, making up about 12per cent of historic Palestine.

It would appear Israel is definitely intent on erasing Palestine off the map.

Gwenyth Bray, Belconnen

It was a pleasure to read Jack Waterford's well-informed article "Science can help us thrive in new economy" (Forum, July 18, p1). The struggle to train and retain students in science, technology, engineering and maths, from primary school to university, should concern us all if we want a bright future for our country in a highly competitive world of ideas.

Fortunately, our governments do seem to understand the problem, but turning things around will take much long-term planning, encouragement and sensible funding.

As Jack notes, pure science is important and should be adequately funded in its own right, but can also lead to important innovations in the applied world.

One area where the federal government has made a big difference is in marine research, where the world-class new Australian research ship Investigator was built at a cost of $120 million and is now in action in our vast marine jurisdiction and beyond. I was involved in the planning for this ship and find it almost incredible that it is only funded to go to sea for 180 days rather than the planned 300 days.

A recent supportive Guardian Australia article correctly noted that the add-on cost of sending the vessel to sea for another 120 days a year is considerable, but not a great deal compared to the cost of building this superb vessel or even compared to the cost of leaving it tied it up at the wharf.

The nation would learn a lot more about its offshore environment and resources, and the government would gain considerable kudos, if the additional sum of less that $10 million a year were found. Such a sum is really not much in the grand scheme of federal funding.

Dr Neville Exon, Chapman

BAN 'EM ALL

So Shane Rattenbury would like people who hold silent protests outside abortion clinics ("Move to ban protests at abortion clinic", July 20, p1) to be heavily fined. While we're about it, let's outlaw those annoying Falun Gong people whose presence outside the Chinese embassy must be equally irksome to progressive Canberrans.

Alan Cowan, Yarralumla

GAY PLEA

To me, Amanda Vanstone's comment piece "Why I support gay marriage" (Times2, July 20, p4) read like a plea to the current prime minister. I only hope that he reads it, opens his mind and feels empowered to respect "... others' different views. That's what is needed now". At least, it could be a start.

Wendy Gesini, Forrest

REALLY ON TRACK

Will the public housing renewal process ultimately result in all those living in the light rail corridor being from the right side of the tracks?

John Bromhead, Rivett

SELECTIVE MEMORY

The sale of Supabarn to Coles is causing concern to Canberrans but did anyone complain about the sale of Magnet Mart in 2013 to Home Timber and Hardware, which is co-owned byWoolworths and Danks, a UScompany?

V. Harris, Yass NSW

YOUR MOVE ON BISHOP

It says so much about Mr Abbott with his declaration that Mrs Bishop is "on probation". What rubbish! She should have been sacked long ago for her dreadful, partisan performance as Speaker. The ALP has a huge responsibility to get organised to ensure Mr Abbott is a one-termer.

Ray O'Brien, Wavell Heights, Qld

'BRONWYN' WIN

Given Tony Abbott's acceptance of Bronwyn Bishop's extraordinary defence of her travel claims, I look forward to the government enacting legislation across the full range of federal crimes and misdemeanours that gives effect to the 'Bronwyn' defence. Failure to do so would demonstrate politicians have a different level of accountability to those they govern.

Dave Herald, Murrumbateman, NSW

TIME IS MONEY TOO

It's not only the scandalous and over-indulgent travel arrangements of our politicians that should be a concern to taxpayers, but the extraordinary amount of parliamentary time taken up debating the issues concerning the likes of Thompson, Slipper and now the high-flying Bronwyn Bishop. After all, we pay for that too.

Tony May, Pearce

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