Meanwhile real scientists are searching for a paradigm shift away from "mathemagics", which routinely employs the concept of infinity to "prove" anything you like.

A black hole, for instance, has finite mass concentrated at its "singularity". The singularity has zero volume and infinite density.

The black hole has no gravitational force, only space-time curvature. There is infinite curvature at the singularity, which means infinite gravity.

Think about that. A finite mass is located in zero volume, it has infinite density and it has infinite gravity.

Do you think any such thing exists?

A black hole has never been observed. If a theorist is unable to discover real objects, which cause the observed effects, it is unscientific – indeed, it is fraudulent – to invent unreal objects and present them as a "factual" discovery of the cause of those effects.

More than a billion dollars has been spent on gravitational wave detectors so far but it is reported that the European Space Agency is planning a multibillion-dollar probe to be launched in about 17 years that would look for gravitational waves from space.

Clearly we don't understand gravity yet.

How about some real investigative reporting in physics instead of showbiz?

There's a great deal of public money to be saved, not least on Cox's show.

Wal Thornhill, Chapman

Tony Walker's commentary piece about the link between the battle of Beersheba and the foundation of Israel ("Not quite right brigade", October 16, p.14) suggests that guilt over the Holocaust "provided impetus" for the UN partition resolution and, implicitly, led to Israel's creation. Yet the British Mandate for Palestine, conferred by the League of Nations following the First World War, was specifically intended to facilitate the establishment of a Jewish state there.

It is not the case that, unlike all other peoples, the Jewish people only warranted a state in their homeland because so many were murdered.

Interestingly, the Palestinian Authority has been demanding the British apologise for the 1917 Balfour Declaration because it pledged support for a Jewish state there.

Walker states that the partition, which actually only gave the Jews areas with a Jewish majority, had disastrous consequences for the Palestinians.

This is true, but only because they and their Arab neighbours declared war with the intention of destroying the new Jewish state. Had they and their Arab neighbours accepted the partition, as the Jews reluctantly did, they would have had a state alongside Israel in 1948, and there would have been no Palestinian refugees.

Jamie Hyams, Australia/Israel and Jewish Affairs Council, South Melbourne, Vic

Tony Abbott has got his way over the Prime Minister – again. He has extracted just what he wanted from Malcolm Turnbull: the dumping of subsidies for renewable energy and the mandating of the use of coal and gas for baseload and dispatchable energy generation ("PM's energy policy to mandate coal, gas use", October 17, p1).

This sends all the wrong signals to the developers of renewable energy sources, especially solar and wind, and surely must dampen enthusiasm for moving into areas such as pumped hydro – which is eminently suited to the generation of both baseload and dispatchable energy.

Thankfully, most of the states, and the companies themselves, will probably continue – though no doubt with reduced certainty and enthusiasm – developing solar and wind capability, along with the accompanying energy storage systems.

It won't be long before the market realises that once existing coal and gas-fired plants have reached their use-by dates, it is more economical to switch to renewable energy sources with energy storage. And this date is not far off.

Douglas Mackenzie, Deakin

When are we going to prevail upon the coal-loving recalcitrants in the Liberal and National parties to get out of the way, and let right-thinking, well-qualified, sensible people steer the future of this country?

Tony Abbott, with his unthinking, uninformed and absurd views, has almost single-handedly created and presided over our policy paralysis in Australia for the past decade, and is guilty of a crime against our national interest, now and into the future, and should no longer be heard.

Sandy Paine, Griffith

I'm aware that climate change isn't proved by individual climate and climate-related events.

But an appreciation of more broadly based and compelling statistical proofs seems to be beyond the likes of Tony Abbott and his supporters.

So they might like to consider two recent events.

The California fires are now considered the deadliest fire event in that state's history.

Hurricane Ophelia is the most eastern category 3 Atlantic hurricane on record.

Just a coincidence? Maybe, but then again, maybe not.

Climate change deniers are gambling with the future.

When will they recognise that doing nothing is a far more dangerous gamble than doing something?

Peter Dark, Karabar, NSW

The researchers from the Universities of Melbourne and Sydney who established a familial link in dole dependence ("Children likely to get welfare if parents did", October 16, p2) have only reopened the old nature-nurture can of worms.

The researchers should be notified of the urgent need to establish whether the ground gets wet when it rains.

Gary J. Wilson, Macgregor

Memo to church leaders against same-sex marriage: Second only to love of God, Jesus commanded us to "love your neighbour as yourself". He taught us who our "neighbours" are, so I know. Do you?

Tim Terrell, Farrer

Keith Mitchell (Letters, October 16) is right to criticise the Australian War Memorial for pinching a line from our national anthem to advertise the memorial.

The memorial market-tested the "we are young and free" line late last year and presumably found the words publicly acceptable.

Dr Nelson certainly likes them, though: he has used them in at least eight speeches since 2013. There are more important reasons to be critical of Dr Nelson: his tendency in his speeches to deliver sentimental and tendentious guff, learned by heart, rather than turn his considerable intellect to new ways of looking at Australia's wars; his unwillingness to engage with the memorial's critics (institutions that believe in their mission should defend it in the marketplace of ideas); his apparently deficient oversight of accountability procedures; the memorial's pursuit of funding from arms manufacturers, a practice that led former senior public servant John Menadue to write recently, "The AWM has lost its way."

The advertisement that Mitchell complains of carries the note "proudly supported by Northrop Grumman".

This is the world's fifth largest arms company by value of sales.

On the other hand, Dr Nelson has presided over some welcome changes at the memorial (the Holocaust exhibition, the recognition of Indigenous deaths in the frontier wars.

David Stephens, Honest History, Bruce

The front page article on poker machine limits ("Pokies limits not feasible", October 16) was well thought out.

The weakness in the reasoning on limits is that, in an inflationary financial system, today's limits will be insufficient in the future.

Whether it is poker machines or roulette wheels limits are not as important as the odds on winning.

There are reasonable gambles or unreasonable gambles and poker machines are of the unreasonable type.

The most reasonable popular form of gambling I know of is the European roulette wheel. The odds in favour of the house on a red or black bet result are less than 3 per cent.

This compares with the 16 per cent exacted by the poker machine.

By comparison the most lucrative gambling casino in America sets all gambling machines, including pokies, to return seven per cent to the house.

If our proposed casino followed suit I can say with the utmost confidence that we would see all the big Canberra poker machine clubs do the same in a matter of months.

This would result in a reduction of the ripoffs that are happening at the moment.

Forget bet limits. Instead, when teaching calculus, include a section devoted to gambling and other matters connected to everyday financial transactions.

Howard Carew, Isaacs

I get what the poker machine industry mean when they say: "Developing a game for a poker machine is a complex and very expensive process"("Pokies limit 'not feasible'," October 16, p1).

Sure, the foundational elements of a random number generator and related look-up table are fairly straightforward, but how do you communicate the outcome to the punter?

Do you have "LOSER!" in big letters or confect wheels with four showing aces and the fifth spinning a bit longer before finishing just off the ace? Do you play a descending bass tuba scale or music that gives you a "missed it by that much" feeling?

Working out the ideal video and sound effects that will match the game's theme and manipulate the punter into keeping on playing and losing is an exacting art, no doubt involving hours of behavioural research and highly paid experts.

Having optimised this for a $10 "spin" (noting that there really aren't any spinning wheels inside the machine), it would be problematic to rework the process for $5 spins when the costs would have to be recovered from a single casino whose revenue per spin would be halved.

Ian Douglas, Jerrabomberra, NSW

Ross Ferrar of the Gaming Technologies Association ("Pokies limit 'not feasible', October 16) decries a $5 limit to poker machines as making the industry unviable.

I'm sorry, Ross, but I don't think anyone owes you, your association, or clubs any sympathy when your industry is based around the science of making people gamble more, for longer, without control.

Families around Australia suffer because of gambling problems, and Canberra has seen its share recently of horror stories with people pouring their life savings into poker machines.

If it's the life of the Gaming Technologies Association or the lives of ordinary Australians, then I, for one, look forward to your demise.

Paul Wayper, Cook

It is outrageously hypocritical for the Catholic Archbishop of Sydney, Anthony Fisher, to tell the government to keep out of the nation's bedrooms when the Catholic Church has sought to meddle in people's bedrooms for millenniums and not only with respect to its own congregation.

In earlier times, the church was quick to mount self-righteously pious campaigns aimed at criminalising "sinful" sexual behaviour between consenting adults, despite having deliberately turned a blind eye and deaf ear to egregious episodes of sexual abuse by its own.

And, more recently, the church has opposed every social campaign calling for the repeal of criminal sanctions against consensual sexual behaviour.

It's about time the Federal Parliament reconsidered the church's tax-exempt status.

Bruce Taggart, Aranda

The Canberra Times wants to hear from you in short bursts. Email 50 or fewer words to letters.editor@canberratimes.com.au.

THE VOTE AND FAITH

The marriage equality debate seems to have increased the number of letters castigating people of faith for voting "no" on the basis of their beliefs. Not all people of faith are voting "no"; many are voting "yes" – because of their faith. Why it is necessary to belittle someone's faith in order to disagree with their views?

D. J. Taylor, Kambah

OVER IT

Enough already! Weinstein is no Einstein. He's not worth any more ink.

A. Whiddett, Forrest

A GREAT START

Australia's appointment to the United Nations Human Rights Council is to be welcomed. It should give the government the opportunity to take more seriously the human rights concerns of many citizens. The challenge for us now is to hold the government to Julie Bishop's words this week – that Australia is a "transparent and accountable nation".

David Purnell, Florey

FAIR'S FAIR ON SUBSIDIES

If the government is to remove all subsidies for developing renewable energy, it is only fair that they also remove the $4 billion given annually to the coal, oil and gas industries for R&D.

Gerry Gillespie, Queanbeyan, NSW

DUAL THREATS

Rod Holesgrove (Letters, October 16) seems to support Waleed Aly's contention that terrorism is a mere irritant, and that climate change is the true threat. I'd like to see him front up to the survivors of the Bali bombing and 9/11 and see how his rhetoric stands up.

Peter Sesterka, Hawker, ACT

ACT RATES PAIN

Increases in rates in ACT driven by Andrew Barr are far worse than energy cost increases which are bleated about by Labour's Gai Brodtmann. When will federal Labour get with ACT Labour to address the community cost of living?

Gary Petherbridge, Barton

WEEKEND PENALTIES

L. Christie (Letters, October 16) posed a valid question for "small" business owners benefiting from lower weekend wage bills. I would also ask how many who don't now open on Sundays plan to do so in future? Or are Sundays sacrosanct family time for the owners?

Keith Hill, Kaleen

IRRESPONSIBLE MOVE

Re "PM's energy policy to mandate coal, gas use." (October 17, p1). And doctors must hand out a packet of cigarettes with each prescription. With this government nothing would surprise us – except responsible governing.

Rosemary Walters, Palmerston