Monday Wormholes

I've been forgetting to browse the arXiv abstracts for odd physics lately, but here are a few recent ones that have caught my attention:

1.  Can extra dimensional effects allow wormholes without exotic matter?

We explore the existence of Lorentzian wormholes in the context of an effective on-brane, scalar-tensor theory of gravity. In such theories, the timelike convergence condition, which is always violated for wormholes, has contributions, via the field equations,from on-brane matter as well as from an effective geometric stress energy generated by a bulk-induced radion field. It is shown that, for a class of wormholes, the required on-brane matter, as seen by an on-brane observer in the Jordan frame, is not exotic and does not violate the Weak Energy Condition. The presence of the effective geometric stress energy in addition to on-brane matter, is largely responsible for creating this intriguing possibility. Thus, if such wormholes are ever found to exist in the Universe, they would clearly provide pointers towards the existence of a warped extra dimension as proposed in the two-brane model of Randall and Sundrum.

2. Possible existence of wormholes in the central regions of halos 

An earlier study [Rahaman et al. (2014) & Kuhfittig (2014)] has demonstrated the possible existence of wormholes in the outer regions of the galactic halo, based on the Navarro-Frenk-White (NFW) density profile. This paper uses the Universal Rotation Curve (URC) dark matter model to obtain analogous results for the central parts of the halo. This result is an important compliment to the earlier result, thereby confirming the possible existence of wormholes in most of the spiral galaxies. 

3. Analytic self-gravitating Skyrmions, cosmological bounces and wormholes 

We present a self-gravitating Skyrmion, an analytic and globally regular solution of the Einstein- Skyrme system in presence of a cosmological constant with winding number w = 1. The static spacetime metric is the direct product R x S3 and the Skyrmion is the self-gravitating generalization of the static hedgehog solution of Manton and Ruback with unit topological charge. This solution can be promoted to a dynamical one in which the spacetime is a cosmology of the Bianchi type-IX with time-dependent scale and squashing coefficients. Remarkably, the Skyrme equations are still identically satisfied for all values of these parameters. Thus, the complete set of field equations for the Einstein-Skyrme-Lambda system in the topological sector reduces to a pair of coupled, autonomous, nonlinear differential equations for the scale factor and a squashing coefficient. These equations admit analytic bouncing cosmological solutions in which the universe contracts to a mini- mum non-vanishing size, and then expands. A non-trivial byproduct of this solution is that a minor modification of the construction gives rise to a family of stationary, regular configurations in General Relativity with negative cosmological constant supported by an SU(2) nonlinear sigma model. These solutions represent traversable wormholes with NUT parameter in which the only "exotic matter" required for their construction is a negative cosmological constant. 

 Thinking about wormholes seems to be very big in theoretic physics at the moment.

The Leyonhjelm Effect?

Gee, I dunno.  Perhaps the Senator for Guns, Tobacco, Infrasound and Things That Annoy Him But Are Not Within Commonwealth Control Anyway (David Leyonhjelm) should ease up on the frequent media appearances and attention seeking tactics.

Because it doesn't seem to be helping his party's candidates, if this weekend's Canning by-election is any guide. Despite being number two on the ballot paper, at the time of writing, the LDP has polled about 5 times less than the Palmer United Party or Australian Christians;  under half of the votes of the Animal Justice Party; about 10 times less than the Greens; and even less than the Pirate Party.

Maybe the more he's exposed, the less his party's vote?   Embarrassing.

Microbes to the rescue

Feeding the world with plant microbiomes | The Saturday Paper

A short but quite interesting report here on how research into newly discovered plant microbiomes may help increase agricultural output.  For example:

Meanwhile, other bacteria can boost agricultural output. Pseudomonas,
which live in the soil around a plant, make hormones goading roots to
grow. In one trial, inoculating wheat with a cocktail of these bugs over
two years increased yields by more than 30 per cent. Another bacteria, Burkholderia,
has been shown to ramp up rice production. O’Sullivan wants to use
these plant steroids to inspire crops to grow during drought. “There is a
lot of potential here,” she says.

Is it too much to hope for the start of an anti-pandering movement?

Donald Trump doesn’t correct birthers, but how is that any worse than the GOP’s standard climate change pandering?

Yes, this is exactly what I want the the sensible Right in Australia (hopefully, in the form of Malcolm Turnbull) to do - to start telling those on their side the truth about how wrong they are (and how stupid, in most cases) on matters such as climate change, and certain economic tropes (such as "reducing taxes always works"; "Keynesian economics is a crock".)

Update:  here's Krugman's acerbic take on the second GOP debate. 

Awesome hyprocrisy of the Abbott mourners

I was expecting one eyed amnesia to some extent from the Right wing commentariat  (a word, incidentally, that I've just realised I've been misspelling frequently - probably because even the correct spelling is not in my brower's dictionary), but the completely hypocritical "a good man undone by the media and the rabid hatred of the Left" mourning of Abbott from the likes of Bolt and his dunderhead followers is still a stunning example of how ridiculous they have become.  Especially in light of the white hot hatred and rumour mongering they encouraged over Gillard - up to and including cheering a royal commission and police investigation looking into whether she got some free work done on her house 22 years ago.

There simply has been no media treatment of a Prime Minister as openly disrespectful and bitterly personal as that by the Right wing schlock jocks and Murdoch tabloid press towards Gillard. 

It's as absurd to argue otherwise as it is to deny climate change is real and deserves a strong political response.  [You can take the "Oh, wait a minute..."  joke as too easy.]

Dangerous drinking

It's a little hard to credit that the person handing over this drink did not realise it was dangerous to consume:

It was an 18th-birthday celebration - and the birthday girl was given a free cocktail to celebrate.

But just seconds after Gaby Scanlon, now 20, drank the Nitro-Jägermeister shot, smoke started billowing from her nose and mouth.

"Immediately she was taken violently ill, retching and vomiting and smoking from her nose and mouth," prosecutor Barry Berlin told an English court.

The liquid nitrogen in the drink, which was used to create a smoking effect, pierced her stomach and killed internal tissue.

The court heard that Ms Scanlon experienced "agonising pain" and required surgery to have her stomach removed and her oesophagus connected to her small bowel...

The bar's director Andrew Dunn had seen cocktails containing liquid nitrogen being served a hotel in London and decided to introduce a range at his newly opened bistro, the court heard.

I think the topic for discussion with the children over dinner this weekend will be "Using your own common sense when at a bar or nightclub". 

Marr on Abbott

Vale, Tony Abbott – both a unique man and a unique failure | David Marr | Australia news | The Guardian

It may be a bit flowery in the Marr fashion, but I don't think he treats Abbott unfairly.

Their base is nuts 'cos they're led by nuts

I've been enjoying the Trump angst sweeping through Republican establishment circles, who can't understand how their "base" can be applauding some politically ridiculous lines coming out of an egotistical, shallow, dill.

But now it's producing something even better - the potential start of a realisation that the base is nuts because the entire party has been led by anti-science dills, more interested in ideology than evidence, for the last decade or so.

As Jonathan Chait writes in his summary entitled At Second Presidential Debate, Republicans Try to Out-Crazy Trump, and Succeed:

The most revealing pair of exchanges came at the end. First, Jake Tapper asked Rubio about former Reagan secretary of State George Shultz’s argument that it would be prudent to take out an insurance policy against the effects of carbon emissions in case scientists are right. The question was designed to cut off every possible escape route. Tapper did not ask Rubio to accept climate science, merely the possibility that it might not be wrong. Nor did he ask him to endorse a specific program. Rubio swatted away the premise of the question, insisting, “We’re not going to destroy our economy.” It was telling that Rubio defined literally any policy response to the theory of anthropogenic global warming as economy-destroying.

Tapper then asked Trump about his statements linking vaccine use to autism, a dangerous conspiracy theory that has been conclusively debunked. Trump cited anecdotal evidence to support his crackpot beliefs. Worse, the two doctors on the stage, Ben Carson and Rand Paul, had chances to correct Trump, and both instead gave him tepid support. It is depressing that a presidential field with two doctors cannot even produce sensible views on medicine, let alone anything else. The party’s decades-long flight from empiricism and reason shows no sign of abating. Alas, from Trump to Rubio to Carly Fiorina, it is filled with talented demagogues well suited to pitch America on nonsense.

What a hide!

Spotted in Gulf News:

Green leafy goodness

Take that kale! Watercress is number one powerhouse vegetable - ABC News (Australian Broadcasting Corporation)

Avert your eyes, Jason Soon - an article all about the good things in green leafy vegetables.

I see that kale is said not to be that great a "superfood" anyway.  I'm relieved to hear it - there are few vegetables I actually ask my wife not to buy, but kale is one of them.   Its tough, rough leaves have never impressed me in the slightest - in fact, I positively dislike it - and I always suspected its popularity was a passing fad.

This report talks up watercress, which is one of my favourite bases for a salad.  It can be bought cheaply from some street markets around Brisbane, at some times of the year, but seems to rarely appear in mainstream fruit and vegetable shops.   There should be more of it.

Maybe cold water is the key?

BBC - Future - The secrets of living to 200 years old

I didn't know bowhead whales are believed to live somewhere between 150 and 210 years.

Update:  I just remembered to check again on the lifespan of the orange roughy (what a great bit of PR it was to rename it from "slimehead") that lives in the deep, cold ocean - 150 years!

Disturbing

Why drivers in China intentionally kill the pedestrians they hit: China’s laws have encouraged the hit to kill phenomenon.

I meant to earlier link to this disturbing article about Chinese society and the (to say the least) problematic way they deal with compensation.

I can only assume there is no compulsory third party insurance as there is Australia (and, I presume, nearly all Western countries?)   Certainly shows the value of it.  

Real men used to cry

Is there anything wrong with men who cry? – Sandra Newman – Aeon

A fun article here looking at the way it seems there used to be no shame in men crying, in most societies at least (Scandinavia excepted, it seems.)   But then something changed, and the reasons proposed are curious:

The most obvious possibility is that this shift is the result of changes
that took place as we moved from a feudal, agrarian society to one that
was urban and industrial. In the Middle Ages, most people spent their
lives among those they had known since birth. A typical village had only
50-300 inhabitants, most of them related by blood or marriage; a
situation like an extended family stuck in an eternal reunion in the
middle of nowhere. Medieval courts were also environments of extreme
intimacy, where courtiers spent entire days in each other’s company,
year after year. Kings routinely conducted business from their beds, at
the foot of which their favourite servants slept at night. We can see
this familiarity also in odd details of royal life, such as the nobleman
in the courts of many European kings whose coveted privilege it was to
assist the king in defecation.

But from the 18th through the 20th centuries, the population became
increasingly urbanised; soon, people were living in the midst of
thousands of strangers. Furthermore, changes in the economy required men
to work together in factories and offices where emotional expression
and even private conversation were discouraged as time-wasting. As Tom
Lutz writes in Crying: The Natural and Cultural History of Tears
(1999), factory managers deliberately trained their workers to suppress
emotion with the aim of boosting productivity: ‘You don’t want emotions
interfering with the smooth running of things.’

Hard to believe...

...that Ridley Scott has made a good science fiction film again.   But it appears he has.  

I guess I'll miss doing things like this....

Standard hypocrisy from a politician, I guess

I can't say I recall Tony Abbott ever complaining about the media's hand in publishing anonymous and self serving leaks when they were doing it in the Rudd/Gillard years.  Did he not use them as the basis for attack in Parliament?

But now, suffering the same fate, he can see the problem...

Update:  oh, and then there is this point too -

I had no idea...

Saudi Arabia squandered its groundwater and agriculture collapsed. California, take note. - Vox

I was just speculating the other day that the Arabian peninsula countries must grow next to nothing of the food they need.  I had no idea that Saudia Arabia in fact had gone on a ridiculous exercise in my lifetime:

Over at Reveal News, Nathan Halverson has a terrific piece
on how Saudi Arabia squandered its groundwater supplies in just a few
short decades. Back in the 1970s, the government allowed landowners to
dig as many wells as they desired, in order to transform the desert into
lush farmland. An agricultural boom followed, and Saudi Arabia
improbably became the world's sixth-largest exporter of wheat.

"By the 1990s, farmers were pumping an average of 5 trillion gallons a
year," Halverson writes. "At that rate, it would take just 25 years to
completely drain Lake Erie." The problem was that Saudi Arabia doesn't
get nearly enough annual rainfall to replace those withdrawals. Its
aquifers had built up over tens of thousands of years and were now being
drained all at once.

Not surprisingly, the party didn't last. By the 2000s, the aquifers
had become dangerously depleted. Wells dried up. Oases that had
persisted since biblical times were now gone. The country will need to
build costly desalination plants for drinking water. Most important,
Saudi Arabia's agricultural output declined sharply, with the amount of
farmland now less than half of what it was in the 1990s. In an attempt
to conserve what water remains, the country has announced that the 2016 wheat harvest will be its last. An entire industry, gone.

 Why do I get the feeling that libertarian types at the time would have been ridiculing environmentalist's warnings that this was a bad idea.  Let the market decide, etc.

Very witty

A few more post Abbott observations...

*  I am somewhat in agreement with those saying that Abbott not making a statement to the media yet makes it look like he's not "manning up" to his loss, in contrast to Gillard.   But is that too sexist in its own way? :)  Does it mean he is white hot angry about it all?   Would make me laugh if he is.   It would be all very karmic in it's own way, no?

*  It must be hurting the egos of Bolt and Jones that they can't convince their side of politics to follow their direction on leadership.   Particularly when they were instrumental on getting Abbott the leadership based on their promotion of climate change denial, which was always utterly foolish.  The tide's turning, guys.   Are you capable of admitting error?

[Update:  I had forgotten this:

Just over a year ago, Jones, the Sydney broadcaster, told Malcolm Turnbull he “had no hope of ever being the leader, you have got to get that into your head”.]

*  I like Turnbull - intelligent, articulate, humane - but he has a very difficult job dealing with those in his Party (and the Nationals) poisoned by too much influence from the American Right (and the likes of the IPA.)  I would like him to be ruthless in his approach to climate denialists in the party - tell them straight up that they have always been wrong and have been conned by populist fools in the media, and ideological driven economists who don't understand a thing about what actual science and scientific bodies all agree on. Someone has to tell them someday, it will do them good.

[Update:  even better, Turnbull could go on Bolt's show and tell him the same thing to his face - that he's been completed fooled and conned by non-scientists and it's about time he grew up and recognised facts.]

*  Has Steve Kates had to up his blood pressure medication yet?   This nuttily obsessed economist hates Turnbull irrationally and with the same vigour with which he thinks Obama and "damaged women" are causing the end of civilisation:

Malcolm is almost the perfect reflection of media opinion. He is like blotting paper, soaking up every conventional opinion without any actual apparent ability to think for himself. He is a non-entity in the Barack Obama mould, filled with vapid thoughts and a high opinion of his own abilities and intellect that is never at any stage reflected in anything he says or any action he takes.

He apparently won on the promise that he would not change any of the more contentious compromises Abbott had been able to meld, which is to say, he won promising not to do the very things that he wants to do, and which the media will look to him to do. The Great Communicator he is not. He is a shallow and pompous blowhard.

 *  I'll be livid if a few, persistent and potentially damaging rumours about Abbott's private life are only now exposed as true by journalists.

Bird love

Birds reveal the evolutionary importance of love

Sort of a cute study here.