Ever think of a question you'd love to put to a scientist, but would feel too silly to actually ask it? Well, some of those questions are ones scientists are asking themselves. Herald science reporter Jamie Morton put some of them to New Zealand researchers.
Why do we dream?
Dreams can allow an alternate experience in an adjunct world where the rules and sensations of waking life differ, said Rosie Gibson, a post-doctoral fellow at Massey University's Sleep/Wake Research Centre.
Traditionally, dreams were believed to offer symbolic insight regarding spirituality or unconscious wishes, enabling us to live with a balanced psyche during waking.
Now a body of research into the neuropsychology of dreaming indicates how dreaming facilitates learning and memory consolidation.
During our nightly periods of rapid eye movement (REM) sleep, areas of the brain used for memory, emotion, visualisation and movement are reactivated whilst the parts necessary for physically playing out that activity are disengaged.
This has led to theories regarding dreaming to erase unnecessary information from memory as well as strengthening the important parts.
"The actual dream experience is deemed a by-product of this activity, which the executive area of the brain attempts to piece together into a coherent story on waking from a dream," Gibson says.
"So the process of dreaming is important for waking life with regards to acquiring and retaining information and mentally rehearsing activities, as well as growth and development through a kind of off-line processing."
What's outside the universe?
Nothing travels faster than light, and a light year is the name given by astronomers to the distance light travels in a single year.
So you might guess that the "observable universe" is a sphere with us at the centre, and a radius of 13.8 billion light years – which reflected the time that has elapsed since the Big Bang, the giant explosion that marked the beginning of the universe.
Anything further away was simply too distant to see.
"In fact, since the universe is expanding, distant objects move away from us between them emitting their light and us seeing it," University of Auckland cosmologist Professor Richard Easther said.
To account for this, we could calculate the actual visible universe was about 40 billion light years in radius - or about 80 billion light years across.
Distant observers would see themselves at the centre of their own "observable universe", which only partially overlaps with ours.
Since our universe was roughly homogenous – that is, its average properties are the same at all places – we think those observers should see a similar universe to us.
And this suggested that the answer to the question "What's outside the observable universe?" was simply "more universe".
"But we can't be sure, since we can't see it," Easther said.
"On grander scales, some theories suggest that our own universe is one of a possibly infinite number of universes that forms a multiverse – each with their own Big Bang and perhaps each with their own laws of physics.
"Again, we can't know for sure, but we can try to build the theoretical tools that let us think about these ideas."
Is time travel possible?
Wellington physicist Matt Visser is the world expert on time travel and he has shown it might be possible.
Interestingly, the speed at which we travel into the future is not always the same.
Clocks in satellites run ever so slightly faster compared to those on the ground because they experience a weaker pull of gravity in orbit. Gravity warps time.
What about travel into the past?
Visser has shown that, in theory, gravity could support tunnels or "wormholes" that connect distant parts of the universe.
However, University of Auckland physicist Professor Shaun Hendy said, there was no evidence that there were any wormholes out there and we had no idea how to go about making one.
"But imagine we figured it out," he said.
"It might then be possible to use the wormhole to take short-cuts across the universe."
We might also be able to use it to travel backward in time - although you couldn't use the wormhole to go back to before it was made.
Physicists don't think you could go back to change history though, even if you had a wormhole handy.
"So don't expect your future self to come back to warn you to go easy at the office Christmas party," Hendy said.
"Just take that from me."
Can we predict earthquakes?
This question is one that keeps many seismologists awake at night, but it is doubtful that we will be able to accurately predict earthquakes, at least in the foreseeable future.
Earthquakes begin on faults that are buried at great depths beneath the Earth's surface, often several kilometres or more deep.
This makes it extremely difficult to know how close these faults are to failing in an earthquake, as we cannot accurately monitor the stress on the fault, or detect signs of the beginnings of an earthquake so far below the Earth's surface.
That said, there are new techniques in place that can be used to give people at some distance from an earthquake - usually 50KM or more away - up to a few minutes of warning that an earthquake has occurred and strong shaking is on its way.
These types of Earthquake Early Warning systems do not predict earthquakes, but they can quickly forecast expected shaking after a large earthquake has started.
Such systems are being used in Japan, Mexico, and the western United States.
Although accurate predictions of earthquakes are an extremely difficult goal, seismologists already provide forecasts of how likely an earthquake is to happen over a specified period of time.
These are called "earthquake forecasts", which in many ways are similar to weather forecasts.
Improved estimates of the likelihood of a damaging earthquake in a specific region in the coming years to decades can provide important information for community planning and infrastructure design.
"There are many steps that can be taken to improve our ability to produce more accurate earthquake forecasts," said Dr Laura Wallace, a geodetic scientist at GNS Science.
"These improvements require better understanding of the underlying physics of earthquakes, and better knowledge of the relationship between large earthquakes and other possible precursory events, such as swarms of earthquakes and slow slip events."
How bad might climate change get?
Let's imagine we do nothing to reduce emissions of carbon dioxide and other greenhouse gases.
By 2100, we'd see the globe warm another one, then two, then three, maybe four degrees above where we are now.
We'd lock in the melting of most of the Antarctic and Greenland ice sheets - plus all of the world's glaciers - so sea levels would rise by around two metres by 2100, with another 60 metres over coming centuries, Victoria University climate scientist Professor James Renwick said.
Many places where heat and humidity are already a problem would become uninhabitable, and heatwaves beyond anything observed in the past would become commonplace everywhere.
Extremes of drought and heavy rain would increase dramatically.
"All of which would lead to mass displacement, water availability problems, and food shortages across the globe," Renwick said.
"Which almost inevitably lead to social breakdown and mass violence - think the situation in Syria and north Africa spreading out around the world. Billions of lives would be at risk."
Will bacteria beat us in the end?
When it comes to mega-problems, anti-microbial resistance is right up there with climate change.
Health authorities are warning that by 2050, 10 million people could be dying every year from bugs that our antibiotics are holding back at the moment.
And there have been many worrying cases already: just this year, New Zealand researchers warned a bacterium behind a common sexually transmitted infection had now grown resistant to many drugs.
It threw up the question: would we soon no longer be able to out-run these nasties?
"That's such a tough question, because not all bacteria or antibiotics are created equally," said Associate Professor Siouxsie Wiles, a University of Auckland microbiologist and author of the book Antibiotic Resistance: The End of Modern Medicine?.
"But we've been doing pretty well up till this current crisis, so I'd like to think the answer was yes if we changed our behaviour in a bunch of different ways."
Firstly, we needed to lower our rates of infectious diseases – the fewer people exposed to and suffering from these diseases, the fewer antibiotics needed.
Secondly, the world needed to heavily invest globally in R&D to develop new antibiotics that acted in different ways.
"We're in our current predicament because the pharmaceutical industry largely pulled out of antibiotic R&D several years ago," Wiles said.
"This means that steady stream of new antibiotics being developed has dried up, while at the same time the antibiotics we do have are becoming less and less effective because of bacterial resistance."
And lastly, we needed to carefully use the antibiotics we did have.
"We'll never overcome bacterial resistance – it's a natural phenomenon that happens because lots of bacteria grow very fast and reach massive numbers – in their millions to trillions."
Within any population of bacteria would be resistant mutants that emerged by sheer chance.
"They then have an advantage when antibiotics are used, whether that's in humans, animals, plants, aquaculture, or when they enter the environment through their manufacturing process," Wiles said.
"If we can tightly control how antibiotics are manufactured and used then we can try and minimise the exposure of bacteria to them.
"But that's a hard thing to do because it will take a global effort, and if our efforts to halt climate change are anything to go by, then it's not clear if this is going to be possible."
Will a machine really steal your job?
Many jobs could be lost and changed as a result of "robot redundancy" in the coming decades.
However, there is a wide debate around if this will happen, how long this will take, and how many jobs will be impacted.
Estimates range from nine per cent to over 50 per cent.
At present, fewer than five per cent of jobs can be done entirely through automation.
However, and more importantly, parts of one's job can be automated – and this is possible when a job is made up of highly repetitive and less complex tasks.
"When parts of the job are automated, you may see a net loss of employees needed overall, or, that nature of the job simply changes to include more social and creative aspects," said Dr David Brougham, of Massey University's School of Management.
As such, more, and different jobs will be created as a result of automation.
We will also invent new experiences, products and services which will create new jobs.
"Employees should constantly assess technology that could do parts of their job, and consider what this will mean for their profession. It would be wise to plan for a possible shift in the labour market as a result of automation and other technological disruptions," Brougham said.
"In addition, technology and market pressure could continue to push away traditional nine-to-five work, as the casualisation of labour may continue to make work more temporary and unstable."
Will self-driving cars become the norm?
As the legendary science fiction writer William Gibson once said, "the future is already here – it's just not evenly distributed".
The immediate future of self-driving cars will be fleets of driverless taxis, shuttles and buses that people can hail like an Uber.
In select areas of the US, services like these are already available.
The latest and greatest example of this is Waymo One, a commercial driverless ride hailing service launched in Phoenix last week by the Google/Alphabet subsidiary.
In the rest of the world, enthusiasts must buy an expensive semi driverless vehicle such as the Tesla Model S, which still requires constant human supervision in case it makes a mistake.
It is hoped that driverless vehicles will bring enormous benefits, such as increased safety, reduced congestion, cheaper mobility and – for those countries that participate in their early development and deployment – high paying jobs and economic growth.
But Kiwis shouldn't expect to see this happen here any time soon.
"In New Zealand we are unlikely to see widespread driverless fleets within the next 20 years," said Michael Cameron, author of the new Law Foundation book Realising the Potential of Driverless Vehicles.
"If we want faster uptake then we need to adopt the proactive approach of US States such as Arizona."
How long will humans be able to live?
Immortality is an age-old quest of humanity but, until the arrival of scientifically-based medical research approaches, we've made little progress.
Advances in medical research, new wonder drugs, super-effective vaccines and amazing surgical methods have made progress towards this goal.
As a result, the average lifespan in New Zealand has increased from 71 years to 82 years since 1970.
Despite this, we still face the fact that the human body has a finite lifespan - and as time passes we start to lose essential functional capability in our tissues and organs.
The main reason for this is that the 70 trillion or so cells that make up our body suffer constant wear and tear, which eventually results in them becoming unable to carry out their designated function or to actually dying.
"Our body is constantly trying to repair and renew these cells, and it is in itself amazing that we are able to maintain such a complex system of so many trillion cells, in a functional form, for up to 100 year or more," said Professor Peter Shepherd, of the University of Auckland's Maurice Wilkins Centre.
"This process, however, eventually becomes overwhelmed - in part because mutations arise in the DNA that is so essential for controlling how our cells work."
It was also due to the cells and tissue accumulating junk-like sugar modifications, fats and cholesterol, and other factors that physically stopped them doing their job properly.
Many researchers around the globe were trying to understand how we could slow the ageing process.
"What we know is that ageing happens slower in some people than others due to differences in our genetic makeup and, of particular relevance at this time of year, the process can be slowed by avoiding things that damage our cells, such as excess sunlight and avoiding unhealthy foods and things like smoking," Shepherd said.
"The question people ask is whether we can really slow down this process significantly in healthy people in a way that could allow people to truly extend our current lifespan potential.
"Some evidence has suggested ultra-low calorie diets might slow ageing and some studies have suggested certain drugs or hormones might slightly increase lifespan."
Overall though, these at best provided small effects and there was no evidence yet that any of these provided a real solution to ageing.
So what was on the near to medium term horizon that might help?
Trying to control 70 trillion existing cells was particularly challenging - but what if we could replace tissues with completely new ones?
This was the promise offered by a new technology called induced pluripotent stem cell technology, or IPS cells.
"There has been a lot of controversy over stem cells in recent years and there are many clinics offering stem cell treatments of dubious clinical benefit - but IPS cells appear to offer more hope of being useful, if we can understand how to use them correctly," Shepherd said.
"IPS cells are a special type of stem cell that can not only make new blood cells but theoretically can make any tissue in the body."
The very recent discovery that we could make IPS cells from most people by a relatively simple genetic reprogramming of existing adult cells won Professor Shinya Yamanaka the Nobel Prize in 2012.
Amazingly, this even worked from cells from adults so effectively showing that the age of a cell can be reset to its original starting point.
Shepherd's lab was looking at whether we could use these to make replacement insulin-producing cells to help treat diabetes.
Elsewhere in the world, a number of clinical trials were underway and benefits – such as slowing macular degeneration - were starting to be reported.
"While there are still many issues to be overcome, this investment in long term scientific research is paying off and has resulted in a huge leap in our understanding of the incredibly complex processes controlling how we age," Shepherd said.
"While there is still no elixir of immortality, these recent advances in research once again show how science continues to make major contributions to extending how long and how well we humans can live."
Can we kill every last possum, stoat and rat?
It only seems like yesterday that Sir John Key stood at Zealandia in Wellington and announced that New Zealand was aiming for a "moon shot": to be free of every last rat, stoat and possum by 2050.
Two and a half years on, how is New Zealand tracking towards the goal?
All over the country, in towns and cities, in the backcountry and on marae, communities have risen to the predator-free challenge, said Dr Andrea Byrom, a Manaaki Whenua – Landcare Research ecologist and director of the Biological Heritage National Science Challenge.
"There was something magic about it, and it captured hearts and minds," she said.
"Community noticeboards are covered with the latest pest-trapping get-togethers and offers of a free trap for your back yard. Kids are getting into it in a big way."
The organisation created by the previous government in 2016, Predator-Free 2050 Limited, has supported five landscape-scale, community- and council-led predator control areas, assisting public-private partnerships across tens of thousands of hectares
The new government doubled down on funding for the movement through the Department of Conservation.
"It's great to see that support for such an ambitious goal is cross-government – that's a vital ingredient if New Zealand is going to pull it off."
On the research front, significant progress has been made on improving the tools we already have to fight predators.
"These discoveries are often in unexpected places – who knew that the statistical process of visualising optimal placement of traps in your GIS could be so fascinating?" Byrom said.
"Yet using GIS to visualise the optimal placement of traps and bait stations – from the comfort of one's computer – has become one important avenue for researchers to investigate before the boots hit the ground."
Another approach called Zero Invasive Predators had a goal of "remove and defend" across large areas.
Species-specific toxins – or baits that targeted only rats, for example, with no harm to other species – were probably the next game-changer over the horizon, and might only be a couple of years away.
"And while we'd all like to think that there might eventually be a magic bullet in the form of gene-edited infertile rats or stoats, we're a decade or more – and an important public discussion – away from deploying such a tool," Byrom said.
What was it about the movement that appealed to Kiwis?
It wasn't actually even about killing predators, Byrom said.
In fact, media coverage this year has provided some thought-provoking pieces about "killing for conservation".
"On this point, the public are smart. New Zealanders seem to have accepted the idea that to save our taonga – kiwi, kaka, kokako, kereru, weta, jewelled geckos – we need to take action to preserve biodiversity, forever."