The Universe contains an estimated two trillion galaxies, and perhaps one billion trillion stars. Could intelligent life be out there? Photo / 123RF
Is breakfast the most important meal? Are we alone in the Universe? Can we live on four hours' sleep? Science reporter Jamie Morton asks the experts.
Here's a scary thought: It's possible the next pandemic could have already begun somewhere.
Scientists estimate that around five new diseases emerge in people every year and any of those has the potential to spread further.
That means if a novel infection has a long incubation period, like HIV, it may already be spreading without us knowing.
But equally another pandemic might be years away.
One problem for scientists is that they're often unable to make good predictions when chance plays a big role in the emergence of new infections.
Most novel emerging infections, and particularly viruses, come from wildlife, so these chance events include someone somewhere coming in contact with an infected wild animal, whether directly through touch or indirectly, including being bitten by a mosquito.
"What we do know is that increasing numbers of people, especially in biodiverse countries, are moving into areas where there are diverse wildlife infected with their own infections that don't currently circulate among us," Massey University infectious disease expert Professor David Hayman said.
"So we are increasing the likelihood of these events and infections emerging."
Trading in wildlife was also increasing, and this means exposure to new infections.
So too did increased livestock farming in these areas, because domesticated animals were also at high densities and may be exposed to new infections, and could act as a bridge between wildlife and us.
These infections, often viruses, could amplify in our domestic animal populations increasing the chances of us becoming infected.
"There have been huge advances in our wellbeing, but the increased population densities of people and our highly connected world mean that once infections of people do occur, infections can spread around the world very rapidly, as we have seen with the Sars-CoV-2 virus that causes Covid-19.
"So, all the conditions that lead to HIV and Covid-19 remain.
"This sounds quite a negative perspective, but the good news is that if we can stop the encroachment of people and livestock in areas which fewer people have previously lived, we can likely reduce habitat destruction, stop the biodiversity crisis and help mitigate climate change, as well as reduce the chances of new outbreaks of infectious diseases."
The short answer is yes - but it's more likely that your life will be shorter with health problems and less fulfilling.
It's currently recommended that adults get seven to nine hours' sleep each night to function at their best and stay well.
Some people may only need six hours' sleep and some may need 10, but sleep durations outside this range are not recommended.
Very few people are natural short sleepers and function well on less sleep than recommended, and what leads to natural short sleep is not well understood.
"The research clearly shows that short sleep increases a person's chances of developing health conditions like high blood pressure, obesity, diabetes, heart disease and mental health disorder," explained Dr Karyn O'Keeffe, of Massey University's Sleep/Wake Centre.
"There is emerging evidence that short sleep may contribute to the development of dementia. Short sleep is also associated with early death."
On a daily basis, when we don't get enough sleep, our quality of life is reduced.
We are less productive at work, less creative in our problem solving, have poorer concentration and memory, and are poorer communicators.
Our moods are more up and down, and we don't react as appropriately in challenging situations. Our ability to carry out safety-critical tasks, like driving, is reduced, making us a danger to ourselves and others around us.
"Our ability to assess how well we are functioning changes when miss out on sleep for a few days in a row," O'Keeffe said.
At first, we notice that we are no longer functioning well, but after a few days, we lose our ability to notice how impaired we are, even though our functioning continues to worsen.
"This means it's possible to get by on short sleep but not be aware of its negative impact."
Gene-editing is a powerful technology that can be used to fight cancer in lots of different ways.
In fact, it's already curing certain cancers in some patients.
That said: cancer is a broad and complex family of diseases and no two are alike, given the same type of cancer might even behave differently in two different cancer patients.
So, even with the best science, a single therapy is unlikely to be able to treat every cancer.
Currently, a particular type of gene-editing is being used quite successfully to treat some blood cancers.
T-cells from our immune system are edited with a new "cancer-detecting claw" - either a T cell receptor (TCR) or a chimeric antigen receptor (CAR) - which allows them to catch and destroy cancer cells.
"This kind of therapy works well because immune cells travel around our bodies in the blood and lymphatics making it easy for them to find and destroy blood cancer cells, once they have the right detectors," said Dr Rachel Peret, of Wellington-based Malaghan Institute of Medical Research.
Some CAR-T cell therapies have already been approved to treat certain leukaemias and lymphomas around the world, and a new clinical trial is underway here in New Zealand.
"Unfortunately current gene-edited immune cell therapies work in some patients but not others, and we don't really understand why," Peret said.
"They also don't work nearly as well in solid tumours like pancreatic and lung cancer as they do in the blood. This means that we need to keep testing more new therapies and combining gene-editing with other therapies."
Another way that gene-editing can be used to beat cancer is to fix genes inside the body that have mutated and gone hay-wire, causing cancer to develop.
Very precise DNA-cutting scissors called CRISPR have been discovered, which allow scientists to cut-out a mutated piece of DNA and to replace it with a perfect new version that doesn't have mutations.
This could be a way to treat existing cancers, or to treat people preventatively, like a vaccine, to stop cancer from ever happening - although this technology remains strictly regulated in New Zealand.
"Researchers continue to investigate these questions, and every year new advances are made," Peret said.
"What was science fiction only yesterday can become real science today and many scientists believe that in the next decade we will develop all the tools needed to beat cancer completely. "
We've long been told our first meal of the day is the one we need the most - but does that stack up with the science?
When the role of breakfast in weight management was reviewed last year, the quality of the research wasn't good enough to draw conclusions.
Dietician Helen Gibbs said that, while everyone had an opinion on breakfast, there were some solid points people could consider when thinking about whether to have it or skip it.
If we felt hungry when we wake, she said, we should eat, as it was a sign our bodies were asking for food.
"If you miss breakfast, what are you likely to eat when you get to eat next?
"Arriving hungry at morning tea is okay if you can make choices to nourish you. Many morning tea choices are high in saturated fat, salt and sugar. You could take breakfast food to eat at morning tea."
As breakfast choices typically provided fibre, we also had to think about where we were going to source this over the rest of the day.
Dieticians recommended between 25g and 30g of fibre each day for adults - and many people received less than half of that.
"If you are missing breakfast you need whole grain and high-fibre options later in the day," she said, noting those options should include more than 6g fibre per 100g.
"If you are uncertain what to eat and when, speak with the nutrition professionals - dieticians."
Ever wonder if we really are the brainiest creatures on Earth?
"One answer to that question is, based on our general measures of intelligence - how we go about doing and thinking about things - is yes, absolutely," said University of Auckland biologist Associate Professor Alex Taylor.
"When it comes to reasoning and social intelligence, we seem spectacularly smart - but there are a couple of massive caveats.
"One is obviously about how we measure intelligence. If there was a test based on sonar, dolphins would be the ones that'd do the best."
It's also worth noting that bottlenose dolphin brains are comparable with our brain when differences in body mass are factored in.
Because human intelligence was largely based on visual modalities, we couldn't begin to imagine what intelligence based on sonar or smell might look like.
"There are some tests where humans don't do as well as some animals. For instance, there's one test on self-control and patience. Humans are great at it when it involves money - but if you use food, then suddenly animals do better than the humans.
"So it's important to realise that we're measuring everything through the lens of what we think is smart, and it's a fairly biased way of testing."
Another big limitation was that we no longer had our closest relatives around to compare ourselves against.
"Neanderthals actually had a larger relative brain size than humans do. Recently it's been suggested some amazing cave paintings in Europe may well have been created by Neanderthals, because they appear to have been present before humans arrived there.
"The fact that our closest relatives have gone extinct puts us in this rather comfortable position where we can say, hey, we look like we're the smartest animals without realising our closest relatives have disappeared or passed on.
"We've put the game on an uneven footing because we're not asking what is smart in an objective way, we're asking what is the most 'human smart' - and surprise, surprise, the answer you get back is human."
It's been one of the most enduring questions of science - and in the SETI Institute (Search for Extraterrestrial Intelligence), the world has a major effort trying to find an answer.
So far, all that's turned up is the odd quick-fire radio signal, all of which can be explained by glitches in detection equipment, local electronic interference, or signals from Earth satellites.
The possibility is still real - but whether we ever get to solve the mystery is another question.
Despite leaps in science that have allowed us to discover thousands of planets orbiting other stars - with a significant number of them in so-called "habitable zones" - the Universe is a vast space.
The observable Universe is estimated to be about 93 billion light years in diameter - our Solar System is one light day across - and could pack about two trillion galaxies, and perhaps one billion trillion stars.
"There's nothing that seems particularly special about the sun or the Earth, or the conditions that gave rise to the origin of life on Earth itself - so it's very likely that process will repeat itself in other places in the Universe," University of Auckland cosmologist and astronomer Professor Richard Easther said.
"But it may still be that intelligent life like us is rare - in the sense that we've only got one good example of that."
That said, modern human beings have only been around for tens of thousands of years, while the Earth has existed for some 4.5 billion years.
"So our existence on the planet as an intelligent species is less than one ten thousandth of that time, so it may be that, even if you have places where life arises, that takes a long time, or it's simply unlikely that complex and intelligent life will ever appear.
"Even if life is common in the universe, it might just mean that intelligent life is unusual - but not unique."
Even in 2021, life on Mars might still be confined to the refrain of a David Bowie song - but that's not to say the prospect of human settlement on the red planet isn't being taken seriously.
Space agencies like Nasa and ESA - as well as private companies like Lockheed Martin, Boeing and Elon Musk's SpaceX - have committed to researching the concept.
The US has plans to send humans to Mars at some point in the 2030s, with Nasa-funded engineers studying ways to build potential human habitats there by producing bricks from pressurised Martian soil.
One private effort - Mars One, co-founded by Dutch entrepreneur Bas Lansdorp - touted itself as the company that would be the first to send humans and recruited candidates for a colony from around the world.
After raising millions of dollars, it went bankrupt last year, being widely panned as a scam that was hardly possible to begin with.
"But I think it's very likely that we will [live on Mars] and it seems that the resources needed to do it will be deployed by governments or wealthy individuals - Elon Musk has made it clear it's an aspiration of his," Easther said.
"From a technical point of view, we've seen real advances in rocketry and that's going to change the way we get access to near-Earth and also deep space."
Perhaps the larger question was, why would anyone want to live there?
If your body was laid bare to the planet's surface, the vacuum of space would boil every fluid in it, then freeze-dry your remains.
Away from the shelter of the ozone layer, the intense sun's UV radiation would fry any exposed skin.
With Antarctic temperatures, no water, little oxygen and gravity, and deadly amounts of carbon dioxide, human life on Mars would be impossible without one of the most elaborate life-support systems designed.
"The biggest challenge, I think, would be in creating a stable and healthy society," Easther said.
"And when you're isolated that much from the rest of humanity, that'd be a much bigger feat than we might realise."
In a lot of ways, it can't.
Carbon dioxide stays in the atmosphere for centuries and a fraction of our emissions to date will still be in the air in 1000 years.
So, we have to live with a warmer climate, higher sea levels, and more intense extremes for a long time into the future.
Climate change commentators have often pointed to the potential to slow or reduce global warming through what's known as geo-engineering.
Some proposals have explored cooling the Earth's surface by injecting reflective particles into the upper atmosphere to scatter and reflect sunlight back to space.
Others involve seeding the oceans with iron to stimulate large-scale phytoplankton blooms, thereby drawing down carbon dioxide out of the atmosphere through photosynthesis.
While such methods could work in principle, many climate scientists oppose undertaking geoengineering until we have a much better understanding of the possible side effects, along with unresolved legal and ethical issues.
One position paper by the American Meteorological Society stated manipulating the Earth system has "considerable potential to trigger adverse and unpredictable consequences".
What we can - and need to - do is to stop the change, and reduce the impacts, Victoria University climate scientist Professor James Renwick said.
"If all emissions of greenhouse gases were to stop today, the globe would warm only a little more, perhaps a couple of tenths of a degree," he said.
"Sea level rise would continue for centuries, but at a much reduced rate compared to what would happen if we don't shut off our emissions."
As a total of 50cm of sea level rise is much more manageable than 5m, or even 1m, stopping emissions now or very soon would avoid some of the worst consequences.
"We could preserve at least a fraction of tropical coral reefs, we could avert the die-off of the Amazon rainforest and the irreversible melting of the West Antarctic ice sheet," Renwick said.
"That's why this decade is so important – if we can get on a rapid downward path with emissions, especially carbon dioxide, we can steer away from truly catastrophic consequences.
"But, we are already living in a changed climate, and that really is the 'new normal', for centuries to come."
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