Society and culture can change beyond recognition in a lifetime—people with criminal convictions for homosexuality are today seeing gay marriage become legal. A bunch of you are reading this on a multifunctional device that would outperform any supercomputer from 20 years ago, and when you’re finished, you’ll put it in your pocket.

The great physicist Niels Bohr is said to have written, “Prediction is very difficult, especially about the future.” As correct as that may be, the world will definitely evolve in the next few decades, and we’ve got a good idea just how some of those changes will play out.

10 A Cash-Free Economy



Cash has had a long history (going through some odd iterations before we got it to the coins and paper we know today). Yet its importance has faded dramatically since this whole computer thing took off. You can now use your smart phone to pay at a vending machine, and cash is looking increasingly archaic and cumbersome.

The cost of maintaining hard currency is up to 1.5 percent of a country’s GDP. In 2008, the US spent $848 million minting coins and used tens of thousands of tons of metal in the process. Counterfeiting (and the law enforcement to combat it) makes a dent, and resources need to go towards moving and guarding money. Criminals and tax evaders enjoy anonymity thanks to cash. In total, maintaining cash costs the US economy $200 billion, more than the UK spends on healthcare. On the subject of healthcare, paper money tends to teem with bacteria.

So will there be a cashless society soon? Almost certainly. Sweden might switch over first. You can no longer get on a bus in Sweden using cash, a direct response to robberies of bus drivers. A bank workers’ union calls for ditching cash altogether to stop bank robberies, and their campaign has attracted supporters such as Bjorn Ulvaeus from ABBA.

There are possible disadvantages to going cashless. The US would need to rethink its tipping culture, for one. There are privacy concerns, as everything you spend would be tracked. Human psychology seems to make us spend more sensibly when we’re forced to part with physical objects from our purses and wallets. And there are street performers to think of—it’ll be a while before that guitarist on the side of the road accepts MasterCard (though at least one already accepts bitcoin). Nevertheless, a country will likely soon make the switch, and you may live long enough to see your own do the same.

9 Peak Population








The worldwide human population has been going up for the last 15,000 years and has increased tenfold in the last 300. The best estimates reckon we hit seven billion a couple of years ago, only 12 years after we hit six billion. It’ll probably take just over another decade to hit eight billion.

Could population peak and start going in the other direction? Some studies say it will, and in the not-too-distant future. One study by demographers from Vienna suggests there’s an 84-percent chance the population will peak before 2100. Scientists from Spain think it could be even sooner—we may see falling numbers of people by 2050.

Of course, there’s the possibility it’ll keep growing. We might hit 10 billion by the end of the next century and see a decline after that. In that case, you might need to live to 150 to see Earth’s population peak.





8 First Person To Reach 150 (And Other Milestones)



It was arbitrary, but the “seven billion” milestone got people’s attention. We might have celebrated reaching 5,159,780,352 if we did numbers slightly differently (that’s not a random number; if you can figure out why it’s significant, show off your cleverness in the comments). But milestones are what they are, and they resonate with people. Breaking a four-minute mile made Roger Bannister famous, hitting 100 years old gets a bigger party than 97 or 102, and we celebrated the arrival of the year 2000 by partying like it was 1999.

British aging expert Aubrey de Gray thinks the first person to hit 150 has probably already been born. It may well be you, in which case congratulations in advance. You’ll have plenty of time to see humanity pass other milestones. If humans are capable of it, someone will run a marathon in under two hours. Haile Gebrselassie, one of the world’s greatest ever distance runners (and the man that held the marathon world record for many years), thinks it’ll happen in a generation. Other people think it’s impossible. The three-minute mile almost certainly is, at least without upgrading the body with drugs or technology.

The world’s first trillionaire is likely to come in the next few decades. Computing will hit a big milestone with the advent of exaflop supercomputers in place of today’s petaflops. We may never, however, reach the next unit prefix, the zetaflop. At least not with silicon chips.

7 The End Of Silicon Chips



Many of you will be familiar with Moore’s Law, an observation that reflects the exponential improvement in computing over the last decades. Originally, it noted that the number of transistors we can fit on integrated circuits doubles roughly every two years. Yet we are reaching the limits of what we can do with silicon computing. While silicon will probably do for a lot of jobs for quite some time, higher-end computing will soon be due for a technological shift.

Computing giant IBM is keen on carbon nanotubes as the solution, and researchers at Stanford have already made a small circuit to demonstrate the technology. Nanotubes are smaller, lighter, and quicker than silicon, and so could allow computing power to continue to increase. Quantum computing, an even greater advance, gets increasingly closer and may define the forefront of computing technology in the near future.





6 The 4-D Printing Revolution



Many people say that the future is going to be all about 3-D printing, and it does offer some pretty awesome potential. But we can go one better in a very literal way using a related technology—4-D printing, which involves objects that assemble themselves.

Getting manufactured goods to do the manufacturing has a number of advantages. For one, it means you won’t have to puzzle over instructions from Ikea as your furniture could put itself together. Programmable materials—that is, materials that change their shape or behavior based on conditions such as temperature—could also enhance 3-D printing. You print an object, then parts of it would reshape themselves afterwards to allow a more complex creation.

Furniture, buildings, and vehicles that can help put themselves together would be particularly helpful in space exploration. Engineers are already working on spacecraft that assemble themselves while in orbit to create the big, bulky solar arrays needed for power.

But 4-D printing really comes into its own on a much smaller scale. Putting together nanomaterials requires a lot of energy and effort using traditional methods. Self-assembly is the most promising route for mass production of nanostructures. A team of chemists from the University of Sheffield in the UK are working on a tiny robot that would assemble itself inside the human body then track down and kill cancer cells.

5 A New Way To Fight Bacteria



Such fantastic new medical advances are becoming increasingly necessary as we see our current methods start to fail us. Antibiotics, which have likely already saved you or someone you know from death, won’t be around for much longer, as we’ve mentioned before. Bacteria are getting resistant, and we need a new tool to fight them.

One possibility is to fight bacterial infections with viral infections—that is, viral infections of the bacteria. Viruses that attack bacteria are known as bacteriophages, and they cause their hosts to literally fall apart. Scientists don’t necessarily even have to use the full virus—a team in Israel have recently isolated a protein from a bacteriophage which could lead to the development of drugs that destroy bacteria from within.

Another possible method is to introduce chemicals that link pre-existing antibodies with infectious agents, assisting the body’s immune response. This technology is being fronted by Kary Mullis, a Nobel Prize winning microbiologist. DARPA, famed for being at the forefront of military technology, is putting its money on nanotechnology. It wants to develop a nanoparticle that can hit bacteria with reprogrammable gene-altering chemicals. That way, as soon as bacteria evolve, the technology can be adjusted at short notice to get around the resistance.

Other teams working on antibiotics that operate differently from current ones, for example by attacking the membrane of the bacteria they target. A team from Taiwan are working on particles that will capture bacteria in groups and then heat up and kill the germs when exposed to laser light. Meanwhile, scientists are also working on preventing infection to reduce the need for antibiotics. Scientists from Singapore have created a positively charged honeycomb-like coating that draws in negatively charged bacteria so that they rupture and die. The team hopes to develop it into an ingestible substance for fighting diseases like pneumonia and meningitis.





4 The Mammal Apocalypse



A quarter of the world’s 4,000 mammal species are under threat of extinction in the next 30 years.

These aren’t obscure species—many scientists predict we could be living in a world without elephants, rhinos, and lions within a quarter of a century. Gorillas are also facing extinction as they are hunted for meat, and their habitats are destroyed by timber and mining operations. That’s not to mention the Siberian tiger, or the 51 species of bat that the IUCN list as endangered.

In a couple of generations, half the animals in our children’s books could be no more relevant than the dodo. In fact, scientists suggest we are currently living through a mass extinction period, like the one that killed the dinosaurs. This “holocene extinction” would be the sixth mass extinction in Earth’s history. And yes, it’s in a large part due to humans.

3 The Last Gasoline Car



While it seems like a battle for the future, the war between electric cars and those with internal combustion engines has a long history. Until 1900, electric cars were the dominant player—less smelly, quieter, and easier to operate than their fossil-fuelled cousins. The first road death in the US involved an electric vehicle, and it wasn’t until the 1910s that the problems of battery technology paved the way for gas guzzlers to define the automobile.

The switch back to electric vehicles has now begun in earnest. Whether or not you accept anthropogenic global warming (as 97 percent of climate scientists do), we’re still stuck with the fact that oil is finite and we may soon run out. We need a more renewable (or at least longer-lasting) method of powering our vehicles. So when will the switch back to electricity be complete?

The oil company Shell suggests the last gasoline car might roll off the production line as soon as 2070. Their report looks at different ways fuel production may go, and in both of their most likely scenarios, they see oil falling by the wayside in the next 60 years.

Potential game changers could accelerate the process. If we crack nuclear fusion—a leap so major that it’s already taken the number one spot on other lists—we’ll have so much clean, dependable, and safe electricity that oil won’t have a chance.





2 The End Of The Landline Telephone



What type of phone do you have? A quarter century ago, that question wouldn’t have had many answers beyond “rotary dial” and “one with buttons.” If you wanted to communicate instantly with someone across the country, you spoke to them using a copper wire network.

Countless lives have no doubt been saved by the existence of emergency numbers like 911 (or 999 or 112, depending on where you live). The US government has therefore forced telecommunications firms to maintain the network’s infrastructure if they want to stay in business. This costs the companies billions, and they argue that this diverts funds from switching us over to newer alternatives.

The old telephone system has seen its usage decline drastically. The number of home landlines in the US is dropping at a rate of 700,000 per month and dropped from 139 million down to 75 million between 2000 and 2008. A huge chunk of communication is now down via IP-based connectivity, rather than the Public Switched Telephone Network of the last century.

Many in rural areas would quite like to see the old telephone network hang around a while longer. For some, it’s the only communication that works. And it has some advantages over newer technologies—it often still operates during power outages. Yet with only five percent of people still sticking exclusively to the Plain Old Telephone System (as it’s been nicknamed), it’s probably inevitable that you’ll see it go the way of the telegram in your lifetime.

1 Conquering Iconic Diseases



For many people reading this, the rise of HIV and AIDS has occurred entirely within their lifetime. It went from being nothing to being one of the world’s most ubiquitous diseases within a generation. Tens of millions of people are living with the disease, and tens of millions more have already died. Yet the tide is turning, and the disease that rose in a generation could be defeated in another.

The number of children infected with HIV each year is falling at an increasing rate, halving since 2003. The statistics on deaths are also impressive—in South Africa alone, 100,000 fewer people died of AIDS-related diseases in 2011 compared to 2005. The key milestone in this fight will be a time when almost no children are born with the disease—an AIDS-free generation. Current medicine can take us there, and a vaccine may arrive and bring the milestone sooner.

The first disease to be eliminated worldwide without a vaccine will probably be Guinea worm disease, a horrible parasitic infection causing hellish burning near the skin, which is spread by unclean drinking water. The number of people with the infection has fallen from 3.5 million in 1986 to 542 cases in 2012. The World Health Organization hopes to get rid of Guinea worm by 2015.

That’s not the only disease on the WHO hit list. Yaws is a bacterial infection that was targeted for eradication in the middle of the last century, and numbers dropped from 50 million to 2.5 million between 1952 and 1964. It’s hovered at that level ever since, but the WHO expects it to be gone by 2020. Yaws has already been eliminated from India, as has polio, another disease which we should all live to see disappear completely.

Alan is particularly looking forward to hoverboards, personal jet packs and living on the moon. You can find him on Twitter, email or read his blog (which he promises to update more often) at skepticalnumber.com.