Part 1 Trends in Global Life Expectancy
People today are living longer than at any point in human history. Virtually every country enjoys a higher life expectancy than it did in the 19th century. In 1870 , the average person could expect to live for 30 years. By 2015 that number had increased to 71 , more than doubling.
The West was the first region to see an increase in life expectancy. Scientific discoveries led to a growing awareness of germs and disease. New medicines and treatments were developed, and people adopted more hygienic lifestyles.Public health measures were a major factor.During the 20th century , the average lifespan in the United States increased by more than 30 years , of which 25 years can be attributed to advances in public health.
Between 1900 and 1950 , Europe's life expectancy grew from 43 years to 65 years. However , this did not reflect the experience of the rest of the world, which largely remained impoverished and underdeveloped. In 1950 , Asia's average life expectancy was 42 and Africa's was 36. In the following decades, living conditions in both continents improved, along with life expectancy. As Asian economies grew , people had better access to health services and greater quantities of food. In Africa however, several countries did not see significant economic growth, but still enjoyed a growing life expectancy.This was due to better access to medicines and vaccines.
As of 2015 , the life expectancies of Asia and Africa were about 72 and 60 years respectively. In all countries, some facts are universal, including higher mortality rates associated with childhood.
Therefore, life expectancy increases with age. Economic conditions also affect life expectancy. For example, in the UK , life expectancy among the wealthiest is several years higher than among the poorest. This may reflect factors such as diet and lifestyle, as well as access to medical care.
And finally, women enjoy an advantage over men. Females have a higher survival rate from birth to old age. Of individuals aged 110 , 90% are women. In fact, for almost all animal species except birds, female have higher survival rates than males.
（Economic conditions also affect life expentancy.）
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part 2 Virtual Heaven
If you could live forever, would you want to? The challenge of keeping your body alive seems impossible, but some scientists are working on an alternative. They want to create a digital copy of your " self " and keep that copy " alive " long after your physical body has stopped functioning.
In effect, their plan is to clone a person electronically. Unlike ordinary physical clones - which have identical features as their parents, but which are independent organisms, each with a different conscious self - your electronic clone would believe itself to be you.How might this be possible?
One plan relies on the development of nanotechnology. Ray Kurzweil, a leading futurist, predicts that within two or three decades we will have tiny transmitters that can be injected into the brain. Once there they would line up alongside neurons and monitor the details of the brain's activity. They would then be able to transmit that information to receivers inside a special helmet, allowing us to map the brain.
As a further step, Kurzweil foresees using these tiny transmitters to connect you to a world of virtual reality. With the transmitters in place, you could think your way onto the Internet. Instead of seeing pictures on a screen, you would see them in your mind. Rather than send emails to your friends, you could meet them on some virtual tropical beach and exchange messages in virtual person.
For a futurist like Ray, this would be heaven, a virtual heaven. Once you upload the brain onto the Internet and log on to that virtual world, your body can be left to decompose while your virtual self can play games for as long as you wish.
However, there is still a problem. To exist on the net, your virtual self will have to reside on the computer of a web-hosting company. These companies want to be paid real money, or they will delete your " self " and sell the space to someone else. With your body long gone how will you pay?