Half life is the number of years people live.
This is an average of the length of a person’s life, and it is measured from birth to death.
But this is a much smaller number than the number that we think of as our average life expectancy.
For example, we think about average life span as something around 20 years.
The actual life span for a person is closer to 10 years, and this is why we are usually so worried about how long we live.
The average human lifespan is around 5.3 years.
As the number gets longer, people start to age more rapidly.
For instance, there is a large gap between the ages of 40 and 50.
And for people over 70, life expectancy is around 45 years.
In the past few decades, life spans have started to decline worldwide, and there is evidence that it is due to an ageing population.
This may be due to the introduction of treatments for cancer, and ageing is linked to some health problems.
In some parts of the world, such as Africa, the number is declining at the same time as mortality rates have risen.
This has led some people to suggest that the world is living too short of a life expectancy, and that we should shorten our lives.
This argument is often used by the proponents of the death penalty.
But, it does not take into account the fact that there are people who will never be sentenced to death and those who will.
And people who are too old to be sentenced are also unlikely to be put to death for some other offence.
This article originally appeared on BBC News website.