Unlike all other creatures on this planet, we are the only ones who know that our time is limited, and this knowledge shapes us as humans. This feeling for the poignancy and transience of our lives has been at the root of so much of what we value in human culture.

Throughout history, the awareness that our time is limited, that our life will eventually end, has driven humans to search for a way out. For centuries, religions have provided one. At the heart of practically all the world's religions, there is the offer of eternal

life, time without end. This is Wells Cathedral in Somerset. For the past eight hundred years, every Christian who's walked in here has been reminded that their soul is immortal. So I imagine that the promise of eternal life was a powerful incentive for the people who worshipped here from their

Bible. They knew that God controlled time. They read that Adam had reached over 900 years of age, and Methuselah, the oldest, he lived to be 969 years. So they knew God had the power over earthly time, and they believed that God could grant them

an infinite life extension. It was essential that graveyards be placed close by so that the living and the dead were almost side-by-side. To the medieval mind, death was viewed as a as a face as nothing but a natural continuation of life. The problem today though is that

many of us are more skeptical. To get everlasting life in heaven, you have to trust that heaven actually exists. Speaking as a scientist, I think that there is a problem with regards to the afterlife and religious immortality, and that is there's no proof that it exists.

Remarkable claims require remarkable proof, but maybe you don't need proof. Well, I do. This awareness that time stretches into a distant past has driven us for thousands of years to ask one of the greatest questions of humanity: when did time itself begin? In the 17th

century, an archbishop from Dublin decided to find out. For James Ussher, the beginning of time was the moment of God's creation of the Earth, the heavens, and all of humanity. So, he started with the Old Testament. All Ussher really had to do was add up the various ages of the

patriarchs because the Bible tells us what age each person was when his son was born. So, for example, Genesis 5 tells us that Adam was 130 years old when his son Seth was born. Seth was 105 years old when his son Enoch was born. But at

the end of the Old Testament, the family trees run out. Between that and the birth of Christ, there was a gaping hole in history. So, Ussher scoured the known world looking for ancient historical sources to bridge the gap. It's extremely difficult. The Babylonians dated the year in spring, the Jewish chronology starts in autumn, and the Greeks use Olympiads. So, he has to bring all those different types of sources together and link them up somehow to them to each other and then to his biblical sources. For 20 years,

Ussher struggled to reconcile the historical records from over 10,000 volumes in his vast library. Finally, in 1650, he determined a date for the beginning of time with stunning precision. In the very first paragraph, Ussher dates the creation of the world -

exactly the evening before the 23rd of October 4004 BC James Ussher had established a very moment of God's creation compared to our lifetimes 6,000 years is an incredible amount of time but around a hundred years later that time scale

was about to be dwarfed for all of us library full of books the earth itself was beginning to present quite a different story and the first man to realize it was a problem was a Scottish farmer by the name of James Hutton here he is James hadn't spent most of his

life marveling at natural processes mainly on his own farm and his investigations would lead to an entirely new idea of time I'm about to look for the clues that led Hutton to rethink the age of the earth an overturned assured 6,000 year history geologist Dave faire

is going to be my guide James Hutton's insights came from Scotland but Dave's brought me to a place where the same features have been carved out on a much larger scale the Grand Canyon in Arizona 270 miles of Colorado River flow across two states

carving out a chasm one mile deep it's created a landscape on an epic scale let's have a seat here now Dave the Colorado River is a small little thing how can the Colorado River gouge out such a huge Canyon the river is digging the canyon deeper at the rate

of one foot every thousand years mm-hmm and in that time it's just all this rubble is eroding down into it from the rain I can imagine how long that's taking because it's all changing the sand as it goes Wow and how much Rock

has been carved out well there's 800 cubic miles of missing rock a mile below us the river continues to cut its path through the rock carrying it away in its silty waters so we're talking about the power of water right any water water carved this

Cathedral out of nothing yep yeah and how long has this erosion been taking place well at least five and a half million years is what they say following similar clues I hadn't realized that ushers 6,000 year age for Earth had to

be wrong unimaginable eons of time are needed for water to carve out valleys and I hadn't noticed something else the layers of rock revealed by erosion showed a still greater scale of time oh here's a nice place to see the strata I see yeah right here yeah this red layer

right here would be a silt stone that formed at the edge of an ocean and you know it took probably a thousand years to form one inch of it so you're telling me that printable all of human recorded history going back to the Babylonians and the Egyptians will be just them just a few

inches and that's not green yeah so this is like like a time machine basically right a thousand years per inch on average on average yeah if you just took the whole length of just the sedimentary rocks in the canyon that have been deposited here aha floods and rivers and

streams and the ocean coming in staggers the imagination it does indeed as you walk down this trail by the way I wanted to tell you that um that every step you take you go about 20,000 years into the past that right yeah yeah and

we've taken quite a few steps already there are a lot more steps on the way down to the river see yep in fact just six inches of the Grand Canyon's rock face is equivalent to Usher's timescale for the whole of Earth's existence the

Earth had begun to reveal the true immensity of time a scale of time that was inconceivable and unending abyss for me Hutton wrote a great passage which summarizes the experience of the Grand Canyon and that is the result therefore of our present inquiry is that we find no vestige of a

beginning no prospect for an end the great vastness of Earth time had been revealed and a scientific quest had begun if the Earth wasn't 6,000 years old then just how old was it it's a question that has only finally been

Michio Kaku on Life After Death, Creationism and Scientific Evidence of Geological Time

Michio Kaku on Life After Death, Creationism and Scientific Evidence of Geological Time