Lecture 6: How Did Everything Begin?

How Did Everything Begin? ..............................................................

LECTURE

“There was neither non-existence nor existence then.” What we’re

talking about is a sort of state in which there’s not quite nothing, but

there’s not quite something; there’s sort of potential. That, in fact, is

very like modern accounts of the vacuum.

—Rigveda, the basic Hindu scriptures

H

ow was the Universe created? This lecture summarizes the modern

answer to this fundamental question and explores the evidence on

which it is based. All human societies have asked how everything

began, and they have all offered answers of some kind. Traditional

answers rested on limited evidence. Yet they were often poetically rich and

philosophically deep, and they mattered because they helped people map

their place in space and time. Most assumed that the Universe had been

created by a deity or deities. Modern scienti¿ c answers do not posit a divine

creator, because such a claim cannot be supported with scienti¿ c evidence.

Besides, it raises the awkward question of how the creator was created.

However, like all other accounts, the modern account also faces the “paradox

of beginnings”: the challenge of explaining how something can come from

nothing. And it offers no solution. We just don’t know what there was before

the moment of creation. We do not even know if time or space existed. In

such cases, scientists will generally admit their ignorance, while continuing

to search for new forms of evidence.

Yet from a moment after the creation, astronomers can tell a well-grounded

scienti¿ c story based on masses of carefully tested evidence. It begins 13.7

billion years ago. To explain this story, we need some very large and very

small numbers, for which we use “exponential” notation. A ¿ gure 1 with two

zeroes (100) represents two 10s multiplied together. The ¿ gure 1,000 (with

3 0s) represents three 10s multiplied together. In exponential notation we

write these numbers as 10^2 and 10^3. We can do the same with fractions. One

hundredth (1/100 or 0.01) is 0.1 multiplied by itself. So we write 10í^2 for

1/100, and 10í^3 for 1/1000.