Transcriber: Delia Cohen Reviewer: Lipeng Chen
Infinity
in its simplest definition
it simply means
without limit.
It's not a destination; it's not a size.
We might have all first heard of No Limit
from Master P in the '90s
and his No Limit Soldiers.
(laughter)
Now the easiest examples of infinity
come from mathematics.
For example,
if I take the integers
the numbers 1, 2, 3, 4,
I could continue on forever
and it has no limit.
But infinities have these
crazy, strange properties.
If you take the numbers
between the whole numbers
take for example
the numbers between 1 and 2.
There are more of them
than there are integers.
So not all infinities have the same sizes.
And in physics, we encounter
these infinite sums.
Take, for example,
if I add all the integers
but I double the integer every time.
If I take 1
plus 2
plus 4
plus 8
plus 16
and I continue to infinity
and I add up all those numbers,
guess what it equals?
It equals negative 1.
Believe it or not.
If you stop before infinity
you get a really big number.
But if you carry it out to infiniity,
you get negative 1.
Now, mathematical abstraction
is one thing
but where does infinity
manifest itself in the real world?
It's really difficult to find.
For example,
some people believe
that space is infinite.
We, with our instruments,
we can measure billions of light years.
And what we've just discovered
is that all of the universe
that we can see
out to our horizon
because beyond that
the light hasn't yet had time to reach us
is only this tiny region
of all the universe that is.
But is it infinite?
In fact, no one really knows.
But the universe may be like
the surface of a ball.
It has no end but yet it's finite.
The universe may actually be like that.
There's another place in physics where
we know infinity actually does show up.
If you take an elementary particle
say like an electron
as it travels through space
it can spontaneously become 2 photons,
2 particles of light.
and each one of these
can spontaneously become
a matter and anti-matter particle.
And each one of them
can spontaneously become
2 photons
and each one of them
can spontaneously become
matter and anti-matter.
And you end up with this infinite sum
of possibilities in particles and photons.
And does that really exist?
Yes, it does.
And the way we know is because
when we do a calculation
with quantum electrodynamics
and then we make a measurement
and we compare the prediction
of the calculation
with the measurement,
it's one of the most accurate predictions
that science is actually able to make.
They agree to 15 decimal places.
And I'll challenge you to attempt to measure
anything to even 7 decimal places.
Now, mathematical abstraction
is one thing.
The universe is one thing.
And elementary particles is one thing.
But where do infinities
really impact our lives?
In the words of Deepak Chopra,
you and I are infinite choice makers.
We live in a field of all possibility
where at all moments
we have access to infinite choices.
And I don't need to look
any farther than my own life
to recognize that just like
adding the ever-doubling integers
to get bigger and bigger numbers
actually ends up giving you
a very small negative number
The sum of all the choices that
we make in our lives
even if many of them are negative
you can find that it sums
to a very large positive value.
And so for me
that infinity is hope.
And that's the infinity
that matters to me.
Thank you.
(applause)