The Importance of Now

time has played

a very important role in our development

as a species

ever since we first became aware of his

passing it has since grown

into a commodity that we feel that we

have ownership of

but we don’t really have control of it

we even use

language such as owning it being able to

spend it

being able to receive it give and take

it

and in fact benjamin franklin actually

aligned

time with value and gave it money

and that is in complete contrast to the

view of einstein

that said that time is actually an

illusion

now these two ideas are two that i would

like to explore over the next

talk that i give now the first question

i want to delve into in order to

understand this

is actually this one how do we

experience time

now in order to do that i’m actually

going to take us into a little world of

physics

so enjoy it with me the first view that

i want to go into

is actually relativity and the first

implication of relativity that einstein

came into

in order to do that i’m going to

introduce us to two characters

the first person is a business woman so

say she’s working in la

and the second character is an astronaut

up on the international space station

so if we take our experience of the day

we wake up in the morning because our

alarm clock says so

we then go and we get our coffee getting

ready for the day

we suddenly see in the corner of our eye

the time it’s like oh we’ve got to go to

work now

we then travel to work we get to work we

get there a little bit late

say sorry we then get another coffee we

then start going about our day

it tells us oh it’s a break time now or

we can have lunch and then it tells us

the end of the day

we get to go home we cook our dinner the

clock even tells us how long

the chicken’s in the oven for and then

it tells us okay it’s a little bit late

you should probably go to bed now you’ve

been watching netflix too long

now that regulation of our day is very

important

the same regulation of our day is

important if we are an astronaut up

there

on the international space station we

need to know when to wake up when to do

our tasks

when to then go to bed they don’t get

the same experience of the day that we

do 24 hours the sun rising the sun

setting

they go around the earth every 90

minutes

so they get a sunset and a sun rise

every 90 minutes so they need to know

the passing of time

now the problem is if we have a clock

and we send it up

and in a very simplistic view we look at

the passing of time

what we actually find is that when we’re

up on the international space station

time passes a little bit slower now that

gives us one very important implication

of relativity and that is that our

position in the universe

is important and in fact

the stronger the gravitational field

that we are in

faster we experience time now if we then

take the second

idea of relativity and in order to do

that

what we’re going to do is we’re going to

hop on a london tube

and let’s say actually when we’re on the

tube

it’s night time so it dims down the

lights what we then do

is we take out our phone and put on our

torch

now what we can actually process in our

brain

is that the light ray passes from our

torch travels down

through the carriage hits a part of the

carriage at the end and it travels back

to our eye

now in our brain we actually know that

light travels a certain speed

and we know the distance and the

distance it comes back

so our brain registers that and it tells

us how long it takes

and that’s from a very simple equation

that speed equals distance over time

if we know the speed and we can gauge

the distance

we know the time that light took to do

that

now as we’re on this tube and we’re

passing along we’re going through

stations

and let’s say that on the side of one of

these stations there’s a woman let’s

call her brenda

she’s standing there she sees this

carriage passing

and what she sees is our torch and she

sees the light

traveling along hitting the same part of

the carriage

and bouncing back to her eyes but to her

the light

has had to travel further to catch up

with the end of the carriage

and therefore come back now in her brain

she knows the speed of light it’s

exactly the same as the speed of light

that we have

but she has seen the light travel a

further distance

using the exact same calculation what we

actually find

is that to her it looked like it

traveled a longer distance

at the same speed it has now taken

longer for the light to do that

these two events occurred at exactly the

same time

and finished at exactly the same time

and what it is telling us is actually

that we

on the carriage experienced time

passing faster than she did she saw it

taking a longer time to occur which

gives us our second implication from

relativity

and that is that our emotion through the

universe

is important so we’ve now got two ideas

our position in the universe is

important for how we experience time

but so is our motion through the

universe

now i want to give you a third and final

bit of physics here

and this is entropy okay now this is a

very complicated idea entropy but i want

to try and make it simple for you

so what we have here on the bottom left

you can see a young girl

and let’s say that she is there blowing

bubbles

now as she blows bubbles the bubbles get

formed

and it floats around in the room based

on the random motion of air

now what that is telling us is that

the universe is trying to spread out

these bubbles

now why why is it doing that it’s doing

that because the

universe has a fundamental law about it

and that is it wants to take all energy

and spread it out now let’s say actually

we want to try and reverse this process

so what we do is we take those bubbles

and we try and move them back together

again so we have to reach out grab

one bring it in reach another one grab

one bring it in

and as we do that what we are having to

do is actually expel

energy to do that now we have to put

work in to go against what the universe

wants to do

and that is another fundamental idea the

universe is always trying to increase

entropy it wants to spread everything

out it explains why my desk at work is

an absolute mess

now this is because the universe

is taking energy and spreading it out

now if you

take that back to the beginning of time

the big bang

what happened ever since then is the

universe is spreading and expanding

trying to spread

the energy out and that tells us the

direction time goes

the time will always flow in the

direction

in which energy spreads out

so there are three key ideas our

position in the universe is important

how we move through the universe is

important that tells us how we as

individuals experience time but we

always

feel time flowing in one direction

forwards

we always go from young to old we never

go back

benjamin button doesn’t actually occur

now my second question then

now we have a slight understanding of

how we experience time

is to look at why is it therefore

important to us

why is time important to us now if we go

all the way back

to the stone age when stonehenge was

actually built

back then the passage of time that was

important to us was the seasons

all we cared about was when was spring

when was summer when was winter coming

when do we do the harvest when do we

have to sow our seeds

but if you come forward we then invented

sundials and we tracked the passage of

time

across the day when was sunrise when was

sunset

throughout the day when was the middle

of the day as we came forward again

we invented the clock the passage of

ours was important

and then we soon get to us now and we

have

atomic clocks we have electronic clocks

we track ever more shorter periods of

time

and that tells us that gives us the

passage of time available

to do our gps to do

our computer processing really fast

now i want to give us a little sort of

story to go along with that something

that we have ourselves experienced

so what i’m going to take us on is a

little sort of story

through messaging someone so let’s say

i’ve got

a very attractive lady in my phone call

her charlie

now i want to meet up with her so i’m

going to send her a message so i am an r

about it and i

go throughout the day and i’m like oh

i’m going to message her now i’m going

to mess you now eventually i sit down

and go i’m going to do it

i’m gonna message her so i write her a

little message i make the big decision

do i put an emoji at the end

yeah i do a nice cheeky message put a

little wink at the end

see if i can get a date i send it i get

the one tick it tells me yes

the message has sent i get the second

tick

yes she’s got it i’m then waiting there

going hmm

okay okay oh blue ticks she’s ready

i’m then waiting i’m then waiting

she’s ready why isn’t she replying maybe

i shouldn’t have put the emoji there

i really shouldn’t have done oh she’s

sending me a message back and then i get

the response

all of that because i programmed it into

this

i know it took 24 seconds but that

was really traumatic between sending the

message

and receiving the reply now that

shows us just how skewed our view of

time has become

24 seconds and we were humming and

arring we were thinking we were thinking

about the next day the next person we

were going to message

all of that though is what we

experienced now but if we go back 100

years

to 1920 imagine we were doing that same

thing then

we would ominar about what we were going

to put in our message we’d come up with

a poem or something write it down

on a piece of paper put it in an

envelope put a stamp on it put it in the

letterbox

i’d have to wait a week to get the

response that yeah we can go out for a

drink

next month but now i send that message

and i’m waiting 24 seconds questioning

my life decisions

before i get the response and go yeah

okay we’re going on a date

now all of that why is our vision

of time so skewed and it all comes down

to this

the idea that we have more transistors

now than we ever did before because we

invented computers we put more

transistors we got faster and faster and

faster and faster machines

also we have faster and faster internet

when i was younger i remember

loading up google when it used to take

ages and we get a layer of pixels

all the way through and then i’d have to

really question what i was going to type

in

and whether it was worth waiting 20

minutes to get the actual information

now i can look up anything i want on my

phone

no matter how trivial now

i’m going to take this into another

realm and that is trading on the stocks

and what i’ve got here on the screen is

the stock exchange there on the

left-hand side

okay we’ve connected it up with the wire

to two computers

okay now what happens is we’ve got a

change in prices in the stocks

and that signal is sent down the wire

and as it travels down the wire it gets

to the junction the signal goes to the

nearest computer first

we get the information then the later

computer gets it a little bit later on

now if i am in an office that is closer

to the stock exchange

i’m able to respond to that price change

faster

i can therefore trade my stocks before

it plummets or buy something before it

skyrockets to then sell it later

whereas someone further away they have

to wait half a second before they can do

that

now all of this means that we actually

have different prices

in the rental properties of offices so

the further one would be cheaper

but if i was closer to the stock

exchange it would be much more pricey

now this can be seen in the new york

skyline if you’re looking at

lower manhattan and i’ve actually got a

few pictures here going over the last

hundred years

looking at the skyline of manhattan i go

from the first one there’s only a few

high-rise buildings all around the stock

exchange but as we go forward

and we go forward through time what

we’re finding out is more and more

office space is being built

closer to the stock exchange and here

you’ve got a sky

view image and you can see this cone of

taller buildings all around the new york

stock exchange

now this idea that we have to be closer

to

the stock exchange in order to make more

and more profit

actually went to some very weird place

very recently

now what happens is we have this new

thing because of our faster computers

that we were talking about

called mass trading you can trade

thousands and thousands of stocks very

quickly

just with the press of a button on a

computer you can write programs to do

the trading for you

and that means we can make massive and

massive profit in very short periods of

time

and if we were trading let’s say in

chicago rather than in new york you

would need to have a really fast

connection

so you used to have optical fiber

connections that used to zigzag all the

way around the country to get to chicago

then companies put mass investments in

to be able to make it straighter and

straighter and stay

straighter now a straight path is as

straight as you can get

so once you’ve built this straight path

that’s the quickest any signal can ever

get

from new york to chicago however back in

2011 a scientist

actually put out there that they found a

faster than light particle they thought

it was a neutrino that went faster than

light

so suddenly we now have a way of getting

a signal from

new york to chicago faster than light

can travel which is how we use

our internet but literally four or five

months later

they had to put out that actually this

was a false detection

they weren’t actually detecting fast

unlike neutrinos now in that time

companies had invested millions of

dollars trying to look into whether or

not this was actually a feasible

way of sending signals from new york

to chicago now that just shows how

skewed we are

we’re trying to fight over milli seconds

of time

remember if we go back in time the

passage of the seasons was what was

important

now it’s milliseconds it’s nanoseconds

and even shorter than that

now my last idea now we’ve got why is it

so important to us

it’s because actually time is money

is to look at well what actually is time

now time is just the way that we track

the passage of events from one to

another

okay and if you ask a geographer a

geographer will look

at the lattices in rock and they would

say

yes that’s the passage of millions and

millions of years so to a geographer

the passage of millions of years is

important to me i just look at that and

go that’s a pretty picture

we get lots of nice different color

rocks okay

if you were to ask an astronomer what’s

important

why is time is important what is the

passage of time

they might think well let’s look at one

particular picture

now this picture if we took the hubble

space telescope

and we pointed it out into space at an

area of the sky

one tenth of the size of the full moon

what you would actually look at and you

stared at it this blank

piece of sky you’d stare at it for

months and you would get this picture

it’s called the hubble deep filled image

now in this image i’ve got it zoomed in

on the right hand side there

it’s the most distant galaxy we’ve ever

seen

about 13 and a half billion light years

away

that means the light left it 13 and a

half billion years ago

and it reached us today

and that is the furthest galaxy we’ve

ever seen now in this picture as well if

you just look at all of the dots

in that image what you actually see is

galaxies

all different distances away and we’re

seeing

layers and layers of time now

geographers

look at layers of rocks that’s millions

of years

astronomers look at that one picture and

they see layers of galaxies

showing the tracing of billions of years

so to an astronomer it’s not nanoseconds

that is important

it’s billions of years really big

difference in time there

now my last little bit is this imagine i

had a graph

okay physicists love graphs i have

time and distance so i have time on a

y-axis

and distance on an x-axis let’s put us

at the middle

because we are very egocentrical species

we are at the center of everything

so i’ve put us at the middle of this

graph and i then trace out

a cone now the cone is called a light

cone

it’s everything we can see because light

has taken time to travel to us

that cone is showing everything that we

can

see now imagine there’s an event

this event occurred outside of our light

cone

it’s further away than we can actually

see now this event

let’s say occurred 15 billion years ago

now we won’t actually expect to see that

until

light has had time to reach us so this

event that occurred

15 billion years ago will actually reach

us sometime in the future

now that brings a really weird

sort of view into our head if you think

about it something that occurred

a long time ago will not occur to us

until the future so that means the past

is actually the future and that is a

really

weird view to have of the world which

something that i want to

just leave you with and that is

what actually is time well time

is just a measure of the largest

distance

between two places thank you

you