Watch carefully.
This is happening right now.
You're walking through a sunlit street.
Notice everything.
The man coming towards you, using the floor as a bin, the somewhat sweaty
woman. Take it all in and then turn your head.
There's a bloke over there having a pretty bad day and in this moment, time
slows. Every second seems to unfurl and linger.
As you watch him flail about.
When you retell this story, you'll use the words it felt like forever.
But it wasn't forever so what's going on?
It turns out that time is far more strange and mysterious than we might
imagine. In fact, it's possible that past, present and future could be an
illusion, and according to some time, doesn't exist at all.
So let's start with your own mind.
Your experience of time is not constant because you don't have a perfect ticking
clock in your brain. In fact, your brain creates your sense of time by
putting your memories into order.
It doesn't count in seconds, it counts in moments it deems important.
Which means it isn't always accurate.
This is why time can feel like it slows down in unusual or stressful
situations.
Confronted with something new or scary, your brain thickens up the event with
more details. Like this quite memorable look of pure horror.
And those denser memories give an impression of having lasted longer.
For this particular man, every moment currently feels like an eternity.
His childhood laden with unfamiliar and mystifying experiences, also seemed to
last a hell of a long time.
Whilst the blur of backaches and paper cuts to follow swept past him in an
instant.
Which is something he's just beginning to realise.
But you see, your memory isn't the only time meddler.
This was me 56 minutes ago.
A combination of alcohol and mindless chatter has filled my brain with the
feel good hormone dopamine.
Which in turn, has sped things up considerably.
On the other hand, physical exercise slows our sense of time, which might
explain why running is so repellent long and boring.
And perhaps this science explains why our lockdown's stressful and strange, y
et without many fun or memorable experiences, might have left me feeling
that it somehow lasted forever and also flew by.
So okay, there's a lot of things twiddling about with our internal sense
of time. And we've all experienced this when we say time flies, when you're
having fun or felt like an eternity, we're referring to our own heads.
But what about the real time outside of our subjective experience,
that consistent, unwavering time that rotates planets and ticks away on our
watches? It turns out that's just as weird.
You see, Einstein's Theory of Relativity literally warped our understanding of
time. Far from being a universal flow from one moment to the next, passing at
the same rate for everyone, these theories show that time and space are
interlinked. You see, as stupid as this sounds, time can be warped by two things
gravity and velocity.
Suddenly, after Einstein's theories, time moved faster in some places than
others.
Every single suggestion of Einstein's theory, every single prediction has been
confirmed up to now with just unbelievable accuracy.
So ultimately, as he created it, the basis is that there is no notion of
simultaneity. It's spatially separated points.
No notion of simultaneity at spatially separated points.
Right. To better understand Julian's point, we'll need to meet our joggers
twin sister, Agnes.
Right now, our jogger is reaching the literal peak of her run.
There at the top of the hill, she reflects on her grotesque finance career
and plays out a fantasy.
What if she stayed up on this hill, quit her job and pitched up a tent among the
birds and the bugs?
Let's humour her fantasy for a moment and say she lives up there for years.
Further away from the Earth's gravitational pull than Agnes, who
remains in her sad basement apartment.
By the time the novelty of hill life wears off, our jogger will return older
than her twin.
Agnes down in her musty basement and closer to sea level, was existing in a
time slowed more by Earth's gravitational pull.
One twin is now older than the other.
It's only a small difference but a difference nonetheless.
And this fact, mad as it sounds, has been scientifically proven.
So yes, your head is older than your feet.
Now let's make the twin situation even madder.
If our jogger was to travel away in a high speed rocket moving at an obscenely
high velocity, she could feasibly return decades younger than her now very
hairy sibling. These revelations seem to confound our sense of time.
Clocks in the UK and China might be adjusted for time difference but surely
we're all experiencing the same time.
Surely now here, is now in China too.
Well, as it turns out, your now is completely different to anyone else's.
Although we can interact with one another and feel we are sharing the same
moment, our time is only ever relative to other people.
Because we occupy different spaces, we exist in different times.
No simultaneity at spatially separated points.
An unsettling fact for sure.
So what comfort does this leave us with?
Perhaps just the pathetic knowledge that whilst our nows can't be shared, they're
at least real, realer than the happened past or the yet to happen future.
Well, maybe that's all wrong, too.
Of course, we experience time as moving in one singular direction.
Cause precedes effect.
The past is set in stone, and the future remains a mystery.
Many physicists believe that this arrow of time arises from something called
entropy. The idea that the universe is becoming increasingly disordered, a
process that only seems to work in one direction.
After this awfully rude man drops his apple, it's exceedingly more likely that
it will decay and disintegrate rather than put itself back together.
And it's perhaps this march towards disorder that explains why time moves
forward. But nowhere in the fundamental laws of physics is there any real
distinction between past and future.
According to science, time could just as easily run backwards.
So what if we were to look at time in a wildly different way?
It's time to introduce the Block Universe theory and for that we'll need
some bread. So here's here's my loaf of bread, of which I'm naturally very
proud. So you can imagine that if we reduce the dimensions of space from 3 to
2, so that would be space at one instant, two dimensional, and then the
vertical direction would be time.
Here, inside our loaf of universe, every point in time can be seen as occurring
simultaneously.
All the times are sort of like other places.
They're still real. You just can't see them.
There is this Latin saying "sub specie aeternitatis" "from the perspective of
eternity"
So you looking at this loaf of bread now are looking at it as if you were seeing
it from the point of view of a divine God, from the perspective of eternity.
It's all there at once.
Our past when you arrived, is just a tiny bit further down the loaf and when
you leave, you'll just be a bit further up the loaf.
Within the Block Universe Theory, the past, present and future are all as real
as each other and all happening somewhere in this space time.
Your future, rather than being an uncertain mystery, is just happening at
a different point in the block.
Similarly, the entire history of the universe, from your ancient ancestors to
the yet to be doomed dinosaurs to the Big Bang itself, all occupy an eternal
point in Julian's bread.
Time isn't passing from past to future because every present moment is already
there. As such, our experience of time is simply an illusion.
This might even mean that our sense of free will is also an illusion.
We feel we can change the future but according to the Block Universe Theory,
it's already set in stone.
Concrete. You're just not there right now.
So if this is true, why can't we stare directly into the moments to come or
turn around and trace back through the past?
Well, perhaps we can only blame our sad half past human perception.
Perhaps it's not the march of time itself that locks us into the present
moment, but our own dunce brains.
We are, after all, not quite the eternal divine beings Julian was referring to.
In this way, the Block Universe theory is by definition, incomprehensible.
We can't see time the fourth dimension, So trying to fully understand this
theory is sort of like trying to imagine the universe before it was
actually a thing yet.
So let's take a quick breath and make things a tiny bit worse, by permitting
Julian to go a step further.
What if time doesn't really exist at all?
There is no such thing of, as time that is quite independent of what you and I
are.
It's not some invisible river which is flowing forever.
Time is what the philosophers say, it's an emergent concept.
It's something that we deduce from other things.
It's an appearance that comes out of other things.
How about we return to the present for a moment?
You want to know what difference this all makes?
Let's say the passage of time is an illusion.
The past is no more real than the future.
That time doesn't exist at all.
Who cares? In 3 minutes, the man you're watching will be dead.
And this moment will be a memory.
Then you will age and also die.
Behind me is the picture of my father when he was seven and then he changed a
lot.
If there were a picture of me at my at that age, I would look very different
now. It is.
It is we that change, not time, because time just isn't there.
We are here. I mean, there's no doubt you're sitting there in the chair
opposite me.
Time may be simply born out of change, but we have no way of escaping this
change.
These theories of time can't free us from our limited perception, but they do
reveal just how bewildering and incomprehensible our universe may be.
It might not be of any comfort to the man but in this moment he is dying.
And in another he is being born.
And both moments may be as real as each other.
When we look at our friends, we see their light as it was, not as it is.
Everything we see has already happened, but still we seem to feel the now,
remember the past, worry and dream about the future.
It may well be that our perception of time is outrageously wrong and one day
physics might prove with certainty, that the future has already happened.
Or that time doesn't fundamentally exist at all.
But as the small self experiencing fractions of the universe we are, all we
can really do is count the seconds, days and years of our brief time here
and wonder perhaps if beginning and end are really as different as they seem.
Watch carefully.
This is happening right now.