On an ordinary day at faculty,
countless hours are spent studying the solutions to questions,
but right now, we will do the alternative.
we are going to focus on questions wherein you cannot examine the answers
due to the fact they may be unknown.
I used to puzzle about plenty of factors as a boy, as an example:
What would it not sense like to be a dog?
Do fish feel pain?
How about bugs?
turned into the huge Bang just an accident?
And is there a God?
And if so, how are we so positive that it's a He and not a She?
Why achieve this many harmless people and animals suffer terrible matters?
Is there certainly a plan for my lifestyles?
Is the future yet to be written,
or is it already written and we just can't see it?
however then, do i've loose will? I imply, who am I anyway?
Am I only a biological machine?
however then, why am I conscious? what's attention?
Will robots become aware in the future?
I suggest, I form of assumed that a few day
i'd be told the solutions to all these questions.
a person ought to know, proper?
bet what? nobody is aware of.
most of these questions puzzle me greater now than ever.
but diving into them is exciting
as it takes you to the threshold of knowledge,
and you in no way recognize what you will locate there.
So, questions that no person on the earth knows the answer to.
[How many universes are there?]
from time to time while i am on an extended plane flight,
I gaze out at all the ones mountains and deserts
and try and get my head round how great our Earth is.
and then I keep in mind that there is an object we see every day
that would actually match one million Earths inside it:
It appears impossibly huge.
but inside the high-quality scheme of things, it's a pinprick,
one of approximately four hundred billion stars in the Milky manner galaxy,
which you may see on a clean night
as a pale white mist stretched throughout the sky.
And it receives worse.
There are perhaps a hundred billion galaxies detectable with the aid of our telescopes.
So if each celebrity become the dimensions of a single grain of sand,
simply the Milky way has enough stars
to fill a 30-foot by means of 30-foot stretch of seaside
3 ft deep with sand.
And the complete Earth would not have enough seashores
to symbolize the stars within the overall universe.
this type of seashore might continue for actually hundreds of millions of miles.
Holy Stephen Hawking, that is lots of stars.
however he and different physicists now consider in a reality
that is unimaginably bigger still.
I suggest, to start with, the 100 billion galaxies
inside range of our telescopes
are possibly a minuscule fraction of the overall.
area itself is expanding at an accelerating pace.
The enormous majority of the galaxies
are separating from us so rapid that mild from them can also in no way reach us.
nonetheless, our bodily reality here in the world
is in detail related to the ones distant, invisible galaxies.
we will consider them as a part of our universe.
They make up a unmarried, giant edifice
obeying the equal bodily laws and all made from the equal sorts of atoms,
electrons, protons, quarks, neutrinos, that make up you and me.
but, latest theories in physics, consisting of one known as string principle,
are actually telling us there could be endless different universes
built on different kinds of debris,
with distinctive properties, obeying one of a kind laws.
most of these universes should never help life,
and can flash inside and out of existence in a nanosecond.
but nevertheless, combined, they make up a giant multiverse
of viable universes in up to eleven dimensions,
offering wonders beyond our wildest creativeness.
The leading version of string theory predicts a multiverse
made up of 10 to the 500 universes.
it truly is a one accompanied by 500 zeros,
more than a few so substantial that if every atom
in our observable universe had its personal universe,
and all of the atoms in all the ones universes each had
their own universe,
and also you repeated that for two extra cycles,
you'd nonetheless be at a tiny fraction of the total,
specifically, one thousand billion trillion trillion trillion trillion trillion trillion
trillion trillion trillion trillion trillion trillion trillion trillionth.
but even that range is minuscule in comparison to another number:
a few physicists assume the distance-time continuum is actually limitless
and that it consists of an countless range of so-called pocket universes
with various properties.
How's your mind doing?
Quantum concept provides an entire new wrinkle.
I imply, the concept's been confirmed proper past all doubt,
however deciphering it's far baffling,
and some physicists think you can best un-baffle it
in case you believe that large numbers of parallel universes
are being spawned each moment,
and lots of these universes might in reality be very like the global we're in,
might include multiple copies of you.
in a single such universe, you'd graduate with honors
and marry the man or woman of your desires, and in another, no longer a lot.
well, there are nonetheless some scientists who might say, hogwash.
The best meaningful answer to the question of what number of universes there are is one.
handiest one universe.
And a few philosophers and mystics might argue
that even our personal universe is an phantasm.
So, as you may see, proper now
there's no settlement on this question, now not even close.
All we know is the answer is somewhere among 0 and infinity.
nicely, I guess we recognize an additional element.
that is a pretty cool time to be studying physics.
We simply is probably undergoing the largest paradigm shift in knowledge
that humanity has ever seen.
[Why can't we see evidence of alien life?]
someplace obtainable in that vast universe
there need to clearly be countless different planets teeming with existence.
but why do not we see any evidence of it?
nicely, that is the well-known query requested by means of Enrico Fermi in 1950:
in which is anyone?
Conspiracy theorists claim that UFOs are journeying all the time
and the reports are simply being protected up,
but certainly, they are not very convincing.
however that leaves a actual riddle.
inside the beyond 12 months, the Kepler space observatory
has located masses of planets simply around nearby stars.
And in case you extrapolate that facts,
it looks like there can be half a trillion planets
simply in our personal galaxy.
If anyone in 10,000 has situations
that would guide a shape of lifestyles,
it truly is nonetheless 50 million possible lifestyles-harboring planets
proper right here within the Milky way.
So right here's the riddle:
our Earth failed to shape
until about nine billion years after the big Bang.
infinite different planets in our galaxy ought to have shaped earlier,
and given existence a chance to get underway
billions, or clearly many tens of millions of years earlier than took place on this planet.
If just a few of them had spawned clever lifestyles
and started out creating technologies,
those technologies would have had hundreds of thousands of years
to grow in complexity and electricity.
on the earth,
we've got visible how dramatically era can accelerate
in just 100 years.
In millions of years, an smart alien civilization
ought to without problems have unfold out throughout the galaxy,
possibly developing massive strength-harvesting artifacts
or fleets of colonizing spaceships
or glorious works of art that fill the night time sky.
not less than, you'd assume they had be revealing their presence,
deliberately or otherwise,
thru electromagnetic indicators of one type or every other.
And yet we see no convincing evidence of any of it.
well, there are various feasible answers, some of them quite darkish.
perhaps a single, superintelligent civilization
has certainly taken over the galaxy
and has imposed strict radio silence
as it's paranoid of any capability competitors.
it is simply sitting there geared up to obliterate
anything that will become a chance.
Or perhaps they may be not that wise,
or perhaps the evolution of an intelligence
capable of developing state-of-the-art technology
is a ways rarer than we've assumed.
in any case, it's best came about once in the world in four billion years.
perhaps even that became fairly fortunate.
perhaps we are the first such civilization in our galaxy.
Or, perhaps civilization consists of with it the seeds of its personal destruction
via the lack of ability to govern the technology it creates.
but there are numerous extra hopeful answers.
For a begin, we're not looking that hard,
and we are spending a pitiful amount of cash on it.
simplest a tiny fraction of the celebrities in our galaxy
have really been checked out intently for signs and symptoms of exciting alerts.
And perhaps we're not looking the right way.
perhaps as civilizations expand,
they speedy find out verbal exchange technologies
far more sophisticated and beneficial than electromagnetic waves.
perhaps all the action takes region within the mysterious
these days located dark rely,
or darkish strength, that seem to account for most of the universe's mass.
Or, maybe we're looking at the wrong scale.
possibly sensible civilizations come to realise
that existence is ultimately simply complex patterns of statistics
interacting with each different in a lovely manner,
and that that could happen more effectively at a small scale.
So, simply as on earth, clunky stereo systems have gotten smaller
to stunning, tiny iPods, maybe smart existence itself,
on the way to lessen its footprint on the surroundings,
has grew to become itself microscopic.
So the sun machine is probably teeming with extraterrestrial beings,
and we're just no longer noticing them.
maybe the very thoughts in our heads are a shape of alien lifestyles.
nicely, okay, it truly is a crazy notion.
The aliens made me say it.
however it is cool that thoughts do appear to have a life all of their own
and that they outlive their creators.
perhaps biological life is just a passing phase.
nicely, within the subsequent 15 years,
we should begin seeing actual spectroscopic records
from promising nearby planets
in an effort to monitor simply how existence-friendly they is probably.
And in the meantime, SETI, the look for Extraterrestrial Intelligence,
is now releasing its statistics to the general public
so that tens of millions of citizen scientists, maybe consisting of you,
can convey the power of the group to sign up for the search.
And right here on the earth, exceptional experiments
are being done to try to create life from scratch,
life that is probably very unique from the DNA bureaucracy we recognize.
All of this will assist us apprehend whether or not the universe is teeming with existence
or whether, indeed, it's simply us.
both answer, in its very own manner,
because although we are on my own,
the truth that we think and dream and ask these questions
would possibly but end up
one of the most important information approximately the universe.
And i've one extra piece of appropriate information for you.
the search for knowledge and understanding by no means gets stupid.
It doesn't. it is honestly the other.
The more you understand, the extra extraordinary the sector appears.
And it is the loopy opportunities, the unanswered questions,
that pull us forward.
So live curious.