i read one science fiction story where
the bad guy gets thrown into a black
hole and he screams in fact he screams
forever i'm dr michio kaku professor of
theoretical physics and best-selling
author of the god equation and i'm here
today to answer your questions on
twitter this is physics support
[Music]
cal is not a cow ask
y'all why do atoms want to bond so much
why don't they just stay single you
aren't missing anything atoms want to
bond together that's why we have
molecules that's why we have people dna
our universe is based on atoms which
like to bond with each other the
electron vibrates back and forth binding
them together and that's why we have
molecules that's why we have you you are
a consequence of the fact that electrons
are shared between
different atoms using the laws of the
quantum theory deborah morozak ask the
question what's your favorite law of
physics mine is momentum conservation
well my favorite law of physics is the
equivalence of matter and energy
einstein's equation e equals m c squared
this is why the sun shines it's why the
stars twinkle it's what lights up the
universe we like to think that matter
and energy are totally different things
how can a rock turn into energy however
if that rock is uranium and that energy
is the fireball of a nuclear bomb you
realize that matter and energy are two
sides of the same coin matter energy is
one unit and they can flip into each
other under certain circumstances like
in the heart of a star sean harris at
infosec hotspot asks does anyone know of
people like michio kaku that can explain
string theory like he does for people
like me and i'm not a genius well
i am michio kaku and i'd be glad to
answer that question first of all most
textbooks say
that an electron is a dot particles that
we see in our atom smashers are dots but
if i had a super microscope i can see
that that dot is actually
a rubber band from a distance this
rubber band looks like a dot close up
you see that it's a vibrating string now
this rubber band can vibrate in many
different modes
each mode can be called a particle so
for example this might be an electron
but if you twirl it in a different way
it becomes a quark and if you twirl it
this way you have to give it a different
name we call it a neutrino now how many
ways can one string vibrate the answer
is obvious an infinite number of
vibrations on the same string and so we
think that all the subatomic particles
of the universe
the quarks the neutrinos the mesons the
protons and neutrons there's a galaxy of
these particles they're nothing but
musical notes on a tiny rubber band a
rubber band so small
that it looks like a dot so what is
physics that we had to struggle with in
high school physics is the harmonies
the harmonies of vibrating strings
physics tells us how these vibrations
move what is chemistry chemistry is when
these strings bump into each other and
form molecules alex add kuransk skong
asked what is a quark what is omg
yeah it's a oh my god we think that
inside the proton there are three quarks
subatomic particles that make up the
protons and neutrons which in turn make
up our universe here's a question from
rick at
sojourner99
we live in four dimensions but can see
three how many dimensions are there
einstein says we live in a four
dimensional world we can go forward
backward left right up down and the
fourth dimension is time but now we're
beyond einstein and we have to go beyond
four dimensions to perhaps let's say 10
11 dimensions but where are these other
dimensions we think they have curled up
they're so small that you cannot enter
them but perhaps we can feel their
effects and where is this other
dimension it is off the plane of your
universe perhaps a parallel universe
hovering right above your universe in
another dimension that we cannot see or
touch but perhaps there's a gateway
connecting them that gateway is the
wormhole it was einstein himself in 1935
who introduced the concept of a wormhole
a gateway between higher dimensional
universes well the next question comes
from jay mozak who asked the quantum
universe was einstein wrong about his
theory of relativity yes and no there's
a famous quote where einstein said the
more successful the quantum theory gets
the sillier it looks he thought that
atomic physics that is quantum mechanics
was incomplete when the nobel prize was
given to people like heisenberg he said
yes give them the nobel prize they're on
to something and so weinstein had
reservations about the quantum theory as
the final theory he thought there had to
be a higher theory a theory even beyond
the quantum theory so einstein was not
totally incorrect obi would shaina lang
ask what is the god equation well
einstein spent the last 30 years of his
life chasing after the god equation an
equation perhaps no more than one inch
long
that would allow us to quote read the
mind of god a theory that would unite
the two branches of physics on one hand
we have the theory of the big general
relativity black holes big bangs and the
theory of the small
quantum theory atomic physics how can
you unite these two into one theory at
the present time these two theories hate
each other they're based on different
mathematics different principles
different concepts and yet we believe in
our heart of hearts there has to be a
master theory out there the holy grail
of physics and that we think is the god
equation the leading and only candidate
for that is string theory and by the way
if you ever find the god equation tell
me first we'll split the nobel prize
money together you and me here's a
question from princeton university press
and that is who is your favorite
physicist
46.2 percent said that einstein was
their favorite physicist
53.8 percent thought that richard
feynman was their favorite physicist my
favorite physicist is
isaac newton he asked the question for
the ages
if an apple falls does the moon also
fall and he realized that he didn't have
the mathematics to calculate a falling
moon so what did he do he invented his
own mathematics called calculus and the
theory was one of the greatest theories
of all time newton's law of gravity and
so during the black plague of 1666 one
of the greatest minds in history went
from superstition and thrust us into the
age of mechanics the industrial
revolution he changed world history you
can't beat that einstein is way up there
so is richard feynman but isaac newton
tops them all the next question comes
from hassan babanji who asks can light
bend around corners if yes or no give
one reason yes
light can bend around corners in fact
that's why we have glass inside your
glasses when light goes into glass it
slows down slightly because it slows
down it deviates from a straight line
and that's why we have your glasses
telescopes microscopes because glass
bends light also gravity can bend light
as einstein showed us and we can
actually see the bending of light as it
goes around a galaxy then the next
question is
can you bend light completely around an
object so the object becomes invisible
and the answer is yes
it's well within the laws of physics
that if you could govern the atomic
structure of glass then light would bend
in a way such that it would completely
go around an object so anything inside
that object becomes invisible one day we
will build a meta material out of
nanotechnology
that will bend visible light
so that anything inside that capsule
will become invisible harry potter watch
out boxy fan 2001 asks how do black
holes distort time and what the hell
does that mean time does not beat
uniformly throughout the universe clocks
on the moon beat a little bit faster
than clocks on the planet earth on
jupiter clock speed slower than on the
planet earth the heavier the planet the
slower time beats this means that on a
star like the sun
time beats even slower and the ultimate
star of course is the black hole the
remnants of a dying star we think that
at the very center of the black hole
time stops what does that mean if you
were to fall into a black hole from your
point of view
it would take perhaps a few minutes
let's say to fall through a black hole
depending upon where you started from
your watch says that you went right
through to the center of the black hole
but from outside somebody with a
telescope
looking at you
from outer space would see you frozen in
time
slowly going
into the black hole because time beats
at a different rate from the outside and
the inside get your head around this
time can beat at different rates at
different points in the universe she'll
be asked
like how are black holes and infinite
density even possible like how does
something get so dense that it collapses
on itself i wanna know we know that if i
take a gigantic star or galaxy and
compress it its gravity is so great that
nothing known to science can escape the
clutches of gravity so light itself is
trapped by the black hole and according
to textbooks it collapses to a point of
infinite density let's be real about
this there's no such thing as infinite
density we just say that in textbooks
because we don't know what happens when
a star collapses into a tiny dot
infinite density is a shorthand of
saying
i don't know we really don't know what
happens at the very center of a black
hole if you do the mathematics very
carefully you realize that the black
hole is spinning and spinning stars
collapse to a ring
they don't collapse to a dot at all and
if you fall through the ring the
mathematics says that you fall not just
to the ring but you fall to the other
side to a parallel universe that is on
the other side of a black hole there's a
white hole everything that falls in gets
blown off the other end the village
celeb at the village salem here's a
question for physics people only
i was sitting in the back seat of a bus
which was going at 120 kilometers per
hour a fly rose from my shoulder and
flew right up front and landed on the
drivers so does it mean the fly was
going faster than the bus let's let
newton answer this question
and that is velocities can add if you
are a bystander looking at the bus and
the fly from outside you would say yes
the velocity of the fly
is the velocity of the bus plus
the velocity of the fly
inside the bus velocities can add now of
course if you're inside the bus
the fly seems to go at a very slow rate
if the bus is really a rocket ship
traveling near the speed of light and a
fly flies inside the rocket ship
apparently breaking the light barrier
how's that possible well einstein would
say that you cannot add velocities in
relativity the fly cannot break the
light barrier no matter how fast that
rocket is moving no matter how fast that
fly is moving you cannot go faster than
the speed of light newtonian physics is
wrong that means that the two velocities
have to be adjusted because of the fact
that time
inside the rocket has slowed down now
this is amazing
but it works and this has been measured
repeatedly with our particle
accelerators and our experiments david h
app highwell asked this question what is
dark matter can it be touched is it
dangerous most of the universe is made
out of dark matter dark matter surrounds
the milky way galaxy if it wasn't for
dark matter the milky way galaxy would
have spun out of control and the earth
would be flung into outer space can it
be touched well no because it would
filter right through your fingertips
right through the atoms of your body is
it dangerous no because it doesn't
interact with us and then here's the big
question
what is it there's a nobel prize out
there waiting for that person who can
figure out what dark matter is he said
hiki tak asks what is the difference
between experimental physics and
theoretical physics experimental physics
engages in reality it does experiments
on things you can touch and feel
theoretical physics tries to explain
how and why that happens einstein did
not do experiments on light beams he did
not do experiments on stars and galaxies
by looking through a telescope einstein
work with a pencil and paper that's
called theoretical physics and the heavy
lifting was done by experimentalists who
built the particle accelerators the
telescopes and the devices that allowed
us to probe into the center of stars and
galaxies jihan h asks the question for
physicists is adding a cape to your
superhero costume enhance your flying
abilities i wish that there was a magic
cape that we can suddenly put on and
soar like superman it doesn't work that
way birds fly not because they flap
their wings birds fly because of the
shape of their wings the shape of the
wings is an airfoil a tear shape
for the bird's wing air flows over the
tear
and under the tear creating a partial
vacuum on top of the wing that partial
vacuum means that air has to flow
upwards to keep that wing afloat it is
bernoulli's principle so it's not the
cape it's the shape of the wing that is
the key to flying these are the
questions for today and remember there's
no such thing as a dumb question years
ago when a young boy was 16 years of age
he asked a dumb question can you outrace
a light beam that 16 year old boy was
albert einstein and that dumb question
opened up the universe
for physicists and for you and me thanks
for watching physics support