today we’re going to see what happens if
you put rocks in a vacuum chamber and
try and explain the result that we get
over the years we have had dozens if not
hundreds of people asking to see what
would happen if we put a rock in a
vacuum chamber I’m pretty sure I already
know the answer but because so many of
you have asked we’re going to try it and
then we’re going to discuss why we’re
seeing what we’re seeing the idea here
is about as simple as it gets
we’ll take a few different types of rock
put them into our vacuum chamber and
suck out all the air I’ve got a few
different types of rock here this one I
just pulled out of a planter box it’s a
pretty standard looking Rock feels heavy
it’s hard I would just call that a rock
this second Rock is a volcanic type of
rock that’s called scoria it’s formed
when lava comes up out of the ground and
hitting lower pressure forms lots of
bubbles and then cools off like that
it’s not quite as light or air filled as
pumice but it is similar these two rocks
are varieties of what at least claim to
be pumice they’re both commercially
available this black one is sold at
fabric stores and is designed for
restoring the proper texture on sweaters
it’s extremely lightweight and basically
feels just like a sponge
except it’s made of rock this second one
is a cleaning stone I just got this at a
department store it costs like a dollar
fifty again this claims to be natural
stone that’s just been cut into this
shape I’m not sure if it’s supposed to
be actual pumice or there’s something a
lot like pumice pumice is another type
of volcanic rock that forms about the
same way as the magma comes up out of
the ground it’s no longer pressurized
and all the dissolved gases in it form
bubbles and it then solidifies in that
state pumice is supposed to be a rock
that’s so light and full of air that it
can actually float on water and we’ll
probably do a little bit of that in a
minute after we’ve done our vacuum tests
I don’t want to vacuum them while
they’re wet so we’re just gonna do our
vacuum test first and if they survived
we’ll try the water thing we’re now
going to take each of these rocks and
give them a chance to experience being
in a vacuum chamber we’re gonna start
with our densest rock just set that down
in there and see what happens as we pull
all the air out
[Music]
[Applause]
[Applause]
all right that didn’t do anything in
fact it did so little that I’m gonna add
a visual aid just to show that things
are getting vacuumed this is a ziploc
bag and it’s just sealed off we’re just
gonna add it’s a tiny bit of air into it
so now let’s see if the bag does
anything while it’s in the chamber with
the rock is just so we can see if we’re
really getting low pressure bag is
already moving bag can barely be held in
place by our vacuum chamber all right so
the bags expand you can see the
difference in the vacuum you can see
what happens oh wow and now it’s
collapsing the bag expanded a ton as we
sucked all the air out of our jars that
rock did not move at all Rock one vacuum
chamber zero let’s move on to our scoria
rock this rock has a lot more air in it
than the last one so maybe it will be
different
I think that’s as low pressure as we’re
gonna get and once again a whole lot of
nothing happening to this rock here that
was air rushing from the valve pushing
on the rock not the change in pressure
all right let’s move on to our really
lightweight rocks this one next up in
density
[Music]
nothing with that stone we’ve got one
that’s about as much vacuum is we’re
gonna pull and really no change at all I
just want to do a little test you can’t
really feel these different rocks but
we’ve got a scale here we’ve got grams
and grams this rock is 147 this rock
which I would say is approximately
double the volume 22 so this rock weighs
more than six times as much as this
pumice brick here and this pumice brick
is probably twice the volume which means
this is 12 or 13 times less dense than
this rock this one has so much air in it
we are going to do a quick demonstration
to see if these two rocks float on water
[Music]
seriously this one is like about the
density of styrofoam I think most
extremely well
[Music]
now that I’ve put this in the water
we’re going to throw it back in the
vacuum chamber and just see if it pulls
[Applause]
not really much there either so the
water that got on this wasn’t really
pulled into the stone at all it was
mostly just done the holes in the
surface of the stone but why is it that
we can put a ziploc bag in with almost
no wear and it balloons up to fill this
whole container but the stones that have
so many little bubbles don’t really seem
to do anything it has to do with how a
vacuum chamber works normal air the air
that’s around us if we are at sea level
that’s approximately fourteen point
seven psi which stands for pounds per
square inch that means that every square
inch on your skin your clothes
everything around you has about 15
pounds of pressure on it that’s like the
size of a large bowling ball pressing
down on it it doesn’t feel like that
because that’s always there that’s what
we’ve grown with and down to our very
cells
that’s what’s normal to us when we start
pulling the air out of the vacuum
chamber it’s no longer pressing on
things so inside this ziplock bag if we
just open this bag put a little bit of
air into it and then put that into the
vacuum chamber when we turn the vacuum
chamber on there’s no longer 15 psi
squishing down on this bag but there is
still a are inside and that air went
into the bag at 15 psi which means if we
pull a perfect vacuum all of that air
would begin to press out with that same
pressure that would be 15 psi of air
inside a ziploc bag and the ziplock bag
can’t really take that much pressure
washed down flat again back to the
almost entirely empty that it is but the
thing is it’s not perfectly empty there
is a little bit of air in this bag and
we can sort of maybe squish it all into
one spot or something like that and we
could see that that tiny tiny amount of
air is what’s expanding on the inside
when the vacuum chamber is turned on so
there you go that’s how much air there
was in this bag and that expanded to
completely fill our little vacuum
chamber so if the bag has a little bit
of air in it and the stones have a
little bit of air in it why is it the
bag inflates but the stones don’t really
change they don’t inflate they don’t
crack they don’t even chip there’s not
dust flying off of them all through the
inside of this rock are tiny little air
bubbles and when you pull the air out
from around them they do start exerting
pressure and as I said 15 psi is a good
amount of pressure each one of these
tiny little bubbles is only one or two
millimeters in diameter and although 15
pounds per square inch is quite a lot
when you divide it up it stops being so
big and I know I’m crossing measurement
systems here but one square inch has
approximately 645 square millimeters in
it and when you divide the 15 psi of the
atmosphere by 645 you end up with point
zero two pounds of pressure point zero
two pounds of pressure isn’t enough to
break through the walls of this stone it
is a soft stone I think I can even just
break it off and crumble it in my
fingers but it’s still not soft enough
that that tiny tiny amount of air can
break through the walls of it so can you
break locks apart by using vacuum no you
cannot break rocks apart by using a
vacuum at least none of the rocks that I
have available to me there may be some
kinds of pumice that are so light and so
weak and so full there that you can pull
them apart and that seems like it would
be pretty fun to do but I’ve never used
one of those rocks I’ve never seen one
as far as I know and I don’t think I’m
gonna be able to get my hands on one but
it’s interesting to learn about why some
things react and some things don’t and
that’s also sort of a thought experiment
when you’re wondering what would happen
something if you put it into a vacuum
chamber is the amount of air that’s
inside it enough that it’s going to
overcome the
sure of whatever’s holding that air in
place so it is good to try things out
although knowing how the vacuum chamber
works and what makes the difference
between something that does or does not
expand can give you at least a start of
an idea when you’re wondering what’s
gonna happen guys that’s not all we’ve
always got more for you to see that box
up at the top will take you directly to
our last video and you should go check
that out the other box will show you
what YouTube thinks you should be
watching next and if you aren’t a
subscriber yet just hit this bomb to get
in the club and that way you’ll never
miss out on the fun don’t forget to ring
that Bell and we will see you in the next one talk to you then
you put rocks in a vacuum chamber and
try and explain the result that we get
over the years we have had dozens if not
hundreds of people asking to see what
would happen if we put a rock in a
vacuum chamber I’m pretty sure I already
know the answer but because so many of
you have asked we’re going to try it and
then we’re going to discuss why we’re
seeing what we’re seeing the idea here
is about as simple as it gets
we’ll take a few different types of rock
put them into our vacuum chamber and
suck out all the air I’ve got a few
different types of rock here this one I
just pulled out of a planter box it’s a
pretty standard looking Rock feels heavy
it’s hard I would just call that a rock
this second Rock is a volcanic type of
rock that’s called scoria it’s formed
when lava comes up out of the ground and
hitting lower pressure forms lots of
bubbles and then cools off like that
it’s not quite as light or air filled as
pumice but it is similar these two rocks
are varieties of what at least claim to
be pumice they’re both commercially
available this black one is sold at
fabric stores and is designed for
restoring the proper texture on sweaters
it’s extremely lightweight and basically
feels just like a sponge
except it’s made of rock this second one
is a cleaning stone I just got this at a
department store it costs like a dollar
fifty again this claims to be natural
stone that’s just been cut into this
shape I’m not sure if it’s supposed to
be actual pumice or there’s something a
lot like pumice pumice is another type
of volcanic rock that forms about the
same way as the magma comes up out of
the ground it’s no longer pressurized
and all the dissolved gases in it form
bubbles and it then solidifies in that
state pumice is supposed to be a rock
that’s so light and full of air that it
can actually float on water and we’ll
probably do a little bit of that in a
minute after we’ve done our vacuum tests
I don’t want to vacuum them while
they’re wet so we’re just gonna do our
vacuum test first and if they survived
we’ll try the water thing we’re now
going to take each of these rocks and
give them a chance to experience being
in a vacuum chamber we’re gonna start
with our densest rock just set that down
in there and see what happens as we pull
all the air out
[Music]
[Applause]
[Applause]
all right that didn’t do anything in
fact it did so little that I’m gonna add
a visual aid just to show that things
are getting vacuumed this is a ziploc
bag and it’s just sealed off we’re just
gonna add it’s a tiny bit of air into it
so now let’s see if the bag does
anything while it’s in the chamber with
the rock is just so we can see if we’re
really getting low pressure bag is
already moving bag can barely be held in
place by our vacuum chamber all right so
the bags expand you can see the
difference in the vacuum you can see
what happens oh wow and now it’s
collapsing the bag expanded a ton as we
sucked all the air out of our jars that
rock did not move at all Rock one vacuum
chamber zero let’s move on to our scoria
rock this rock has a lot more air in it
than the last one so maybe it will be
different
I think that’s as low pressure as we’re
gonna get and once again a whole lot of
nothing happening to this rock here that
was air rushing from the valve pushing
on the rock not the change in pressure
all right let’s move on to our really
lightweight rocks this one next up in
density
[Music]
nothing with that stone we’ve got one
that’s about as much vacuum is we’re
gonna pull and really no change at all I
just want to do a little test you can’t
really feel these different rocks but
we’ve got a scale here we’ve got grams
and grams this rock is 147 this rock
which I would say is approximately
double the volume 22 so this rock weighs
more than six times as much as this
pumice brick here and this pumice brick
is probably twice the volume which means
this is 12 or 13 times less dense than
this rock this one has so much air in it
we are going to do a quick demonstration
to see if these two rocks float on water
[Music]
seriously this one is like about the
density of styrofoam I think most
extremely well
[Music]
now that I’ve put this in the water
we’re going to throw it back in the
vacuum chamber and just see if it pulls
[Applause]
not really much there either so the
water that got on this wasn’t really
pulled into the stone at all it was
mostly just done the holes in the
surface of the stone but why is it that
we can put a ziploc bag in with almost
no wear and it balloons up to fill this
whole container but the stones that have
so many little bubbles don’t really seem
to do anything it has to do with how a
vacuum chamber works normal air the air
that’s around us if we are at sea level
that’s approximately fourteen point
seven psi which stands for pounds per
square inch that means that every square
inch on your skin your clothes
everything around you has about 15
pounds of pressure on it that’s like the
size of a large bowling ball pressing
down on it it doesn’t feel like that
because that’s always there that’s what
we’ve grown with and down to our very
cells
that’s what’s normal to us when we start
pulling the air out of the vacuum
chamber it’s no longer pressing on
things so inside this ziplock bag if we
just open this bag put a little bit of
air into it and then put that into the
vacuum chamber when we turn the vacuum
chamber on there’s no longer 15 psi
squishing down on this bag but there is
still a are inside and that air went
into the bag at 15 psi which means if we
pull a perfect vacuum all of that air
would begin to press out with that same
pressure that would be 15 psi of air
inside a ziploc bag and the ziplock bag
can’t really take that much pressure
washed down flat again back to the
almost entirely empty that it is but the
thing is it’s not perfectly empty there
is a little bit of air in this bag and
we can sort of maybe squish it all into
one spot or something like that and we
could see that that tiny tiny amount of
air is what’s expanding on the inside
when the vacuum chamber is turned on so
there you go that’s how much air there
was in this bag and that expanded to
completely fill our little vacuum
chamber so if the bag has a little bit
of air in it and the stones have a
little bit of air in it why is it the
bag inflates but the stones don’t really
change they don’t inflate they don’t
crack they don’t even chip there’s not
dust flying off of them all through the
inside of this rock are tiny little air
bubbles and when you pull the air out
from around them they do start exerting
pressure and as I said 15 psi is a good
amount of pressure each one of these
tiny little bubbles is only one or two
millimeters in diameter and although 15
pounds per square inch is quite a lot
when you divide it up it stops being so
big and I know I’m crossing measurement
systems here but one square inch has
approximately 645 square millimeters in
it and when you divide the 15 psi of the
atmosphere by 645 you end up with point
zero two pounds of pressure point zero
two pounds of pressure isn’t enough to
break through the walls of this stone it
is a soft stone I think I can even just
break it off and crumble it in my
fingers but it’s still not soft enough
that that tiny tiny amount of air can
break through the walls of it so can you
break locks apart by using vacuum no you
cannot break rocks apart by using a
vacuum at least none of the rocks that I
have available to me there may be some
kinds of pumice that are so light and so
weak and so full there that you can pull
them apart and that seems like it would
be pretty fun to do but I’ve never used
one of those rocks I’ve never seen one
as far as I know and I don’t think I’m
gonna be able to get my hands on one but
it’s interesting to learn about why some
things react and some things don’t and
that’s also sort of a thought experiment
when you’re wondering what would happen
something if you put it into a vacuum
chamber is the amount of air that’s
inside it enough that it’s going to
overcome the
sure of whatever’s holding that air in
place so it is good to try things out
although knowing how the vacuum chamber
works and what makes the difference
between something that does or does not
expand can give you at least a start of
an idea when you’re wondering what’s
gonna happen guys that’s not all we’ve
always got more for you to see that box
up at the top will take you directly to
our last video and you should go check
that out the other box will show you
what YouTube thinks you should be
watching next and if you aren’t a
subscriber yet just hit this bomb to get
in the club and that way you’ll never
miss out on the fun don’t forget to ring
that Bell and we will see you in the next one talk to you then
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