Wow right off the bat that’s pretty
impressive hey what’s up guys welcome
back to lab today I am here with Cody
from Cody’s lab you know this guy you
love this guy I got him here today
because we’re playing with mercury
now the inspiration for today’s video
comes out the comments from Brown
thunder who says do a video explaining
what the inches of mercury mean so I
have Cody here from Cody’s lab to help
me explain exactly why we measure in
inches of mercury so the vacuum gauge
here which is a very common type you’d
see here in the US you see these outer
numbers here they’re actually
referencing inches of mercury mercury
used to be used as a way to measure
differential pressure because a heavy
liquid and it takes a lot to pull it up
the tube and it takes if you measure the
distance you’re pulling of the tube you
can know how much of a cue you have this
gauge just does it without mercury now
back in December I tried a project where
actually built this vacuum chamber just
using simple materials from the story in
this case a glass cookie jar and I have
this liquid filled gauge on the top and
as we suck the air out of the jar we
measure things in inches of mercury I
got three pounds of liquid mercury right
here the purest stuff I’ve had and what
I find is really impressed about these
these are very very tiny bottles be like
an ounce of water but when you pick
these things up they are impressively
heavy it don’t drop I mean this is about
1 pound of mercury if you can imagine
that so it’s actually it’s a little bit
of a mind blow to feel that it feels
about same weight as brass or copper
maybe a little bit heavier so these
bottles are actually full of dental
mercury this is what dentists used to
use to make fillings you know mix this
with powdered silver push it into a
cavity and it harden up and be
chemically resistant and quick fix your
tooth which is kind of mind-blowing if
you think about putting mercury in your
mouth now what would actually happen if
we got mercury in our mouth would that
be concerned as metallic mercury it’s
actually fairly okay spit it out you’ll
be fine okay
it’s only when it’s dissolved into a
solution that can be
absorbed another body it’s really a
problem so this is a branded argenteum
now that’s actually the word for silver
and I’m pretty sure this is just
referencing that this is Quicksilver
which is another name for mercury yeah I
always thought Quicksilver had to do
with surfing so like the shirts I used
to wear Quicksilver but actually
Quicksilver in a second term is mercury
I think it’s called Quicksilver because
it’s silvery in color and if you drop it
it moves quickly a couple it moves very
quickly and we don’t want to drop that
today so mercury is an extremely heavy
liquid it’s very dense 13 times heavier
than water and so if you try to pull it
up a tube you’ll reach a point where you
cannot pull it up any more because you
know you’re not really sucking a liquid
of the tube just the atmospheric
pressure pushing it up into the vacuum
you’re creating at sea level you get
about fourteen point seven pounds per
square inch pushing down and so you
should be able to lift the equivalent of
14 pounds of mercury so we have a long
glass tube here it’s very narrow and
Cody just challenged me to see if we
could put one end into a bottle of
mercury and suck the other end like a
straw and see we could suck a hard
enough to get the mercury in our mouth
so that is a risk I’m willing to take
for you can we suck mercury vertically
through a tube you know a distance of
four and a half feet so drop down to the
comment to take a second to tell us who
you think sucks more you really
[Music]
alright guys a quick update these rods
are a little bit too long so Kota just
used his cool little glass cutting tool
when we trimmed them down to about 36
inches or about three feet so I have one
job and my only job right now is to make
sure the bottom of this measuring stick
stays level with the top of the mercury
when Cody starts sucking we’re going to
be able to measure in real inches of
mercury how much vacuum he’s able to
pull all right Cody you ready for this
all right let’s see what you got
Wow right off the bat that’s pretty
impressive he’s already up to 20 so you
got 19 inches of mercury and go any
harder than that maybe if I tried really
hard all right let’s try it again
all right 19 inches is good it’s not
that impressive you start freezing
nitrogen around 22 oh there’s 22 but all
we can do what do you see there 22 and
3/4 okay here it comes LFO bounces on
the way up boom okay so at 21 22 it’s
kind of bouncing there so Stuart settles
out for about 21 and 3/4 how’s your
mouth stealing Cody ah it takes a lot of
work so I’m just like kind of pumping
the air with my tongue trying to
evacuate as much of the air out of tube
as I can especially as hard as I
possibly can and I was unable to pull
the mercury all the way up to the vacuum
pump that I’m using says it can pull 25
inches of mercury and I filled with a
lot of the reactions I do it’s right
around 22 inches of mercury that I see
balloons expanding I see water boiling
XSEDE liquid nitrogen freezing Cody got
up to 21 it’s like almost 20 to 21 and
3/4 which actually wasn’t too bad so
theoretically if you could suck hard
enough for long enough you might be able
to freeze liquid nitrogen like yourself
that’s cool all right I’m going to jump
in and see what I can do
[Music]
we’ll do that
[Music]
4.4
[Music]
the best licks more shall we get to the
point where saliva boiling ya mean want
to pull out but yet hey oh yeah see
there’s none of that
Oh whoo that was interesting though it
felt like as I was moving the tube up
the mercury is actually dropping back
down the tube like it was jiggling even
though I was moving yeah as you move the
rod up you know a mercury actually went
back down yeah mercury is always going
to stay at the same height above the
surface of the Merc which is interesting
right it’s not like you can just plug it
and move this thing around it’s like as
I moved it up the mercury went down as I
moved it down the mercury went back up
[Music]
this time I’m going to try and pull it
out and I’m going to set it back down
beside the disks there okay here we go
[Music]
Oh
[Music]
yeah career fect oh that’s amazing
let’s take a second to just talk about
what happened there so what we saw here
is actually pulled a vacuum above the
mercury the air pressure pushed some
retreat up the tube and we weren’t able
to get a perfect vacuum but we were able
to actually get a pretty decent vacuum
we pulled the mercury of 23 something
check out my tongue I was trying to hold
the vacuum with my tongue it’s like
sucking my tongue down inside I think
it’s an interesting point it’s not
necessarily that I was sucking the
liquid up it’s just I was reducing the
pressure and the outside air pressure
was pushing the mercury back ups all
right and since mercury is so heavy the
distance that air pressure can push it
up is just a couple of pieces yeah once
you get up around there 24 25 it gets
very very difficult to go any higher
like what would you consider a perfect
vacuum in inches of mercury so at this
altitude we’re not at sea level right
now 25 inches of mercury would be about
a certain vacuum if you’re at sea level
would be about 29 that’s really
interesting because when you think about
it the closer you get to sea level the
more atmosphere you have pressing down
and so when you reduce the atmosphere
inside the tube there’s actually more
pressure to push it up so at sea level
29 inches of mercury might be close to
perfect vacuum and our altitude here
it’s closer to 25 so that’s very
interesting that by sucking it by mouth
we can actually approach very very
closely to those numbers however that
last inch of mercury is kind of where
all the magic happens now we’re going to
hook the vacuum pump up and see how high
the vacuum pump can pull the mercury
when I bought this vacuum pump here it
claims to be able to do 25 inches of
mercury which we read on our gauge all
the time so we’re put that to the test
with real mercury and real inches and
observe the difference exactly cody’s
over here trying to rig everything
together with glass and torches and do
everything professional I think I’m just
going to shove this down the tube use a
little electrical tape and see if we can
Jimmy rig it that way
all right what do you think that can do
it yeah we’ll get a glass tube connected
to the poly vacuum tube we’re going to
draw with the machine power and see how
machine compares all right here we go
man versus machine
let’s kick on the pump well that’s back
[Music]
so it’s like to turn men women can go
ahead yeah a little bit of momentum
there probably turn it on now top of the
mercury 25-ish be a high-pressure day
there’s a little over 25 yeah 3 almost
on a twenty six twenty five and three
quarters and the bottom of the ruler is
matching the top of the mercury it is
1325 and three quarters yeah is it
creeping its way up a little bit more
not really it’s just kind of hold I know
you always knew you’re right but now I
know why you’re right right on right on
so cool let’s talk about this for a
second Kody sucked the mercury up almost
22 inches of mercury I got almost to 24
and I think this elevation a full vacuum
would be somewhere around 25 little more
than 25 we’ve got this way up to 26 – is
that really accurate both the air
pressure is high you know it’s this nice
day then the pressure will be higher and
the mercury will go a lot more fact
that’s how barometers work and to go
over to my channel that was a little
ordinary building next so very cool
experiment man versus machine I think
what we saw is the machine actually
sucks about an inch or two of mercury
more than we do but what’s interesting
is that inch or two makes all the
difference in watching the actual
reactions inside of a space another
thing is just making sense to me now is
the reason that they probably use
Mercury’s in the old thermometers is
because it’s such a dense metal so it
takes a lot to move it and that way you
can compact it into a small space it’s
one reason I mean if you used like a
really light metal like aluminum your
thermometer would have to be like ten
times bigger
yeah like the old alcohol thermometers
actually had a spiral because out
and so mark no kidding that’s cool so on
the periodic table of elements
mercury is actually listed HG correct
great that’s why if you look at the
gauge you’re actually going to see a
little in Hg it’s actually measured in
inches of mercury now you know if you
guys like these mercury experiments and
the things that we’re doing to glass
tubes check out what we’re doing on
Cody’s labs channel we’re building
barometers to actually measure the
differential and pressure around us
every day like on a good day so the
pressure is higher than on a rainy day
and we’re elemér it can be used to
predict that very old technology but
still very relevant today and we use it
all the time you just don’t know about
it because now it’s on Google weather so
hopefully this helps answer the question
of why gauges are measured in inches of
mercury that puts a little visual with
it and of course a big thanks to our
friend Brown thunder for requesting this
in the comments below you can go ahead
and check your youtube inbox Brown
thunder or sending 25 bucks thanks for
joining us for this experiment today
we’ll be looking for you the next one
talk to you there it comes a little bit
numb from stretching so hard
don’t put mercury in your mouth guys
[Music]
you
impressive hey what’s up guys welcome
back to lab today I am here with Cody
from Cody’s lab you know this guy you
love this guy I got him here today
because we’re playing with mercury
now the inspiration for today’s video
comes out the comments from Brown
thunder who says do a video explaining
what the inches of mercury mean so I
have Cody here from Cody’s lab to help
me explain exactly why we measure in
inches of mercury so the vacuum gauge
here which is a very common type you’d
see here in the US you see these outer
numbers here they’re actually
referencing inches of mercury mercury
used to be used as a way to measure
differential pressure because a heavy
liquid and it takes a lot to pull it up
the tube and it takes if you measure the
distance you’re pulling of the tube you
can know how much of a cue you have this
gauge just does it without mercury now
back in December I tried a project where
actually built this vacuum chamber just
using simple materials from the story in
this case a glass cookie jar and I have
this liquid filled gauge on the top and
as we suck the air out of the jar we
measure things in inches of mercury I
got three pounds of liquid mercury right
here the purest stuff I’ve had and what
I find is really impressed about these
these are very very tiny bottles be like
an ounce of water but when you pick
these things up they are impressively
heavy it don’t drop I mean this is about
1 pound of mercury if you can imagine
that so it’s actually it’s a little bit
of a mind blow to feel that it feels
about same weight as brass or copper
maybe a little bit heavier so these
bottles are actually full of dental
mercury this is what dentists used to
use to make fillings you know mix this
with powdered silver push it into a
cavity and it harden up and be
chemically resistant and quick fix your
tooth which is kind of mind-blowing if
you think about putting mercury in your
mouth now what would actually happen if
we got mercury in our mouth would that
be concerned as metallic mercury it’s
actually fairly okay spit it out you’ll
be fine okay
it’s only when it’s dissolved into a
solution that can be
absorbed another body it’s really a
problem so this is a branded argenteum
now that’s actually the word for silver
and I’m pretty sure this is just
referencing that this is Quicksilver
which is another name for mercury yeah I
always thought Quicksilver had to do
with surfing so like the shirts I used
to wear Quicksilver but actually
Quicksilver in a second term is mercury
I think it’s called Quicksilver because
it’s silvery in color and if you drop it
it moves quickly a couple it moves very
quickly and we don’t want to drop that
today so mercury is an extremely heavy
liquid it’s very dense 13 times heavier
than water and so if you try to pull it
up a tube you’ll reach a point where you
cannot pull it up any more because you
know you’re not really sucking a liquid
of the tube just the atmospheric
pressure pushing it up into the vacuum
you’re creating at sea level you get
about fourteen point seven pounds per
square inch pushing down and so you
should be able to lift the equivalent of
14 pounds of mercury so we have a long
glass tube here it’s very narrow and
Cody just challenged me to see if we
could put one end into a bottle of
mercury and suck the other end like a
straw and see we could suck a hard
enough to get the mercury in our mouth
so that is a risk I’m willing to take
for you can we suck mercury vertically
through a tube you know a distance of
four and a half feet so drop down to the
comment to take a second to tell us who
you think sucks more you really
[Music]
alright guys a quick update these rods
are a little bit too long so Kota just
used his cool little glass cutting tool
when we trimmed them down to about 36
inches or about three feet so I have one
job and my only job right now is to make
sure the bottom of this measuring stick
stays level with the top of the mercury
when Cody starts sucking we’re going to
be able to measure in real inches of
mercury how much vacuum he’s able to
pull all right Cody you ready for this
all right let’s see what you got
Wow right off the bat that’s pretty
impressive he’s already up to 20 so you
got 19 inches of mercury and go any
harder than that maybe if I tried really
hard all right let’s try it again
all right 19 inches is good it’s not
that impressive you start freezing
nitrogen around 22 oh there’s 22 but all
we can do what do you see there 22 and
3/4 okay here it comes LFO bounces on
the way up boom okay so at 21 22 it’s
kind of bouncing there so Stuart settles
out for about 21 and 3/4 how’s your
mouth stealing Cody ah it takes a lot of
work so I’m just like kind of pumping
the air with my tongue trying to
evacuate as much of the air out of tube
as I can especially as hard as I
possibly can and I was unable to pull
the mercury all the way up to the vacuum
pump that I’m using says it can pull 25
inches of mercury and I filled with a
lot of the reactions I do it’s right
around 22 inches of mercury that I see
balloons expanding I see water boiling
XSEDE liquid nitrogen freezing Cody got
up to 21 it’s like almost 20 to 21 and
3/4 which actually wasn’t too bad so
theoretically if you could suck hard
enough for long enough you might be able
to freeze liquid nitrogen like yourself
that’s cool all right I’m going to jump
in and see what I can do
[Music]
we’ll do that
[Music]
4.4
[Music]
the best licks more shall we get to the
point where saliva boiling ya mean want
to pull out but yet hey oh yeah see
there’s none of that
Oh whoo that was interesting though it
felt like as I was moving the tube up
the mercury is actually dropping back
down the tube like it was jiggling even
though I was moving yeah as you move the
rod up you know a mercury actually went
back down yeah mercury is always going
to stay at the same height above the
surface of the Merc which is interesting
right it’s not like you can just plug it
and move this thing around it’s like as
I moved it up the mercury went down as I
moved it down the mercury went back up
[Music]
this time I’m going to try and pull it
out and I’m going to set it back down
beside the disks there okay here we go
[Music]
Oh
[Music]
yeah career fect oh that’s amazing
let’s take a second to just talk about
what happened there so what we saw here
is actually pulled a vacuum above the
mercury the air pressure pushed some
retreat up the tube and we weren’t able
to get a perfect vacuum but we were able
to actually get a pretty decent vacuum
we pulled the mercury of 23 something
check out my tongue I was trying to hold
the vacuum with my tongue it’s like
sucking my tongue down inside I think
it’s an interesting point it’s not
necessarily that I was sucking the
liquid up it’s just I was reducing the
pressure and the outside air pressure
was pushing the mercury back ups all
right and since mercury is so heavy the
distance that air pressure can push it
up is just a couple of pieces yeah once
you get up around there 24 25 it gets
very very difficult to go any higher
like what would you consider a perfect
vacuum in inches of mercury so at this
altitude we’re not at sea level right
now 25 inches of mercury would be about
a certain vacuum if you’re at sea level
would be about 29 that’s really
interesting because when you think about
it the closer you get to sea level the
more atmosphere you have pressing down
and so when you reduce the atmosphere
inside the tube there’s actually more
pressure to push it up so at sea level
29 inches of mercury might be close to
perfect vacuum and our altitude here
it’s closer to 25 so that’s very
interesting that by sucking it by mouth
we can actually approach very very
closely to those numbers however that
last inch of mercury is kind of where
all the magic happens now we’re going to
hook the vacuum pump up and see how high
the vacuum pump can pull the mercury
when I bought this vacuum pump here it
claims to be able to do 25 inches of
mercury which we read on our gauge all
the time so we’re put that to the test
with real mercury and real inches and
observe the difference exactly cody’s
over here trying to rig everything
together with glass and torches and do
everything professional I think I’m just
going to shove this down the tube use a
little electrical tape and see if we can
Jimmy rig it that way
all right what do you think that can do
it yeah we’ll get a glass tube connected
to the poly vacuum tube we’re going to
draw with the machine power and see how
machine compares all right here we go
man versus machine
let’s kick on the pump well that’s back
[Music]
so it’s like to turn men women can go
ahead yeah a little bit of momentum
there probably turn it on now top of the
mercury 25-ish be a high-pressure day
there’s a little over 25 yeah 3 almost
on a twenty six twenty five and three
quarters and the bottom of the ruler is
matching the top of the mercury it is
1325 and three quarters yeah is it
creeping its way up a little bit more
not really it’s just kind of hold I know
you always knew you’re right but now I
know why you’re right right on right on
so cool let’s talk about this for a
second Kody sucked the mercury up almost
22 inches of mercury I got almost to 24
and I think this elevation a full vacuum
would be somewhere around 25 little more
than 25 we’ve got this way up to 26 – is
that really accurate both the air
pressure is high you know it’s this nice
day then the pressure will be higher and
the mercury will go a lot more fact
that’s how barometers work and to go
over to my channel that was a little
ordinary building next so very cool
experiment man versus machine I think
what we saw is the machine actually
sucks about an inch or two of mercury
more than we do but what’s interesting
is that inch or two makes all the
difference in watching the actual
reactions inside of a space another
thing is just making sense to me now is
the reason that they probably use
Mercury’s in the old thermometers is
because it’s such a dense metal so it
takes a lot to move it and that way you
can compact it into a small space it’s
one reason I mean if you used like a
really light metal like aluminum your
thermometer would have to be like ten
times bigger
yeah like the old alcohol thermometers
actually had a spiral because out
and so mark no kidding that’s cool so on
the periodic table of elements
mercury is actually listed HG correct
great that’s why if you look at the
gauge you’re actually going to see a
little in Hg it’s actually measured in
inches of mercury now you know if you
guys like these mercury experiments and
the things that we’re doing to glass
tubes check out what we’re doing on
Cody’s labs channel we’re building
barometers to actually measure the
differential and pressure around us
every day like on a good day so the
pressure is higher than on a rainy day
and we’re elemér it can be used to
predict that very old technology but
still very relevant today and we use it
all the time you just don’t know about
it because now it’s on Google weather so
hopefully this helps answer the question
of why gauges are measured in inches of
mercury that puts a little visual with
it and of course a big thanks to our
friend Brown thunder for requesting this
in the comments below you can go ahead
and check your youtube inbox Brown
thunder or sending 25 bucks thanks for
joining us for this experiment today
we’ll be looking for you the next one
talk to you there it comes a little bit
numb from stretching so hard
don’t put mercury in your mouth guys
[Music]
you
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