Hi everybody ! Today's episode is about microgravity.
So there's this company called Novespace that makes zero-G flights
They had invited and we had been trying to schedule this for some time already
And I thought it was a good opportunity
to ask some international youtubers
to join me on that flight.
So, I asked Derek Muller from Veritasium
as well as Dianna Cowern from Physics Girl
to join me...
...on this...
...parabolic flight.
it's been quite hard to organize, but we made it.
And when they made it to France
we first had a meetup at the ESPCI in Paris (Physics and Chemistry college)
it wad pretty cool
then we all travelled to Bordeaux
for the pre-flight briefing.
(Jean-François Clervoy / Novespace CEO & former astronaut)
This is a rule in aeronautics
you don't get to fly
without a pre-flight briefing.
whenever you get on a plane,
you always have goals.
even the pilot who will say : now we go up 4.000ft
now let's bring our speed to 250 knots
now let's go down 3.000ft — constantly with a goal.
hence the pre-flight briefing,
in which we've learned about
the other activities conducted on the same flight, namely
two people making VR experiments
in zero-G.
let me say that again...
Virtual reality experiments...
in zero-G.
I haven't tested it, but it sound pretty terrifying.
we also had a dancer onboard
who was microgravity-dancing
if I can find out her name and her website, channel or whatever
I put the links in the description because
she does amazing things, she's like the Lindsey Stirling of dancers...
but more on her later, you'll see...
after the briefing, obviously, we all got our medical shot
...so that we wouldn't...
...puke
ok. Feels like doing the...
well, we could do it, actually!
— sure! — ok, let's!
(doctor) ever got a tattoo ?
nope.
well, it's...not the same.
alright.
well, that's just an injection
relax your arm...
...there's the muscle (note : hell yeah)
all done ?
(doctor) no swimming now.
no swimming for...
...6 years!
you should've told me before!
(doctor) what's your name ?
Benamran
(me) Bruce / (doctor) Bruno
no, Bruce...did they write Bruno ?
(doctor) yeah...sorry
Bruno is my cousin...
...so be it.
let's take a minute to talk about what's happening
in a former video I made about our senses
I had explained how we could get seasick
and when you're on a parabolic flight,
there are parts of the flight in which
you're subjected to hypergravity.
actually, the microgravity is not really a problem
it's really the hypergravity
when you feel almost twice as heavy
and when you move your head
your internal ear...
...responsible for the interpreting those movements...
...doesn't get why those movements are twice as intense as usual...
...and this is when you can get sick.
So, we get shot with scopolamine (or hyoscine)
which is...quite some drug, actually...
maybe I'll make another video about scopolamine
because there's a lot to say about it
for example, I let you google the fact
it's known and sometimes referred to as "the thieves drug"
well, well, well...
and which, on high dose, can induce...
...hallucinations, delirium, and so on...
but its first effect is to prevent your brain
from sending a signal to throw up.
researching this topic, i found out that
rats do not throw up.
rats are totally vomit free.
So how do rats do if and when they get poisoned ? well...
...first of all, they developed some fine-tuned taste and smell senses...
...and whenever they discover some unknown food...
...they have their elders and their sicks taste the food first.
that's nice.
So! One of the scopolamine side-effect
— you'll be able to spot that quite easily —
...besides the fact your mouth is totally dry
you almost completely stop secreting saliva and other fluids
you get totally...(vacuum sound)...sucked up
besides that, scopolamine will get you quite euphoric
add the fact then when you float in zero-g you get naturally elated,
and it's no wonder why...
...you'll constantly be hearing people going
"it's awesome / it's great / Weeeeee"
that drug gets you high...and a bit dumb
it doesn't make you agressive or anything...just a bit dumb.
Obviouly, since we were on a flight with Veritasium and Physics Girl,
you can easily understand...
...that the sound recorded on the plane...
...is mainly in english.
That being said, we didn't take a zero gravity flight just for fun
even though I can assure you we did intend to have a lot of fun.
but we tried to do it quite seriously
and decided to make some experiments
and see the behavior of some things
in microgravity.
I'm going to let Derek and Dianna explain on their channel
the experiments they conducted on the plane
with varying degrees of success
Because it's one thing to imagine an experiment when you're on the ground
but when you're up there, you simply lose control of about everything.
so it sometimes gets quite difficult...
but I guess it's just the way it is. (there's a french lame joke here, don't mind it)
Now about the experiments I've made, two of which were quite similar and yet not exactly the same
At first, I wanted to check the behavior of a helium balloon
in microgravity, but also during the whole time of a parabola, that's to say
during the acceleration phase
during the injection phase, which is the microgravity time,
and during the pull-out phase, in which we get hypergravity again
I wanted to see a helium balloon under those conditions
similarly
I was carrying a half-filled bottle of water
we dyed the water blue so we could see it clearly,
but it really is only water
the bottle was about half full,
so it was about half full of air as well
and I wanted to watch this air bubble
in microgravity.
Moreover, I also wanted to...
...witness a couple of things...
...I knew about newtonian physics
that is about body movements
when they occur in complete zero-g
I mean, you do expect
a movement to go uninterrupted
as long as there's no obstacle to its course.
and whenever there's a collision, there's supposed to be a reaction (Newton's third law)
well, you'll see...
Last but not least, another thing I wanted to do...
...if you have ever watched a parabolic flight...
...you may have noticed that...
...when we enter the weightless phase...
...everybody on the plane is lifted up off the ground.
There's no reason for that, actually...
there doesn't seem to be an impulse pushing them all up
well I made an experiment to figure this out...
I just wish I could get rid of those balloons... I don't know what to do with them now...
I'll try and attach them somewhere...
Let's take a moment to explain precisely what happens
during a parabola
to create microgravity conditions
You've all probably already seen this chart
showing that the plane goes up, and we get about 1.8g
and then
"injection" phase, we enter the microgravity conditions
which feels really close to no gravity at all
it's something around .01g I think
then it's "pull-out", the recuperation phase,
in which we have yet again hypergravity.
So how does this work ? The explanation is
really simple
that everybody has already experimented.
If you have an object in your hand and throw it in the air like so
at the time the object loses contact with your hand
when it's in mid-air
it is actually in zero-g.
because it is submitted only to its own weight.
I've already talked about that in my video about general relativity
when Einstein was looking at workers on a roof, he was wondering
whether, should one of them fall off the roof,
he would feel his own weight while falling
the answer is "no". Being only submitted to his own weight, he would be in zero-g.
But you understand the plane won't let us fall down to the ground
the plane should lift us up and then get us back safely
in order to lift us, we need an upward acceleration
in my example, the movement is only vertical
but with a plane moving forward, it describes a parabola
so...upward acceleration
to give us momentum...
after that, we "take off" and float in zero-g...
and then the recovery
and we should get back on the floor safely
so the plane should get along with our movement
and only then "grab us" back on the floor
and make us steady again after our free-fall.
what soccer players call "trapping"
soccer or any sport with a ball
this is trapping 101.
you follow and absorb the movement of the ball until it stops completely
this means at some point you need to block it.
this means you accelerate against the movement.
It's the end of the parabola
the second hypergravity phase
to make us steady again.
funny thing, when you're on the plane, you don't feel at all
the plane is going up or going down.
one may think it's like a rollercoaster
when it suddenly starts going down
it's not!
because on a rollercoaster,
you are tied to the car you're in
and your body is forced to go down
while everything inside your body is floating
this could make you sick.
here, everything floats...
we're not sick and we don't fell like we're going either up or down
About the helium balloon,
there was a video on Smarter Every Day that you can watch here
in which Destin (the host) showed that when he accelerates in a car
with a helium balloon inside his car
the balloon will be pushed to the front of the car
it isn't pulled to the back as we could imagine it would
but it's pushed to the front.
and when the car slows down, the balloon goes to the back.
and we wanted to see what would happen
in zero-g, and whether, during the hypergravity phases,
would the balloons be pushed towards the front of the plane
we're slowing down, balloons go to the back.
it's funny.
it's really counter-intuitive
the balloons actually seem to point to our trajectory
we're turning to the right and...voilà...
when we enter hypergravity, what happens is the following
from our own prospective, we're pushed down, the plane accelerates upward
we're pushed down to the floor, not to the front or to the back
the string attached to the balloon stretches out
the balloon is pushed upward.
but as soon as we enter microgravity
the parabola isn't perfect; in the beginning
there's always a short time during which
the plane accelerates to the front
that's why you can watch us float to the back of the cabin
and during this time, the balloons go to the front.
but when we really get in microgravity, the balloons then behave
like any air-inflated balloon, bouncing as they can along their movement
and they won't change trajectory until the string is stretched again.
conclusion : this experiment is a success.
we took advantage of the first parabola
to do this experiment because, as we were told,
we shouldn't do anything special the first time in zero-g
and just let go
And you're about to find out some of us let go better than others.
I don't want to snitch about it
but one of us...
— who hosts a youtube channel called Veritasium —
who, during the whole flight...
looks like he has a hard time controling his movements.
I won't brag about it because I kind of feel the same
but clearly Dianna was more comfortable (and sooner than us)
even though she hit the walls a lot
it's a good thing there's foam on every wall
because you hit them a lot
when you float in zero-g
and it should be said that
even though we know
— the tree of us,
four if you include Derek's camera operator —
the four of us know exactly what microgravity is and how it works
and how we can't control a damn thing
yet, we couldn't help having this quite moronic reflex
to try and swim our way in the cabin.
it really doesn't help.
I could make bloopers ouf of it...really...
then I used the second parabola to send a message
to Michael Stevens of the VSauce channel
because we hoped he could make it with us
unfortunately for us — but good for him —
he was on tour with Adam Savage (formerly a MythBuster)
the show (called "Brain Candy") looks incredible
I really hope they'll tour in Europe, because it looks really good
anyway, i've sent him this little message...
a bit cheesy, that's true
scopolamine will do that to you.
we were all being totally inane in da plane (no pun intended)
You can as well see Jean-François Clervoy
CEO of Novespace and a former astronaut
who participated in repairing the Hubble telescope
that guy is for real!
and he can't help showing off on each parabola
doing squats during hypergravity phase
sitting upside down on the ceiling (he really is the BEST GUY EVER)
yet he can afford it, he really has earned it.
then : the bottle of water
we're currently flying normally, it kind of feels like being simply on the ground
if I shake this bottle of blue-dyed water, bubbles will appear
and will quickly go up
the way we're totally used to...
...everyday.
it's going to be a bit different in zero-g.
of course, in microgravity, air bubbles have no reason
to go rather up than down...
if I shake the bottle
bubbles have no reason to go in any direction
whether up or down
let me shake this a bit more, so that it shows more
you can see the bubbles remain in the middle
with everything floating, it's quite surreal.
besides, just as for the helium balloons, when the bottle is spinning,
the water (which is denser and has a greater inertia) is pushed to the ends of the bottle more than the air within
so the air remains in the center.
and this looks on my face, I call it my scopolamine face.
you can see that the staff people of Novespace
with us in the cabin
are always running after us to make sure
our feet are oriented to the floor before the end of the parabolas.
because when gravity gets back, we go from 0g to 1.8g really fast.
even though it's a foam floor, they don't want us to fall down, which we would all the time.
at least we would the first 5 or 6 parabolas.
because we don't control anything while upside down screaming "weeeeeee"
so they're always around saying "feet down, feet down" (in english)
it means "les pieds en bas" (in french)
then there was this question I had
everytime I've watched people in zero-g, whenever they enter 0g
they all take off the floor
is the plane falling a little bit faster?
in weightlessness, there's no reason to take off
if you have no movement, you keep "not moving"
and go along the plane's movement.
to explain this, we made this simple experiment with foam balls, really light foam balls.
when we entered hypergravity, we've put those balls next to us on the floor
and you can see that when we're lifted up
the balls actually only roll on the floor.
So we concluded the following :
we are actually pushed upward
by the floor which is lined with foam
when it doesn't support our weights
from the hypergravity phase
it stretches out
and pushes us. And this slight push is enough to lift us up.
whereas, for the foam balls
they were too light to press on the floor
and so they roll until they hit something
and then only take off.
anyway, it was funny to figure out that
the simple streching out of foam under our bottoms
is suffiscient to lift us up.
as you have seen so far, we constantly try and hold to something while floating in zero-g
there are straps all over the place so that we can hold onto those.
but the dancer onboard decided to dance in front of a green screen
and the green screen made those straps totally inaccessible.
so she couldn't hold on to anything...and so she did
whatever she could.
I'm not showing you more of her as I imagine
she's making her own video
but just a few seconds to that you can imagine how hard it must be.
And as it was my fifth parabola,
I suddenly trusted I was now good enough to float the way I wanted.
I was not.
Then we had this parabola during which i've had a T.A.R.D.I.S. float, because...
...because I was given an opportunity to have a T.A.R.D.I.S. flying around.
That being said
it was not uninteresting, because it showed
things we know about newtonian mechanics,
that is if you initiate a movement and then let go with no other force,
there's no reason why the movement should stop
and it goes on, up until I interrupt it.
Dianna made a more interesting experiment with a gyroscope, you can see it on her video
but I made a T.A.R.D.I.S fly
word.
the "human ring" is a thing they do on every flight
when you're there, it's totally insane.
imagine there are people above you, under you, next to you...
and it doesn't feel at all like being up or down or whatever...
you just seem to spin around as if it was normal.
and I think it looks great as well.
even though it's a bit ridiculous...I mean look at our faces...
but we didn't care. Again, thanks to scopolamine, we were nothing but happy to do it.
So, the human ring. Scientifically, it's totally pointless
but for fun ? It's really nice.
almost as nice — around the same level of "nicehoodness" — as what comes next.
what comes next — and please, see no sexism in what's coming, there isn't any —
we played volleyball...
...with Dianna being the ball...
I call it the Diannaball
This foolish thing showed us another thing about newtonian mechanics
which was totally unexpected. Watch closely as Derek send back Dianna
boy, this is a weird thing to say out loud.
when Derek sends Dianna back to me
his foot slides out of the strap it was in
leaving Derek with nothing to hold on to.
There you can see a real life demonstration of Newton's third law
as he pushes Dianna, he's pushed back the opposite way with the same intensity.
(take into account the point of view of the camera and the weight differences)
So even this "Diannaball" thing
turned out to be a valid scientific experiment.
Of course, we did all the silly things anyone would do, like sitting on the ceiling
I won't show you everything, there are a lot of videos like this out there...
But the parabola when they throw waterballs at you I'm gonna show
when you try to drink it
I'm actually really proud because I managed to drink one of those
You can hear me proudly yell "I got some"
But more than that
two things happen during this parabola
First, Derek is desperately trying to get some water
and since it was shot high speed (aka "in slow motion")
when he fails, it looks like he's hours late to the battle.
It's a bit ridiculous so...
...of course you can watch it
it's quite satisfying, obviously in a mean way :)
first attempt to kick me in the nuts : FAIL
second attempt, the so-called "guileful kick back" : SUCCESS
and two hours later...
If you pay close attention, you can hear a small sound, like a thud
meaning that Dianna hit her head
and she hit her head big time
I let you see how she hit her head (she was fine, by the way)
This looked totally crazy, I let you see on her video if she talks about it
but you should also go and watch Derek's video
he made a burning flame in zero-g
and he tried some things with his famous slinky.
The next parabola, the 13th, is a martian gravity and no longer zero-g
the plane behaves in such a way we all feel as if our weight is divided by three.
I have nothing to show about this parabola, as I was in the cockpit.
I just wanted to watch the pilots, because there are three pilots
working simulaneously to maintain
the microgravity or any given pseudogravity
one of them takes care of the pitch
while another one takes care of the roll and the yaw
and the third one takes only care of the thrust
their common goal being, in zero-g, that the plane should have lift and drag as close to null as possible.
you can get close to that goal handling the orientation of the plane
and the thrust — to counterbalance the drag.
This is an insanely meticulous knowledge, all three pilots work together
and they do it great.
with a second yoke attached to the plane's, this pilot can only affect the pitch, making the plane go up or down
His only role during a parabola is to give the plane a perfect parabola trajectory.
If he tries to go right or left, it doesn't affect the plane.
This pilot, during a parabola, is here to cancel any drag of the plane with thrust, but should never create any acceleration we could feel in the cabin.
Finally, this pilot makes sure the plane constantly gives the optimal angle in its trajectory, managing only the roll and the yaw
using straps tied to the yoke; he cannot affect the pitch of the plane, as we can see in the next angle.
(strap)
watch closely the altimeter (on the right) and the pitch of the plane (on the left) — hypergravity phase
zero-g phase
hypergravity phase
that let me put the martian gravity parabola aside
since I didn't do anything during this one.
then, there were two lunar-gravity parabolas
I had a lot of fun.
I don't know why but I wanted to do something quite epic on those ones
like an Iron Man or a Spider-man jump, something like this.
something full of testosterone, one might say
something I'd be proud of, that would hit the viewer in the face...
if you listen carefully, while I brace myself, you can hear someone from the staff (Sebastien Rouquette, from CNES)
say : "be careful, do not jump up! jump in front of you"
which naturally led to this
but after that, as promised, the most epic jump in my whole life
I show you all the angles, because I'm really proud
first time I do something like that
I even ended up doing a front flip
only time in my life I made a front flip. Or as I say it
only time in my life I made a front flip!
that's the drugs talking
Second lunar parabola
quite the same, although I made a ridiculous jump (but I didn't jump up this time)
but there's one thing I wanted to do for a while and which was almost impossible in zero-g
but very easy under lunar gravity
I wanted to be in mid-air as gravity reappeared
what you can see by the end of this parabola
it clearly misses a sound effect so that you really feel it
Then they made a little surprise...only 15 parabolas were officially scheduled
and they surprised us with a sixteenth one, in zero-g
and we needed to make that one count.
and we did whatever we felt like.
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