0:00:01.610,0:00:03.943
- It says kilonewtons...

0:00:04.830,0:00:06.700
And after this video,

0:00:06.700,0:00:09.240
you will have a much better understanding

0:00:09.240,0:00:12.940
than probably 99% of the[br]rest of the climbers,

0:00:12.940,0:00:16.010
what these kilonewtons actually mean,

0:00:16.010,0:00:20.420
and what forces are involved[br]in real climbing falls.

0:00:20.420,0:00:23.710
And then I will explain[br]why big, big whippers

0:00:23.710,0:00:27.140
are often much softer than small falls.

0:00:27.140,0:00:30.280
But first, let's find out what is force.

0:00:30.280,0:00:32.610
I like to play with my[br]Instagram followers,

0:00:32.610,0:00:36.310
so I decided to ask them[br]what comes to their mind

0:00:36.310,0:00:38.710
when they hear the word force.

0:00:38.710,0:00:40.040
Half of the people said

0:00:40.040,0:00:43.440
that it has something[br]to do with "Star Wars".

0:00:43.440,0:00:44.590
Fair enough.

0:00:44.590,0:00:46.480
And then before you start thinking

0:00:46.480,0:00:50.640
that half of my Instagram[br]followers are really smart,

0:00:50.640,0:00:53.870
I have to say that majority[br]of them didn't vote it at all.

0:00:53.870,0:00:55.413
So I imagine something like...

0:00:55.413,0:00:57.883
What is force?

0:00:57.883,0:01:00.600
(lively music)[br](electronic buzzing)

0:01:00.600,0:01:03.060
Okay, but those who wanted to sound smart

0:01:03.060,0:01:07.150
said that force is mass[br]times acceleration,

0:01:07.150,0:01:09.860
which is the formula[br]that Newton, this guy,

0:01:09.860,0:01:10.917
came up with.

0:01:10.917,0:01:11.820
- [Newton] Ooh yah.

0:01:11.820,0:01:14.400
And that's why we[br]measure force in Newtons.

0:01:14.400,0:01:17.210
Which to me is a little bit[br]funny when you think about it,

0:01:17.210,0:01:18.550
imagine Newton.

0:01:18.550,0:01:21.133
(gentle music)

0:01:22.230,0:01:24.987
So we measure mass in kilograms,

0:01:27.555,0:01:32.555
and we measure acceleration[br]in meters per second squared.

0:01:35.480,0:01:40.057
Then we should measure force in Newtons.

0:01:40.057,0:01:42.965
(clapping)

0:01:42.965,0:01:45.427
So to put this formula into perspective,

0:01:45.427,0:01:48.990
it's like one Newton, this guy,

0:01:48.990,0:01:52.250
is pushing one kilogram of mass

0:01:52.250,0:01:55.330
and that makes that mass to accelerate

0:01:55.330,0:01:58.870
by one meter per second, every second.

0:01:58.870,0:02:01.560
So here I have a carabiner.

0:02:01.560,0:02:06.470
If I put all my weight on it, like so,

0:02:06.470,0:02:08.840
the question is, what's[br]the force right now

0:02:08.840,0:02:10.110
into this carabiner?

0:02:10.110,0:02:12.470
So if we look back to the formula,

0:02:12.470,0:02:15.920
we can say that mass is my mass

0:02:15.920,0:02:18.543
multiplied by acceleration.

0:02:19.350,0:02:21.300
What acceleration?[br]I'm hanging on a tree.

0:02:21.300,0:02:24.040
There is no movement,[br]no acceleration...

0:02:24.945,0:02:28.175
or is there an acceleration?

0:02:28.175,0:02:29.882
(upbeat music)

0:02:29.882,0:02:33.790
Look, so you've probably[br]seen this experiment before,

0:02:33.790,0:02:37.500
I have heavy object and a light object.

0:02:37.500,0:02:39.410
And the question is, if I let go

0:02:39.410,0:02:41.640
both of them at the same time,

0:02:41.640,0:02:43.943
which one is gonna hit the ground first?

0:02:45.220,0:02:46.053
Let's try.

0:02:55.910,0:02:58.560
So yes, they fell at the same time,

0:02:58.560,0:03:00.270
because that's what gravity does,

0:03:00.270,0:03:04.370
it makes objects fall at[br]exactly the same acceleration

0:03:04.370,0:03:08.803
of 9.8 meters per second per second.

0:03:15.790,0:03:18.510
So then I'm hanging on this carabiner,

0:03:18.510,0:03:20.390
gravity is pulling me down.

0:03:20.390,0:03:23.290
But in order for me to not move down,

0:03:23.290,0:03:27.270
there must be opposite force,[br]which would be pulling me up.

0:03:27.270,0:03:29.490
Here I have a spring.

0:03:29.490,0:03:32.670
While the gravity is[br]pulling the rock down,

0:03:32.670,0:03:35.370
the spring is pulling the rock up.

0:03:35.370,0:03:39.230
So the carabiner is actually[br]like a very, very stiff spring,

0:03:39.230,0:03:41.150
which is pulling me up.

0:03:41.150,0:03:44.270
The molecules of the carabiner[br]when I'm hanging on it

0:03:44.270,0:03:46.050
are being spread apart,

0:03:46.050,0:03:49.850
but they like to stay[br]together, so they pull back.

0:03:49.850,0:03:52.520
You can't see this[br]expansion of the *carabiner

0:03:52.520,0:03:56.123
on low forces, but you can on big ones.

0:04:02.210,0:04:04.870
And so it turns out that this carabiner

0:04:04.870,0:04:08.080
has to accelerate my weight up

0:04:08.080,0:04:12.680
at the same 9.8 meters per second squared,

0:04:12.680,0:04:16.290
which turns out to be about 600 Newtons.

0:04:16.290,0:04:21.290
Yep, 600 of these need to[br]hold one skinny guy like me.

0:04:28.800,0:04:32.210
Okay, moving on, this carabiner says

0:04:32.210,0:04:37.210
that it can hold up to 26 kilonewtons.

0:04:37.567,0:04:41.000
Kilonewton is basically[br]a thousand Newtons.

0:04:41.000,0:04:45.483
So it means that it[br]could hold about 40 me.

0:04:46.650,0:04:48.610
I wish I would have a clone machine,

0:04:48.610,0:04:50.763
so I could demonstrate this to you.

0:04:52.520,0:04:57.520
Then imagine how many videos[br]all of these me could create.

0:04:57.958,0:05:01.040
(bright music)

0:05:01.040,0:05:05.870
So if you wanna see us[br]create more videos like this,

0:05:05.870,0:05:09.150
click the join button, it really helps.

0:05:09.150,0:05:12.050
And I promise I will[br]spend every single penny

0:05:12.050,0:05:15.699
I get from you guys on[br]buying a clone machine.

0:05:15.699,0:05:17.349
Enjoy.

0:05:17.349,0:05:22.180
(chuckling) Okay, so you can hang 40 me

0:05:22.180,0:05:26.570
on one single carabiner,[br]that's pretty impressive.

0:05:26.570,0:05:29.520
Although there are things[br]that you must know.

0:05:29.520,0:05:31.950
First of all, all of these ratings

0:05:31.950,0:05:33.980
are for new equipment,

0:05:33.980,0:05:37.510
wear and tear does not[br]go into that rating.

0:05:37.510,0:05:39.190
How bad is that?

0:05:39.190,0:05:42.686
Well, I asked my friend,[br]Ryan from YouTube channel,

0:05:42.686,0:05:45.770
HowNOTtoHighline because he has a hobby

0:05:45.770,0:05:47.870
of breaking stuff.

0:05:47.870,0:05:50.200
And according to his tests,

0:05:50.200,0:05:53.490
most of the metals tend[br]to last pretty well.

0:05:53.490,0:05:58.490
Although with soft things,[br]things are totally different.

0:05:58.740,0:06:02.033
- [Ryan] Black Diamond sling[br]with a 22 kilonewton MBS.

0:06:03.089,0:06:04.313
(machine whirs)

0:06:04.313,0:06:07.063
(metallic clang)

0:06:09.071,0:06:12.770
What? Was the MBS[br]on 22 kilonewtons?

0:06:12.770,0:06:13.603
- [Man] Yeah.

0:06:13.603,0:06:18.300
- Yep, a sling rated at 22[br]kilonewtons broke at six.

0:06:19.490,0:06:20.670
And here is another one.

0:06:20.670,0:06:24.970
- [Ryan] Woo, that's a great condition.

0:06:24.970,0:06:26.193
- [Man] Would not whip.

0:06:27.580,0:06:28.723
- [Ryan] No, not whip.

0:06:30.270,0:06:32.000
I would tie my dog to this though.

0:06:32.000,0:06:34.667
(machine whirs)

0:06:36.912,0:06:38.042
All right.

0:06:38.042,0:06:40.417
- [Man] I wouldn't tie[br]a very big dog with that.

0:06:40.417,0:06:44.640
- [Ryan] (giggling) All right,[br]let's see how big of a dog

0:06:44.640,0:06:47.470
could you have tied with this?

0:06:47.470,0:06:49.740
Ooh, a Chihuahua.

0:06:49.740,0:06:50.690
(man chuckles)

0:06:50.690,0:06:53.250
- Yeah, so if you're one of these people

0:06:53.250,0:06:56.330
who like to save money and use very old,

0:06:56.330,0:06:58.780
worn down slings, good luck.

0:06:58.780,0:07:00.345
- [Ryan] 24 kilonewtons,

0:07:00.345,0:07:03.012
(machine whirs)

0:07:04.067,0:07:05.580
that did not stretch that much.

0:07:05.580,0:07:08.286
Oh, guess, guess.

0:07:08.286,0:07:09.119
- [Man] I saw.

0:07:09.119,0:07:13.440
- [Ryan] Four kilonewtons,[br]what the fuck, man?

0:07:13.440,0:07:18.440
- 4,000 Newtons, okay how[br]much does such sling can hold?

0:07:19.420,0:07:20.660
Well, that's pretty easy.

0:07:20.660,0:07:24.700
Just divide 4,000 Newtons by 9.8.

0:07:24.700,0:07:29.700
Or if you want easier, by 10[br]and you get 400 kilograms.

0:07:29.870,0:07:32.763
That sounds quite a lot. [br]No? 400 kilograms?

0:07:33.940,0:07:38.940
Well, all of these conversions[br]from force to kilograms

0:07:38.950,0:07:41.270
that I have been talking so far

0:07:41.270,0:07:45.690
are based on the fact that the[br]weight is hanging statically.

0:07:45.690,0:07:49.541
Once the thing starts[br]falling, everything changes.

0:07:49.541,0:07:50.425
- [Man] Go.

0:07:50.425,0:07:53.800
(metallic clanking)

0:07:53.800,0:07:56.840
- So what you have just[br]seen is a clip from DMM,

0:07:56.840,0:07:59.900
where they dropped 80 kilograms of mass,

0:07:59.900,0:08:03.510
and that broke a brand new Dyneema sling.

0:08:03.510,0:08:06.590
Now my goal is not to scare[br]you, it's the opposite.

0:08:06.590,0:08:09.520
I want to bring the[br]awareness that climbing gear

0:08:09.520,0:08:14.393
is not magic, and if you use[br]it incorrectly, it might fail.

0:08:16.600,0:08:19.350
Fun fact, do you know[br]this joke that climbers

0:08:19.350,0:08:21.830
like to say when they[br]fail on their climbs?

0:08:21.830,0:08:24.890
That today is a high gravity day.

0:08:24.890,0:08:27.070
Well, turns out that's true,

0:08:27.070,0:08:30.200
gravity does change from month to month.

0:08:30.200,0:08:32.580
So if you are one of those people

0:08:32.580,0:08:35.830
who like to complain that[br]today is a bad humidity,

0:08:35.830,0:08:38.760
or bad temperature, now you[br]have a right to complain

0:08:38.760,0:08:41.690
that today's a bad gravity day, yay!

0:08:41.690,0:08:43.950
Okay, let's see what happens

0:08:43.950,0:08:47.873
when objects like us,[br]climbers, start falling.

0:08:51.100,0:08:54.090
That was a 10 meters fall.

0:08:54.090,0:08:56.070
Let's see how much force such fall

0:08:56.070,0:08:58.010
would generate to the climber.

0:08:58.010,0:09:00.210
The formula for that would be similar

0:09:00.210,0:09:03.540
to what we had before, except[br]that we need to multiply

0:09:03.540,0:09:07.010
this by the distance[br]the climber was falling,

0:09:07.010,0:09:11.123
and divide by the distance[br]the climber was slowing down.

0:09:16.870,0:09:18.340
And did you actually notice

0:09:18.340,0:09:20.933
how soft the fall for the climber was?

0:09:23.200,0:09:26.460
So imagine driving a car in a highway,

0:09:26.460,0:09:31.460
and pressing on the brake[br]gently while you come to a stop.

0:09:31.620,0:09:33.110
No problems right?

0:09:33.110,0:09:35.090
Now imagine you are not driving so fast,

0:09:35.090,0:09:37.650
you're in a city, you're driving slowly,

0:09:37.650,0:09:39.043
but you slam on the brake,

0:09:40.200,0:09:43.370
that would not feel very nice, right?

0:09:43.370,0:09:45.700
So here is the first thing[br]I want you to remember

0:09:45.700,0:09:48.820
out of this video, the[br]impact to the climber

0:09:48.820,0:09:51.660
will always be multiplied by the distance

0:09:51.660,0:09:54.990
the climber was falling,[br]divided by the distance

0:09:54.990,0:09:57.360
of the slow down phase.

0:09:57.360,0:10:00.100
So let's calculate, their falling distance

0:10:00.100,0:10:02.300
was about four quickdraws,

0:10:02.300,0:10:04.573
and their slowdown distance was about

0:10:04.573,0:10:06.630
two and a half quickdraws.

0:10:06.630,0:10:09.480
And we get about 860 Newtons.

0:10:09.480,0:10:12.360
Or if we would replace her with a standard

0:10:12.360,0:10:17.360
80 kilogram climber, that[br]would be about 1.3 kilonewtons,

0:10:18.490,0:10:19.910
which is not much.

0:10:19.910,0:10:22.210
Although this formula [br]has a little problem

0:10:22.210,0:10:26.470
because it will always give you[br]the value of it just slightly lower

0:10:26.470,0:10:28.810
than it would be in real life.

0:10:28.810,0:10:31.718
But showing you how to[br]calculate more precisely

0:10:31.718,0:10:33.970
would mean that most of you would probably

0:10:33.970,0:10:35.950
just leave this video right here.

0:10:35.950,0:10:37.830
But we don't need to do that,

0:10:37.830,0:10:41.630
because we can rely on real[br]life experimental data.

0:10:41.630,0:10:44.810
And who is the boss at[br]providing such data for us?

0:10:44.810,0:10:46.180
- Hi, I'm Ryan Jenks and-

0:10:46.180,0:10:49.260
- And then that's enough[br]advertisement for you.

0:10:49.260,0:10:50.750
What they did in this video,

0:10:50.750,0:10:54.440
they put a device measuring[br]the force on the climber,

0:10:54.440,0:10:56.633
and made a series of falls.

0:10:58.859,0:11:00.743
- (laughing) Zach.

0:11:07.410,0:11:09.143
For science, woo hoo.

0:11:12.978,0:11:14.728
That puts me at 1.87.

0:11:15.950,0:11:18.190
- So most of the falls,[br]that in my opinion,

0:11:18.190,0:11:20.340
would be a good belaying example,

0:11:20.340,0:11:22.710
were below two kilonewtons.

0:11:22.710,0:11:26.430
Now let's take a look at[br]these two extreme examples.

0:11:26.430,0:11:29.560
Climber on the left is[br]five meters above the bolt,

0:11:29.560,0:11:31.950
so that would be 10 meters fall

0:11:31.950,0:11:34.030
plus the slack in the system.

0:11:34.030,0:11:37.090
The belayer probably has[br]about one meter of slack.

0:11:37.090,0:11:40.150
And then there is probably[br]one more meter of slack

0:11:40.150,0:11:41.590
in between the quickdraws.

0:11:41.590,0:11:44.970
So in total, we are[br]looking at 12 meters fall.

0:11:44.970,0:11:48.470
While climber on the right is[br]only one meter above the bolt.

0:11:48.470,0:11:51.320
And let's say that[br]belayer is really afraid,

0:11:51.320,0:11:54.660
and he's going to give a very[br]hard catch for the climber.

0:11:54.660,0:11:57.183
So we are looking at two meters fall.

0:11:58.040,0:12:03.040
So a massive 12 meters fall,[br]or a small two meters fall.

0:12:03.090,0:12:06.440
Which one do you think[br]is going to be softer for the climber?

0:12:06.440,0:12:08.420
Well, let's see, we know how much

0:12:08.420,0:12:11.440
the climbers will fall.[br]But now we need to find out

0:12:11.440,0:12:14.880
the slowed down distances[br]for both of the cases.

0:12:14.880,0:12:17.700
And that depends mainly on two things.

0:12:17.700,0:12:20.580
First is the displacement of the belayer.

0:12:20.580,0:12:24.090
On a big, big whipper, the[br]belayer will probably fly

0:12:24.090,0:12:27.220
about two meters, while on a small fall,

0:12:27.220,0:12:30.110
let's assume very common[br]mistake for beginners,

0:12:30.110,0:12:32.560
where the belayer just takes the slack out

0:12:32.560,0:12:34.430
and belays very hard.

0:12:34.430,0:12:38.210
And the second factor is[br]the stretch of the rope.

0:12:38.210,0:12:41.430
Rope manufacturers claim[br]that if you put 80 kilogram

0:12:41.430,0:12:44.700
mass on a dynamic rope statically,

0:12:44.700,0:12:49.160
like so, without movement,[br]the rope will stretch 10%.

0:12:49.160,0:12:52.600
And dynamic stretch, when[br]you take a lead fall,

0:12:52.600,0:12:55.440
is up to 30%.

0:12:55.440,0:12:58.550
Well up to 30% is not very helpful for us.

0:12:58.550,0:13:01.590
What we need to know is[br]the stretch of this rope

0:13:01.590,0:13:04.530
from two to four kilonewtons force,

0:13:04.530,0:13:06.810
that's where the lead falls are.

0:13:06.810,0:13:09.250
And yet again, I was texting Ryan.

0:13:09.250,0:13:11.280
- So, I'm gonna pull some dynamic rope,

0:13:11.280,0:13:12.820
to see how much it stretches.

0:13:12.820,0:13:14.928
At first, we thought[br]it's gonna be very easy,

0:13:14.928,0:13:17.990
just go to the park, stretch[br]the rope to different forces,

0:13:17.990,0:13:21.110
and measure the elongation of the rope.

0:13:21.110,0:13:24.660
Well, sometimes easy is hard.

0:13:24.660,0:13:27.570
When you stretch the rope to certain force

0:13:27.570,0:13:30.120
and leave it there, the force will start

0:13:30.120,0:13:33.580
dropping on the rope, the[br]rope kind of just gives up.

0:13:33.580,0:13:36.890
While this is very interesting,[br]it's not critical for us.

0:13:36.890,0:13:39.500
The only thing he needed[br]to do is to pull the rope

0:13:39.500,0:13:42.390
as fast as he can to desired force,

0:13:42.390,0:13:44.290
and measure the stretch.

0:13:44.290,0:13:49.290
- [Ryan] Okay, oh my God,[br]that's the seven mark...

0:13:49.610,0:13:55.490
6.9 meters... it stretches...[br]when you pull it...

0:13:55.630,0:13:59.380
a dynamic rope... to four kilonewtons.

0:13:59.380,0:14:01.480
But then there is[br]another interesting factor,

0:14:01.480,0:14:04.200
once you load the rope to high forces,

0:14:04.200,0:14:06.090
it takes some time for the rope

0:14:06.090,0:14:08.590
to get back to its original length.

0:14:08.590,0:14:11.490
This is what's known as rope resting,

0:14:11.490,0:14:13.810
and it was really cool[br]to see this in action.

0:14:13.810,0:14:16.913
- [Ryan] See the Grigri[br]getting pulled back slowly?

0:14:19.540,0:14:22.838
Super interesting, probably[br]way more interesting

0:14:22.838,0:14:25.260
to me than it is to you right now.

0:14:25.260,0:14:27.860
So after he spent like[br]four hours in the park

0:14:27.860,0:14:31.460
pulling the ropes, the[br]results were that on forces

0:14:31.460,0:14:33.890
from two to four kilonewtons,

0:14:33.890,0:14:37.750
the rope stretched to about 20%.

0:14:37.750,0:14:41.180
Great, so let's use that[br]in our calculations.

0:14:41.180,0:14:45.240
On a big fall, we have 27[br]meters of rope in total,

0:14:45.240,0:14:49.570
so that would be 5.4 meters of stretch.

0:14:49.570,0:14:52.600
While in a small fall, we[br]have five meters of rope,

0:14:52.600,0:14:54.940
and that would be one meter of stretch.

0:14:54.940,0:14:58.600
However, our belayer is[br]panicking and taking hard,

0:14:58.600,0:15:02.170
so he will take half of[br]that stretch for himself,

0:15:02.170,0:15:06.540
leaving only half a meter[br]of stretch for the climber.

0:15:06.540,0:15:09.660
And ta-da, the big, big whipper

0:15:09.660,0:15:13.580
will be two and a half[br]times softer for the climber

0:15:13.580,0:15:15.113
than the small fall.

0:15:16.470,0:15:17.870
Oh, I love fun facts,

0:15:17.870,0:15:19.180
here is another one.

0:15:19.180,0:15:21.830
Imagine that you were climbing and failed,

0:15:21.830,0:15:25.370
but humidity was good,[br]temperature was good,

0:15:25.370,0:15:27.483
even the gravity was good that day.

0:15:28.370,0:15:30.030
You can still blame the moon.

0:15:30.030,0:15:33.330
- [Narrator] Negligibly but truly,

0:15:33.330,0:15:36.460
you weigh about a million[br]of your weight less

0:15:36.460,0:15:38.740
when the moon is directly above you.

0:15:38.740,0:15:41.360
- So if you wanna ascend,[br]climb when the moon

0:15:41.360,0:15:45.520
is directly above you, you're welcome.

0:15:45.520,0:15:48.360
I remember I was projecting[br]this really long route

0:15:48.360,0:15:52.010
of 35 meters, and the first[br]time I managed to link

0:15:52.010,0:15:54.707
all the cruxes and arrive at the anchor,

0:15:54.707,0:15:57.300
the moment when I was pulling the rope up

0:15:57.300,0:15:58.650
to clip the anchor,

0:15:58.650,0:16:00.810
my belayer couldn't see me very well,

0:16:00.810,0:16:03.300
so he just gave me a lot of slack.

0:16:03.300,0:16:06.930
And on top of that, the[br]bolt before the anchor

0:16:06.930,0:16:10.230
was really far, really ran out.

0:16:10.230,0:16:12.800
So while I was dragging the rope up,

0:16:12.800,0:16:15.720
I lost my balance and took a fall.

0:16:15.720,0:16:17.510
The wall is flying in front of me,

0:16:17.510,0:16:20.140
and I'm thinking, "Why I'm still falling?

0:16:20.140,0:16:21.930
Hmm, this is unusual."

0:16:21.930,0:16:23.470
Then I stopped and looked up,

0:16:23.470,0:16:25.970
it was maybe five or[br]six Quickdraws above me,

0:16:25.970,0:16:29.390
probably about 15 meters of fall.

0:16:29.390,0:16:34.320
But the fall was super soft,[br]it's like riding an elevator.

0:16:34.320,0:16:36.860
So here is another[br]takeaway out of this video,

0:16:36.860,0:16:39.130
if the climber is really high up,

0:16:39.130,0:16:41.700
he has a lot of rope to absorb the fall.

0:16:41.700,0:16:44.930
So as long as he doesn't[br]fall onto something,

0:16:44.930,0:16:49.220
the fall will be soft, no[br]matter how you belay that.

0:16:49.220,0:16:51.960
However, if the climber is not so high,

0:16:51.960,0:16:54.790
he doesn't have so much[br]rope to absorb the fall,

0:16:54.790,0:16:59.680
The soft dynamic delaying[br]is really important,

0:16:59.680,0:17:02.050
and you can ask any light climber,

0:17:02.050,0:17:05.620
how many times they[br]had their ankles broken

0:17:05.620,0:17:07.550
due to hard catches.

0:17:07.550,0:17:09.300
Okay, let's switch gears a little bit.

0:17:09.300,0:17:11.300
Let's talk about friction,

0:17:11.300,0:17:13.710
'cause the more friction you have,

0:17:13.710,0:17:17.000
the harder the fall for[br]the climber will be.

0:17:17.000,0:17:19.540
And here is a very[br]extreme example of that.

0:17:19.540,0:17:23.730
- As you can see right[br]here, we Z dragged it.

0:17:23.730,0:17:27.560
And so we're gonna have a[br]lot of friction when I fall.

0:17:27.560,0:17:29.241
And whoo, for science.

0:17:29.241,0:17:30.541
Do it!

0:17:30.541,0:17:31.374
Oh my God!

0:17:34.280,0:17:36.330
- So when you have a lot of friction,

0:17:36.330,0:17:39.740
the rope close to the[br]climber stretches normally,

0:17:39.740,0:17:43.960
but the rope closer to belayer[br]doesn't stretch that much.

0:17:43.960,0:17:46.770
It's like having shorter[br]rope and heavier belayer

0:17:46.770,0:17:47.820
at the same time.

0:17:47.820,0:17:50.230
And although the force to the harness

0:17:50.230,0:17:52.500
was only two and a half kilonewtons,

0:17:52.500,0:17:55.918
a lot of the force went[br]pendulum into the wall.

0:17:55.918,0:17:57.330
- Do it.

0:17:57.330,0:17:59.530
- And that's how we break ankles.

0:17:59.530,0:18:03.410
So extending the Quickdraws[br]not only helps you to clip

0:18:03.410,0:18:05.286
and avoid situations like this,

0:18:05.286,0:18:06.119
(upbeat music)

0:18:06.119,0:18:09.119
(climber straining)

0:18:16.650,0:18:20.650
But also reduces the impact[br]forces for the climbers.

0:18:20.650,0:18:23.930
Okay, let's circle back to the DMM test,

0:18:23.930,0:18:25.720
breaking the sling.

0:18:25.720,0:18:29.730
Dyneema slings are very static,[br]they don't stretch at all.

0:18:29.730,0:18:31.520
And I hope that by now you understand

0:18:31.520,0:18:34.980
that this sudden stop[br]can create huge forces.

0:18:34.980,0:18:37.600
If not, ask somebody to slap you.

0:18:37.600,0:18:40.650
This stop on the face will be basically

0:18:40.650,0:18:41.950
what you need to understand.

0:18:41.950,0:18:43.860
So let's make a very wild

0:18:43.860,0:18:46.230
and probably very inaccurate guess

0:18:46.230,0:18:51.160
that this sling would stretch[br]to about five centimeters.

0:18:51.160,0:18:54.590
So if we drop 80 kilograms of mass,

0:18:54.590,0:18:57.980
the distance of 120 centimeters,

0:18:57.980,0:19:01.960
and the absorption distance[br]is only five centimeters,

0:19:01.960,0:19:06.160
we are looking at 19 kilonewtons.

0:19:06.160,0:19:08.850
If that is not gonna break the sling,

0:19:08.850,0:19:11.990
it's definitely gonna break you.

0:19:11.990,0:19:14.070
Woo, if you're still watching,

0:19:14.070,0:19:16.030
that probably means that you should be

0:19:16.030,0:19:18.440
at least a little bit geeky.

0:19:18.440,0:19:20.443
So here is a dessert for you.

0:19:21.320,0:19:23.840
There is no gravity.

0:19:23.840,0:19:27.120
Yeah, objects don't attract each other,

0:19:27.120,0:19:28.880
there is only space time.

0:19:28.880,0:19:31.800
- You feel as though you're[br]being pushed into the ground,

0:19:31.800,0:19:34.110
not because of a force called gravity,

0:19:34.110,0:19:36.360
but because time is moving faster

0:19:36.360,0:19:38.890
for your head than for your feet.

0:19:38.890,0:19:41.440
- This and all the other[br]resources that I use

0:19:41.440,0:19:44.590
to create this video will[br]be in the description.

0:19:44.590,0:19:47.280
And now please go send some love to Ryan

0:19:47.280,0:19:50.460
for providing me with all[br]of his experimental data

0:19:50.460,0:19:52.360
that I used in this video.

0:19:52.360,0:19:55.460
So don't forget to subscribe[br]and support our channels

0:19:55.460,0:19:57.960
if you wanna see more content like this.

0:19:57.960,0:19:58.793
Enjoy.