[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:05.68,0:00:08.68,Default,,0000,0000,0000,,French fries are delicious.
Dialogue: 0,0:00:08.68,0:00:12.68,Default,,0000,0000,0000,,French fries with ketchup are a little slice of heaven.
Dialogue: 0,0:00:12.68,0:00:14.43,Default,,0000,0000,0000,,The problem is it's basically impossible
Dialogue: 0,0:00:14.43,0:00:16.46,Default,,0000,0000,0000,,to pour the exactly right amount.
Dialogue: 0,0:00:16.46,0:00:19.77,Default,,0000,0000,0000,,We're so used to pouring ketchup that we don't realize
Dialogue: 0,0:00:19.77,0:00:21.85,Default,,0000,0000,0000,,how weird its behavior is.
Dialogue: 0,0:00:21.85,0:00:26.43,Default,,0000,0000,0000,,Imagine a ketchup bottle filled with a straight up solid like steel.
Dialogue: 0,0:00:26.43,0:00:29.48,Default,,0000,0000,0000,,No amount of shaking would ever get the steel out.
Dialogue: 0,0:00:29.48,0:00:32.40,Default,,0000,0000,0000,,Now imagine that same bottle full of a liquid like water.
Dialogue: 0,0:00:32.40,0:00:34.43,Default,,0000,0000,0000,,That would pour like a dream.
Dialogue: 0,0:00:34.43,0:00:36.85,Default,,0000,0000,0000,,Ketchup, though, can't seem to make up its mind.
Dialogue: 0,0:00:36.85,0:00:38.93,Default,,0000,0000,0000,,Is it is a solid? Or a liquid?
Dialogue: 0,0:00:38.93,0:00:41.65,Default,,0000,0000,0000,,The answer is, it depends.
Dialogue: 0,0:00:41.65,0:00:44.85,Default,,0000,0000,0000,,The world's most common fluids like water, oils and alcohols
Dialogue: 0,0:00:44.85,0:00:47.60,Default,,0000,0000,0000,,respond to force linearly.
Dialogue: 0,0:00:47.60,0:00:51.24,Default,,0000,0000,0000,,If you push on them twice as hard, they move twice as fast.
Dialogue: 0,0:00:51.24,0:00:54.36,Default,,0000,0000,0000,,Sir Isaac Newton, of apple fame, first proposed this relationship,
Dialogue: 0,0:00:54.36,0:00:57.74,Default,,0000,0000,0000,,and so those fluids are called Newtonian fluids.
Dialogue: 0,0:00:57.74,0:01:00.70,Default,,0000,0000,0000,,Ketchup, though, is part of a merry band of linear rule breakers
Dialogue: 0,0:01:00.70,0:01:03.29,Default,,0000,0000,0000,,called Non-Newtonian fluids.
Dialogue: 0,0:01:03.29,0:01:06.37,Default,,0000,0000,0000,,Mayonnaise, toothpaste, blood, paint, peanut butter
Dialogue: 0,0:01:06.37,0:01:09.87,Default,,0000,0000,0000,,and lots of other fluids respond to force non-linearly.
Dialogue: 0,0:01:09.87,0:01:11.92,Default,,0000,0000,0000,,That is, their apparent thickness changes
Dialogue: 0,0:01:11.92,0:01:15.34,Default,,0000,0000,0000,,depending on how hard you push, or how long, or how fast.
Dialogue: 0,0:01:15.34,0:01:18.55,Default,,0000,0000,0000,,And ketchup is actually Non-Newtonian in two different ways.
Dialogue: 0,0:01:18.55,0:01:22.85,Default,,0000,0000,0000,,Way number one: the harder you push, the thinner ketchup seems to get.
Dialogue: 0,0:01:22.85,0:01:24.72,Default,,0000,0000,0000,,Below a certain pushing force,
Dialogue: 0,0:01:24.72,0:01:26.72,Default,,0000,0000,0000,,ketchup basically behaves like a solid.
Dialogue: 0,0:01:26.72,0:01:29.13,Default,,0000,0000,0000,,But once you pass that breaking point,
Dialogue: 0,0:01:29.13,0:01:33.38,Default,,0000,0000,0000,,it switches gears and becomes a thousand times thinner than it was before.
Dialogue: 0,0:01:33.38,0:01:35.38,Default,,0000,0000,0000,,Sound familiar right?
Dialogue: 0,0:01:35.38,0:01:39.28,Default,,0000,0000,0000,,Way number two: if you push with a force below the threshold force
Dialogue: 0,0:01:39.28,0:01:41.57,Default,,0000,0000,0000,,eventually, the ketchup will start to flow.
Dialogue: 0,0:01:41.57,0:01:45.16,Default,,0000,0000,0000,,In this case, time, not force, is they key to releasing ketchup
Dialogue: 0,0:01:45.16,0:01:46.99,Default,,0000,0000,0000,,from its glassy prison.
Dialogue: 0,0:01:46.99,0:01:49.62,Default,,0000,0000,0000,,Alright, so, why does ketchup act all weird?
Dialogue: 0,0:01:49.62,0:01:52.63,Default,,0000,0000,0000,,Well, it's made from tomatoes, pulverized, smashed, thrashed,
Dialogue: 0,0:01:52.63,0:01:55.46,Default,,0000,0000,0000,,utterly destroyed tomatoes.
Dialogue: 0,0:01:55.46,0:01:56.80,Default,,0000,0000,0000,,See these tiny particles?
Dialogue: 0,0:01:56.80,0:01:58.59,Default,,0000,0000,0000,,This is what remains of tomatoes cells
Dialogue: 0,0:01:58.59,0:02:01.22,Default,,0000,0000,0000,,after they go through the ketchup treatment.
Dialogue: 0,0:02:01.22,0:02:02.92,Default,,0000,0000,0000,,And the liquid around those particles?
Dialogue: 0,0:02:02.92,0:02:05.97,Default,,0000,0000,0000,,That's mostly water and some vinegar, sugar, and spices.
Dialogue: 0,0:02:05.97,0:02:08.19,Default,,0000,0000,0000,,When ketchup is just sitting around,
Dialogue: 0,0:02:08.19,0:02:11.55,Default,,0000,0000,0000,,the tomato particles are evenly and randomly distributed.
Dialogue: 0,0:02:11.55,0:02:13.97,Default,,0000,0000,0000,,Now, let's say you apply a weak force very quickly.
Dialogue: 0,0:02:13.97,0:02:15.52,Default,,0000,0000,0000,,The particles bump into each other,
Dialogue: 0,0:02:15.52,0:02:17.22,Default,,0000,0000,0000,,but can't get out of each other's way,
Dialogue: 0,0:02:17.22,0:02:18.72,Default,,0000,0000,0000,,so the ketchup doesn't flow.
Dialogue: 0,0:02:18.72,0:02:21.78,Default,,0000,0000,0000,,Now, let's say you apply a strong force very quickly.
Dialogue: 0,0:02:21.78,0:02:24.61,Default,,0000,0000,0000,,That extra force is enough to squish the tomato particles,
Dialogue: 0,0:02:24.61,0:02:25.94,Default,,0000,0000,0000,,so maybe instead of little spheres,
Dialogue: 0,0:02:25.94,0:02:28.83,Default,,0000,0000,0000,,they get smushed into little ellipses, and boom!
Dialogue: 0,0:02:28.83,0:02:30.78,Default,,0000,0000,0000,,Now you have enough space for one group of particles
Dialogue: 0,0:02:30.78,0:02:33.63,Default,,0000,0000,0000,,to get passed others and the ketchup flows.
Dialogue: 0,0:02:33.63,0:02:37.72,Default,,0000,0000,0000,,Now let's say you apply a very weak force but for a very long time.
Dialogue: 0,0:02:37.72,0:02:41.25,Default,,0000,0000,0000,,Turns out, we're not exactly sure what happens in this scenario.
Dialogue: 0,0:02:41.25,0:02:45.01,Default,,0000,0000,0000,,One possibility is that the tomato particles near the walls of the container
Dialogue: 0,0:02:45.01,0:02:47.30,Default,,0000,0000,0000,,slowly get bumped towards the middle,
Dialogue: 0,0:02:47.30,0:02:48.80,Default,,0000,0000,0000,,leaving the soup they were dissolved in,
Dialogue: 0,0:02:48.80,0:02:50.38,Default,,0000,0000,0000,,which remember is basically water,
Dialogue: 0,0:02:50.38,0:02:51.88,Default,,0000,0000,0000,,near the edges.
Dialogue: 0,0:02:51.88,0:02:54.38,Default,,0000,0000,0000,,That water serves as a lubricant betwen the glass bottle
Dialogue: 0,0:02:54.38,0:02:56.44,Default,,0000,0000,0000,,and the center plug of ketchup,
Dialogue: 0,0:02:56.44,0:02:58.55,Default,,0000,0000,0000,,and so the ketchup flows.
Dialogue: 0,0:02:58.55,0:03:01.94,Default,,0000,0000,0000,,Another possibility is that the particles slowly rearrange themselves
Dialogue: 0,0:03:01.94,0:03:05.80,Default,,0000,0000,0000,,into lots of small groups, which then flow past each other.
Dialogue: 0,0:03:05.80,0:03:08.13,Default,,0000,0000,0000,,Scientists who study fluid flows are still actively researching
Dialogue: 0,0:03:08.13,0:03:11.33,Default,,0000,0000,0000,,how ketchup and its merry friends work.
Dialogue: 0,0:03:11.33,0:03:13.41,Default,,0000,0000,0000,,Ketchup basically gets thinner the harder you push,
Dialogue: 0,0:03:13.41,0:03:16.50,Default,,0000,0000,0000,,but other substances, like oobleck or some natural peanut butters,
Dialogue: 0,0:03:16.50,0:03:19.30,Default,,0000,0000,0000,,actually get thicker the harder you push.
Dialogue: 0,0:03:19.30,0:03:21.72,Default,,0000,0000,0000,,Others can climb up rotating rods,
Dialogue: 0,0:03:21.72,0:03:24.09,Default,,0000,0000,0000,,or continue to pour themselves out of a beeker,
Dialogue: 0,0:03:24.09,0:03:26.01,Default,,0000,0000,0000,,once you get them started.
Dialogue: 0,0:03:26.01,0:03:27.38,Default,,0000,0000,0000,,From a physics perspective, though,
Dialogue: 0,0:03:27.38,0:03:30.22,Default,,0000,0000,0000,,ketchup is one of the more complicated mixtures out there.
Dialogue: 0,0:03:30.22,0:03:32.47,Default,,0000,0000,0000,,And as if that weren't enough, the balance of ingredients
Dialogue: 0,0:03:32.47,0:03:35.30,Default,,0000,0000,0000,,and the presence of natural thickeners like xanthan gum,
Dialogue: 0,0:03:35.30,0:03:37.93,Default,,0000,0000,0000,,which is also found in many fruit drinks and milkshakes,
Dialogue: 0,0:03:37.93,0:03:39.60,Default,,0000,0000,0000,,can mean that two different ketchups
Dialogue: 0,0:03:39.60,0:03:41.55,Default,,0000,0000,0000,,can behave completely differently.
Dialogue: 0,0:03:41.55,0:03:44.23,Default,,0000,0000,0000,,But most will show two telltale properties:
Dialogue: 0,0:03:44.23,0:03:46.07,Default,,0000,0000,0000,,sudden thinning at a threshold force,
Dialogue: 0,0:03:46.07,0:03:48.32,Default,,0000,0000,0000,,and more gradual thinning after a small force
Dialogue: 0,0:03:48.32,0:03:50.36,Default,,0000,0000,0000,,is applied for a long time.
Dialogue: 0,0:03:50.36,0:03:53.33,Default,,0000,0000,0000,,And that means you could get ketchup out of the bottle in two ways:
Dialogue: 0,0:03:53.33,0:03:55.97,Default,,0000,0000,0000,,either give it a series of long, slow languid shakes
Dialogue: 0,0:03:55.97,0:03:58.47,Default,,0000,0000,0000,,making sure you don't ever stop applying force,
Dialogue: 0,0:03:58.47,0:04:02.50,Default,,0000,0000,0000,,or you could hit the bottle once very, very hard.
Dialogue: 0,0:04:02.50,0:04:04.72,Default,,0000,0000,0000,,What the real pros do is keep the lid on,
Dialogue: 0,0:04:04.72,0:04:07.13,Default,,0000,0000,0000,,give the bottle a few short, sharp shakes
Dialogue: 0,0:04:07.13,0:04:08.55,Default,,0000,0000,0000,,to wake up all those tomato particles,
Dialogue: 0,0:04:08.55,0:04:10.43,Default,,0000,0000,0000,,and then take the lid off
Dialogue: 0,0:04:10.43,0:04:13.80,Default,,0000,0000,0000,,and do a nice controlled pour onto their heavenly fries.