Bizarre travelling flame discovery

Steve Mould
20 Apr 202414:34

Summary

TLDRThe video script describes an intriguing experiment involving lighter fluid and a ring-shaped trough, which leads to the discovery of a self-sustaining, circular flame. The host dives into the science behind this phenomenon, exploring the concept of 'excitable mediums' and how they can lead to such peculiar behaviors. The video also discusses the design variables that affect the flame's behavior, such as the width and angle of the trough's opening. The host's curiosity is piqued by a subscriber's accidental discovery, leading to a series of experiments and designs that manipulate the flame's path in various shapes, including a maze. The script touches on the broader implications and examples of excitable mediums in nature and technology, like cellular automata and forest fires. The video concludes with a call to action for responsible experimentation and a sponsorship message from Jane Street, a firm that shares the host's passion for problem-solving and technology.

Takeaways

  • ๐Ÿ”ฅ The phenomenon of a flame circulating around a ring-shaped trough is due to the properties of lighter fluid as an excitable medium.
  • ๐Ÿ”ง Rudy Stevens' design of a cap for a small closed ecosystem led to the discovery of this phenomenon when using lighter fluid to heat and mold the cap.
  • ๐Ÿ“ Oscar Morris created a parameterized CAD file to allow for the adjustment of variables such as the size and width of the ring, and the angle of the opening.
  • โš™๏ธ The optimal configuration for the trough was found to be five millimeters wide with a semi-circular cross-section for sustained flame circulation.
  • ๐ŸŒ€ The flame circulates due to a balance between the evaporation rate of the lighter fluid and the heat generated by the burning vapor.
  • ๐Ÿ” The concept of excitable mediums is characterized by the potential to switch to an excited state, a refractory period, and the ability to influence neighboring parts.
  • ๐ŸŒฟ The ring of lighter fluid acts as an excitable medium, similar to other natural phenomena like forest fires or the spread of certain infections.
  • ๐ŸŒ The script explores the idea of a continuous loop of flame in a ring-shaped forest, which would require a significant circumference to sustain.
  • ๐ŸŽจ Additional designs such as a split ring, spiral, and figure-eight trough were created to observe different flame behaviors.
  • โš–๏ธ The behavior of the flame is influenced by the physical design of the trough, including the width, depth, and shape of the ring.
  • โš™๏ธ The video concludes with a call to action for responsible experimentation with the designs and a prompt for viewers to share their own ideas for flame paths.

Q & A

  • What is an excitable medium?

    -An excitable medium is a substance that has the potential to switch to an excited state, such as hydrocarbon vapor that can ignite. It must also meet three additional criteria: it cannot be excited again immediately after being excited, it has a refractory period before it can be excited again, and any part of the medium can become excited if a neighboring part is excited.

  • What is the phenomenon observed when lighter fluid is poured into a ring-shaped trough and ignited?

    -The lighter fluid, being volatile, continuously evaporates creating a mixture of hydrocarbon gas and oxygen above the liquid. When ignited, this mixture creates a flame that travels around the ring due to the continuous evaporation and replenishment of vapor, similar to a fuse arranged into a ring.

  • Why did the original ring trough design not always catch fire easily or burn for very long?

    -The original design might not have been optimal in terms of the width of the trough and the size of the opening. A trough that is too wide catches fire all at once instead of forming a whizzing flame, while a too-small trough allows the flame to work but doesn't last very long.

  • How did varying the size of the opening in the ring trough affect the flame?

    -With a very small opening, it's hard for the lighter fluid to catch on fire and when it does, the flame is small and short-lived. Conversely, if the opening is too large, the entire trough catches fire instead of forming a whizzing flame. An optimum configuration is found with a semi-circular cross-section and a specific width.

  • What is the role of the vapor in maintaining the flame in the ring-shaped trough?

    -The vapor acts like a fuse in a ring. As the flame travels around the ring, the heat from the burning vapor increases the rate of evaporation, providing a steady source of new vapor to keep the fire going. This allows the flame to continue around the ring as the vapor is replenished.

  • Why did the design with a small opening and an increased width of the trough not yield interesting results?

    -The design showed some of the same behavior as the original but only in short bursts, and it was not sustainable. It did not create a continuous or particularly interesting flame pattern.

  • How does the direction of the opening in the ring trough affect the flame?

    -Making the opening point inwards or outwards did not seem to make a significant difference in the flame behavior, suggesting that the direction of the opening is not a critical factor for the flame to travel around the ring.

  • What is the significance of the refractory time in the context of excitable mediums?

    -The refractory time is the period after the medium has been excited during which it cannot be excited again. This time is crucial as it allows the medium to return to an excitable state, enabling phenomena such as the continuous flame in the ring-shaped trough.

  • What are some other examples of excitable mediums in nature?

    -Examples of excitable mediums in nature include signaling in organisms, heart fibrillation, and the spread of infections like geographic tongue. These can often be modeled as excitable mediums due to their similar behavior of switching to an excited state under certain conditions.

  • How does the design of the ring-shaped trough affect the continuous flame phenomenon?

    -The design of the trough, particularly the width and the size of the opening, significantly affects the flame's ability to travel continuously around the ring. An optimal design with a specific width and semi-circular cross-section allows for a sustained flame, while deviations from this can prevent the flame from being sustained or alter its behavior.

  • What is the connection between the ring of lighter fluid and the concept of cellular automata?

    -The behavior of the flame traveling around the ring of lighter fluid is reminiscent of cellular automata, which are systems made up of a regular grid of cells that evolve through a series of discrete time steps according to a set of rules. Both exhibit interesting and complex patterns emerging from simple underlying principles.

  • What safety considerations should be taken into account when replicating the ring-shaped trough experiment?

    -Lighter fluid is highly flammable and dangerous, so the experiment should only be conducted by responsible adults in a controlled environment. Precautions should be taken to avoid fire hazards and ensure that the experiment does not pose a risk to people or property.

Outlines

00:00

๐Ÿ”ฅ Exploring Excitable Media: The Whirling Flame Trough

The video begins with an intriguing demonstration of a ring-shaped trough filled with lighter fluid, which when ignited, produces a continuous, circular flame. The host expresses fascination with this phenomenon and delves into the concept of 'excitable mediums,' leading to an exploration of various designs that alter flame behavior. The experiment was inspired by Rudy Stevens, who discovered the effect while using lighter fluid to heat and mold a cap for a closed ecosystem. The host then collaborates with Oscar Morris to create a customizable CAD file to experiment with different trough dimensions, aiming to optimize the design for a more consistent and longer-lasting flame. Through this process, it's discovered that a five-millimeter wide trough with a semi-circular cross-section works best. The video concludes with a scientific explanation of the lighter fluid's volatility causing the continuous flame, comparing it to the functioning of a candle and hypothesizing why the flame behaves as it does in the ring.

05:01

๐ŸŒ€ The Science Behind the Ring of Fire: Excitable Mediums

The video continues by likening the ring of lighter fluid to a loop of fuse that regrows after being burned, or a loop of dominoes that reset themselves as they fall. This behavior is characteristic of an 'excitable medium,' which is a system capable of entering an excited state after a certain refractory period. The host explains that the lighter fluid ring acts as an excitable medium due to the hydrocarbon vapor's potential to ignite when mixed with oxygen. The video further explores the concept by discussing how the flame can sustain itself by the time it completes a circuit around the ring, allowing for continuous burning. The explanation extends to other examples of excitable mediums in nature, such as heart fibrillation and the spread of infections like geographic tongue. Additionally, the host touches on the behavior of bubbles on hot chocolate, Mexican waves in sports stadiums, and forest fires, all of which can be modeled as excitable mediums. The video also humorously addresses the hypothetical scenario of a ring-shaped forest large enough to sustain a continuous forest fire, which leads to a calculation by a listener on the host's podcast.

10:01

๐ŸŽจ Creative Designs with Excitable Media: Flames in Shapes

The host presents additional designs created by Oscar to further explore the properties of excitable mediums. These include a split ring that rejoins, a spiral, a figure-eight, and a central ring with arms that emit flames each time the main flame passes. Each design is tested with lighter fluid, and the host observes the unique flame behaviors that result, such as brief sustained flames, directional changes, and spawning points for new flames. The video also features a modification of the spiral design to create a continuous loop of flame, achieved by adding an extra circle that feeds the spiral with flames. Despite some unexpected behaviors due to the remaining lighter fluid, the designs generally work as intended. The host cautions that handling lighter fluid is dangerous and should be done by responsible adults. The video ends with a call to action for viewers to print out the designs, share ideas, and engage with the host's community. It concludes with a sponsorship message for Jane Street, a quantitative trading firm that shares the host's passion for solving complex problems and is currently offering educational programs for students interested in technology and problem-solving.

Mindmap

Keywords

๐Ÿ’กExcitable Mediums

Excitable mediums are a concept in physics and biology where a system can switch to an excited state after being stimulated. In the video, it's used to describe how the lighter fluid and its vapor can ignite and create a continuous flame around a ring. The video explains that after being excited, the medium can't be excited again immediately but after a refractory period, it can be excited again, which is why the flame keeps circulating around the ring.

๐Ÿ’กVolatile Substances

Volatile substances are those that easily evaporate at room temperature. In the context of the video, lighter fluid is described as a volatile substance due to its tendency to evaporate and mix with oxygen in the air, leading to the continuous burning of the vapor when ignited. The volatility of the lighter fluid is key to the demonstration of the ring-shaped flame.

๐Ÿ’กCapillary Action

Capillary action is the ability of a liquid to flow in narrow spaces without the assistance of external forces, due to intermolecular forces between the liquid and the containing surface. The video mentions capillary action in the context of how a candle works, where the melted wax is drawn up through the wick by this action before being vaporized and burned.

๐Ÿ’กParameterized CAD File

A parameterized CAD (Computer-Aided Design) file is a type of design file where certain variables can be adjusted to modify the design. In the video, the host asks Oscar Morris to create a parameterized CAD file for the ring-shaped trough so that he can experiment with different sizes, widths, and angles to see how these variables affect the flame's behavior.

๐Ÿ’ก

๐Ÿ’กRefractory Time

Refractory time refers to the period during which a substance cannot react or be excited again after an initial reaction or excitation. In the video, it is used to explain the time it takes for the vapor above the lighter fluid to become excitable again after the flame has passed, which is crucial for the continuous movement of the flame around the ring.

๐Ÿ’กHydrocarbon Molecules

Hydrocarbon molecules are compounds made up entirely of carbon and hydrogen atoms. The lighter fluid in the video is composed of short-chain hydrocarbon molecules that evaporate and mix with oxygen to form a combustible gas. When this gas is ignited, it creates the flame that can circle the ring-shaped trough.

๐Ÿ’กCellular Automata

Cellular automata are mathematical models that simulate complex systems based on simple rules and initial conditions. The video draws a parallel between the behavior of the flame around the ring and cellular automata, like the Game of Life, where simple rules can lead to complex and interesting patterns. The excitable medium of the lighter fluid ring is an example of a real-world cellular automaton.

๐Ÿ’กPathological Excitable Medium

A pathological excitable medium is a term used in biology to describe a system that exhibits abnormal excitable behavior, such as heart fibrillation. The video mentions this to illustrate the application of the concept of excitable mediums in biological systems, showing the breadth of the concept beyond the physical demonstration with the lighter fluid.

๐Ÿ’กQuantitative Trading Firm

A quantitative trading firm, like Jane Street mentioned in the video, uses mathematical models, machine learning, and statistical analysis to make trading decisions in financial markets. The video script mentions Jane Street as an example of a company that employs techniques from various technical fields to solve complex problems, aligning with the video's theme of exploring complex phenomena through experimentation and analysis.

๐Ÿ’กSustainable Flame

A sustainable flame is one that can continue to burn without external intervention, once ignited. The video discusses the conditions necessary for a flame to be sustainable in the context of the ring-shaped trough, such as the optimal width and the semi-circular cross-section of the trough, which allow the flame to keep circulating due to the continuous supply of vaporized lighter fluid.

Highlights

The experiment with lighter fluid in a ring-shaped trough creates a fascinating visual of a flame circulating around the ring.

The phenomenon led to an exploration of 'excitable mediums', which are substances that can switch to an excited state under certain conditions.

A parameterized CAD file was used to tweak variables such as the size of the trough, the width of the ring, and the angle of the opening to observe their effects on flame behavior.

An optimal width of five millimeters for the trough was identified for maintaining a consistent flame without it catching fire all at once.

The size of the opening in the trough significantly impacts the flame's ability to ignite and sustain, with a sweet spot found for optimal performance.

The direction in which the opening points (inward or outward) does not affect the flame's behavior, contrary to initial hypotheses.

The lighter fluid's volatility causes it to evaporate, creating a mixture of hydrocarbon gas and oxygen that ignites upon contact with a flame.

A hypothesis is proposed that the thin ring of vapor above the lighter fluid is akin to a fuse, igniting and traveling around the ring due to the evaporation rate.

The ring of lighter fluid serves as an example of an excitable medium, with criteria including a refractory time before it can be excited again.

The concept of excitable mediums is applicable in various fields, including biology, with examples like heart fibrillation and geographic tongue.

The video explores the idea of a continuous forest fire in a ring-shaped forest, which would require a circumference of 87,600 kilometers to sustain.

Innovative designs such as a split ring, spiral, and figure-eight-shaped trough were tested to observe unique flame patterns and behaviors.

A maze-like design was created where the flame appears to solve a maze, showcasing the potential for creative applications of excitable mediums.

The video concludes with a call to action for responsible experimentation with the provided designs and a prompt for viewers to share their own ideas.

The video is sponsored by Jane Street, a quantitative trading firm that employs techniques from various fields to trade on global markets and encourages curious minds to apply for their programs.

The video provides a link for viewers to print out the designs for themselves, emphasizing the importance of responsible handling of lighter fluid.

Transcripts

00:00

(upbeat jazz music)

00:08

- Watch what happens when I pour lighter fluid

00:09

into this ring-shaped trough and then set light to it.

00:12

Look, the flame goes round and round.

00:15

Isn't that weird?

00:16

I really wanted to figure out what was going on,

00:17

and in doing so, I fell down a bit of a rabbit hole

00:20

about things called excitable mediums.

00:23

Excitable mediums are really interesting,

00:25

and by the end I had a handful of designs

00:28

that made the flames do really bizarre things.

00:31

This one in particular is a lot of fun,

00:33

but first, why was I dowsing my 3D prints

00:37

in lighter fluid in the first place?

00:38

Well, it's actually something one of my subscribers noticed,

00:41

and they sent me an email.

00:42

Rudy Stevens designed the part as a cap

00:45

for a small, closed ecosystem he was working on.

00:47

To make it a snug fit, he decided to heat it up

00:50

and mold it in place.

00:51

Using lighter fluid for the task,

00:53

he stumbled upon this weird phenomenon,

00:55

so, of course, I said, "That's amazing.

00:57

"Please send me the file so I can try it for myself,"

01:00

and, you know, it worked like a charm,

01:02

but it got me thinking, is this trough optimal?

01:05

Like, it can be quite hard to get the flame started,

01:08

and it doesn't always burn for very long once it is.

01:11

So, I asked Oscar Morris to design me

01:13

a parameterized CAD file so I could tweak the variables

01:17

and see what effect that had.

01:18

This is what Oscar does for a living, by the way.

01:20

The link to his website in the description.

01:22

See how I can change the size of the trough,

01:25

the width of the ring, the size of the opening.

01:27

I can also change the angle of the opening.

01:30

I wanted to have that ability,

01:31

because you'll notice in Rudy's design

01:33

that the opening is pointing inward slightly,

01:35

and I wondered if that was important.

01:37

The first thing I varied was just the width of the trough,

01:40

but I also varied the size of the ring slightly,

01:42

so I could nest them all together on the print bed

01:45

and print them at the same time.

01:46

I don't think that made much of a difference,

01:48

and it turns out there is a bit

01:49

of a sweet spot around five millimeters.

01:51

If the trough is too wide,

01:53

the whole thing just catches fire

01:55

instead of forming, like, a whizzing flame,

01:58

and if the trough is too small, well, it works,

02:01

but it doesn't last very long.

02:02

With the width of the trough fixed at five millimeters,

02:05

I then varied the size of the opening.

02:07

With a very small opening,

02:08

it's hard for the lighter fluid to catch on fire.

02:11

When it does, you get a small flame

02:13

that seems to travel very slowly for a short time

02:15

and then go out.

02:16

Conversely, if the trough is too open,

02:18

the whole thing tends to set on fire

02:20

instead of having a flame whizzing round.

02:22

It's a bit like when the trough was too wide,

02:25

you can get a whizzing flame eventually

02:27

when there's only a bit of lighter fluid,

02:29

but then it doesn't last very long.

02:31

I also thought it'd be interesting to try a small opening,

02:33

but where the width of the trough is increased

02:36

until that small opening is five millimeters,

02:39

but it didn't do anything interesting.

02:40

Like, it shows some of the same behavior,

02:43

but just in little bursts, and it's not sustainable.

02:46

Making the opening point inwards or outwards

02:49

didn't seem to make a difference, and in the end,

02:51

the optimum configuration seemed to be

02:54

a trough that was five millimeters wide

02:57

with a semi-circular cross-section.

02:59

I managed to get two flames going around at the same time

03:02

at one point, not sure how I managed that.

03:04

So, what's going on?

03:05

Well, when you burn lighter fluid,

03:07

you're not actually burning the liquid.

03:09

Instead, because the lighter fluid is really volatile,

03:12

it's constantly evaporating.

03:15

That's why it has such a strong smell.

03:17

So, above this little pool of lighter fluid,

03:19

there's a whole bunch of short-chain hydrocarbon molecules,

03:23

whizzing about and mixing with the oxygen in the air,

03:26

so when a flame is introduced,

03:28

that mixture of hydrocarbon gas and oxygen ignites.

03:32

The heat from the burning vapor

03:34

increases the rate of evaporation,

03:36

so that you have a steady source of new vapor

03:38

to keep the fire going.

03:39

It's similar to how a candle works, actually,

03:41

except that with a candle,

03:43

the flame first melts the solid wax,

03:45

which is then drawn up through the wick by capillary action

03:49

and then vaporized before being burnt in the air.

03:53

My hypothesis is that when you have

03:55

a very thin reservoir of lighter fluid like this,

03:58

then you only have a thin ring of vapor above the liquid.

04:01

So, when it's ignited, the flame isn't as hot,

04:05

which means the evaporation rate of the liquid fuel

04:07

doesn't increase that much,

04:08

and so the flame can't be maintained in that spot,

04:11

but to the left and right of that initial flame,

04:13

there's all this unburnt vapor,

04:15

so you get two flames running around the ring,

04:18

and they die when they meet at the opposite side.

04:21

So, that ring of vapor is a bit like a fuse,

04:23

arranged into a ring.

04:24

If you light it at one point, it travels around.

04:27

If you keep relighting it,

04:29

eventually, you get one flame going round on its own,

04:32

presumably because of some imbalance in the reservoir

04:35

or something like that.

04:36

I had some success forcing a single flame by putting my hand

04:39

over the ring just to one side of the ignition point,

04:42

then quickly removing my hand after it had blocked

04:44

one of the flames,

04:45

but why does it keep going round and round?

04:47

Well, brilliantly, in the time it takes for the flame to do

04:50

one full circuit of the ring,

04:53

enough lighter fluid has evaporated at the starting point

04:56

for the flame to be able to continue,

04:58

and so you get this flame that whizzes

05:00

round and round and round.

05:01

It's a bit like if you had a loop of fuse,

05:03

but somehow, by the time the flame got back round

05:06

to where it started,

05:08

the fuse had, like, regrown or something.

05:11

It's like knocking down a loop of dominoes,

05:12

except where you've got some mechanism running behind,

05:16

putting them back up again.

05:17

In other words, this mad contraption from JK Brickworks,

05:21

a link to that video in the card in the description.

05:23

The vapor explanation would also explain

05:25

why it doesn't work particularly well

05:27

when the trough is too wide.

05:29

A wider trough means more vapor, which means a hotter flame,

05:32

which means faster evaporation,

05:34

and so the flame can maintain itself in that position.

05:37

It also explains why a trough with high walls works better.

05:41

It puts a bit of distance between the flame and the liquid,

05:44

so that the heat from the flame

05:45

can't cause too much additional evaporation.

05:48

That's compared to what we saw when the trough was shallow,

05:51

and the flame was just everywhere all at once,

05:54

but presumably, if you close the trough too much,

05:56

then you have an issue with oxygen supply maybe,

06:00

I'm not sure.

06:00

So, this ring of lighter fluid, it turns out,

06:03

is an example of an excitable medium.

06:06

An excitable medium is something that has the potential

06:09

to switch to an excited state.

06:12

In this case, it's the hydrocarbon vapor

06:14

that has the potential to be on fire.

06:17

That's not the full definition, though.

06:19

There are three other criteria

06:20

that make it an interesting subject.

06:23

The first is that after it has been excited,

06:25

it can't be excited again right away.

06:27

The second characteristic is that

06:29

after a certain amount of time,

06:31

the medium is once again excitable.

06:33

That's called the refractory time,

06:35

and crucially, any part of the medium will become excited

06:38

if a neighboring part of the medium is excited.

06:40

It's such a simple definition, but it fully explains

06:43

the fire going round and round the ring,

06:45

and it's interesting that Rudy stumbled upon

06:47

just the right parameters for an excitable medium to emerge,

06:51

a thin enough channel,

06:52

so that the vapor isn't excitable immediately

06:55

after it catches fire,

06:56

and a ring with long enough circumference

06:58

that by the time one circuit is completed,

07:01

the refractory time of the medium has passed,

07:04

and the gas above the ring is once again excitable.

07:06

It's kind of reminiscent of cellular automata,

07:10

interesting movements that arise from simple rules.

07:14

You're probably familiar with the Game of Life,

07:16

for example, but this is a cellular automata model

07:19

of an excitable medium,

07:21

and it evolves in these interesting ways.

07:23

There's lots of examples in biology.

07:24

Signaling in organisms can often be modeled

07:27

as an excitable medium.

07:28

Heart fibrillation is an example

07:30

of a pathological excitable medium.

07:32

There's an infection called geographic tongue,

07:35

and it's believed to be a very slow example

07:38

of an excitable medium.

07:39

The infection spreads, the tongue recovers,

07:42

can't be infected again immediately,

07:44

but after some refractory time, the infection can come back,

07:47

and you get this complex pattern on the tongue.

07:50

Someone called Ollie sent me this video of the bubbles

07:53

on the surface of a hot chocolate collapsing.

07:55

The bubbles are slowly evaporating, so they're ready to pop,

07:58

which is to say they are excitable,

08:01

and to some extent each bubble is being supported

08:04

by its neighboring bubbles, so if one bubble collapses,

08:07

it's likely that the other bubbles around it will collapse,

08:10

and so it spreads as this pulse wave

08:12

across the surface of the hot chocolate.

08:14

Sometimes, you think, "That's interesting enough

08:16

"for someone to write a paper about,"

08:18

and then you find out they already have.

08:20

Mexican waves in sports stadiums are another example.

08:23

The people are the excitable medium in that case,

08:26

and just like with the lighter fluid ring,

08:28

it's possible to get a wave

08:29

that goes round and round and round, and forest fires.

08:32

It's possible for a forest to be

08:34

in the excited state of on fire,

08:36

and it fulfills all the other criteria, too,

08:39

it's just that the refractory time is incredibly long.

08:42

The forest has to regrow before another pulse wave

08:45

can pass through it.

08:46

On our podcast, Matt Parker asked the important question,

08:49

"How large would a ring-shaped forest need to be

08:51

"to sustain a continuous forest fire

08:53

"going round and the ring forest,

08:56

"just like the flame going round and round

08:59

"the ring of lighter fluid?"

09:00

The podcast is called, "A Podcast of Unnecessary Detail,"

09:03

by the way, and one of our listeners went ahead

09:05

and did the calculations.

09:06

This is very rough,

09:07

but the front of a forest fire progresses

09:11

at about 10 kilometers per hour,

09:13

which is surprisingly fast, actually,

09:15

and some forest fires happen as often as annually,

09:19

which means the refractory time can be as little

09:21

as one year or 8,760 hours.

09:26

So, if the fire front travels at 10 kilometers per hour,

09:30

and the refractory time of a forest is 8,760 hours,

09:36

then the circumference of a ring-shaped forest

09:38

would need to be 87,600 kilometers.

09:41

The circumference of the Earth is less than half that,

09:45

at 40,000 kilometers,

09:46

so if there was a forest all the way around

09:49

the circumference of the Earth,

09:50

it would not be long enough to sustain a never-ending fire

09:54

that goes round and round and round,

09:56

but I mean, you could zigzag the forest,

09:58

or maybe you could make the forest out of bamboo,

10:00

because that grows back quickly,

10:01

but anyway, there you go.

10:02

That is how excitable mediums can lead to spinning flames.

10:06

Finally, I got Oscar to design

10:07

a few more cool things for me.

10:09

I wanted to see what would happen if the ring split in two

10:12

and then came back together.

10:13

That's cool, isn't it?

10:15

It's interesting to see that you occasionally get,

10:17

just very briefly, a sustained flame in one position,

10:22

and it can cause other flames to change direction

10:25

or sometimes it can act almost like a spawning point,

10:29

so you get more and more flames

10:31

coming from that one location.

10:33

And here's a spiral.

10:38

(lighter clicks)

10:41

And here's a figure-eight-shaped trough.

10:44

I really didn't think this would work,

10:46

because obviously there's a raised section

10:49

where one track goes over the other,

10:51

so you have it slanting either side,

10:53

and I thought the lighter fluid would drain away from there.

10:56

Like, it definitely does,

10:58

but I guess enough of the lighter fluid

11:00

sticks around up there for the fire to go round and round

11:04

at least a few times before it goes out.

11:07

Then, there's this design, that has a flame

11:09

going round a central ring,

11:10

and every time it passes one of the arms,

11:13

a flame shoots out across the arm.

11:15

That's cool, isn't it?

11:17

And here's a modification of the spiral.

11:20

The issue with the spiral is it's not a closed loop,

11:22

so you set fire to one end, it travels round and round

11:26

until it reaches the other end, and then it stops.

11:29

Wouldn't it be good if you could keep it going somehow?

11:32

That's what the extra circle is for.

11:35

The flame that goes round around the circle

11:36

should keep firing flames down the spiral.

11:40

In reality, when you have these junctions,

11:41

you often end up with a sustained flame at that junction,

11:45

and that seems to be powering

11:47

the continuous supply of flames around the spiral,

11:51

but eventually, as the lighter fluid

11:52

dries out more and more, the design works as intended.

11:56

Now, there is still quite a bit of lighter fluid

11:57

in the middle, so there's a bit of strange behavior there.

12:00

It even sends one flame back in the opposite direction.

12:03

If you want to print out any of these for yourself,

12:04

there's a link in the description for that.

12:07

Lighter fluid is dangerous,

12:08

so that would be something for responsible adults only,

12:12

and if you have any ideas for tracks

12:14

that you would like to see, send me an email,

12:16

tell me on my Discord server.

12:17

For example, just before I was about to export this video,

12:20

Rudy sent me another design.

12:23

This is the flames solving a maze.

12:26

How cool is that?

12:26

It's actually quite nice T-shirt.

12:29

I don't really go for science T-shirts.

12:30

It's quite subtle, though.

12:31

This video is sponsored by Jane Street.

12:33

Jane Street is a quantitative trading firm

12:35

with offices in New York, London, Hong Kong,

12:38

Amsterdam, and Singapore.

12:39

They use techniques from machine learning,

12:40

distributed systems, programmable hardware,

12:42

and statistics to trade on markets around the world.

12:45

They're also a bunch of people who love

12:47

solving interesting problems, and they're passionate

12:50

about a lot of the same things that we are.

12:52

For an example of their nerdiness,

12:54

they designed this T-shirt, look.

12:56

It shows, like, how particles move in a cloud chamber.

13:02

You know, if you've got, like, maybe a magnetic field

13:05

and a particle whizzes in, it's going to spiral,

13:07

because of the magnetic field,

13:08

but some of them aren't, if they're not charged,

13:10

and it kind of slows them down, traps them,

13:12

and you use it in science, like in the large hadron collider

13:15

and things like that, but like embedded in there

13:18

is the Jane Street logo.

13:19

They currently have a few educational programs

13:21

that are accepting applications in both their New York

13:24

and London offices for pre-university

13:26

and university students.

13:28

These programs are part of Jane Street's commitment

13:30

to give as many people as possible a chance to learn

13:33

more about what they do.

13:34

The programs themselves are all a bit different,

13:36

but focus on topics that you might be interested in,

13:39

things like complex mathematical theory,

13:41

programming, statistics and more,

13:42

and it's definitely worth saying

13:43

you don't need a background in finance to apply.

13:46

Jane Street is looking for curious people

13:48

from any background with a passion for technology

13:51

and creative problem solving.

13:52

In other words, people like you.

13:54

Check out the link in the description now

13:56

to see what opportunities are currently open

13:58

and to see if any of them might be for you.

14:00

They currently have three programs open in NYC

14:02

and one in London,

14:04

and applications are closing in just a few weeks,

14:06

so check out Jane Street today.

14:08

Hope you enjoyed this video.

14:09

If you did, don't forget to hit subscribe

14:11

and the algorithm thinks you'll enjoy this video next.

14:14

(upbeat jazz music)

Rate This
โ˜…
โ˜…
โ˜…
โ˜…
โ˜…

5.0 / 5 (0 votes)

Related Tags
Excitable MediumsFlame Phenomena3D PrintingScience ExperimentLighter FluidCAD DesignPhysicsChemical ReactionsInnovationEducational Content