When air is compressed very quickly, it can reach high temperatures. In this demonstration we show how cotton wool can reach the point of auto-ignition by quick compression of air in the fire syringe.
+Faris Shamren learn how a diesel engine works before you write down a reply. a diesel DOESN'T USE A SPARK PLUG. the fuel is ignited through compression.
+Bartosz Olszewski A diesel does not have a spark plug. It has a glow plug which is a very different thing. There is no spark what so ever. The glow plug has a resistor wire at the inserted end that will heat up, enabling the fuel to ignite.
***** Airbenders could also increase the air pressure under anything (be it rocks, water or metal) to make it float. I always thought they were a little OP but this video and you're comment has shown me that they're basically the avatar. Still no spirit bending of course but I'll wait until someone figures out how they can do it.
This is certainly the first time that I actually understood the concept of compression heating/not heating gas in thermodynamics! Thank you Derek and Nigel!
I am thinking that diesel engines are slightly more efficient than regular gasoline because the diesel combusts at high pressure, while the gasoline needs the spark plugs. This means that the gas engine has to produce energy for the battery which is used by the spark plugs along with the A/C, radio, headlights, etc. while the diesel engine does not need to power the spark plug. Is this correct?
Brady Kent The actual power take-off for the spark is negligible next to the reduction in moving mass that gasoline engines can get away with by working at low pressure. Diesel engines are more efficient both because of the greater compression ratio and also, more importantly, the greater power density(by mass, not volume) of diesel fuel itself.
soupflood NOOOOOO THEY USE GLOW PLUGS!!!! DIESEL IS ONLY USED IN COMPRESSION IGNITION!!!!! mainly because theres oils in the diesel and it would foul the spark plugs almost instantly or you would have carbon deposits in the engine.
This is slightly inaccurate. They fail to mention that plunging also increases the partial pressure of O2 in the chamber, which lowers the temperature at which combustion occurs. In other words, the cotton is igniting at a lower temperature than it would ignite at ordinary atmospheric pressure.
What is partial pressure? And while you're at it, can you please explain why water boils at a temp. lower than 100 deg in lower pressure or vacuum? Are these related?
+Vishnu “awguy” Manivannan Partial Pressure is the pressure that one certain substance contributes with. So if the O2-% in the air is around 20%, you'd expect the partial pressure of O2 in the atmosphere to be about 20kPa. Now that they compress the air, let's say to 10 times the atmospheric pressure, the partial pressure of O2 will also increase by 10 times, to 200kPa in this case. A higher partial pressure of O2 in an environment makes it easier for an object to burn, and it burns more completely. The reason that water (or any substance for that matter) boils at a lower temperature in lower pressure is a bit related to this. Every substance that is able to be in gas-form has a property that dictates the "maximum partial pressure at a given temperature". For example, this might be around 20 kPa for water at 20C. This means that at 20C the air will be saturated with water when that partial pressure of water reaches 20kPa, so no more water will evaporate. And the reason that water boils at 100C is that at 100C the maximum partial pressure of water is the same as the atmospheric pressure, so at that temperature water could potentially "replace" all other substances in the air. And at this point all of the energy you put into your boiling water goes to evaporating more water, instead of heating up the liquid water. When you reduce the atmospheric pressure to let's say 80kPa, water would instead start boiling at the temperature at which it's maximum partial pressure is 80kPa. Which obviously is a lower temperature than 100C.
Wow lol it's very interesting see go back and see these older, significantly less polished episodes when compared to your new, more refined episode. It really illustrates just how far you have come over the years. Congrats on your success! Thank you for your passionate enthusiasm and Keep it up! I hope to be able to make the comparisons again in another 10 years
@FishyArchaeologist You got it - the sliding plunger speeds up the molecules. It doesn't have to be going incredibly fast, it just needs to increase the KE of the molecules it hits.
sometimes we are economical with language - it saves listing all the components individually. Is there a better way to say it? I don't imagine most people have difficulty understanding that the air is composed of a variety of different molecules and atoms.
For all those in the future with me where threading exists, this was in response to a concern that there’s no such thing as “air molecules”, and they would have preferred something like “the molecules in the air”. Interestingly, I’ve definitely heard the latter phrase more often in newer videos.
@@justins8802 This is literally the reason why science and tech content creators on this platform like Tom Scott, Vsauce, CrashCourse, and even Linus Tech Tips (although a bit less) are quite pedantic about terminology in videos. But I suppose that's a good thing.. not inconspicuous though
If I'm not mistaken, this is the basic concept behind a diesel engine. I remember when my father first started teaching me about diesel engines when he would bring me on the tractor trailer and show me how to use it, and this very thing was what he showed me. He explained it in conjunction with the 'glowplug' when we had to change them out one winter. Because the engine block is so cold in the winter, the motor has heating rods in them to help warm up the engine so that when you turn over the motor (with the electric starter) the heat doesn't get absorbed by the engine block which doesn't allow it to accomplish an "adiabatic compression". I remember being so blown away by it. Like it altered my perspective of science. Of course I was only 12 or so at the time. There was all sorts of science to learn both on the farm and on the tractor trailer, and my father was never short on explaining it all.
I worked on the waste water treatment plant in Helsinki. It's an underground facility and there are huge airpumps to pump air into those vats that have aerobic bacters. There were huge heat exchangers after the pumps so that the water where the air was pumped would not start to boil. The heat from the exchanger was used to heat the facility and it almost was enough for the whole facility. There was a powerstation using the gas that was got from the fermentation of the waste after the bacterial treatment. It's waste heat was the rest of the heat the facility needed. The electricity generated there was about half of the power need of the facility. The final waste after the fermentation were transported to nearby compost facility that made almost all the landscaping mulch that the municipal needed. Later the local power company started to use the heat of the output water to generate pipable cold.
I found out about Veritasium just a few years ago and have regularly watched your videos since. Then, I was sent here by my Thermal Physics prof. Wow, this video is 9 years old! A surprise to be sure, but a welcome one.
HEY, GENIUS, STICK A DROP OF WATER IN IT INSTEAD OF AN INCINDIARY COMPOUND. DOESNT WORK WITH A STANDARD DIESEL IN AN AUTOMOBILE, BUT AT LEAST 3 FREIGHTERS WITH HIGH COMPRESSION ENGINES IN WW2 RAN COMPLETELY ON SALT WATER FOR DAYS, NOT REALIZING IT UNTIL REACHING PORT. THE SALT WATER RUINED THE ENGINES, BUT THE FACT THAT THEY RAN WITHOUT EVEN BEING HOOKED UP TO THE HEAVY FUEL OIL FOR AN OCEAN CROSSING IS PHENOMINAL.
Our physics teacher showed this to us but after he hit the piston down, because of the combustion the piston shot up into the ceiling and broke a lamp with poisonous stuff in it that then fell down on the students, pure chaos. Best physics lesson ever.
Yeah I'm surprised they didn't mention it's a Southeast Asian invention from thousands of years ago used to start fires. Not that their point was to portray a new invention. It's just that the idea of introducing a curious phenomenon wouldn't be far off from also explaining its curious origins. Not to mention the relative precision required to achieve it 🤷♂️
And that, ladies and gentlemen, is how diesel engines work! Of course they have fuel heaters and glowplugs(for cold starts), but the general idea is the same.
a proper diesel engine has a hook cast into the block, to hang the blowtorch there for the "Rudolf Diesel commemoration hour".... Also, it can not be one-cylindered enough, says Heinrich Lanz
Takes much much more pressure to ignite diesel this way. Not even a starter on a diesel can do it, thats why glow plugs are in the engine to kickstart it.
Jesse Haskins Not true. Cummins diesels in Dodge Rams don't use glowplugs. Glow plugs are only necessary for cold weather conditions. The Cummins uses an engine heater in place of glowplugs.
danneu8 Right, A Block Heater! All that is needed is to generate enough heat to ignite the diesel without any compression because the engine is at rest when started.
@@wireboy253 lol what is this crap? My tractor doesn't even have glowplugs. It is a little hard to start in cold weather, but it CAN start and run. Also i think that this piston creates enough heat to ignite diesel. Also a starter and a glow plug are 2 totally different things. The starter is for turning the engine over and the glow plug is for heating the fuel. This sentence doesn't make any sense: "Not even a starter on a diesel can do it, thats why glow plugs are in the engine to kickstart it." Comparing them is totally stupid.
Temperature isn't caused by the number of collisions with other molecules as was implied by saying that it was caused by molecules being closer together. It is because you are doing work on the molecules and increasing their speeds. Conceptually, this transfer is caused by the fact that the plunger is moving downward so when molecules hit it, they leave with a greater speed.
Viheeth Wijewardhane Yes. Have you ever used the small disposable co2 tubes for soft airguns? They can sometimes get so cold that frost builds up on them when you empty the tube quickly.
Yes, try getting a can of compressed air and see how cold it gets when you hold the valve open. Compressing, removing the heat and decompressing is actually the easiest way to make dry ice and liquid nitrogen
@@toby1248 Compressed air cans mostly cool down due to evaporative cooling of the liquid inside, but you're still right. Decompressing the gas creates cooling.
The same principal as a fire piston, pressurized air builds heat and in turn will ignite any material inside that is flammable. The fire piston is a tube in which a small amount of fibers from dried plants are placed, then when the cylinder is smacked down it ignites and makes an ember, when removed and blown will make a fire. Cool science!!!
I’ve stumbled across a couple of these 2011 videos tonight... is it me or is his style of interviewing/working with others around this time to flirt with them?... I’m thankful with the evolution of Veritasium!
Yes, you're correct. Either way they don't ignite anything they just aid in the combustion by heating up the area thus helping the combustion process along which only occurs due to the pressure.
This technology is originated from Malay Archipelago. The original name is Gobek Api aka "Fire Crusher-Plunger". It was used as 1st portable lighter and become widely used in the 12th century when gun powder become available from China. Later in 17th century, the technology arrived in Europe and US where the scientist claims the patent as "Fire Piston".
There is a concept about this in germany called "Feuerpumpe" (direct translation: Firepump). Its used a piece of charcloth and the pneumatic principle behind it to light the cloth and to start a fire. it was spread quite a bit a time ago and was considered as a "lighter".
Thats the fire piston. Discovered in the Philippines back in the 16th century. Robert Doyle first played around with the fire piston given to him by Galileo and soon discovered the reason behind its then miraculous fire creating power. As one might say it was the Philippines who created the first piston.
A piston implies that the pressure extends out a piston. You press down on this to compress it, and it doesn't go anywhere after that. In essence, it's not called a piston because it's not a piston
Ignition temperature of cotton is about 400C at atmospheric pressure. Increasing the partial pressure of O2 will lower that ignition point by a great amount. the fire piston works by a combination of increasing heat through compression and increasing partial pressure of O2 with compression. Carbonized cotton fabric is pretty much a standard fuel for the fire pistons used by survivalist. Also called "char cloth".
An engine works by putting fuel in the whatever it is called then spark plugs create a spark that explodes the fuel the explosion force the cylinder down. The cylimder is connected to a crankshaft in such a way that the downward force is changed into rotational energy but since there is multiple cylinders at different stages of this then there is always a downward force making the crankshaft spin. Then the spinning crankshaft causes the cylinder that just got pushed down to go back up and push the exhaust out. If you don't understand still you should probably watch an animation of it.
I had since looked into it myself, but never came back to comment. If anyone is interested: Pressure decreases the auto-ignition point. Pressure increases the boiling point. At 2:17 he states that the auto-ignition temp was 400°C, but doesn't state at what pressure, I am going to assume ~100 kPa (1 atmosphere) So the pressure from the syringe may not be increasing the air temp to 400° since the additional pressure will be decreasing the auto-ignition point. I have yet to find out what is the likely temp the air is being heated to in this scenario.
This is also the same as a Fire Piston. A survival tool when used helps you create a fire out in the wilderness. Replace the wool in this video with a little dry tinder and you have a nice little smoldering piece of wood to start a fire with.
It's not about the heat, it's about the chemical reaction of oxidization that increases under greater pressure and so exceeds a treshold of combustive oxidization, which is bursting into flames. Heat is only a product, not the cause.
Sniper of the Dark If you had known the rule of the welders - never weld if gloves in case they get greased - you'd have understood why oxidazation is generating heat, and not the other way round, at least in most cases.
Heat is the wrong word. It's temperature (they are different). The temperature of the apparatus gets very high for a short amount of time, which causes the ignition. It's only a small amount of heat (at least before the fire, an independent energy source). Same principle applies to sparklers. The little pieces flying off are momentarily hundreds or thousands of degrees, but because they're tiny and have very little mass, it's not enough heat to be harmful.
mustacheman19 No. Spark plugs are for gasoline engines. Heater plugs, more commonly known as glow plugs, heat up the diesel vapor, lowering the pressure required for combustion. Mostly used in cold climates.
My dad and I made one a few years back, it comes in handy when camping and you want to make w fire. Just use some char cloth that becomes an ember, then you can put that in some flammable stuff and boom, fire!
You also need to consider the increase in partial pressure of O2. Many materials are more combustible as O2 pressure increases. Cotton will ignite much more easily when the air is compressed.
A bike has a spark plug and a coil that generates the voltage needed to create the spark. Once it rotates, it's enough to keep the motor running. Kick starting a motorcycle only provides the initial inertia to get the fuel compression and first spark going, after which the motor can run by itself.
They actually use glow plugs to heat up the engine block. This makes it easier for the fuel to ignite because less energy is lost heating up the cold metal.
Although you can't see it, in most weight scales, the fulcrum is placed slightly above the center of mass of the seesaw bit. Think of an upside down T that's been super-shortened and widened.This means that when no single weight weighs more than another, the scale falls naturally to it's lowest point, an even plane. This is also the reason that when weights are only slightly different, the angle of the balance is only a little bit skewed.
It’s the movement that creates the fire, not the collision. Heat is just rapidly moving particles so the sudden and extreme heat ignites the cotton instantly.
That’s why doing it slowly doesn’t do anything, heat takes time to pass through glass because it’s one of the best solid insulators, the real reason is because the larticles simply aren’t moving fast enough. The collision is important too though becaise the collision is how the heat spreads to the cotton and the heat sets the cotton on fire, the collision isn’t what generates heat is all I was saying.
Oh cool, I saw one of these over at the Hendrik Ball channel the last time I got stuck in it. Keep up the awesome videos where you explain things! (I don't know what it is, but I feel like I completely butchered that sentence grammatically.)
Omg the sexual tension is beyond belief, hahaha. Am i the only one seeing this. "Let's go see if we can auto ignite some other things -_o" "Yeah, maybe some (pubic & anal) hair" (from friction).
A significant factor, on the topic if how fast you move the plunger, is the seal and the pressure. If you press it slowly, since the seal isn't perfect, you lose pressure, and, therefore, temperature. How significant these two factors are is uncertain. You could install a tiny camera to detect the flame and then insulate the syringe well. Or you could measure the rise in temperature in the surrounding medium to calculate heat loss (only useful in this test if there is no flame).
I'm surprised that you didn't mention that that's how a diesel engine works
+vancouverbuspilot
truely fascinating
+Faris Shamren learn how a diesel engine works before you write down a reply. a diesel DOESN'T USE A SPARK PLUG. the fuel is ignited through compression.
I just like the fact that this discussion happens 4 jears after the innitial upload of the video
+Bartosz Olszewski A diesel does not have a spark plug. It has a glow plug which is a very different thing. There is no spark what so ever. The glow plug has a resistor wire at the inserted end that will heat up, enabling the fuel to ignite.
+Bartosz Olszewski I'm pretty sure do to the lack of response the only reason the spark plug comment was made just to upset people
So does this means that airbenders can also firebend?
Ang is a air bender....he is also a waterbender....and a fire ended....and a earth ended.....
***** If they're smart airbenders.
Ammon Richards I'm not stupid, air, fire,water and earth are from Avatar. Please no hate
***** Airbenders could also increase the air pressure under anything (be it rocks, water or metal) to make it float.
I always thought they were a little OP but this video and you're comment has shown me that they're basically the avatar.
Still no spirit bending of course but I'll wait until someone figures out how they can do it.
You could say the same about Waterbenders. They could bend huge chunks of ice and scalding water, possibly making pseudo Earth/Firebending.
wow im really late. a thousand diesel enthusiasts saw this already before I got here.
now 1.29 million
dw bro im later:)
@@nilschristianhalvorsen5386 same😎
@@nilschristianhalvorsen5386 bro im even later than u
Damn every comment other than this is about diesel engines
This is certainly the first time that I actually understood the concept of compression heating/not heating gas in thermodynamics! Thank you Derek and Nigel!
I agree
This is the principle Diesel engines were built upon.
I am thinking that diesel engines are slightly more efficient than regular gasoline because the diesel combusts at high pressure, while the gasoline needs the spark plugs. This means that the gas engine has to produce energy for the battery which is used by the spark plugs along with the A/C, radio, headlights, etc. while the diesel engine does not need to power the spark plug. Is this correct?
Brady Kent
Recent diesel models do use sparks.
Brady Kent
The actual power take-off for the spark is negligible next to the reduction in moving mass that gasoline engines can get away with by working at low pressure. Diesel engines are more efficient both because of the greater compression ratio and also, more importantly, the greater power density(by mass, not volume) of diesel fuel itself.
soupflood NOOOOOO THEY USE GLOW PLUGS!!!! DIESEL IS ONLY USED IN COMPRESSION IGNITION!!!!!
mainly because theres oils in the diesel and it would foul the spark plugs almost instantly or you would have carbon deposits in the engine.
Ferriswheel
yes
A HANDHELD MICROPHONE truly this is the distant past
2011?
oh my sweet summer child...
@@fayeharrison1741 yes?
@@elliottg5987 2011 wasn't that long ago
@@Armadurapersonal just one single decade ago.
That's like, 10 years though
This is slightly inaccurate. They fail to mention that plunging also increases the partial pressure of O2 in the chamber, which lowers the temperature at which combustion occurs. In other words, the cotton is igniting at a lower temperature than it would ignite at ordinary atmospheric pressure.
What is partial pressure? And while you're at it, can you please explain why water boils at a temp. lower than 100 deg in lower pressure or vacuum? Are these related?
+Vishnu “awguy” Manivannan Partial Pressure is the pressure that one certain substance contributes with. So if the O2-% in the air is around 20%, you'd expect the partial pressure of O2 in the atmosphere to be about 20kPa. Now that they compress the air, let's say to 10 times the atmospheric pressure, the partial pressure of O2 will also increase by 10 times, to 200kPa in this case. A higher partial pressure of O2 in an environment makes it easier for an object to burn, and it burns more completely.
The reason that water (or any substance for that matter) boils at a lower temperature in lower pressure is a bit related to this. Every substance that is able to be in gas-form has a property that dictates the "maximum partial pressure at a given temperature". For example, this might be around 20 kPa for water at 20C. This means that at 20C the air will be saturated with water when that partial pressure of water reaches 20kPa, so no more water will evaporate. And the reason that water boils at 100C is that at 100C the maximum partial pressure of water is the same as the atmospheric pressure, so at that temperature water could potentially "replace" all other substances in the air. And at this point all of the energy you put into your boiling water goes to evaporating more water, instead of heating up the liquid water.
When you reduce the atmospheric pressure to let's say 80kPa, water would instead start boiling at the temperature at which it's maximum partial pressure is 80kPa. Which obviously is a lower temperature than 100C.
daniel355273 Perfect explanation, I really do appreciate the time and effort you put into typing it out.
+John Smith doesn't mean that it's inaccurate?
+daniel355273 "When you reduce the atmospheric pressure to let's say 80kPa, ....." Did you mean increase? If so, then I understood! thanks!
Wow lol it's very interesting see go back and see these older, significantly less polished episodes when compared to your new, more refined episode. It really illustrates just how far you have come over the years.
Congrats on your success! Thank you for your passionate enthusiasm and Keep it up! I hope to be able to make the comparisons again in another 10 years
@FishyArchaeologist You got it - the sliding plunger speeds up the molecules. It doesn't have to be going incredibly fast, it just needs to increase the KE of the molecules it hits.
Yeah
Why is ur comment only have 3 likes?
@@Cuins. 4 now. You're welcome Veritasium.
16@@iansrving
Watching this from 2019 , he hasn’t aged a day
sometimes we are economical with language - it saves listing all the components individually. Is there a better way to say it? I don't imagine most people have difficulty understanding that the air is composed of a variety of different molecules and atoms.
For all those in the future with me where threading exists, this was in response to a concern that there’s no such thing as “air molecules”, and they would have preferred something like “the molecules in the air”. Interestingly, I’ve definitely heard the latter phrase more often in newer videos.
I have seen tons of replies in your comments. This one is special and lucky.
@@justins8802 This is literally the reason why science and tech content creators on this platform like Tom Scott, Vsauce, CrashCourse, and even Linus Tech Tips (although a bit less) are quite pedantic about terminology in videos. But I suppose that's a good thing.. not inconspicuous though
@@slykhajiit2 I know, then you have Destin over at Smarter Every Day playing fast and loose like a maniac ;-)
@@justins8802 lol
that was a good one
I can so much relate with the adiabatic compression. We are studying it now and today I saw a practical demonstration of it. Quite fascinating!!!
If I'm not mistaken, this is the basic concept behind a diesel engine. I remember when my father first started teaching me about diesel engines when he would bring me on the tractor trailer and show me how to use it, and this very thing was what he showed me. He explained it in conjunction with the 'glowplug' when we had to change them out one winter. Because the engine block is so cold in the winter, the motor has heating rods in them to help warm up the engine so that when you turn over the motor (with the electric starter) the heat doesn't get absorbed by the engine block which doesn't allow it to accomplish an "adiabatic compression".
I remember being so blown away by it. Like it altered my perspective of science. Of course I was only 12 or so at the time.
There was all sorts of science to learn both on the farm and on the tractor trailer, and my father was never short on explaining it all.
I worked on the waste water treatment plant in Helsinki. It's an underground facility and there are huge airpumps to pump air into those vats that have aerobic bacters. There were huge heat exchangers after the pumps so that the water where the air was pumped would not start to boil. The heat from the exchanger was used to heat the facility and it almost was enough for the whole facility. There was a powerstation using the gas that was got from the fermentation of the waste after the bacterial treatment. It's waste heat was the rest of the heat the facility needed. The electricity generated there was about half of the power need of the facility. The final waste after the fermentation were transported to nearby compost facility that made almost all the landscaping mulch that the municipal needed. Later the local power company started to use the heat of the output water to generate pipable cold.
Who came here after the Oceangate Titan (Titanic sub) imploded?
I found out about Veritasium just a few years ago and have regularly watched your videos since. Then, I was sent here by my Thermal Physics prof. Wow, this video is 9 years old! A surprise to be sure, but a welcome one.
I like how the quality was as good as it is today.
I don't know how i got here and spent 3 hours watching these videos but I feel smarter now.
This feels like a school project and he is infront of the class presenting something and the teacher is on the side helping him what to say.
I've known about compression firestarters for awhile now but it's kind of cool to see it happen in a transparent tube.
Please redo this video to showcase what can happen to a sub once it’s 13k’ under water and implodes.
Now put some diesel in there and lets see that thing explode
Haha
@@Elimarzordan you give comment to 5 years old post ,man you need think your live more
@@memesfromdeepspace1075 Maybe I'm a little lonely 😥
@@Elimarzordan yeah me to sometimes
h
In bushcraft we call theses fire pistons.
That sounds like a website for 70's porn.
Yes.
@@faisal3398 lmao
In real life, too
HEY, GENIUS, STICK A DROP OF WATER IN IT INSTEAD OF AN INCINDIARY COMPOUND. DOESNT WORK WITH A STANDARD DIESEL IN AN AUTOMOBILE, BUT AT LEAST 3 FREIGHTERS WITH HIGH COMPRESSION ENGINES IN WW2 RAN COMPLETELY ON SALT WATER FOR DAYS, NOT REALIZING IT UNTIL REACHING PORT. THE SALT WATER RUINED THE ENGINES, BUT THE FACT THAT THEY RAN WITHOUT EVEN BEING HOOKED UP TO THE HEAVY FUEL OIL FOR AN OCEAN CROSSING IS PHENOMINAL.
Very minutare scenario but I imagine (to some degree )this is essentially how the titan imploded .
Our physics teacher showed this to us but after he hit the piston down, because of the combustion the piston shot up into the ceiling and broke a lamp with poisonous stuff in it that then fell down on the students, pure chaos. Best physics lesson ever.
Is it just me or do these two have chemistry
This guy did his phd on how to make good physics videos. He knows what he is doing.
Congrats, y'all have "rediscovered" the ancient Malaysian Fire Piston.
duxdawg Thanks for introducing me to the most mind blowing thing I have ever heard of!!!!
Yeah I'm surprised they didn't mention it's a Southeast Asian invention from thousands of years ago used to start fires. Not that their point was to portray a new invention. It's just that the idea of introducing a curious phenomenon wouldn't be far off from also explaining its curious origins. Not to mention the relative precision required to achieve it 🤷♂️
This channel has come a long way
And that, ladies and gentlemen, is how diesel engines work!
Of course they have fuel heaters and glowplugs(for cold starts), but the general idea is the same.
a proper diesel engine has a hook cast into the block, to hang the blowtorch there for the "Rudolf Diesel commemoration hour"....
Also, it can not be one-cylindered enough, says Heinrich Lanz
thank you for demonstrating the principle behind a diesel engine
That's how a diesel engine works. Diesel ignites under pressure. I wonder if they could ignite diesel in that glass tube
Takes much much more pressure to ignite diesel this way. Not even a starter on a diesel can do it, thats why glow plugs are in the engine to kickstart it.
Jesse Haskins Not true. Cummins diesels in Dodge Rams don't use glowplugs. Glow plugs are only necessary for cold weather conditions. The Cummins uses an engine heater in place of glowplugs.
danneu8
Right, A Block Heater! All that is needed is to generate enough heat to ignite the diesel without any compression because the engine is at rest when started.
Shasta Reil The block heater on these engines doesn't ignite the diesel though. The starter can generate enough torque to achieve ignition.
@@wireboy253 lol what is this crap? My tractor doesn't even have glowplugs. It is a little hard to start in cold weather, but it CAN start and run. Also i think that this piston creates enough heat to ignite diesel.
Also a starter and a glow plug are 2 totally different things. The starter is for turning the engine over and the glow plug is for heating the fuel. This sentence doesn't make any sense:
"Not even a starter on a diesel can do it, thats why glow plugs are in the engine to kickstart it."
Comparing them is totally stupid.
Perfect and simple example of compression ignition. If that sounds unfamiliar this will: it's the principle behind every diesel engine ever build.
Temperature isn't caused by the number of collisions with other molecules as was implied by saying that it was caused by molecules being closer together. It is because you are doing work on the molecules and increasing their speeds. Conceptually, this transfer is caused by the fact that the plunger is moving downward so when molecules hit it, they leave with a greater speed.
I like the banter, please get him back on!
you can't he is a teacher
my science teacher
funny right
Veritasium does that mean if you do the same experiment in reverse you could super cool an object instantly ?
Viheeth Wijewardhane
Yes. Have you ever used the small disposable co2 tubes for soft airguns? They can sometimes get so cold that frost builds up on them when you empty the tube quickly.
Yes, try getting a can of compressed air and see how cold it gets when you hold the valve open. Compressing, removing the heat and decompressing is actually the easiest way to make dry ice and liquid nitrogen
Search UA-cam for "making alcohol cloud" or "adiabatic expansion"
@@toby1248 Compressed air cans mostly cool down due to evaporative cooling of the liquid inside, but you're still right. Decompressing the gas creates cooling.
I started watching these Veritasium videos about an hour ago and I cannot stop watching them. ._. It's like it was their plan all along.
0:39 Derek's accent climbs out of the woodwork
The king of random mad this a while ago. I want to make one. R.I.P. Grant Thompson, thanks for teaching me so much.
"Let's see if we can auto-ignite some other things" That's what he said
Veritasium seemed gay on that move, hahaha, his looks on the guy were kinda sticky xD
When you see a old video, you can notice how the quality of the content improved.
It"s also called a fire piston
The same principal as a fire piston, pressurized air builds heat and in turn will ignite any material inside that is flammable. The fire piston is a tube in which a small amount of fibers from dried plants are placed, then when the cylinder is smacked down it ignites and makes an ember, when removed and blown will make a fire.
Cool science!!!
I love it, how the algorithm has brought me here after 10 years :D
I’ve stumbled across a couple of these 2011 videos tonight... is it me or is his style of interviewing/working with others around this time to flirt with them?... I’m thankful with the evolution of Veritasium!
My thermodynamics professor did this demo for us (: so fun
beautiful
You have a professor specifically for thermodynamics?
Yes, you're correct. Either way they don't ignite anything they just aid in the combustion by heating up the area thus helping the combustion process along which only occurs due to the pressure.
Am I the only one who thinks he sounds 100% like Elon Musk???
It's his son
X Æ A-12
Yes
i was about to ask why they cant do it slow, but they answered my question. thanks guys!
LMAO the chemistry between them
same thought
@@REALchocochan hes my old teacher in science - the one on the right
This technology is originated from Malay Archipelago. The original name is Gobek Api aka "Fire Crusher-Plunger". It was used as 1st portable lighter and become widely used in the 12th century when gun powder become available from China. Later in 17th century, the technology arrived in Europe and US where the scientist claims the patent as "Fire Piston".
how the nature and scale of Veritasium's videos have changed
There is a concept about this in germany called "Feuerpumpe" (direct translation: Firepump).
Its used a piece of charcloth and the pneumatic principle behind it to light the cloth and to start a fire.
it was spread quite a bit a time ago and was considered as a "lighter".
+Christoph Schmitt I applaud you for knowing that...if you search fire piston on youtube... they are really easy to make
congrats, you demonstrated how a diesel engine works
Its called "Fire Piston." A very useful tool and is in use since WWII.
Published in 2011 but watching in 2019.
Thats the fire piston. Discovered in the Philippines back in the 16th century. Robert Doyle first played around with the fire piston given to him by Galileo and soon discovered the reason behind its then miraculous fire creating power. As one might say it was the Philippines who created the first piston.
That Asian guy does a good Australian accent lol
his ausssie stop being a racist
The passengers were the cotton in the Titan submersible.
is this not called a fire piston?
ikr?
A piston implies that the pressure extends out a piston. You press down on this to compress it, and it doesn't go anywhere after that.
In essence, it's not called a piston because it's not a piston
You have absolutely no idea what you're talking about whatsoever.
Spencer LaBooty You must be trolling. Watch the video, it's clearly a piston.
If you say so
Wow thank you! I think I understood part of my Thermo class
Makes me think about what happens in a deep sea implosion.
Ignition temperature of cotton is about 400C at atmospheric pressure. Increasing the partial pressure of O2 will lower that ignition point by a great amount. the fire piston works by a combination of increasing heat through compression and increasing partial pressure of O2 with compression. Carbonized cotton fabric is pretty much a standard fuel for the fire pistons used by survivalist. Also called "char cloth".
yes..this is how diesel engines work...
No it doesn't.
An engine works by putting fuel in the whatever it is called then spark plugs create a spark that explodes the fuel the explosion force the cylinder down. The cylimder is connected to a crankshaft in such a way that the downward force is changed into rotational energy but since there is multiple cylinders at different stages of this then there is always a downward force making the crankshaft spin. Then the spinning crankshaft causes the cylinder that just got pushed down to go back up and push the exhaust out. If you don't understand still you should probably watch an animation of it.
Wait nvm
You said desiel not gasoline
@@macaroon_nuggets8008 fail
A gasoline bike has spark plugs, and a battery to charge the spark system. While compression probably helps, it's the spark which really sets it off.
Random question..
Pressure changes the 'boiling point' of a substance.
Does it also change the auto-ignition point?
These 2 point are independent. The both affected by pressure, but shows completely different effects.
I had since looked into it myself, but never came back to comment.
If anyone is interested:
Pressure decreases the auto-ignition point.
Pressure increases the boiling point.
At 2:17 he states that the auto-ignition temp was 400°C, but doesn't state at what pressure, I am going to assume ~100 kPa (1 atmosphere)
So the pressure from the syringe may not be increasing the air temp to 400° since the additional pressure will be decreasing the auto-ignition point.
I have yet to find out what is the likely temp the air is being heated to in this scenario.
This is also the same as a Fire Piston. A survival tool when used helps you create a fire out in the wilderness. Replace the wool in this video with a little dry tinder and you have a nice little smoldering piece of wood to start a fire with.
It's not about the heat, it's about the chemical reaction of oxidization that increases under greater pressure and so exceeds a treshold of combustive oxidization, which is bursting into flames. Heat is only a product, not the cause.
*oxidization
Allen Thayer
thx
maybe it's a result of both
Sniper of the Dark
If you had known the rule of the welders - never weld if gloves in case they get greased - you'd have understood why oxidazation is generating heat, and not the other way round, at least in most cases.
Heat is the wrong word. It's temperature (they are different). The temperature of the apparatus gets very high for a short amount of time, which causes the ignition. It's only a small amount of heat (at least before the fire, an independent energy source). Same principle applies to sparklers. The little pieces flying off are momentarily hundreds or thousands of degrees, but because they're tiny and have very little mass, it's not enough heat to be harmful.
Campers and hikers use a fire piston to ignite char cloth when they are in the woods, It is the same thing.
This is exactly how diesel engines work.
But I've never refueled with cotton wool.
These are sold commercially for survival kits as a fire-starter method (I have one ;) ). Cool vid!
is this similar to how a diesel engine works?
Plant Gollum It is exactly how they work. Although some of them have heater plugs, to help raise the fuel temperature in cold climates.
Luben Lambov are you talking about spark plugs?
mustacheman19 No. Spark plugs are for gasoline engines. Heater plugs, more commonly known as glow plugs, heat up the diesel vapor, lowering the pressure required for combustion. Mostly used in cold climates.
Luben Lambov yep. And to start the engine
HardwareG33k They're only used to start the engine if the weather is cold. Otherwise the starter takes care of the whole thing.
My dad and I made one a few years back, it comes in handy when camping and you want to make w fire. Just use some char cloth that becomes an ember, then you can put that in some flammable stuff and boom, fire!
+Lev I applaud you for knowing what a fire piston is
Adiabatic compression.
You also need to consider the increase in partial pressure of O2. Many materials are more combustible as O2 pressure increases. Cotton will ignite much more easily when the air is compressed.
Exactly!
Isn't this the thingamajiger that causes the bottom of spacecraft to heat upon reentry to Earth?
Diesel engines
Pies4Lunch =|
Wat
No. That's due to friction between Air molecules and the space craft.
This is rapid compression, which is a bit different.
Spiritbombx100 Hm.
No, not friction, compression, like the video
A bike has a spark plug and a coil that generates the voltage needed to create the spark. Once it rotates, it's enough to keep the motor running. Kick starting a motorcycle only provides the initial inertia to get the fuel compression and first spark going, after which the motor can run by itself.
that's how diesel engines ignite fuel without a spark plug.
also the gasoline engines take this effect into account.
Wow, watching this in 2019 it is crazy to hear how much his accent has changed.
Mantis Shrimp!
These are also called fire pistons, they are widely used as fire starters in survival and camping situations.
"There's some corton wall en dere"
They actually use glow plugs to heat up the engine block. This makes it easier for the fuel to ignite because less energy is lost heating up the cold metal.
This is how the diesel engines work
This is a really awesome video
Does this mean if you were to slowly compress air, allowing the heat to escape, rapidly decompressing it would cool the chamber drastically?
That's how fridges with compressors work.
By decompressing gas in the inside and compressing it outside.
Repeatedly.
Thats how refridgerators work
Although you can't see it, in most weight scales, the fulcrum is placed slightly above the center of mass of the seesaw bit. Think of an upside down T that's been super-shortened and widened.This means that when no single weight weighs more than another, the scale falls naturally to it's lowest point, an even plane. This is also the reason that when weights are only slightly different, the angle of the balance is only a little bit skewed.
Fire pistons are old tech
Every video with Nigel in it buffers slowly!
Yeah you see this every day, it's called a Diesel engine...
Seemed like they were challenging each other for dominance which having strong eye contact.🤣
pretty much sure the dude is high.
cool thanks! Always learning something new from youtube :)
This guy kinda sounds like Elon Musk.
It’s the movement that creates the fire, not the collision. Heat is just rapidly moving particles so the sudden and extreme heat ignites the cotton instantly.
That’s why doing it slowly doesn’t do anything, heat takes time to pass through glass because it’s one of the best solid insulators, the real reason is because the larticles simply aren’t moving fast enough. The collision is important too though becaise the collision is how the heat spreads to the cotton and the heat sets the cotton on fire, the collision isn’t what generates heat is all I was saying.
diesel engine
Oh cool, I saw one of these over at the Hendrik Ball channel the last time I got stuck in it. Keep up the awesome videos where you explain things! (I don't know what it is, but I feel like I completely butchered that sentence grammatically.)
Omg the sexual tension is beyond belief, hahaha. Am i the only one seeing this. "Let's go see if we can auto ignite some other things -_o"
"Yeah, maybe some (pubic & anal) hair" (from friction).
nope, it's just you
you watch some weird porn
A significant factor, on the topic if how fast you move the plunger, is the seal and the pressure. If you press it slowly, since the seal isn't perfect, you lose pressure, and, therefore, temperature. How significant these two factors are is uncertain. You could install a tiny camera to detect the flame and then insulate the syringe well. Or you could measure the rise in temperature in the surrounding medium to calculate heat loss (only useful in this test if there is no flame).