Score
Title
331
How To Search ELI5: A Quick Reminder About Rule 7
4679
ELI5: How come spent nuclear fuel is constantly being cooled for about 2 decades? Why can't we just use the spent fuel to boil water to spin turbines?
11691
ELI5:How does the human ear discern between a quiet noise and a distant noise?
7
ELI5: Why aren't aspect ratios expressed in simplest form?
15765
ELI5: How do smelling salts wake you up after you’ve been unconscious?
1
ELI5: why do we know so little about blue whales?
1
ELI5: Why are "prior bad acts" not allowed in the criminal cases?
4
ELI5: How do cellphones know what signal from what network to listen to? What is different about different networks' cell towers that a phone can decipher which one to listen to?
14
ELI5: how can electrons just be ok on their own and fly around?
3
ELI5: How exactly could a boat be driven ashore by ice?
2
ELI5: Why do we jerk forward when we sneeze? If we're expelling mass forward, shouldn't the jerk be in the opposite direction?
20
ELI5: Object oriented vs. Functional programming
0
ELI5: Why is it when a woman gets an epidural, there's a chance she'll always have some sort of pain that can't be treated for the rest of her life?
0
ELI5: Why is it hard to swallow without a liquid in your mouth?
0
ELI5 What makes a person allergic to something?
6
ELI5: Why are clouds distinctly different shapes but easily categorizable?
12
ELI5: How can a program teach itself to play a game like mario cart?
5
ELI5: Does activated charcoal passively collect fumes as any other surface or is there a 'pull' effect?
1
ELI5: Why do rechargable batteries gradually last for a shorter and shorter amount of time, even when you charge them fully?
2
ELI5: Why is your voice deeper when you have a cold?
1
ELI5: why is it hard to reproduce metallic colors (shine) accurately on display screen?
3
ELI5: Why do we still have the common cold if we already had it once, shouldn't our bodies be prepared for it ?
12
ELI5: How come taking an extended break from something sometimes makes you come back to it stronger than ever?
7
ELI5: What is Artificial neural networking?
2
ELI5: What is "Clearing" and how does it work? (Finance)
0
ELI5: why is that after you have had a beard or mustache you will always see its contour forever eve if you shave everyday completely?
56
ELI5: The long term effects of blasting music with earphones/headphones
0
ELI5: Drone battery life
2
ELI5: How can a screwball or curveball change direction in flight?
1
ELI5: Why do two windows open make for a better draft?
0
ELI5 : Why is it that when we read or think about something we don't hear a distinct voice associated with it.
6
ELI5: Why does black-top (AKA asphalt, tarmac, macadam, etc) fade from black to gray?
2
ELI5: How androgens relate to blood pressure
394
ELI5: What happens that makes beer taste terrible after warming up and then re-chilling? What makes beer 'skunky'?
2
ELI5: Why disconnecting and reconnecting the modem "works"?
0
ELI5: What is culture?
8
ELI5: Why do you have to salt pasta water? Why isn't the pasta already salted?
2
ELI5: what makes marshmallows inflate in the microwave?
8568
ELI5: How is it possible that ISP's can see what your up to online? I thought HTTPs encrypted your traffic so it can't be read?
10
ELI5: Vector components?
1
ELI5: What is the haze that appears in the neck of a bottle of beer when it is first opened?
24 WRSaunders Grease is an oil, it's a liquid at burning temperatures. Oil and water don't mix, so when you squirt water on grease you get balls of water in oil and vice versa. The balls of water in oil are a big problem. The oil is over 212˚F (100˚C) so the water boils into steam. The steam expands, spreading the oil into a big, thin sheet, before it pops. Now you have a big, thin sheet of burning oil and the pop sends it flying through the air. Super-bad.
6 slash178 Oil is less dense than water, so oil floats on top. When you add water to a hot pan covered in oil, the water slips underneath the oil, is quickly heated to boiling temp. When water boils, it becomes steam. Steam takes up more space than the liquid water, so it forms a bubble under the oil. This bubble fills up with more and more vapor until it pops, spewing oil all over the place. It doesn't matter whether the oil is on fire or not. The same thing will happen, except then the oil being spewed all over the place by bursting bubbles is *on fire*. When the flaming oil is airborne it is in contact with oxygen on all sides. Fire consumes oxygen, so this big increase in available oxygen causes the fire to flare up even bigger. Trying to put out a grease fire with water is one of the top reasons of buildings burning down worldwide. Instead of adding water, put a lid on the pot. The fire will consume all the oxygen inside the covered pot and then burn out.
2 wilsonator501 When you pour water on an oil fire the water mixes with the hot burning oil whilst simultaneously being vaporised. These two processes happening simultaneously results in an explosion with burning oil being fired in every direction. This is why you should smother an oil fire with a wet cloth.
2 Wishbone51 The reason why the flames increase, is because the grease will float to the top of the water, and because of the water, the grease is now flowing, catching other things on fire.
1 shokalion Grease or oil has the capability of being heated, and staying liquid at temperatures way hotter than water boils, like over double the temperature. And that's before it begins burning. When it's burning the liquid oil underneath is going to be stupidly hot. A given amount of water increases in volume by **1700 times** when it turns to steam. Water is denser than oil, so it pours in, and goes straight under the surface, and is almost instantly flash-boiled to steam by the 200^o C oil. The steam, expanding suddenly (pretty much exploding), blows the oil everywhere. Oil that's in small droplets burns *far* more effectively, and you've just turned most of the pot into small droplets, in the vicinity of an already burning fire. The result is a massive fireball.
1 super_ag The reason water usually puts out fires is it lowers the temperature of the fuel by absorbing heat very rapidly or smothering the flame by depriving it of oxygen. With a grease fire, water is useless. The water does not mix with grease, so it just sinks to the bottom of the grease puddle where it doesn't absorb very much heat due to the lower surface area. It can't smother the flame either because it sinks to the bottom of the pan. This is why it doesn't put the flame out. The problem is made worse by the fact that grease has a higher boiling point than water. This means when you pour water into flaming hot grease, the water violently boils and throws flaming balls of grease everywhere. With just a grease fire, you have a limited surface area for the grease to catch fire. When you add water, it increases the surface area of the grease, allowing for a bigger ball of fire. [Here](https://youtu.be/Fj5ex0cDTUs?t=113) is a good example of what I'm talking about.
1 Jimmigill When water falls into hot oil, it flash boils. This boiling causes the water to very quickly expand a few times it's volume at room temperature(I don't know the exact numbers). This pushes the oil out creating more surface area to burn as opposed to a calm surface. At the same time, introducing more air-and therefore oxygen- into the mix. The correct way to put out a geese fire is to slowly cover it from one edge to another with a flat object that won't burn.
1 kodack10 For two reasons. Differences in density, and hydrophilic versus hydrophobic. Oil is lighter than water and floats on top of it. It is also hydrophobic meaning it does not mix with water. So pouring water on an oil or grease fire causes the burning oil to float on top of the water and continue to burn. Imagine a small grease fire. The amount of burning grease exposed to the air is relatively small. Only the exposed surface area of the grease burns. Now add water. The water increases the bulk which increases the surface area of the oil, which allows more of it to burn than before, making a larger fire. The hot oil will also often pop in the presence of water as the water flashes to steam, exploding bits of grease and oil upwards, mixing even further with the air and causing a flash over burn.
23 0 WRSaunders Grease is an oil, it's a liquid at burning temperatures. Oil and water don't mix, so when you squirt water on grease you get balls of water in oil and vice versa. The balls of water in oil are a big problem. The oil is over 212˚F (100˚C) so the water boils into steam. The steam expands, spreading the oil into a big, thin sheet, before it pops. Now you have a big, thin sheet of burning oil and the pop sends it flying through the air. Super-bad.
6 0 slash178 Oil is less dense than water, so oil floats on top. When you add water to a hot pan covered in oil, the water slips underneath the oil, is quickly heated to boiling temp. When water boils, it becomes steam. Steam takes up more space than the liquid water, so it forms a bubble under the oil. This bubble fills up with more and more vapor until it pops, spewing oil all over the place. It doesn't matter whether the oil is on fire or not. The same thing will happen, except then the oil being spewed all over the place by bursting bubbles is *on fire*. When the flaming oil is airborne it is in contact with oxygen on all sides. Fire consumes oxygen, so this big increase in available oxygen causes the fire to flare up even bigger. Trying to put out a grease fire with water is one of the top reasons of buildings burning down worldwide. Instead of adding water, put a lid on the pot. The fire will consume all the oxygen inside the covered pot and then burn out.
2 0 wilsonator501 When you pour water on an oil fire the water mixes with the hot burning oil whilst simultaneously being vaporised. These two processes happening simultaneously results in an explosion with burning oil being fired in every direction. This is why you should smother an oil fire with a wet cloth.
2 0 Wishbone51 The reason why the flames increase, is because the grease will float to the top of the water, and because of the water, the grease is now flowing, catching other things on fire.
1 0 shokalion Grease or oil has the capability of being heated, and staying liquid at temperatures way hotter than water boils, like over double the temperature. And that's before it begins burning. When it's burning the liquid oil underneath is going to be stupidly hot. A given amount of water increases in volume by **1700 times** when it turns to steam. Water is denser than oil, so it pours in, and goes straight under the surface, and is almost instantly flash-boiled to steam by the 200^o C oil. The steam, expanding suddenly (pretty much exploding), blows the oil everywhere. Oil that's in small droplets burns *far* more effectively, and you've just turned most of the pot into small droplets, in the vicinity of an already burning fire. The result is a massive fireball.
1 0 super_ag The reason water usually puts out fires is it lowers the temperature of the fuel by absorbing heat very rapidly or smothering the flame by depriving it of oxygen. With a grease fire, water is useless. The water does not mix with grease, so it just sinks to the bottom of the grease puddle where it doesn't absorb very much heat due to the lower surface area. It can't smother the flame either because it sinks to the bottom of the pan. This is why it doesn't put the flame out. The problem is made worse by the fact that grease has a higher boiling point than water. This means when you pour water into flaming hot grease, the water violently boils and throws flaming balls of grease everywhere. With just a grease fire, you have a limited surface area for the grease to catch fire. When you add water, it increases the surface area of the grease, allowing for a bigger ball of fire. [Here](https://youtu.be/Fj5ex0cDTUs?t=113) is a good example of what I'm talking about.
1 0 Jimmigill When water falls into hot oil, it flash boils. This boiling causes the water to very quickly expand a few times it's volume at room temperature(I don't know the exact numbers). This pushes the oil out creating more surface area to burn as opposed to a calm surface. At the same time, introducing more air-and therefore oxygen- into the mix. The correct way to put out a geese fire is to slowly cover it from one edge to another with a flat object that won't burn.
1 0 kodack10 For two reasons. Differences in density, and hydrophilic versus hydrophobic. Oil is lighter than water and floats on top of it. It is also hydrophobic meaning it does not mix with water. So pouring water on an oil or grease fire causes the burning oil to float on top of the water and continue to burn. Imagine a small grease fire. The amount of burning grease exposed to the air is relatively small. Only the exposed surface area of the grease burns. Now add water. The water increases the bulk which increases the surface area of the oil, which allows more of it to burn than before, making a larger fire. The hot oil will also often pop in the presence of water as the water flashes to steam, exploding bits of grease and oil upwards, mixing even further with the air and causing a flash over burn.