Score
Title
858
How To Search ELI5: A Quick Reminder About Rule 7
14644
ELI5: Why do cars travel in packs on the highway, even when there are no traffic stops to create groups?
11
ELI5: Why are our fingertips, ear holes and nostrils all approximately the same size?
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ELI5: Why do body parts (fingers, eyes, etc) twitch randomly?
11
ELI5 Retarded Time
4
ELI5: Umbral Moonshine
4
ELI5: Why do jet skis shoot a stream of water straight up when they go forward?
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ELI5: Why are some sounds, like nails on a chalkboard, so universally hated by humans?
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ELI5: How does ethylene make fruits and vegetables ripen faster?
3
ELI5: Why are solar gardens good investments for wealthy people?
3
ELI5: Why does a copied URL dirrct me yo a different page?
2
ELI5: Why is it not blinding to look directly at the sun early in a sun rise or late into a sun set?
2
ELI5 why is the polar star always north?
12
ELI5: How many ants does it take to make a functioning ant colony?
17
ELI5: SD. SS. SA. Gestapo. Wehrmacht. Sipo. Kripo. What were they all and how do they relate to each other?
4
ELI5: If I use the same amount of coffee grounds but more water, does my caffeine content change?
2
ELI5: Why do animals appear to care so much for their young, but not so much when the 'children' get older?
3
ELI5; What is the difference between a break and a fracture?
6
ELI5: Air movement in a house
2
ELI5: Why does the wind typically pick up during the middle of the day and die down in the evenings?
1
ELI5: Why does NASCAR race on oval tracks, rather than the more complicated layouts of other motorsports?
4
ELI5: How can sperm cells "swim" through something as thick as seminal fluid? You wouldn't be able to swim through honey for example.
4
ELI5: Why can't there be an "universe's point of reference" in relativism?
2
ELI5: Why do our eyes lose focus after staring at something for a while?
5
ELI5: Why/how can most species of animals hold their breath underwater for far longer than humans can?
1
ELI5: Risk Parity strategies in investing - how they work and what are the advantages/disadvantages?
1
ELI5: How is a bank started?
2
ELI5:Why is eating healthy 80% of being healthy?
1
ELI5: How is it possible to perceive a game servers tick rate going from 30 to 60 when your ping is not that fast?
5
ELI5: Objectively, what are the limitations of carbon dating?
1
ELI5: Security as a Service
0
ELI5: How do space shuttles launch off the modified 747s?
1
ELI5: What the hell is Umbral Moonshine?
8
ELI5: Why are cones and pyramids exactly 1/3 of a cylinder or prism's volume?
1
ELI5: How much does food affect building strength?
6
ELI5: What causes exhausts to have that rasp-y sound people tend to associate with tuners? (civics, integras, etc)
2
ELI5: Why is it stated sharks will suffocate if they quit swimming, but I see examples like the white-tipped reef shark who spend the day laying on the bottom?
0
ELI5: Why are steroids more popular in baseball than football or basketball?
0
ELI5: Why does the body make women throw up or get nauseous when pregnant?
16
ELI5: When and why did 8 hours of sleep become the standard for a solid night’s rest?
2
ELI5:How some stars become pulsars?
10 accidentallybrill * Hardness: Scratch-ability. If it wears or rubs against another material, does it wear out or does the other thing wear out? Chalk is one of the softest materials, diamond is one of the hardest. * Toughness: How quickly it can absorb a lot of energy. Example: you hit it with a hammer: Not tough, it shatters (diamond). Very tough, the hammer goes 'clunk' (magnesium steel). Toughness is also called Impact Strength. Dropping your laptop is also an example of material toughness at work. (Protip: do not attempt) * Young's Modulus: Stiffness. Very low modulus means the material is flexible and can stretch (weak plastic). Very high modulus means the material is stiff and does not bend at all (tungsten carbide). Something that is very stiff but not strong is "brittle". * Strength: There are several varieties of strength but they refer to how much force can be applied THROUGH the material. The way to measure this is force per area. The area used is the cross section of the thinnest part of where the force will be pushing or pulling through the thing you're examining. Force per area is pressure, so strength is measured in Pounds per Square Inch (PSI), Kilopounds per Square Inch (KSI) and MegaPascals (MPa). * Yield Strength: how much force does it take for the material to begin to bend or stretch *permanently*. (As far as most designs go, most kinds of things "are broken" if they reach the Yield point. A bent screw isn't shattered, but it can't do its job properly any more.) If you press on a paperclip, the maximum amount of push you can apply BEFORE it actually begins to change shape is its Yield Strength. * Ultimate Strength: how much force does it take for the material to break into pieces. (Some materials, like rubber, don't have a yield strength. They just flex and flex and flex and suddenly fail.) Bending a ruler until it snaps is an example of ultimate strength for that ruler. * Yield Limit: how much force does it take for the material to bend or stretch, AND still be able to return to its original shape. (Example: squishing a plastic cup in your hand, but not to the point where it snaps the rim.) Different directions of forces have different names, and have different strength measurements associated with them. * Tensile - pulling. How much force does it take to pull a thing until it bends or breaks. * Compression - pushing or squishing. How much force does it take to squash a thing. * Bending - self explanatory. * Buckling - bending caused by compression of thinner parts. * Shear - cutting action, or being pulled and pushed at the same time near the same place in opposite directions It gets more complicated (i.e. worse) the deeper you go. I haven't even mentioned *plasticity* or *stress*, and forces can be far more complicated than just the five I mentioned.
9 0 accidentallybrill * Hardness: Scratch-ability. If it wears or rubs against another material, does it wear out or does the other thing wear out? Chalk is one of the softest materials, diamond is one of the hardest. * Toughness: How quickly it can absorb a lot of energy. Example: you hit it with a hammer: Not tough, it shatters (diamond). Very tough, the hammer goes 'clunk' (magnesium steel). Toughness is also called Impact Strength. Dropping your laptop is also an example of material toughness at work. (Protip: do not attempt) * Young's Modulus: Stiffness. Very low modulus means the material is flexible and can stretch (weak plastic). Very high modulus means the material is stiff and does not bend at all (tungsten carbide). Something that is very stiff but not strong is "brittle". * Strength: There are several varieties of strength but they refer to how much force can be applied THROUGH the material. The way to measure this is force per area. The area used is the cross section of the thinnest part of where the force will be pushing or pulling through the thing you're examining. Force per area is pressure, so strength is measured in Pounds per Square Inch (PSI), Kilopounds per Square Inch (KSI) and MegaPascals (MPa). * Yield Strength: how much force does it take for the material to begin to bend or stretch *permanently*. (As far as most designs go, most kinds of things "are broken" if they reach the Yield point. A bent screw isn't shattered, but it can't do its job properly any more.) If you press on a paperclip, the maximum amount of push you can apply BEFORE it actually begins to change shape is its Yield Strength. * Ultimate Strength: how much force does it take for the material to break into pieces. (Some materials, like rubber, don't have a yield strength. They just flex and flex and flex and suddenly fail.) Bending a ruler until it snaps is an example of ultimate strength for that ruler. * Yield Limit: how much force does it take for the material to bend or stretch, AND still be able to return to its original shape. (Example: squishing a plastic cup in your hand, but not to the point where it snaps the rim.) Different directions of forces have different names, and have different strength measurements associated with them. * Tensile - pulling. How much force does it take to pull a thing until it bends or breaks. * Compression - pushing or squishing. How much force does it take to squash a thing. * Bending - self explanatory. * Buckling - bending caused by compression of thinner parts. * Shear - cutting action, or being pulled and pushed at the same time near the same place in opposite directions It gets more complicated (i.e. worse) the deeper you go. I haven't even mentioned *plasticity* or *stress*, and forces can be far more complicated than just the five I mentioned.