SciShow

Aug 19

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Aug 18

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sheamus-mcwong said: Why do jet airplanes get better fuel efficiency at high altitudes?

Because there’s less air! OK, so there are two reasons airplanes have to expend fuel. First, to keep themselves off the ground and second to keep themselves moving forward.

Lots of air around helps planes get lift, but planes can generate more lift in other ways…by having larger wings or traveling more quickly, and more quickly is what we want…so let’s just do that! Energy expended to move the plane forward is only limited by the amount of drag on the plane and the only way to reduce that is to make the plane more aerodynamic (which we’ve done pretty much everything we can to achieve) and by making it fly through thinner air. There are far fewer air molecules at 30,000 feet than at sea level, so the plane is literally running into fewer molecules and thus it can travel more efficiently.

Of course, at a certain height, planes have to have such large wings or travel so fast to generate lift that this efficiency gain is no longer productive. The engineers have done the math and found the optimal height for efficient travel and designed planes to operate best at that height. Yay engineers!

-Hank

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Aug 15

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Anonymous said: Are you guys the science side of tumblr

Yes…..and you’re welcome.

Aug 14

[video]

explainers-nysci:

Fight your Fear with Five Shark Facts:
1: Approximately 3.17 sharks are killed by humans every second while only less than 6 humans are killed by sharks every year. 
2: Sharks are relatively high in the food chain and keep populations of prey in check. 
3: Sharks have roamed the ocean for almost 400 million years, even before the dinosaurs. 
4: Your chances of encountering a Shark is very rare. You are more likely to get struck with lightning than to encounter a Shark.
5: Sharks are a slow growing species that don’t breed often. They are vulnerable to extinction.
Sharks have a bad rep above the ocean. Their creepy grins, appetite for meat and sharp teeth make it hard to appreciate them. While it may seem like they are out to get us, sharks are a magnificent species that need to be protected.
Sources

explainers-nysci:

Fight your Fear with Five Shark Facts:

1: Approximately 3.17 sharks are killed by humans every second while only less than 6 humans are killed by sharks every year. 

2: Sharks are relatively high in the food chain and keep populations of prey in check. 

3: Sharks have roamed the ocean for almost 400 million years, even before the dinosaurs. 

4: Your chances of encountering a Shark is very rare. You are more likely to get struck with lightning than to encounter a Shark.

5: Sharks are a slow growing species that don’t breed often. They are vulnerable to extinction.

Sharks have a bad rep above the ocean. Their creepy grins, appetite for meat and sharp teeth make it hard to appreciate them. While it may seem like they are out to get us, sharks are a magnificent species that need to be protected.

Sources

(via nysci)

Aug 13

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