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  • You know, making all these videos is pretty exhausting work.

  • What I need is a vacation.

  • Somewhere far away, preferably exotic, and must be exciting! Korea?

  • Or maybe Japan?

  • Great food, fantastic culture, plenty of ways to embarrass myself by misunderstanding the

  • local customs.

  • What's not to love?

  • But I noticed something strange while booking my Asian getaway.

  • My plane seems to be making a detour over Alaska

  • Why is my airline going out of its way to avoid the Pacific Ocean?

  • Is this a mistake?

  • Did I accidentally sign up for the caribou route?

  • At first you might think it was a safety issue.

  • The Pacific is the largest and deepest of the world's oceans.

  • If a plane encounters a problem over a seemingly endless and bottomless pond of water, the

  • pilots are going to have a rough time finding a safe spot to set her down.

  • Alaska might not be overpopulated with international airports, but it's a lot better than the

  • middle of the ocean.

  • How's that for a tourism slogan?

  • Alaska, at least it's better than sinking!”

  • Okay, I apologize Alaska

  • Guessing that it was a safety precaution wouldn't be entirely wrong.

  • When planning a route, many pilots prefer to maximize the number of airports along their

  • path.

  • Emergencies are incredibly rare relative to how many planes take to the skies every day.

  • But I can't think of many things more stressful than losing an engine 30,000 feet over the

  • middle of the Pacific Ocean.

  • That said, it isn't the main reason airlines tend to avoid making a straight shot east

  • to west.

  • Ultimately, it comes down to saving fuel and time.

  • It's easy to forget that an airline is a business.

  • A business whose profits depends on how quickly and cheaply it can move passengers between

  • destinations.

  • People also prefer to get to their next stop as quickly as possible, so it's a win-win

  • for both airlines and passengers.

  • Long story short, which is not my forte, speed is usually the primary factor in determining

  • a plane's flight path.

  • Excluding special circumstances such as passing through the jet streams or other meteorological

  • concerns, the fastest croute is almost always the one closest to a straight line.

  • But wait, just look at that flight pathit's anything BUT a straight line!

  • Well, yeah, when you look at it on a flat map.

  • But our planet isn't flat now, is it?

  • It can be confusing since we're used to looking at our world on a two-dimensional

  • plane.

  • Unless you bust out a globe each time you need to check where some city or country is

  • located, you probably look at a world map.

  • So, on a 2D map, making a giant rainbow to avoid the Pacific Ocean looks like a much

  • longer route.

  • But since the Earth is a sphere (eh, more or less, but more on that later), a straight

  • line is going to look very different in three-dimensional spaces.

  • Ok, let's do a little experiment.

  • Got a globe nearby?

  • Oh yeah, I just said most of us use Google maps...

  • Alright, here, I'll show you on mine.

  • I'll put one end of a string on Los Angeles and the other end on Tokyo.

  • When I pull it taught, you'll notice that the string isn't running exactly parallel

  • to the lines of latitude printed on the globe.

  • Instead, it'll bend slightly upwards as it follows the curvature of this mini Earth

  • I got at the bookstore down the road.

  • This effect is even more pronounced in practice because my globe isn't a perfect recreation

  • of the real deal.

  • In fact, the problem is that it's too perfect!

  • You see, unlike a globe, the Earth isn't a perfect sphere.

  • Our planet is slightly bigger around the middle, kinda like me after the holidays!

  • Wait who wrote that?

  • Humph!

  • When looking at pictures taken from outer space, the difference isn't enough to notice.

  • The planet is so big that it's easy to lose track of a few hundred miles here and there.

  • But check it out: if you could take a giant string and measure the Earth's circumference

  • through the poles, you'd need 24,860 miles of string.

  • But if you do the same thing at the equator, it'd jump up to 24,900 miles.

  • Why is that, you ask?

  • It's because our planet rotates on its axis.

  • Ever spin yourself really fast on the playground merry-go-round when you were a kid?

  • Remember feeling like the thing was going to throw you out to the sides?

  • No I remember I was throwing up a lot.

  • Not a good ride for me.

  • Anyway, Something similar happens to the Earth's midsection as it spinsthe force causes

  • it to bulge out.

  • Yes, it's spinning fast enough to do that!

  • Anybody tuning in from the equator right now, you're currently moving about 1,000 mph!

  • That 40-mile difference in the Earth's width might not seem like very much.

  • But when it comes to the surface area of an entire planet, that little bit of added girth

  • can go a long way.

  • The combination of these two factors, the curvature of the Earth and its extra equatorial

  • width, ooh I like that, mean that curving toward the poles is a shorter distance than

  • flying (what seems like on a map) “straightacross!

  • None of this is to say that planes never cross the Pacific Ocean.

  • People have to get to Australia somehow!

  • I guess

  • I'm not so much into giant insects and spiders but, hey, to each his own!

  • Just kidding Australia!

  • Anyway, planes will also venture over open water to avoid storms.

  • While aircraft can outclimb some types of severe weather such as hurricanes and tropical

  • storms, seemingly mundane thunderstorms are surprisingly challenging!

  • With clouds reaching altitudes of over 60,000 feet, airplanes are advised to steer around

  • instead of into or over them.

  • It's almost unheard of for modern aircraft to be brought down by severe weather, but

  • bad enough turbulence can cause injuries to passengers and crew as they (and all the stuff

  • they've packed with them!) get tossed around the cabin.

  • The takeaway here is keep your seatbelts fastened at all times.

  • Another reason planes will sometimes brave an oceanic voyage is to take advantage of

  • the smoother ride.

  • Even in clear weather, there's much less turbulence over water than over land.

  • This is because the primary source of turbulence is hot air rising up from the ground.

  • Hey there's a lot of hot air rising up from this microphone!

  • Water distributes heat a lot better than soil, so flights over the ocean are often much smoother.

  • The other primary consideration for determining flight paths are air currents, namely the

  • jet streams.

  • These high-altitude air currents exist near the top of the troposphere.

  • That's the lowest layer of the Earth's atmosphere and the one where most weather occurs.

  • The border between the troposphere and the next layer up, the stratosphere, is known

  • as the tropopause.

  • Its altitude fluctuates between 4 and 12 miles above the Earth's surface.

  • This fluctuation results in rapid shifts in air temperature and pressure, which creates

  • a wind tunnel that can reach speeds of over 200 mph!

  • These extreme speeds are most common in winter when the temperature difference is greatest,

  • but regular wind speeds of 80 – 140 mph are nothing to scoff at!

  • So keep your scoffing to yourself!

  • There are 4 main jet streams, 2 in each hemisphere, and thanks to the Earth's rotation, they

  • mostly flow west to east.

  • The two most important for air travel are the polar jet stream, which forms near the

  • arctic circle, and the subtropical jet stream near the equator.

  • Both are thousands of miles long despite being only a few miles wide.

  • Flying with a jet stream can shave several hours off of a trip, but flying into it can

  • slow the plane down considerably.

  • It's also worth noting the risks associated with jet streams.

  • The biggest hazard is a kind of turbulence known as clear-air turbulence, which occurs

  • along the edges of the streams.

  • This kind of turbulence is nearly impossible to predict and far more intense than the usual

  • variety.

  • Turbulence-related accidents are rare, but they are possible.

  • One particularly serious incident happened in 1997, when a plane flying from Tokyo to

  • Honolulu suddenly dropped after hitting a patch of clear-air turbulence.

  • The pilots were able to regain control, but many passengers had been thrown from their

  • seats really hard by the sudden descent.

  • With that danger in mind, flight plans need to be carefully calculated to take advantage

  • of the jet streams without putting the plane at risk.

  • Repeat after me, keep your seat belts on at all times while flying.

  • Understanding why planes take the routes they do often comes down to facts we don't usually

  • think about in everyday life.

  • The jet stream mostly affects things tens of thousands of feet in the air, and the curvature

  • of the Earth doesn't really matter unless you're traveling hundreds of miles per hour

  • over vast distances.

  • I don't know about you, but my car can't quite manage either of those things.

  • At least not yet.

  • I have a few ideas, but we'll save that for a video titled "7 Things You Shouldn't Strap

  • Rockets To."

  • Ha ha.

  • Hey, if you learned something new today, then give the video a like and share it with a

  • friend!

  • And here are some other cool videos I think you'll enjoy.

  • Just click to the left or right, and stay on the Bright Side of life!

You know, making all these videos is pretty exhausting work.

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