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Guns in space

Hey, Vsauce. Michael here.

And what do you say we get outta here...

to space and into an orbit.

space - космос, пространство
orbit - орбита

That way we could just float around and be free from the influence of gravity.

to float - плавать, всплывать, держаться на поверхности
influence - влияние, воздействие

Except not really.

except - кроме, за исключением

Astronauts orbiting around the Earth

experience pretty much the same gravitational pull that you and I are feeling right now.

to experience - испытывать

The major difference is that those astronauts are falling,

major - крупный, большой, главный
difference - разница, различие

constantly, towards Earth, but their angular velocity is so large

constantly - постоянно
towards - в направлении
angular - угловой
velocity - скорость

that they're falling just as fast as Earth curves away from them.

to curve - кривить, изгибать(ся), сгибать, гнуть

Now, of course, this is nothing New...ton's Cannon hasn't already taught us.

сannon - пушка

Gravity makes stuff fall

gravity - гравитация

and, in particular, Newton realized that it makes objects accelerate towards the Earth

in particular - в частности, в особенности
to realize - реализовать, понимать, осознавать, осуществлять
to accelerate - ускорять(ся)

the same amount independently of how fast they're moving horizontally.

amount - количество, сумма
independently - независимо
horizontally - горизонтально

That's called relativity.

relativity - относительность

And, of course, orbiting is just falling,

but falling where you move horizontally fast enough

that the Earth falls away faster

In order to successfully fall and miss the Earth,

in order - для того что бы
successfully - успешно

unless you dug a tunnel,

to dug - копать

you need to be travelling at over 17,000 mph or 8 km every second.

to travel - путешествовать

So, you'd probably incinerate from friction with the air,

incinerate - сжигать, испепелять
friction - трение

well before you had a chance to enjoy the trip.

to enjoy - наслаждаться, пользоваться
trip - поездка, путешествие

Of course, Newton's thought experiment involved the Earth,

to involve - привлекать, вовлекать

but on something smaller, like the Moon,

the cannon wouldn't have to throw its projectile nearly as fast

projectile - снаряд

for it to complete an orbit.

to complete - завершать, завершить

In fact, if you had a powerful enough gun on the Moon

powerful - мощный, сильный, могучий

and you fired that gun at the horizon and then waited a little bit,

to fire - стрелять, выстреливать

you could get hit in the back of the head by the same bullet.

to hit - бить, поражать
bullet - пуля

Henry calculated that the bullet would have to travel about 1,600 m/s,

to calculate - вычислять, рассчитывать

which is exactly how fast the Paris gun fires.

And that's a powerful gun, it's no squirt gun.

squirt - шприц, струя (to squirt - бить струей)

But if you had a squirt gun,

out there in space,

and you fired a stream of water at the Sun,

stream - поток, ручей, струя

how much water would it take to put out the Sun?

to put out - тушить, гасить

I mean, in general, putting water on something hot

in general - в основном, в общем

would cause that something hot to lose some heat,

heat - тепло, жара, нагрев, жар

especially since the water will be frozen

because it's out there in space.

But, here's the issue.

The Sun is not a big ball of hydrogen on fire.

hydrogen - водород

Instead, the Sun is powered by fusion.

instead - вместо, взамен
fusion - слияние, сплав

Fusion of Hydrogen nuclei,

nuclei - ядро

which is kind of like the chemical bonds

bond - связь, соединение

between the Hydrogen and Oxygen that make up water,

except on a much smaller and much more powerful scale.

scale - масштаб, скала

Now, before I get tackled by nuclear physicists from one side,

to tackle - схватить, биться, энергично браться
nuclear - ядерный, атомный

and chemists from the other, let me explain.

A bond of any sort,

whether between planets, molecules, atoms, nuclei or quarks

is just a happenstance where two or more particles together

happenstance - случайность
particle - частица

have a lower total energy than when they were apart.

apart - отдельно, обособленно, порознь

Like if you get married and your taxes go down.

tax - налог

So, when you form a bond,

to form - формировать, образовывать

that extra energy that the two solitary particles had is released,

solitary - одинокий, уединенный
to release - выпускать

and because of a little relation we called E=mc²,

relation - связь, отношение, соотношение

this actually means that the mass of the pair goes down a little bit too.

pair - пара

For example, every fusion reactions

turns a little bit of Hydrogenous mass into light.

Sunlight, for example, amounts to a loss of 100 quadrillion kg each year.

sunlight - солнечный свет
to amount - составлять
loss - потеря, убыток

That's the equivalent of a medium sized asteroid.

equivalent - эквивалент
medium - средний

But stars have a lot of mass

and the more massive a star is, the hotter it burns.

massive - массивный, массовый

And adding a bunch of water to the Sun

bunch - пучок, гроздь, связка

would only cause it to be more massive,

to cause - вызывать, быть причиной

so it would burn brighter, not go out.

to burn - сжигать, гореть, жечь

Of course, it would also burn faster,

which means that its life would be shorter.

For instance, if you were to add

for instance - например

20 solar masses of water to the Sun,

you would decrease its life expectancy from the current 5 billion years

to decrease - уменьшать(ся)
expectancy - ожидание
current - текущий

to only a few hundred million more years.

But there's a faster way to put out the Sun.

Take that water, or whatever material you want,

material - материал, вещество

and shoot it into the Sun

to shoot - выстрелить, стрелять

in a way that causes everything to get spread out and scattered,

to spread - распространять(ся)
to scatter - разбрасывать, рассеивать, раскидывать

so that there's no longer the critical density needed for fusion to occur.

critical - критический
density - плотность
to occur - происходить, иметь место

Now, no matter which avenue of putting out the Sun you pick,

avenue - проспект, авеню

both would be a disaster.

disaster - катастрофа

Literally, disaster.

literally - буквально

From "Dis," meaning "against," and "aster" meaning star,

you would have literally turned our own star against us.

to turn - повернуть, свернуть, превращать

If you were somehow able to avoid that disaster

somehow - как-нибудь, как-то
to avoid - избегать

by magically appearing in inter-galactic space,

to appear - появляться

here's a fun experiment to try.

Take out your gun and fire a bullet.

That bullet will be forever alone.

That's because the universe is expanding,

to expand - расширять(ся)

and if you were a few megaparsec's away

a few - немного, несколько

from the nearest galactic cluster,

cluster - скопление

on average those galaxies

on average - в среднем

would be 200 km father away from you every passing second.

In space terms, 200 km per second is pretty slow.

pretty - довольно, достаточно

It's barely as fast as the solar system orbits the center of the Milky Way.

barely - едва, только

And stars closer to the center of the galaxy can orbit 10 times faster.

But a measly bullet travels only a few km every second

measly - жалкий

and would have no chance of reaching the receding galaxies, ever.

to reach - достигать, доходить
to recede - отступить, удаляться

It makes you realize how tiny we are

tiny - крошечный, крохотный

compared to the scale of the universe.

compared to - по сравнению с, в сравнении с

But it also makes you realize how close together we all are here on Earth.

Of course, to get from one side of the Earth to the other,

you have to fly over half the sphere.

sphere - сфера, шар

So, what if instead there was a tunnel through the Earth?

tunnel - туннель, тоннель

Let's jump over to my channel, Minute Physics, to see what happens.

Click here and I'll see you on the other side.

Oh, and as always, thanks for watching.