Name: 為什麼外星人還沒有發現我們？ (Why Haven't Aliens Found Us Yet?)
Uploaded: 2021-01-14T06:06:38.000Z
Duration: 4 min 6 s
Description: 【看影片學英語】數萬部 YouTube 影片，搭配英漢字典即點即查，輕鬆掌握單字發音與用法，長久累積看電影不必再看字幕。

Life goals: meet an alien or at least answer the question; are we alone in the universe?

What I’m saying is WHERE ARE ALL THE ALIENS?

Probability tells us that our galaxy should be teeming with life. Our universe is about

14 billion years old. Our Solar System and our Earth are only 4.5 billion years old.

But the universe is a big place, and there are plenty of other solar systems that are

wayyy older even in our own galaxy. So intelligent life should have evolved millions of years

sooner than we did and they should have taken over the galaxy by now. At that rate, we should

have some evidence that the truth, or life, is out there. So what’s the deal with the

radio silence? This is the very question physicist Enrico Fermi asked in the 1950s, specifically

“Where is everybody?”. This idea that alien life should be out there, but we haven’t

heard anything is called the Fermi Paradox.

Most solutions to the paradox can be broken down into two broad categories, aliens don’t

If aliens don’t exist, it might be because a planet that can sustain life is rare, and

that complex life-- such as plants and animals-- would evolve is even RARER. This is creatively

called the Rare Earth Hypothesis, which suggests that we are actually alone. Another idea is

that an intelligent, colonizing, intergalactic lifeform is incredibly rare. Robin Dale Hanson,

an associate professor of economics at George Mason University, described this idea as ‘The

He suggests that each stage of evolution might just be really hard to reach. For aliens evolve

and become visible to us, they would need the right star system, reproductive molecules

like RNA, simple life, complex life, sexual reproduction, multicellular life, tool using

life, where we are now, and last but not least, colonization explosion, or the ability to

take over the galaxy. He suggests each of these steps is very improbable, let alone

all of them. And one or more of these steps is “the Great Filter”, meaning that it’s

so incredibly difficult to pass, that nothing in the universe has done it.

Since we’ve already made it through most of these steps, it stands to reason that the

biggest hurdle of “The Great Filter” might be where we are now or where we nearly are.

If that’s the case, that means we are approaching the filter.. and odds are, we will destroy

ourselves before we become interstellar, just like everyone else in the universe probably

But okay what if aliens DO exist? Where are they? One hypothesis supported by Author Michael

Michaud is that aliens are just shutting the hell up. And for good reason, self protection.

The universe could be a giant hostile place filled with warfaring colonizing civilizations.

So by staying at home and staying quiet, they aren’t drawing attention to themselves to

But some people think extraterrestrial life is here. And that maybe they just don’t

care. Maybe they don’t find us interesting enough. Or maybe they’re nice aliens, who

care about us a whole lot. So much so that they won’t even touch us. One theory published

in the journal Icarus in 1973 suggests that we are part of some sort of protected zone,

almost like a preserve or a zoo! But maybe they ARE here and reaching out to

us. But we just can’t communicate with them, maybe we’re just bad at reading the signs.

Maybe they communicate with technologies that are different from radio waves, like lasers,

or something we haven’t even conceived yet!

There’s so many more solutions to the Fermi paradox, one physicist Stephen Webb lists

at least 50 solutions in his book “If the Universe Is Teeming with Aliens ... WHERE

IS EVERYBODY?”. But he actually believes we are alone.

No matter what, I want to believe we’re not alone. But perhaps the universe is too

While we haven’t heard anything from other civilizations that doesn’t mean we’ll

stop scanning the skies anytime soon. In fact, NASA’s got a new telescope in the works

that will see further than we’ve ever seen before.

If you want an incredible behind-the-scenes look at the new James Webb Space Telescope,

make sure to check out Discovery’s brand new documentary Telescope! The world premiere

is this Saturday, February 20 at 9pm on the Discovery Channel. We’ll be watching too!

So what do you think? Do you think life is out there? Or what’s your favorite solution

to the paradox? Let us know down in the comments below