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  • 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?

  • Hey guys, Julia here for DNews

  • 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

  • exist, or they do exist.

  • 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 asThe

  • Great Filter’.

  • 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 isthe Great Filter”, meaning that it’s

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

  • Since weve already made it through most of these steps, it stands to reason that the

  • biggest hurdle ofThe Great Filtermight 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

  • did.

  • 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

  • keep themselves safe.

  • 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 theyre 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 were 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 bookIf the Universe Is Teeming with Aliens ... WHERE

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

  • No matter what, I want to believe were not alone. But perhaps the universe is too

  • vast for us to ever know.

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

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

  • that will see further than weve 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. Well 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

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

Subtitles and vocabulary

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B2 US universe life paradox fermi filter galaxy

Why Haven't Aliens Found Us Yet?

  • 77 9
    林奉毅 posted on 2016/05/13
Video vocabulary

Keywords

incredibly

US /ɪnˈkrɛdəblɪ/

UK /ɪnˈkredəbli/

  • adverb
  • To a great degree; very; amazingly
  • To an extremely high degree; remarkably.
  • To an extremely high degree; remarkably.
  • Extremely; so much so it is hard to believe
  • To an extremely high degree; very.
  • To an extreme degree; very.
  • In a way that is difficult to believe; surprisingly.
life

US /laɪf/

UK /laɪf/

  • noun
  • All the living things e.g. animals, plants, humans
  • Period of time things live, from birth to death
exist

US /ɪɡˈzɪst/

UK /ɪɡ'zɪst/

  • verb
  • To be present, alive or real
  • other
  • To be real; to have objective reality or being.
  • To live, especially in very difficult conditions
  • To occur or be found
universe

US /ˈjunəˌvɚs/

UK /ˈju:nɪvɜ:s/

  • noun
  • A particular sphere of activity, interest, or experience.
  • A virtual or simulated environment, especially in computing.
  • All of space that contains planets and stars
  • Things surrounding a person, affecting their life
  • other
  • A particular sphere of activity, interest, or experience.
  • All existing matter and space considered as a whole; the cosmos.
  • other
  • All existing matter and space considered as a whole; the cosmos.
filter

US /ˈfɪltɚ/

UK /'fɪltə(r)/

  • noun
  • A digital effect or setting that modifies an image or video.
  • A program or device that filters data.
  • Device to remove certain types of light, sound
  • Device to remove unwanted things from liquid, gas
  • A transparent screen used in front of a camera lens to change the light.
  • other
  • To apply a digital effect or setting to modify an image or video.
  • To selectively prevent the passage of (information or people).
  • To pass (light, sound, etc.) through a filter to reduce its intensity or alter its quality.
  • To pass (a liquid, gas, light, or sound) through a device to remove unwanted material.
  • To pass slowly or gradually.
  • verb
  • To remove certain types of light, sound
  • To remove unwanted substances from a liquid or gas
  • other
  • To move or pass gradually or slowly.
  • Of a motorcycle or cyclist: to move between lanes of slower-moving or stationary traffic.
rare

US /rɛr/

UK /reə(r)/

  • adjective
  • (Of meat) cooked, but still red and juicy
  • Unusual or out of the ordinary; not common
evolve

US /ɪˈvɑlv/

UK /ɪ'vɒlv/

  • other
  • To develop gradually.
  • To develop gradually, especially from a simple to a more complex form.
  • verb
  • To change or develop gradually.
  • To develop gradually.
  • To develop certain features
  • To develop or change slowly over time
  • To slowly change or develop into something better
  • other
  • To develop (something) gradually.
communicate

US /kəˈmjunɪˌket/

UK /kə'mju:nɪkeɪt/

  • verb
  • To give and exchange information
  • To convey information, ideas, or feelings through language or other means.
  • other
  • To share or exchange information, news, ideas, feelings, etc.
  • To share or exchange information, news, ideas, feelings, etc.
  • other
  • To convey or express (information, feelings, etc.) in speech, writing, or by other means
  • To convey or make known (information, feelings, etc.)
hear

US /hɪr/

UK /hɪə(r)/

  • verb
  • To be aware of sound; to perceive with the ear
  • To be told or find out information or facts
  • To consider or listen to a court case
  • To perceive with the ear the sound made by someone or something.
stay

US /ste/

UK /steɪ/

  • verb
  • To keep trying without giving up
  • To remain in the same place and not move away
  • To spend time visiting a place or someone's home
  • noun
  • Legal order to stop or delay an action
  • Strong rope or wire that supports a ship's mast
  • Period of time spent living in or visiting a place