Name: 天文学者だけど「宇宙」について質問ある？ | Tech Support | WIRED Japan
Uploaded: 2026-01-23T18:25:41.000Z
Duration: 25 min 54 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

I'm Jackie Faraday from the American Museum of Natural History.

Let's answer your questions from the Internet.

SupportJomer asks, hey, Siri, how old is the universe?

The universe is roughly 14 billion years old.

And we get to that answer by looking out into the cosmos and seeing the most distant things that we can.

The most distant thing in the observable universe is the cosmic microwave background radiation.

And right behind me, we have a representation of what the cosmic microwave background radiation looks like.

Bluer colors or redder colors, showing tiny temperature fluctuations for what might have been going on about 13.8 billion years ago.

Urposefully lit asks, so did we decide if 3i Atlas is a comet or an alien ship?

At this point, I'm trying to see if I need to get my life together.

Three Eye ATLAS is one of three objects that were discovered that have a velocity that suggests that they are not gravitationally bound to the Sun.

They didn't come from the leftover material that is in our solar system, which is where the majority of our comets come from.

Oumuamua came in and had a composition that was most like what we would call an asteroid.

Borisov grew a tail like we would usually see happen with comets as they get close to the Sun.

So you see a nice beautiful tail as they get hotter and closer to the sun.

all the imagery that we've seen thus far indicates that it's got a tail like a comet.

So three Eye ATLAS is still a really exciting object, even.

Even if it isn't the alien ship that's gonna take everybody to a different place.

3i Atlas is an object formed out of the material from another solar system.

5 defense asks, is the universe infinite?

In an infinite universe, it's infinite in all directions.

Lines of light stay parallel forever, what we refer to as a flat universe.

In a finite universe, the structure would have to curve back on itself.

So it could be a curved structure, like a spherical structure, or it could be open on either sides like a saddle.

Studying the shape of the universe is a major aspect of astrophysical research.

All we're really referring to in this case is how light, as it's moving, is moving either parallel or it's curved.

So Our current thinking now suggests that we live in an infinite universe.

Universe BG 3963 asks, Are we living in a multiverse?

I can't answer that yes or no, because nobody knows.

There's nothing I can tell you that says that it is impossible.

So if you could, for instance, get to a point where you saw our universe from a bird's eye view, could you see other universes out there that had their own big bangs that started them?

That is a possibility and one that scientists look into.

That's not answering the question, though.

If we live in a parallel universe where there's multiple versions of every scenario of every day you've ever lived, this is simply, are we the only universe that is?

Or is it possible that there are many out there?

And the answer to that question is maybe.

Okay, Im Irish says in Interstellar, why didn't approaching the black hole cause spaghetti fication?

Spaghettification is the idea that that as you get closer and closer to something that's very, very massive, the part of you that's approaching it gets yanked with a force so big that it starts to pull you apart.

And if you've watched the movie Interstellar, Matthew McConaughey's character enters the event horizon.

The event horizon is the point of no return.

You have to get closer and closer and closer to the singularity or the center of that supermassive black hole.

And because it's 100 million solar masses, he has to get way closer to the center of the singularity before he feels that spaghettification doesn't mean he would have been feeling something.

He would have been feeling something, but he wouldn't have been spaghettified.

Just remember the difference between a supermassive black hole versus a stellar mass black hole.

Very different gravitational pulls on your body.

Mikaba asks what's at the center of the Milky Way?

A supermassive black hole, which we call Sagittarius A.

Also at the center of our galaxy, there's gas and there's dust.

I think of it like Metropolis or Times Square.

It's where a lot of material is congregating, but

all of it is kind of surrounding this supermassive black hole.

OMBX from Reddit asks what came first, stars or galaxies?

The short answer is stars will come first.

The first stars, because they were basically just hydrogen, were really large objects, probably 100 times the mass of our own sun.

And those didn't live for very long because they're so massive and so as they blew up, they created the next generation of materials that could come together to make more stars.

And as more stars formed, they clumped together.

And those clumps, as they came together, formed galaxies, and the galaxies then formed together, and.

And all of it comes together to make the cosmic web that we know and love and live in today.

Bradley Marquez asks, what is the largest single structure discovered in the universe?

The largest structures that we know of are roughly a billion light years across.

And what they are are these gigantic walls of galaxies.

So the image that's behind me is from a map that's been made of the Sloan Digital Sky Survey galaxies.

It's a telescope that was in the United States, and

it measured how far away all the galaxies are.

And there are some structures that we can tell are all linked together where the galaxies are all held together into a coherent structure.

And for many years, that was the largest structure, but

now there's a couple of others that are in competition for it.

They stretch a billion light years across.

The Milky Way is a part of its own structure, and we call that Laniakea.

Astronomers have looked at that structure and seen a couple of things.

One, it kind of looks like a spider web with filaments that are coming in and weaving around.

Those filaments are made of galaxies, and then in the gaps between them, you can see there's voids.

Much of this is being shaped by dark matter.

So this Webb, this structure, which is the hierarchical map of the universe, is carved out by material that we can't even see.

DJ Anim wants to know what exactly is dark energy and dark matter?

When you look out across the cosmos, you see the galaxies clump together.

But in studying the way everything moved, we realized the stars in the galaxy were orbiting in a way we did not fully understand.

Ones on the outside were moving faster than we thought they should be.

Huge clusters of galaxies were being held together seemingly by nothing, some gravitational thing that was giving off no light whatsoever.

Dark matter has the same gravitational properties that you and I have, but