Hello, SFIA audio listeners, in this month's Nebula exclusive, Big Alien Theory,

we're asked at the reason alien civilizations might be rare is because most aliens are huge.

To hear it and every episode early and add free, plus hours of bonus content,

check out go.nebola.t.v.t.v. And use my code, Isaac Arthur.

Good afternoon, everyone, and welcome to the SFIA monthly live stream Q&A.

We'll get started in just a moment, but go ahead and start getting your questions in the chat

window so our moderators can start relaying those to me as soon as we start.

Please try to keep the questions concise and watch your spelling and try to be polite

to others in the chat.

We usually go for about an hour so you probably want to grab a drink and a snack, though

we'll take a break about halfway through too.

With all that said, welcome and let's get started.

And welcome to our July 25th live stream for Science and Futures of Isaac Arthur.

I'm a aforementioned host, Isaac Arthur.

And we're joined today by my co-host, my lovely wife, Sarah Fowler, Arthur, who will we ask you his questions.

And she has her eyeglasses on today or sunglasses on today because she got stuck on the face by B,

which happened to be last week, I am sunborn.

So we're just getting that out of the way as we get questions in for the audience to be asked, and we will go ahead and start off with one from last month.

Yes, our first question is from ATWA, and thank you for the super chat.

Her question is, are we even getting close to understanding gravity and dark matter?

It depends on what you mean about getting close to it.

These days, we tend to know what the effects most of

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