This TED Talk features nuclear expert Emma Belcher recorded live at TEDx Mid-Atlantic 2019.

So you know when you're doubled over in pain and you're wondering, is it your appendix or

maybe ate something funny? Well, when that happens to me, I call my friend Sasha.

Sasha's a doctor, and I say, should I rush to the nearest emergency room in a panic?

Or am I okay to relax and just wait it out?

Yes, I am that annoying friend.

But in September 2017, friends of mine were suddenly calling me for my professional

opinion. And no, I'm not a doctor, but they were asking me questions of life and death.

So what was going on in September 2017?

Well, North Korea was suddenly and scarily all over the news.

Kim Jong-un had tested missiles,

potentially capable of hitting major US cities.

And President Trump had responded with tweets of fire and fury.

And there was real concern that tensions would escalate to a potential war or even nuclear weapons use.

So what my friends were calling and asking was,

should they panic or are they okay to relax?

But really, they were asking me a fundamental question. Am I safe?

While I was reassuring them that no, they didn't need to worry just yet,

the irony of their question dawned on me.

What they hadn't really thought about is that we've all been living under a much larger cloud

for decades, potentially a mushroom cloud,

without giving it much thought.

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