photons

The Universe’s First Moments

/ Emma / 6 Comments

Imagine a time before galaxies existed, before the first stars had been born, before the most basic building blocks of matter–atoms–had formed.

This was mere moments after the Big Bang.

No one understands how matter and energy behave under the extreme conditions of the Big Bang itself. We can’t tell the story of the universe from exactly zero. But we can rewind the clock all the way back to the universe’s first one-millionth of a second.

So, what was the universe like back then?

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How Were Atoms Discovered?

/ Emma / Leave a comment

Welcome to my fourth “Science Answers” post! If you have a question, you can ask it in the comments here, or ask it in an email. Or find me on Facebook!

Q: (1) How did scientists find elements in the first place? Could there be more undiscovered elements?
(2) How did scientists create the periodic table?
(3) How do we know that everything is made up of atoms, when atoms are so small that they can’t even reflect light (a necessity for seeing them)?
(asked by Mukesh Garbyal)

Really good questions! I was asked these in a comment on my post “Types of Atoms,” and chose to answer them in a post of their own.

Let’s take this apart. I actually want to address the third part of the question first, since it contains a misconception: atoms can reflect light. Their interaction with light is actually why we can see anything in the world.

How?

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Energy Flow from the Sun’s Core

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wind and water.jpg

Ask any climate scientist how we should power our world without fossil fuels, and they’re bound to tell you about wind and solar power.

You might be surprised to know that both of these come from the sun. Solar panels collect the sun’s energy directly, but we wouldn’t even have wind if not for the sun.

Why? Because in order to move, you need energy. And not just you. I’m talking about every speck of material on Planet Earth that shifts an inch. It’s because it has energy.

That energy can come from a lot of places. Earth is still a dynamic world with a hot interior, but it’s not hot enough to sustain all the life and other movement on its surface. A lot of our planet’s energy comes from the sun.

But here’s the big question. How the heck does it get here?

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Atoms and Radiation

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Pillars of Creation.jpg

Everything we know about space comes from radiation.

Now wait just a moment here. That statement explains how astronomy is such a successful field of science—it’s based entirely on the information we can glean from radiation, after all. But how does that make sense?

I mean, it’s one thing to study radiation. It’s quite another thing to study matter, the “stuff” in the universe. How does one have anything to do with the other?

Well…that’s where atoms come in. Radiation does, in fact, have a lot to do with the “stuff” it comes from. And if it weren’t for that basic principle, astronomy as a science wouldn’t work.

Thankfully for astronomers, it does. So what’s the secret, then? What does radiation have to do with matter?

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The Spectrum of Light

/ Emma / 7 Comments
Rainbow-Stretching-Hilly-Forest-Mountains.jpg.638x0_q80_crop-smart.jpg

Does this look familiar?

People think of rainbows as a symbol of happiness and fortune. There are even myths that leprechauns hide gold at the end of a rainbow. That’s more of a tease than good fortune, if you ask me, because it’s impossible to reach the end of a rainbow.

That’s right. Impossible.

Some people wonder if rainbows look the same from the back. The answer’s no. They don’t. You wouldn’t see a rainbow if you were standing behind it.

Whoa…why would that be?

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