The Secrets of Magnets

Welcome to my first “Science Answers” post! About a month ago, I sent out a post requesting science questions from all of you; you can find it here. This post addresses the first of the questions I was asked. If you have a question, you can ask it in the comments here or on that post, or ask it in an email. Or find me on Facebook!

And by the way…I do apologize for getting this post out so late. But here you are.

Q: What is magnetism? And what’s the difference between electromagnetism and the “magnetism” found in minerals? (asked by Simon)

So…let’s start with something most of us are familiar with.

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Can I just say, I’ve never seen a fridge with so many magnets?

Usually, the magnets in our lives serve practical purposes. In your typical household, these fridge magnets would be used to hold up notes, photos, recipes, etc. that you’d want to display in your kitchen.

(Of course, magnet collecting is a perfectly reasonable hobby, if the sheer variety on this fridge is any indication.)

Magnets are something we take for granted. But they are even more a part of our lives than we realize. Continue reading

Science Questions, Anybody? (#1)

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I want to try out something new. Up until now, for every post on this blog, I have chosen a topic and written about it in the hopes that you’re curious about it.

This time, I want to know what you are curious about.

You’re welcome to ask any question about science. No matter what it is, I will do my best to answer it. If I don’t immediately know the answer, I’ll research it. And remember—there are no stupid questions, only stupid answers.

Just leave your question in the comments below. If you’re not a WordPress user, you’ll need to enter your name and email address, but I’m the only person who will ever see your email.

I will answer every question that’s asked. Depending on how many there are, I’ll either answer them all in a post coming up soon, or I’ll answer one in each of a series of posts to be published over the next few days.

If you think you know the answer to your question but aren’t quite sure, you’re still welcome to ask it—and even let me know what you think the answer is! I’ll make sure to point out what you’re right about when I answer your question.

I’ll also reproduce the question and credit you (the name you use in the comment form) for asking it. Then I’ll answer your question in detail. If anything’s still not clear afterwards, you are welcome to comment again or email me.

All answers will be archived on my “Myth & Science” page, underneath the “Science Answers” drop-down menu.

I’ll keep comments open for a few weeks. But if you miss out on this first “Science Questions, Anybody?”, don’t worry about it. I’ll do this again sometime soon.

Questions, anyone?

Evidence vs. Belief

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I remember something my ninth grade advanced biology teacher told our class. It was essentially a story about an invisible dragon.

Now why, you ask, would a biology teacher teach us about an invisible dragon?

Her message had nothing to do with the dragon, and everything to do with the lengths one of the story’s characters went to in order to disprove the dragon’s existence. Her intention was to help her students distinguish between evidence and belief.

On a broader level, her intention was to show us the difference between science and religion. See, back when I was in eighth and ninth grade, there seemed to be a lot of controversy in schools surrounding science and religion.

Teachers of students that age felt the need to preempt their entire class with a disclaimer—that students were still free to believe whatever they believed, no matter what science the class taught.

Most teachers just made a general announcement on the first day. But my biology teacher told us this story about a dragon—and it continues to impact me to this day.

It goes like this: Continue reading

The True Brightness of Stars

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Have you ever looked up at the night sky and noticed that while relatively bright stars outline the constellations, there are numerous other stars that are almost too faint to see with the naked eye?

If you ever noticed this, you probably guessed that the brighter stars are literally brighter, and the fainter stars truly are fainter. Or maybe you guessed that they don’t vary in brightness that much, but fainter stars are much farther away.

But that’s not really true…or, at least, it’s not the whole answer.

So what’s the real reason why some stars appear to be brighter than others—and how can we tell how bright they really are? Continue reading

Stars and Proper Motion

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Recognize this constellation?

Well, at the time stamp of about 2000 AD (CE), I think you will. It’s one of the most famous constellations in the night sky.

Well, technically, it’s not a constellation at all.

It’s an asterism—a commonly recognized grouping of stars that isn’t actually official as a constellation. There are tons of asterisms that you no doubt recognize…the Summer Triangle, the Great Square of Pegasus, the Big Dipper.

That’s right. That mess of stars up there that keeps changing for some reason…that’s the oft-recognized Big Dipper, part of the constellation Ursa Major.

So why the heck are the stars moving? Continue reading

Distances Between Stars

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When you look up into the sky on a clear night away from the glare of the city, you see trillions upon trillions of stars.

Thousands of years ago, the classical astronomers saw the same thing you do today—except perhaps a little different, due to the ever-changing cosmos. And, like you, they weren’t satisfied with just looking. They wanted to know what was out there.

For hundreds of years, they developed model after model to explain why the stars seemed to orbit the Earth and why certain objects in the sky—which they named planetsseemed to wander backwards from time to time.

Tycho Brahe, an astronomer known mainly for what he got wrong, dismissed the idea of the Earth orbiting the sun because he could detect no parallax between the stars.

If he had been able to measure parallax, he might have realized that the universe was much larger than any of his fellow classical astronomers imagined.

So what is parallax…and how can it help us measure the distances between stars? Continue reading

Solar Weather

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When you hear the word “weather,” you probably think of clouds and lightning bolts and rainstorms. Maybe, if you live in particularly high elevation or latitude, you think snowstorms or even blizzards.

We humans are used to these weather patterns. They’re the norm here on Earth. But would you be surprised to hear that the sun has weather of its own?

The sun doesn’t have clouds. Electricity doesn’t crackle through its atmosphere and build up as lightning. Its surface sits comfortably at about 5800 K, which is 9980°F and 5526°C—so it doesn’t even get close to cold enough for rain or snow.

So what kind of weather does the sun have? Continue reading

The Sun’s Magnetic Show

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Do you recognize the name Galileo Galilei?

Galileo was the classical astronomer who made the drawing above. I have little idea what his writing actually says—it’s in Latin—but it’s clear enough what this early diagram is all about.

It’s a drawing of his observations of the sun.

And it’s proof, discovered way back in Galileo’s time but not accepted until much later, that the sun actually rotates.

How do we know that? Continue reading