Life vs. Rocks: What Makes Them Different?

Welcome to my third “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 third 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!

Q: What is the division between the physical and life sciences? For example, why do we think of rocks in a different category than we do plants and animals? (asked by Katherine)

Okay, wow. Another great question! This one is almost as fundamental as gravity, which I answered earlier.

Gravity may be pretty much the singular reason why the universe works the way it does, but the difference between the physical and life sciences is an important distinction when trying to understand the world around us.

So let’s start with what we know. When you hear “physical science,” what do you think of?

 

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You might think of any number of things—but I’ll bet you that none of those things are alive in the traditional sense.

So, how about the biological sciences? What does that make you think of?

 

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Maybe plants…or cute animals?

Whatever you think of, I’m going to guess they’re all alive.

But what makes something alive or not alive? What makes zebras leap and run, whereas rocks are forever immobile? What makes these living beings different from a vast galaxy or the Pillars of Creation? Continue reading

What is Gravity, Anyway?

Welcome to my second “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 second 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!

Q: What is gravity? (asked by Simon)

Wow…great question. This is a question the greatest scientific minds have asked and tried to answer for centuries. It’s a question not even Stephen Hawking, the scientific genius of the century, has fully answered.

There are a few parts to the gravity question, and they have each been addressed one by one over time:

  • How does gravity work?
  • What is gravity?
  • Why does gravity work?

Isaac Newton stood on the shoulders of the giants before him—Aristotle, Ptolemy, Copernicus, and Kepler—and figured out how gravity works. But he was at a loss to explain what exactly this mysterious force was.

Einstein built on Newton’s work and came up with a theory for what gravity is—that is, distortions in space-time.

spacetime

We have yet to understand why gravity works. Why is space-time warped? Why do objects distort it as if it were the material of a trampoline? What exactly is the nature of space?

But, lucky for me, the question above specifically asks what gravity is. And that, I can explain.

The best way to do that is to turn one of gravity’s oldest tricks, one that has perplexed scientists and philosophers for thousands of years: What makes the planets move? Continue reading

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.

fridge magnets.jpg

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