Radio Astronomy: Advantages

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Whoa…what’s this thing?

It’s a radio telescope, the largest in the world. It’s so huge that a normal support system can’t support its weight. So it’s basically suspended between three mountaintops. It’s 300 m across, which is 1000 feet. It’s huge.

This is the kind of construction endeavor that radio astronomers must try if they want to get much detail from radio waves. The radio wavelengths of the electromagnetic spectrum are really, really weak. You need huge telescopes to collect enough.

But, as ever, astronomers face the same basic problem: money.

Huge telescopes are expensive. It’s unfortunate for astronomers, but true—just think of the cost of labor of basically burying a whole valley under a radio dish.

So why bother? Continue reading

Einstein: Space-Time Curvature

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When you hear about “space-time,” it’s just a way to say that space is related to time. And the curvature of space-time, as Albert Einstein predicted, is the way space and time alike literally bend around a mass such as the Earth or the sun.

That’s what’s diagramed above. This is a three-dimensional concept diagram of the way space sort of “clings” to an object. Notice the way it sort of tightens up when you get close to Earth? And because time is part of this whole equation…time sort of tightens up, too.

I assume that explains the “twin paradox,” as it’s called. That’s where the space-traveling twin returns home to Earth younger than their Earth bound twin.

Why? Seems to me it’s because time was tighter and passed faster on Earth, while it spread out and passed a bit slower for the traveler. (Don’t quote me on that, I just guessed that from this diagram.)

Einstein figured all this out. But scientists need evidence. Trusting Einstein’s genius wasn’t enough for them. How did they accept relativity as fact? Continue reading

Einstein: General Relativity

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Albert Einstein may have been the genius among physicists, but like all others before his time, he stood on the shoulders of giants.

Einstein did not propose that the sun was the center of the solar system; that idea was already widely accepted when he came around. He didn’t discover elliptical orbits; that distinction belongs with Johannes Kepler.

But Kepler never could figure out why planets orbit the sun in ellipses instead of circles. Even Isaac Newton, who at last identified gravity as the reason we stick to Earth’s surface, couldn’t explain what gravity was—only how it worked.

Einstein provided that explanation with his general theory of relativity. Continue reading

Einstein: Special Relativity

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Albert Einstein’s name literally sends shivers down my spine.

This is the man who discovered physics as we know it. This is the man who filled in the gaps where even Newton’s laws of motion went wrong and expanded our understanding of the universe.

This man was a genius in every right—even if his social skills were somewhat lacking.

By the way…I can’t help but notice this is my first post with actual photographs of the scientist in question, instead of portraits. We’re moving along, people…

So. To the point. Einstein is famous for taking revolutionary and widely accepted laws of physics—those that Newton figured out—and showing where there were some holes in the math. But Einstein wasn’t just an annoying critic.

He took it all a step further…and showed us how physics really works.

He came up with the idea of relativity. Continue reading

Newton and Gravity

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So, the moon stays in orbit around the Earth, right?

Yeah, I thought so. But why? The moon’s orbit is not a straight line, which means it’s accelerated motion (using the physics definition, which is absolutely any change in speed or direction).

And in order for acceleration to happen, according to Newton’s first law of motion, a force has to happen—meaning, something has to reach out, touch the moon, and drag it into orbit around Earth.

Well, that doesn’t happen, last I checked. I mean, it’s not like we have some kind of giant cord connecting us to the moon. How crazy would that be?

So why does the moon orbit the Earth? Continue reading

The Lunar Eclipse

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Have you ever heard of the blood moon?

It’s named for its red appearance. Sometimes it’s even mistaken for Mars, as in the case of the “Mars hoax” back in 2002. It was claimed then that Mars would look as large as the full moon on August 27.

In truth, Mars will never appear as large as the full moon to the naked eye (a fancy way of saying that you’re not looking through a telescope or binoculars). What really happened was that the moon passed through the Earth’s shadow.

Wait a second. The Earth has a shadow? And it’s red? Continue reading

Where Are We?

In the 4th century B. C. E. (Before Common Era), scientists believed the Earth was the center of the universe. Before that, they were convinced the Earth was flat.

Now, most of us know that the Earth is not the center of the universe—nor is it flat. (Although there are definitely those who still believe we live atop a flat disk world, hurtling upwards through space.)

Not only is the Earth not the center of the universe, neither is the sun—and it’s not even the exact center of our solar system (you can read more on that here).

And if we zoomed out much farther and took a look at our galaxy from above—or below, take your pick—we’d find that the sun is not even near the center of its own galaxy.

It is, in fact, located in a small “spur” of stars just off one of the spiraling arms of the galaxy. And if our universe is in fact infinite—as the prevailing theory describes—then there can’t even be a center, so our galaxy is not the center of anything.

But what does all of this mean? Where exactly are we in the universe?

Continue reading