When we observe our sun’s corona, we discover something odd.
It’s really, really hot.
But…wait a second. How is that odd? Shouldn’t the sun be hot?
Well…yes. It should, and it is. Its surface temperature is almost ten thousand degrees Fahrenheit, and its core is many times hotter. But there’s a basic law of physics that says energy flows from hotter regions to cooler regions.
The core and photosphere (the visible surface) follow this rule. Even the chromosphere, the lower atmosphere, does as it’s told. But the corona is made up of gases that are hotter than the chromosphere.
What’s up with that? Continue reading
This diagram is a tiny bit misleading.
Here, it looks like the chromosphere is the visible surface of the sun, with the photosphere just below. Really, we never see the chromosphere. If you ever look through a solar telescope at the sun, the photosphere is the surface that you see.
The sun is structured a lot like the Earth, just in that it has a core, a dense region between the core and the surface, a “surface” layer, and a few atmospheric layers. The chromosphere is part of that solar atmosphere. And you never see it.
Well…almost never. Continue reading
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
This is adapted from a post I wrote for the wonderful Momma over at A Momma’s View. For the original version, click here.
The total solar eclipse is an incredible phenomenon, one that I hope to see myself someday.
It isn’t often that an astronomical event occurs of such magnitude that people of all walks of life from all around the globe are drawn to one measly 65-mile wide strip of land, to crowd in like sardines as they watch the world change around them.
What’s important to realize about a total solar eclipse, versus just an annular one, is that it’s a people event.
Scientists do take this opportunity to study the sun’s corona, an outer layer of gases that’s usually too faint to be seen. But in general, this is an event for crowds to enjoy.
And enjoy it they do. I have never known another event of astronomical significance to populate the web and turn heads like a total solar eclipse.
But what happens during a solar eclipse? What can you expect to see, and how can you protect your eyes from the sun’s damaging rays? Continue reading
A solar eclipse is the most amazing astronomical sight you’ll ever see.
Not only is it the only time you’ll ever be able to clearly see the “new moon” phase of the moon, it’s the only time you’ll ever see the sun’s corona. And it’s the only time that, under very specific circumstances, you can actually look directly at the sun for a few moments.
But before you get too excited about that, let me tell you what’s happening in the sky—and give you a few important safety warnings!
(This is just the first of a few posts that will talk about solar eclipses; they’re all worthy of a read. Even if you don’t read all of mine, make absolutely certain you’re caught up on safety warnings before you view a solar eclipse!) Continue reading