Free printable SSAT practice test for Grade 8

Let me be clear about one thing: I was only at the recital because my mother had confiscated my car keys until I agreed to go. I had quit piano two years earlier, at fifteen, and I had never regretted it for a single afternoon. Lessons had been a weekly sentence, Mrs. Abernathy's metronome ticking like the clock in a dentist's waiting room. When I stopped, I felt nothing but relief, and I said so to anyone who asked, and to several people who did not.

So I sat in the third row of the community hall with my arms folded, prepared to be bored. The program listed eleven students. My sister, Lena, was ninth, playing a Chopin nocturne, the one in E-flat. I knew it was the one in E-flat only because it was printed in the program.

The first eight performers were what you would expect. A boy in a clip-on tie rushed through a minuet as though it were chasing him. A girl stopped twice in the same measure and started over both times, her face burning. I happened to notice that she had been fine until her left hand crossed over, which is where everyone gets lost, but I mention it only because it was obvious.

Then Lena walked out. She sat, adjusted the bench a quarter of an inch, and waited, which is something Mrs. Abernathy used to tell us to do and which I never once managed. The opening was steady. By the second page she had sped up slightly, and I caught myself leaning forward, because the trill near the bottom of that page is a trap if you take it too fast, and she was taking it too fast.

She didn't fall into it. She came out of the trill clean and let the last chord ring until it dissolved into the hum of the heating vents. People applauded. I applauded too, because it would have been rude not to.

Afterward, in the lobby, Lena found me by the table of lemon bars.

"You were doing it again," she said.

"Doing what?"

"Your fingers. On your knee. The whole time." She grinned. "You played the entire left hand. Mom saw."

I told her that was ridiculous, that it was a nervous habit, that it could have been any song at all. She just took a lemon bar and went off to find her teacher.

On the drive home, with my keys returned, I did not turn on the radio. When we got back, I went upstairs and rearranged a few things in my closet, nothing important, just a box of old sheet music I had been meaning to throw out for two years and had somehow kept forgetting to. I set it on my desk, where it would be easier to remember.

On a clear night, the stars seem to hang in a single moment, as if the sky were a photograph taken just now. In fact, it is something stranger: a collage assembled from many different pasts. Every point of light you see left its source long ago, and each has been traveling for a different length of time.

The reason is that light, though astonishingly fast, is not instantaneous. In empty space it covers about 186,000 miles every second. That speed is so great that for much of history people assumed light arrived the instant it was given off. One of the first serious challenges to that idea came in the 1670s, when the Danish astronomer Ole Romer noticed that the eclipses of Jupiter's moon Io came earlier or later than predicted, depending on whether Earth was moving toward Jupiter or away from it. The most reasonable explanation was that light needed extra time to cross the extra distance. Light, in other words, had a finite speed, and that speed could be measured.

Once that was established, distance and time became two ways of describing the same thing. Sunlight takes a little more than eight minutes to reach Earth, so we always see the Sun as it was about eight minutes earlier. For greater distances, astronomers use the light-year, a unit that sounds like a measure of time but is actually a measure of length: the distance light travels in one year, nearly six trillion miles.

Finding out how far away a particular star is proved far harder. The method that finally worked is called parallax. Hold a finger at arm's length and look at it first with one eye and then with the other; the finger appears to jump against the background. Astronomers do the same thing on an enormous scale, observing a nearby star from opposite sides of Earth's orbit, six months apart, and measuring how much it seems to shift against far more distant stars. The shift is tiny, much smaller than the unaided eye can detect, and it was not measured successfully until 1838, when Friedrich Bessel reported the distance to a star called 61 Cygni.

The results were humbling. The nearest star beyond the Sun, Proxima Centauri, is a little more than four light-years away, so its light is over four years old when it arrives. The Andromeda Galaxy, often described as the most distant object visible without a telescope, is about 2.5 million light-years away. The faint smudge it makes on a dark autumn night is light that set out before modern humans existed.

This delay is not merely a curiosity; it is one of astronomy's most powerful tools. Because light from remote objects is old, telescopes that gather extremely faint light are, in effect, looking into the past. By studying galaxies at greater and greater distances, astronomers can observe the universe at earlier stages of its history, much as a geologist reads older rock in deeper layers. The night sky, it turns out, is less a picture than an archive.