Our star has been slow to give up its secrets. To study the sun is to enter a realm that is Surpassingly Weird.
By Curt Suplee
To astronomers good seeing means the air will permit a sharp and stable image of celestial objects. And indeed, it’s almost surreal, the sapphire clarity over La Palma, one of the westernmost Canary Islands.
“Hold your arm out until your thumb just barely covers the sun,” says Goran Scharmer, director of the Royal Swedish Academy of Sciences’ Institute for Solar Physics. “When it’s dark blue right up to the edge of your thumb, it’s going to be a coronal sky.”
Coronal sky itself doesn’t guarantee good seeing, but it’s one sign of a calm, dust-free atmosphere. That’s why Scharmer and his team are here atop the rim of an ancient caldera, half a mile above the cloud deck, continuing a quest as old as man: studying the fire in the sky.
It has been burning for 4.6 billion years, even before there was an Earth to bask in its all-sustaining glow. Yet it is only in the past two decades that scientists truly have begun to understand the thermonuclear reactor we call the sun.
By big-time galactic standards, our star is quite undistinguished. Sure, it’s so huge that a million Earths would fit comfortably inside. And it’s so dense that the sunbeams you see today began their journey from the center of the sun before the last ice age, taking hundreds of thousands of years to elbow their way out to the glowing photosphere before making the 8-minute, 93-million-mile trip across space to your eyes.
Yet the sun falls into the general stellar category of yellow runts called type G, a species so monotonously common that there are billions of them in the Milky Way alone. And it appears to be remarkably stable so far, with an energy output that varies no more than one-tenth of one percent over the course of a decade, and not much more over centuries.
But nothing else in the universe — save only our planet itself — is more immediately important to us. The sun is the origin of virtually all the energy that sustains life, the source of our weather, arbiter of our climate, and, of course, our closest connection to the processes that populate galaxies and power the cosmos.
1. What does good seeing mean to astronomers?
a. – when image of celestial objects is sharp and stable
b. – when the air is stable
c. – when the sky is clear
2. Who is Goran Scharmer?
a. – he is a member of the French scientists’ team
b. – he is a director of the Royal Swedish Academy of Sciences’ Institute for Solar Physics
c. – he is a professor of Swedish Institute of Sciences
3. What does the coronal sky provide?
a. – good seeing
b. – a calm, dust-free atmosphere
c. – the sapphire clarity
4. How long have people been studying the sun?
a. – for many years
b. – since last century
c. – the quest is being continued as old as man
5. When have the scientists begun to understand the thermonuclear reactor we call the sun?
a. – since last century
b. – only in the past two decades
c. – not much more than a century ago
6. When did the sunbeams we see today begin their journey?
a. – before the last ice age
b. – even before there was an Earth to bask in its all-sustaining glow
c. – hundreds of years ago
7. How often does an energy output vary?
a. – no more than one-tenth of one percent over the course of a decade
b. – no more than one-tenth of one percent over centuries
c. – no more than one-tenth of ten percent over the course of a decade
Exercise 12. Using information from the texts of Part 4. Solar Energy, questions from exercises 3 and 11 and statements from exercise 8, discuss the possible ways of solar energy use.
Exercise 13. Read and translate from English into Russian using a dictionary (See Student’s Individual Task: Unit 16., Part 4., Ex. 2.)
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