Why is a full moon, yellower and bigger when it is coming up than when it is hig

Why is a full moon, yellower and bigger when it iscoming up than when it is higher in the sky?

That's a good question about something that we all cansee. Let's talk about the moon's color first.

We see the moon only because of the sunlight thatfalls on it and is reflected. Actually, the moon is not a very good reflector,because its surface is all rocks and dirt. We see it in almost its true colorwhen it is high in the sky.

When the moon first comes up, its light reaches oureyes after an extra-long path through the atmosphere (大气). There are lots of particles (微粒) scattering (分散) light inthat long path. Blue light is scattered more than other colors, which meansthat it doesn't reach your eyes. The light that is left over looks yellow toyour eye.

Now about the other question—why the moon seems tochange in size. That's more complicated. It's not an effect of the atmosphere,the way color is; it's not caused by something fooling your eyes. It seems,instead, to be caused by something that fools your brain—an illusion(错觉).

Here's a drawing that creates an illusion. The twocones(圆锥体) are really the same size. But the rest ofthe drawing makes the right-hand cone seem farther away. Your brain knows thatfaraway objects are really larger than they look. It decides that theright-hand cone must be larger because it seems to be farther away.

Similarly, when you see the moon just come up over aline of trees or houses—or whatever makes the horizon(地平线)—it may be that your brain decides that the moon mustbe larger because it seems to be farther away.

1.The moon doesn't reflect the sunlight very well because________________.

A．it is high inthe sky                       B．its surfaceis rough

C．its surfaceis white                       D．it isn't agood reflector

2.Which statement is true according to the passage?

A．In the courseof its rising, the moon is getting smaller and smaller

B．The size ofthe moon is more complicated than its color

C．Theatmosphere has the same effect on the moon's size as on its color

D．The change inthe moon's size is caused by an illusion while that in its color is caused bythe atmosphere

3.After reading this passage, you can possibly answerone of the following questions. Which one? ______.

A．Why is thesun bigger when it rises over the horizon?

B．Why does thesun look bigger when it rises over the horizon?

C．Why does thesun look golden?

D．Why does thesun rise in the east?

4.Who do you think probably wrote thispassage?________.

A．A novelist                             B．A reporter

C．A scienceeditor                        D．An Englishteacher．

试题答案

【答案】

1.B

2.D

3.B

4.C

【解析】

试题