Question

2. What the radiation is not. (2 pts.) What observation of Penzias and Wilson's contradicts the hypothesis that the radiation they discovered comes from the nearby Andromeda Galaxy a. (2 pts.) At long wavelengths, diffraction is a serious complication. If the antenna is pointed toward the zenith, radiation from the horizon can diffract into the antenna, and it would appear that there is radiation coming from the direction of the zenith. What observation of Penzias and Wilson contradicts the hypothesis that the radiation they discovered comes from New Jersey, where their antenna is located b.

Answer 1

Solution:

a) Far from confirming the Peebles-Dicke model, the Penzias-Wilson discovery clearly ruled out the closed oscillating model. Thus arose a third version of the big bang—which became known as the standard model—an open universe in a permanent state of expansion.

In 1755, Kant postulated the existence of distant collections of stars, which he called "island universes." Yet as late as 1924, the entire universe was estimated to be only 200,000 light years in diameter, and consisted of just three galaxies—our own and the two neighbouring ones. Then the American cosmologist, Edwin Powell Hubble, using the new 100 inch telescope at Mount Wilson, showed the Andromeda nebula to be far outside our own galaxy. Later, other galaxies were discovered still further away. Kant’s "island universes" hypothesis was shown to be correct. Thus the universe was rapidly "expanded"—in the minds of men—and has continued to expand ever since, as more and more distant objects are discovered.

In 1929, Edwin Hubble, using a powerful new telescope, showed that the universe was far bigger than had been previously thought. Moreover, he noticed a previously unobserved phenomenon. When light reaches our eyes from a moving source, it creates a change in frequency. This may be expressed in terms of the colours of the spectrum. When a source is travelling towards us, its light is perceived to shift towards the high frequency (violet) end of the spectrum. When it moves away, we perceive a shift towards the low frequence (red) end of the spectrum. This theory, first worked out by the Austrian Christian Doppler, and called the "Doppler Effect" after him, had major implications for astronomy.

Far from confirming the Peebles-Dicke model, the Penzias-Wilson discovery clearly ruled out the closed oscillating model. Thus arose a third version of the big bang—which became known as the standard model—an open universe in a permanent state of expansion.

In 1755, Kant postulated the existence of distant collections of stars, which he called "island universes." Yet as late as 1924, the entire universe was estimated to be only 200,000 light years in diameter, and consisted of just three galaxies—our own and the two neighbouring ones. Then the American cosmologist, Edwin Powell Hubble, using the new 100 inch telescope at Mount Wilson, showed the Andromeda nebula to be far outside our own galaxy. Later, other galaxies were discovered still further away. Kant’s "island universes" hypothesis was shown to be correct. Thus the universe was rapidly "expanded"—in the minds of men—and has continued to expand ever since, as more and more distant objects are discovered.

In 1929, Edwin Hubble, using a powerful new telescope, showed that the universe was far bigger than had been previously thought. Moreover, he noticed a previously unobserved phenomenon. When light reaches our eyes from a moving source, it creates a change in frequency. This may be expressed in terms of the colours of the spectrum. When a source is travelling towards us, its light is perceived to shift towards the high frequency (violet) end of the spectrum. When it moves away, we perceive a shift towards the low frequence (red) end of the spectrum. This theory, first worked out by the Austrian Christian Doppler, and called the "Doppler Effect" after him, had major implications for astronomy.