Radio communication between distant places on Earth is possible because the
A) ionosphere reflects radio signals.
B) ionosphere transmits radio signals.
C) stratosphere reflects radio signals.
D) exosphere reflects radio signals.
Question 2
Which of statement below about black holes is not true?
A) Although we are not 100 certain that black holes exist, we have strong observational evidence in favor of their existence.
B) If you watch someone else fall into a black hole, you will never see him (or her) cross the event horizon; you'll only see him fade from view as the light he emits or reflects becomes more and more redshifted.
C) A spaceship passing near a 10-solar-mass black hole is much more likely to be destroyed than a spaceship passing at the same distance from the center of a 10-solar-mass main-sequence star.
D) If you fell into a black hole, you would experience time to be running normally as you plunged rapidly across the event horizon.
Tides on Earth
Lightning on Earth
Sample communication analysis
El Anatsui, Between Earth and Heaven.
Earth’s Revolution
When viewed from the Earth, Venus subtends an angle of about 1 arcminute (1/60°) when it is at ...