00:01
Okay, so in this question, we have five questions and multiple choice.
00:04
And the first one asks, what was the biggest contribution of tycho brahe to astronomy? we have a, accurate observation of stars and planets, b, heliocentric universe, c, measurement of earth circumference, and d phased venus.
00:14
He is most definitely known for his accurate observations of the stars and planets to the point where he was so keen to get really precise, accurate data that the impact of the wind on the buildings that he'd had his instruments in that caused the buildings to sway, even by a fraction of a metre, but it was affecting his results.
00:38
So what he did was he took his instruments and he actually embedded them into the bedrock of the ground outside, so it wouldn't be affected by the weather or by vibrations due to wind.
00:51
So a is your answer for the first question.
00:53
And then for question two, we asked who among the greek philosophers provided this argument for spherical earth, ships ' holes disappear when they sail over the horizon.
01:03
This is attributed to aristotle, so that's a as well, aristotle.
01:07
But it's almost a bit of an unfair question because it was erotophanes who first gave an accurate estimation for the circumference of the earth.
01:21
And he did this using some pretty simple trigonometry, really.
01:26
He knew that at a certain point, or because the sun's so far away, the sun's rays come in basically parallel to each other.
01:34
So at a certain point, they'd come in and they'd be directly over a tower in saim.
01:41
But in alexandria, there's an identical tower, and it made an angle of, well, i said an angle theta here with that tower...