Seasons and tides Lesson 40 of the physics course of Mova's primary school: 17 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: the lesson at school .
0 The Earth is tilted, so as it travels round the Sun each year, first one half and then the other leans towards the Sun; the half that leans in gets high, direct sunshine and long days, and that is summer. 1 Shine a torch straight down on the table and the spot is small and bright; tilt it and the spot spreads out bigger and dimmer, and that is why a low winter Sun warms so much less. 2 Seasons are not caused by the Earth getting closer to the Sun: the Earth is actually nearest to the Sun in January, in the northern winter, and Australians eat Christmas lunch on the beach. 3 The Moon's pull raises the oceans into a bulge on the side facing it and another on the far side, and as the Earth spins each beach passes through both bulges, so the sea comes in and goes out twice a day. 4 On a flat beach the tide can come back in faster than you can walk, so always check the tide times before you explore a sandbank. 5 The Earth is tilted, so for half the year your half leans towards the Sun, gets more direct sunlight and longer days, and has summer. 6 Seasons are not caused by distance from the Sun; the Earth is nearest to the Sun in January. 7 The two halves of the Earth have opposite seasons, so Christmas comes in summer in Australia. 8 In summer the Sun climbs high and takes a long path across the sky; near the North Pole it does not set at all in midsummer. 9 A high Sun puts its light on a small patch and a low Sun spreads the same light over a big patch, so a low Sun warms less. 10 Near the equator the Sun is high all year, so there is no snowy winter; many places there have wet and dry seasons instead. 11 The Moon's gravity pulls the oceans into a bulge on the near side and another on the far side, and each place passes through both as the Earth spins, giving two high tides a day. 12 Tides come about 50 minutes later each day, because the Moon moves on in its orbit. 13 When the Sun and Moon pull in line, at full and new Moon, tides are biggest; these are called spring tides, though they have nothing to do with spring. 14 On some flat beaches the sea comes back in faster than you can walk; if cut off, call the coastguard rather than try to wade. 15 The Moon pulls lakes too, but a lake is too small to show a tide you can see; even the solid ground rises and falls a few centimetres each day. 16 A year is the time the Earth takes to go round the Sun, about 365 and a quarter days, so every fourth year has an extra day, 29 February, to keep the seasons in place on the calendar. ← previous Day and night, and the Moon's facesnext → Alice's fall and her sizes: falling, the centre of the Earth, giants and tiny people↑ back to Physics This page in Markdown → https://md.mova.elamur.ai/free/en/corpora/school/physics/40-seasons-and-tides/