Mind blowing at 0.30
https://www.youtube.com/watch?v=dBwNadry-TU
according to Neil deGrasse Tyson - Tides do NOT raise or fall
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Posted: Jan 15, 2021 - 11:54 AM
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Posted: Jan 15, 2021 - 02:10 PM
Thanks for posting this, because you caused me to learn stuff I didn't know (in spite of the host's annoying interruptions). However, I saw that in this video another guy adds one clarification, which is that the tides actually result more from a pressing than a stretching force: https://www.youtube.com/watch?v=pwChk4S99i4. Pretty interesting, and all good stuff.
Edited by CatFan57 on Jan 15, 2021 - 03:56 PM.
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Posted: Jan 16, 2021 - 09:04 AM
I thought most people understood the reason for tides. Grade 10 physics explains the law of universal gravitation, ie anything with mass attracts everything else with mass.
The attractive force is the relationship of distance between the centres of each mass, & the magnitude of each mass. Gravity pulls us to the Center of the earth, not the surface, the surface just gets in the way. One exam question I remember was how much less do you “weigh”if standing on top of Mt Everest vs the equator or N Pole.
Our moon, being much closer than the sun, has a greater tidal effect, even though the sun is a much larger mass. Of course all Coasties know that the highest tides occur when both are in alignment.
He was correct in why tides don’t actually go in & out, (that’s splitting hairs because while true in the open ocean, land barriers do get in the way & funnel water into horizontal motion), however the diagram showing the earth spinning inside the ocean was not correct.
In the same way the earth does not spin inside the atmosphere, it does not spin inside the ocean. Earths rate of rotation at the equator is about 1000mph. If it rotated inside the ocean, well, the 1000mph tsunami would ensure nothing survived. We don’t notice this rotation because everything on/in earth rotates with it.
As earth rotates, the bulge remains aligned with the moon & sun, with the bulge “moving”, much like a wave crossing a lake, but luckily for us, the earth does not spin inside the ocean.
Edited by Edchris177 on Jan 16, 2021 - 09:13 AM.
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Posted: Jan 17, 2021 - 11:00 PM
Good clarification, I thought that didn't make sense.
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Posted: Jan 19, 2021 - 02:53 AM
You'll be disappointed to hear that, at least in the states, current HS physics classes do not have a standard curriculum that includes gravity and kinematics anymore. My son spent the whole year studying electromagnetism and nuclear physics, while his friend under another teacher had dissimilar content. It made us both sad. We love physics.
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Posted: Jan 19, 2021 - 10:33 AM
So Physics but not much of Newton.. yes, kind of weird.. Here in Chile they wanted to eliminate History from secondary school, take that!... and then we wonder why we repeat the same mistakes over and over... -
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Posted: Jan 19, 2021 - 11:08 AM
10th grade Physics?! You had 10th grade Physics? Luxury! My school system spent most of it's energy on teaching the Lost Cause.
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Posted: Jan 19, 2021 - 05:30 PM
The curriculum in Canada is not standardized across the Country, education is the purvey of Provinces. I grew up in Western Canada, on the edge of the Rockies.
HS physics there consisted of two entities, statics & mechanics, followed by light, electricity & magnetism. It was set up to prepare one for university, taking a science degree or engineering.
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