The Three Gorges Dam in China, the world's largest hydroelectric dam, has been found to have a surprising effect on the length of our days. By altering the distribution of water mass around the globe, it slows down the Earth's rotation, making each day 5.3 microseconds longer. This may seem like a negligible change, but considering the cumulative impact over time, it adds up.
The concept behind this phenomenon is based on angular momentum and moment of inertia. Angular momentum, which depends on an object's mass, velocity, and distance from its axis of rotation, remains constant if there are no external forces acting upon it. However, altering the distribution of mass around the Earth can change its moment of inertia, thus affecting its angular momentum.
To understand this concept better, imagine a rotating desk chair or a car on wheels. If you apply force to a spinning wheel and then suddenly stop it with your arms, the rotation slows down due to an increase in its moment of inertia relative to its angular velocity. This effect is more pronounced when the mass is concentrated closer to the axis of rotation.
In the case of the Three Gorges Dam, it alters the distribution of water mass around the globe by building a massive lake at a specific latitude. By moving this mass farther away from the Earth's axis of rotation, it increases the planet's moment of inertia and decreases its angular velocity. This change in angular momentum results in each day becoming slightly longer.
The impact of such changes might be perceived as negligible on an individual level, but their collective effect over millions of years could have significant implications for our global climate, tides, and the stability of Earth's axis.
The concept behind this phenomenon is based on angular momentum and moment of inertia. Angular momentum, which depends on an object's mass, velocity, and distance from its axis of rotation, remains constant if there are no external forces acting upon it. However, altering the distribution of mass around the Earth can change its moment of inertia, thus affecting its angular momentum.
To understand this concept better, imagine a rotating desk chair or a car on wheels. If you apply force to a spinning wheel and then suddenly stop it with your arms, the rotation slows down due to an increase in its moment of inertia relative to its angular velocity. This effect is more pronounced when the mass is concentrated closer to the axis of rotation.
In the case of the Three Gorges Dam, it alters the distribution of water mass around the globe by building a massive lake at a specific latitude. By moving this mass farther away from the Earth's axis of rotation, it increases the planet's moment of inertia and decreases its angular velocity. This change in angular momentum results in each day becoming slightly longer.
The impact of such changes might be perceived as negligible on an individual level, but their collective effect over millions of years could have significant implications for our global climate, tides, and the stability of Earth's axis.
I'm not convinced by this claim about the Three Gorges Dam slowing down the Earth's rotation. Can someone provide a source on where they got these 5.3 microsecond numbers from? It seems suspiciously made up to me... 
. I guess that's why they call it a cumulative impact...
. 5.3 microseconds may not seem like much, but if that's added up over millions of years, what does that say about our place in the universe? Are we just accidentally changing the rhythm of the planet? 
. We need more research on this to figure out the bigger picture 
.
But on a more serious note, I think this is actually a really good thing for us 
. But honestly, if the world started slowing down because of a dam, I think I'd actually be kind of okay with that 
.
. Like I know the Three Gorges Dam is already a massive project, but to think that it's actually slowing down the Earth's rotation? Mind blown! It's crazy to think about how even tiny changes like that can add up over time. And you're right, it's not just individual days, but also millions of years from now. That's some wild stuff 
I'm curious to see if there are any other human-made projects that have similar effects on our planet...
! like think about it, over millions of years, those extra 5.3 micros have added up and could make a HUGE difference in our climate and tides 
. it's kinda cool to see science come together with engineering to impact the big picture 
?
like what even is angular momentum? 
so if this keeps going on for millions of years it could have some pretty big effects on our planet 
. It's wild to think about how that affects everything from our day length to ocean currents 
. We should be monitoring these changes and trying to understand how they'll impact us in the long run. It's like, we're all connected to this planet, you know? 
who needs a consistent schedule anyway? It's not like it's gonna make or break my life or anything. And can you imagine how cool it'd be to have a perpetual winter wonderland or something? The more I think about it, the more I'm convinced that slowing down our rotation is actually kinda good for us. Less earthquakes, less volcanic eruptions... maybe even a chance for some of those pesky ice ages to return 
. The Three Gorges Dam altering the Earth's rotation by slowing it down isn't a huge deal on its own but considering the long game, it adds up 
. I'm just wondering, how will this affect our kids' birthdays? Will they have to celebrate on a slightly longer day every year? 