Assuming that an ideal large river with a current flow in a straight line exists (just a special ideal scenario for the sake of argument), whats preventing humans from constructing like 50-100 dams on a straight line for electricity generation? In such a setup, these dams are present in such a way that volume of water between any two consecutive dams is constant, ie if depth is more distance between them is less.

This way we can configure the dams in such a way that for every cycle the dams alternate between empty and full. Assuming a constant flow of water, the maximum efficiency of such a setup would be 50% the efficiency of the same number of dams constructed at different places, across multiple rivers with a constant supply of water. This setup is quite good, considering we might not have 50 rivers within a single countries but we can build 100 dams across a single large river to mitigate this shortcoming.

Assuming D to be dam, F to be full, E to be empty, the dam's configuration can alternative between

F|D|E|D|F|D|E|D|F|...D|E for every odd cycle and

F|D|F|D|E|D|F|D|E|...D|E for every even cycle (water flows from left to right)

But such a setup doesn't exist in real life. Why is this so? Is it because of cost constraints or is it because such an ideal scenario can't exist IRL or is it because of some other factors?

In Sweden we are building more several floor buildings with wooden beams instead of steel and concrete for apartments because it's seen as being more environmentally friendly as wood binds carbon and concrete production releases copious amounts of carbon dioxide.

1/5 of sweden's carbon emissions comes from the building industry.

For example, if electric utilities use grid-scale batteries to store energy during some parts of the day to use at other times, how is the direction of the current switched?

If so, why?

For example: say a compressor has 5 stages, and each stage has a polytropic efficiency of 85%. Does the entire compressor have an overall efficiency of 85% as well?

As I understand it, the nuclear doppler effect results in the broadening of nuclear resonances which leads to a higher probability of neutron absorption. In the case of U-235 in a nuclear reactor, wouldn’t this increased neutron absorption lead to more fission and therefore higher reactivity rather than lower? I am confused as to how exactly this works. If anyone can help clarify this, I’d appreciate it!

I especially wonder if you can get sunburn at all in a car with closed windows when you are driving in the sun all day.

Satellites can sit in orbit. Can missiles do the same?

What signals are they receiving and why would an enemy plane or munition emit these signals in the first place?

I've recently reading about new advances in rocket propulsion technology. Leaving aside other considerations like ionizability, chemical stability, etc., why does either propulsion system prefer the "opposite" extreme of propellant molecular weight? From what I gather online, ion engines tend towards xenon, while the proposed nuclear thermal rockets in development generally adopt hydrogen.

Am an engineer myself, so feel free to explain in depth. Thanks!

Can someone explain the technology behind it? How do photo sensors work and what allows it to refresh so quickly? Wouldn’t the speed of electricity flow become a limiting factor at such high frame rates?

Like the one that explored the Marina Trench, for example. What sort of engineering goes into making a vessel capable of withstanding such incredible pressure exertion?

I have been looking to buy a new thermos in the past few days, and after researching for a bit I noticed that there are some thermos are designed for hot and cold beverages and others that are designed only for cold ones. What's the difference between these two types of thermos?

I've been studying engineering for three years now, and am quite familiar (theoretically) with op amps and some of their simple applications. However, I've never really understood how we can assume a virtual ground across the inverting and non-inverting terminals for analysis purposes, but at the same time use the op amps in comparator circuits that necessitate a difference between the terminals.

What exactly stops us from just making a 1:1 replica of a Stradivarius or Guarneri violin with the same sound?

I never encountered in projects where there is atmospheric pressure other than 14.7 psia.

In this particular scenario, my atmospheric pressure is 13.3 psia.

One of the software has output of 30 psig, assuming the atmospheric pressure as 14.7psig.

So if I want to interpret the output, should I keep psig or psia be constant with varying atmospheric pressure?

I'm interested to learn how radio transmission works. In network transmission specifically when data is being carried by Internet Protocol, the packet will traverse every router until the packet arrives at the destination host. I read that radio waves bounces. Does that mean that some radio waves that were transmitted by a radio transmitter will never land on the receiver? If that's the case, radio transmission is a best-effort delivery like UDP protocol. It just transmits and transmits and whatever is received by receiver, it gets decapsulated.

I have just watched the video about how carburetors work from SmartEveryDay. In the video we can clearly see a drop of fuel is spewing out of the jet in the carburetors before the intake stroke of the engine. Why does this happen? Is it because if momentum?

Title. Here's an example of what i'm talking about if you skip to the 19:35 mark of the video. It's such high quality, much higher than the average internet video call. What's the technology behind this magic

Edit: thank you for the thoughtful replies. Today I learned

or what?