Maarten88 · HackerTrans

há 2 mesesdiscuss

You are thinking about a slow boat in displacement mode, or a wave-surf board with very small fins. But I can tell you that the wetted surface area of my wing-foil board is exactly zero after takeoff, and all wet surfaces of the foil are, for a significant percentage, in laminar flow. Same for a windsurf board planing: just the last 50cm of the board is touching the water and the fin is extremely significant for drag.

Maarten88

há 2 mesesdiscuss

> Surfboards will have a Reynolds number of 10^7 which is entirely turbulent.

A fin, foil or daggerboard below the board/boat is operating well within the range of Reynolds' numbers where laminar flow is relevant.

Maarten88

há 2 mesesdiscuss

Any competitive sailor or foil-racer knows that the underwater surface has the least friction and best laminar flow when sanded with fine-grid sandpaper, around 1000 to 1500 grid.

It always surprised me that this was not true in air and airplane wings were supposedly best when glossy. So now it turns out that this is indeed not true, and airfoils also benefit from micro-roughness for lowest friction.

Now the surprising question to me is how is it possible that something so simple was not known in this very well-researched and well-funded field. It probably was known, just not by the paper-publishing researchers.

Maarten88

há 4 mesesdiscuss

> I don't know which side is more likely right in this scenario.

What are the motives? Follow the money? Who profits most might give an indication of who is more likely wrong.

Maarten88

há 4 mesesdiscuss

You know the carbon footprint concept was literally created by BP marketing, to place the blame for climate change on society, and distract from all the evil stuff they did to promote more fossil fuel consumption and sabotage climate science.

The Climate Town channel on Youtube has lots of video's on this, such as this one: https://www.youtube.com/watch?v=1J9LOqiXdpE

Maarten88

há 5 mesesdiscuss

> people who believe that crashing the US, including the dollar, enables them to build a US like they want

Yes, it's strange how dumb some rich/succesful people are. As I understand it, no civilization ever has done such a thing. If a civilization and its institutions crash, it remains failed/dysfunctional for a very long time. The only way to improve society is in small steps.

I hope the people who finance this all will wake up to the reality that it may well cost them everything, too.

Maarten88

há 4 anosdiscuss

Car drivers who hate bikes are dumb. Why don't they understand that every bike trip means one car less in traffic, thus freeing up space for their car?

Maarten88

há 7 anosdiscuss

Because the truth has a liberal bias?

What is the argument you are making against the seemingly neutral argument that defends tolerance? Why is the right at odds with tolerance?

Maarten88

há 9 anosdiscuss

And landlocked, no natural resources, just a lot of people, so they need to export something to get foreign currency. IT is ideal so they are educating for that.

Also safe and not corrupt. Can't bribe yourself out of a speeding ticket there...

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