Today I Learned

[Ivan Seeking]

This year I learned about Suction Specific Speed - a dimensionless number that provides a key bit of information about centrifugal pumps that you cannot derive from the pump curve (at least not in any obvious way).

Industry experience has shown that when the Net Suction Specific Speed has a value less than 6000 ( in US units), the pump is in danger of recirculation or cavitation, and loss of flow. This does require the pump curve is adjusted for viscosity.
https://www.michael-smith-engineers.co.uk/resources/useful-info/specific-speed#:~:text=Industry experience has shown that,in pump wear and maintenance
A closely related equation, the Specific Speed determines the most efficient type of impeller and is based on the net Head at the Best Efficiency Point rather than the Net Positive Suction Head. {NPSH]

 

[DaveC426913]

This year I learned about Suction Specific Speed ...

I forgot the thread title, and thought we awere still talking about Flat Earth, and assumed Suction Specific Speed was going to be the Flerfers' latest rationalization about the Sun's movements.

 

[Ivan Seeking]

This year Last year I learned about salt-cooled fission reactors and other things .
https://www.terrapower.com/
(a Bill Gates company)

On Netflix

 

[jack action]

TIL about windcatchers.

Neglected by modern architects in the latter half of the 20th century, the early 21st century saw them used again to increase ventilation and cut power demand for air-conditioning. Generally, the cost of construction for a windcatcher-ventilated building is less than that of a similar building with conventional heating, ventilation, and air conditioning (HVAC) systems. The maintenance costs are also lower. Unlike powered air-conditioning and fans, windcatchers are silent and continue to function when the electrical grid power fails (a particular concern in places where grid power is unreliable or expensive).

 

[jack action]

TIL

The interesting number paradox is a humorous paradox which arises from the attempt to classify every natural number as either "interesting" or "uninteresting". The paradox states that every natural number is interesting. The "proof" is by contradiction: if there exists a non-empty set of uninteresting natural numbers, there would be a smallest uninteresting number – but the smallest uninteresting number is itself interesting because it is the smallest uninteresting number, thus producing a contradiction.

Furthermore, I also learned that it could be applied to people, thus every person is interesting because the most uninteresting person will always be interesting.

 

[Hornbein]

TIL


Furthermore, I also learned that it could be applied to people, thus every person is interesting because the most uninteresting person will always be interesting.

I rode a train from Turpan to Kashgar. The topography was exactly the same for hundreds of miles. I found this fascinating.

Flying back on the airplane I could see that we had ridden alongside a mountain range that was completely straight and the same height the whole way.

 

[Ivan Seeking]

I rode a train from Turpan to Kashgar. The topography was exactly the same for hundreds of miles. I found this fascinating.

Flying back on the airplane I could see that we had ridden alongside a mountain range that was completely straight and the same height the whole way.

From the North end of Los Angeles to the South end of Orange County, you can drive in solid city for over 100 miles.

 

[Ivan Seeking]

Last year I learned how to make a valve for liquid salt running at over 800 C

 

[BillTre]

From the North end of Los Angeles to the South end of Orange County, you can drive in solid city for over 100 miles.

More so on the east coast.

 

[Ivan Seeking]

More so on the east coast.

Really? I did not know that! In S California it would be solid city from LA to San Diego, but the San Onofre nuclear power plant required a large unpopulated radius. That is shut down now but I haven't been down there for a long time. I don't know if that area is filling in yet or not. They still have 3.5 million pounds of nuclear waste.

 

[BillTre]

Northern VA to Massachusetts at east.
They have a railroad too.

 

[DaveC426913]

What do we define as solid city? Pretty sure I could drive from one end of the Golden Horseshoe (Greater Toronto and burbs) to the other and it would be city the whole way. That's 100 miles.

 

[Ivan Seeking]

What do we define as solid city? Pretty sure I could drive from one end of the Golden Horseshoe (Greater Toronto and burbs) to the other and it would be city the whole way. That's 100 miles.

I meant non-stop buildings, asphalt, and concrete.