- High temperatures - Intermittent solar input not a problem - tall central structure (?? maybe a plus given the paper's tall storage vessels)

But high temperature air receivers have their own problems, mostly around receiver material properties (thermal cycling / stress) and heat loss. It's really hard to focus a lot of light from the sun into a tiny aperture, because the sun isn't really a point source, and no mirror is perfectly shaped.

I would plant one, but their trunks get huge quickly, and I see a lot of busted sidewalks around here due to that.

https://www.portland.gov/trees/sequoiadendron-giganteum

"Though water itself does not absorb much light, and neither does the hydrogel material itself, when the two combine they become strong absorbers, Chen says. That allows the material to harness the energy of the solar photons efficiently and exceed the thermal limit, without the need for any dark dyes for absorption."

So when water is combined with hydrogel, they absorb more light -> more light = more energy -> more energy = more evaporation.

Comments URL: https://news.ycombinator.com/item?id=32267126

Points: 3

# Comments: 0

I've only been part of one startup, and it went nowhere, but it's very common (ubiquitous?) for prospective employees to be sold the "if we IPO for $1xB" line when that likelihood is laughably small; hence my suggestion to lower the expectations with some lower numbers.

But props for getting this all down!

Do 5% of startups actually reach 1B valuation in 4 years? No. Uber took 10 years to IPO. I don't know the average, but I would imagine based on a cursory search that it's closer to 7 or 8 years for highly valued companies in the past decade. And 5% seems extremely high for billion dollar IPOs.

Also, only 2 startups are compared in the NPV calculation. What about joining a BigCo / FAANG? That would really put it into context.

On the other hand, the math gets slightly better if you assume you leave after some amount of vesting. I thought danluu had a post about this, but can't find it. Staying in a startup until the bitter end is almost never the optimal choice, especially if you have inside knowledge of its progress.

https://tldroptions.io/ - This was posted a few years back, and while it doesn't give tell you the likelihood of a particular size of exit, it does help give an idea of the type of dilution and final equity value (with no discounting though).

I may be misremembering, but I think Athletic Brewing mentioned their beers are closer to 0.2 -> 0.3% on average.

But even at 0.5%, that would be 10 NA beers to add up to one average alcoholic beer at 5% assuming equal volumes.

But if you looked at the previous year's numbers, it was something like 18% or 15%. And the previous year's actual attrition was closer to 5-8%. So perhaps you could extrapolate if you had the attrition rates combined with survey data, but surveys are a much weaker signal.

I think it's obvious this list doesn't take into account cultural properties or medium sized cities, as others have commented.

If you want the least bias, you should find someone to review something that hasn't been deeply involved in designing it. And for pieces of code that are small enough, reading and getting up to speed shouldn't take that much time. I prefer sending reviews to engineers that are familiar with the area of the code, but we don't do pair-programming so the implementation hasn't been seen before.

We do, however, do a lot of design work before a single line of code is written.

*also this is at google.

Utilities can't design just for the average month, but the worst ones, and the worst hours of the worst days. Building new peak demand (peaker) plants is very expensive and most consumers probably don't see the actual market prices during those times. Shifting load by a very small percent could result in a decent cost savings and/or avoid building new capacity.

- Ask for check -> waiter brings check -> put card in fold, wait ?? minutes for waiter to return to grab card -> wait ?? minutes for waiter to run card and return it -> sign receipt and leave.

On a busy night, this ritual could last 15-20 minutes.

To be fair, in some countries in Europe (and a small number of restaurants I've been to in the US), it's more like:

- ask for check -> waiter brings hand terminal to table -> swipe card, then leave