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deepnotderp

4,517 karma · joined November 3, 2016

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deepnotderp··on Who invented the transistor?
> t also required just the right combination of natural resources (coal) and economic conditionsL deforestation

This argument is repeated often, but I don't think it's really true. Both Savery and Newcomen's engines were initially aimed at evacuating flooded metal mines and not coal mines.

deepnotderp··on Diamond Thermal Conductivity: A New Era in Chip Cooling
It’s difficult to cmp diamond is the issue I’d assume
deepnotderp··on New England's last coal plant has stopped operating, according to its owners
Yay for fracking!

Yay for natural gas!

deepnotderp··on OpenAI's H1 2025: $4.3B in income, $13.5B in loss
New hardware could greatly reduce inference and training costs and solve that issue
deepnotderp··on Microsoft doubles down on small modular reactors and fusion energy
Yes but one of the reasons that coal is being replaced by gas is because of the capex of the steam turbine
deepnotderp··on Microsoft doubles down on small modular reactors and fusion energy
Oh my bad, you’re right

Re: Nat gas, agreed, it’s not solar though, storage is much more expensive

Thermal energy still needs to drive a turbine to generate electricity

deepnotderp··on Disrupting the DRAM roadmap with capacitor-less IGZO-DRAM technology
Sure, but conventional DRAM endurance is 10^15 or more
deepnotderp··on Microsoft doubles down on small modular reactors and fusion energy
$3/GJ is $108/MWH which any large scale fission buildout would easily beat for thermal energy costs
deepnotderp··on Disrupting the DRAM roadmap with capacitor-less IGZO-DRAM technology
10^11 cycles is not “practically unlimited endurance”, that’s less than a second of use at 1 GHz
deepnotderp··on Microsoft doubles down on small modular reactors and fusion energy
Thermal storage has very poor discharge rates unfortunately (usually slower than a day), as well as surprisingly high cost once you factor in inefficiencies and turbine cost
deepnotderp··on Can cheaper lasers handle short distances?
MCF has a bunch of challenges, eg no good pigtail connector, need for rotational alignment, inability to radix (MCF is great for point to point, less good if you want to fan out from one chip to multiple chips), etc

And then even after all that, it’s still 1-2 orders of magnitude lower density than waveguides

deepnotderp··on The unlikely revival of nuclear batteries
They do have higher energy density, it’s just a low power density
deepnotderp··on Solar-plus-storage technology is improving quickly
This is a lot of words to say “solar + battery lcoe is $70/MWH and gas is $40/MWH, but most places outside the U.S. don’t have access to tons of cheap gas so it’s more expensive there”

And no, they are wrong, gas is still currently cheaper ($40 is less than $70)

deepnotderp··on Copper is Faster than Fiber (2017) [pdf]
FEC latency is >> propagation delays at these distances, so that's probably the dominant factor in most cases
deepnotderp··on Photo calorie app Cal AI was built by two teenagers
Hyperspectral camera?
deepnotderp··on U.S. homelessness jumps to record high amid affordable housing shortage
We need to move zoning to the federal level like Japan

We must decide whether we’ll be a civilization that bows to NIMBYism and stays stuck in squalor or allow building the future.

deepnotderp··on New research suggests that Walmart makes the communities it operates in poorer
Once again nonsense, productivity has been increasing in America over the last 20 years but real wages have not.

As always, don’t confuse textbook theory with real life!

deepnotderp··on New research suggests that Walmart makes the communities it operates in poorer
Nonsense.

“Free trade” here refers to inter-country globalized trade across borders, not free markets within a confine.

There’s a much stronger case to be made that industrial policy has resulted in prosperity for Asia, ironically the opposite of free trade :)

deepnotderp··on A Short Introduction to Automotive Lidar Technology
You can actually make curved dies already- there’s a company doing that for image sensors, if you thin silicon down it becomes flexible
deepnotderp··on A Short Introduction to Automotive Lidar Technology
No, there’s a class system for laser safety

The rating is for you to stick your eyes right up to it for a long period of time and still be fine

deepnotderp··on A Short Introduction to Automotive Lidar Technology
The SNR for flash Lidar is really low because you spread the beam out over such a large area.

Most automotive Lidar already operate in a “photon starved regime”, ~200-300 photons per return[0]. If you spread that over the entire scene, your snr drops quickly.

This forces you into 1550nm, and a large detector array and high power laser at 1550nm is extremely expensive.

As for MEMS, it’s been a while but I think FOV/steering angle range , steering speed and even maximum beam power were concerns

EDIT: my Lidar friend Jake reminded me that the appetizer size is also an issue with MEMS- smaller aperture = less light collected = lower SNR

[0] https://www.hamamatsu.com/content/dam/hamamatsu-photonics/si...

deepnotderp··on Personality Basins
I enjoy how people are dunking on this by saying “omg this is what happens when engineers dare to have thoughts on other topics” when this is very similar to the theory for CBT in psychology
deepnotderp··on The price of shutting down coal power, and what would be gained
Nah, nat gas is cheaper

The problem is that not all parts of the world have access to cheap nat gas

deepnotderp··on C-Motive's electrostatic motors use printed circuit boards instead of magnets
There are new dielectric refrigerants that aren’t as polluting, but they’re more expensive
deepnotderp··on Hardware Acceleration of LLMs: A comprehensive survey and comparison
It’s expensive, not needed for most consumer workloads and ironically, is actually often worse for latency for many patterns, even though it’s much higher bandwidth
deepnotderp··on How Does OpenAI Survive?
GPT-4 could’ve written this article better- hey there’s an use case right there!
deepnotderp··on Nevada’s public employee pension fund invests passively and beats peers (2016)
Whenever the topic of index funds come up, people should remember:

1. The benchmark for hedge funds is not the sp500, it’s the bond market

2. Because the sp500 is inherently a bet, that America’s top few companies will perform well. This is not a purely risk free, hands off bet.

If you bought the Japanese Index fund, the Nikkei, even today it hasn’t returned to its 1980 peak

You might say “I’ll just get a global index”- in which case congrats, you’ve underperformed hedge funds!

3. There are more factors than just investment returns- ie volatility (Sharpe), drawdowns, etc

So despite what HN seems to think, the hedge fund industry is not in fact, full of idiots.

deepnotderp··on AI models that cost $1B to train are underway, $100B models coming
TSMC spends ~$30B every 2 years
deepnotderp··on TSMC experimenting with rectangular wafers vs. round for more chips per wafer
You could with plasma/chemical dicing, and people have

But it breaks too much of the existing flow to be worthwhile

deepnotderp··on FDA denies petition against use of phthalates in food packaging
FDA rejects MDMA and allows phthalates- what an agency :(
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