Hacker News Reader

blacksmytheon How Boston City Hall was born

Sounds like one solution would be to apply a sealant that looks like bare concrete.

blacksmytheon Caltech, long a bastion of male students, enrolls first class of majority women

Caltech - where your best just isn't good enough.

  https://www.flickr.com/photos/pixieza/79223350

blacksmytheon 30-year fixed mortgage rate just hit 8% for the first time since 2000

It is amazing how much less time it takes to pay off a 30 year mortgage if you increase the payments 10%. The first good many years are paying mostly just the interest.

blacksmytheon Everything with a battery should have an off switch

I have a very cheap plastic one with a dial, which works amazing well for the cost (<$10). I don't remember where I bought it, but it looks like this one: https://www.summitracing.com/parts/sum-900003

blacksmytheon Big cars are killing Americans

Kinetic energy is a good measure for a baseball, because essentially all of the kinetic energy is being transferred from the small object to you.

Kinetic energy is not a good measure for a car or B-52, as after the collision the large object has essentially the same kinetic energy, and a very small fraction has been transferred to you.

A bicycle is more toward the small object side, as a pedestrian is going to absorb a good fraction of the kinetic energy of the rider, which is much larger than the kinetic energy of the bicycle itself.

blacksmytheon Generating Coherent Noise Using Fourier Transforms

  >> Taking the FFT, modifying frequency amplitudes

Modifying amplitude and phase. In the time domain you can't modify frequency amplitude without modifying the phase. If you modify just the FFT amplitude, you can end up with non-causal impulse responses.

blacksmytheon Caltech Awards 10,000th PhD Degree

AMA95 is one of the few Caltech classes that I still think about, mostly because it was not useful. Almost all of my other classes have been useful over the years.

I wish that the math sequence for non-math majors had included linear algebra instead.

blacksmytheon State of JavaScript 2019

  >> makes sure to walk the trainees through the confusing states you can get into, 
  >> then we explain what happened, why, and how to correctly get out of them

Is this something you could share?

blacksmytheon First all-electric seaplane takes flight in B.C.

You have to convert the wood to charcoal to burn hot enough for a blacksmith forge: https://en.wikipedia.org/wiki/Charcoal

I highly recommend a visit to Plimouth Plantation to anyone interested in 1700's era technology: https://www.plimoth.org/

Or Old Sturbridge Village for 1800's era technology: https://www.osv.org/

blacksmytheon The 40% Keyboard

I don't travel with an extra keyboard, but I do take a mouse.

An external mouse is so much better, and hardly takes up any space.

blacksmytheon Why a mock doesn’t work

The talk that you link to: https://www.infoq.com/presentations/tdd-original/

  Ian Cooper reminds what was Kent's original proposition on TDD, what misunderstandings occurred along the way,
   and suggests a better approach to TDD, one that supports development rather impeding it.

blacksmytheon Bankrupt Maker Faire revives, reduced to Make Community

"Table saws in use in the United States: Estimates range between 6 million and 10 million... in any particular year, about one table saw in 229 will be in an accident that sends someone to the emergency room." https://www.popularwoodworking.com/article/table-saw-injury-...

blacksmytheon Choking game, also known as the fainting game

  >> bet it's considerably higher than per hour of cruising around on a motorbike..

I would imagine so as well.

"Haaf was described as an experienced skydiver with over 1,200 jumps and was a frequent visitor to Skydive Cross Keys" https://www.courierpostonline.com/story/news/local/south-jer...

blacksmytheon Most Bike-Friendly Cities on the Planet

  Copenhagen, Amsterdam, Utrecht, Antwerp, Strasbourg, Bordeaux, Oslo, Paris, Vienna, Helsinki,
    Bremen, Bogotá, Ljubljana, Berlin, Tokyo, Taipei, Vancouver, Montreal, Hamburg

blacksmytheon Use YouTube to improve your English pronunciation

Fun for foreigners (both in Tokyo area):

Itabashi Station: https://en.wikipedia.org/wiki/Itabashi_Station

Iidabashi_Station https://en.wikipedia.org/wiki/Iidabashi_Station

(the major difference you hear is the long ii, rather than the t/d difference)

blacksmytheon Learning Chess at 40 (2016)

  >>  last few times I tried to play chess, my mind would just drift off designing a program to do it so I wouldn't have to bother.

That describes exactly how I feel about Sudoku.

I do find a good game of chess to be enjoyable, though.

blacksmytheon Proposal: A built-in Go error check function, try

  >> without `go fmt` "fixing" it

Great point.

And this line should be indented relative to the 'happy path' lines!

blacksmytheon A Story About Piracy

  >> no idea how to get a random PDF onto my kindle.

Amazon gives you an email address; just attach the file to an email.

https://www.amazon.com/gp/sendtokindle/email

blacksmytheon Nine years of Go

grpc-go: https://github.com/grpc/grpc-go

blacksmytheon Turns Out Wearing a Hi-Vis Vest Gets You into Everything for Free

  >> A lot of people ask why I have a surgical laceration kit 
    in my go-bag given that I am not qualified to actually use it. 
    My reasoning stems from what I have seen across many disasters that have occurred all over the world. 
    In the most likely scenario for the bay area, an earthquake (like the Loma Prieta quake or the Northridge quake), 
    all these people are moving around and then boom, everything stops moving. 
    At that instant in time you have a cross section of people evenly distributed across an area, 
    then some percentage of them will be health care workers (Nurses, Doctors, PAs etc). 
    And the hospitals will be far away.

blacksmytheon Zip Trees

Thanks for clarifying :)

blacksmytheon Zip Trees

  >> One can view a zip tree as a treap (Seidel and Aragon 1996) in which priority ties are allowed and 
  >> in which insertions and deletions are done by unmerging and merging paths ("unzipping" and "zipping")

blacksmytheon Larry Wall's Very Own Home Page

I think Python defaultdict does some of what you are looking for.

https://docs.python.org/3/library/collections.html#collectio...

blacksmytheon SETI spots dozens of new mysterious signals emanating from distant galaxy

Not true. See beam divergence:

  https://en.wikipedia.org/wiki/Gaussian_beam

blacksmytheon A2Z: A computer designed and built from scratch. Custom CPU on FPGA (2017)

  >> easier to undo than solder

Bonus fun - there would almost always be multiple wiring errors to find after wirewrapping.

You start with empty wirewrap sockets, wirewrap the board, then 'buzz' the board with an audio buzzer to check every connection, then add the electronic chips, then start debugging the circuit.

blacksmytheon Reversing the effects of long programming sessions

  >> finally finishing what I started... Go to bed

I find that I sleep far better if I don't think about work for a half hour before bed.

Even better if it's an hour without work before bed.

blacksmytheon Why Use an FPGA Instead of a CPU or GPU?

  >> The tricky bit on these systems is how much effort/time it takes 
  >> to move data and context between the "main" CPU and the FPGA and then back again

The sweet spot for FPGAs is when the data is streaming. You can build hardware where the data is passed from one stage to another, and doesn't go to RAM at all. Particularly where the data is coming in fast, but with low resolution (huge FPGA advantage for fixed point instead of floating point).

FGPAs are much more efficient for signal processing from data collected from an A/D converter (e.g. software defined radio) or initial video processing from an image sensor.

blacksmytheon Uber shuts down self-driving trucks unit

  >> if you time traveled and showed Siri/Cortana to an AI researcher from 1960 they’d be incredibly disappointed.

If you time traveled and showed 2013 me what self driving cars would be doing in 2018, 2013 me would have been astounded.

blacksmytheon Ask HN: What info do you wish every job posting included?

Worth looking at: Adobe, Blue Cross Blue Shield, Cisco, Esri, Fog Creek, Garmin, HP, Mathworks, Microsoft Research, Panel, SAS, Stack Overflow, VMWare, XTime

blacksmytheon Itsy-Chipsy: Make your own $100 ASIC

Depends on clock rate. This is not for building a microprocessor.

Static power on 180 nm circuit should be negligible, which won't be the case on a 14 nm FPGA.