redfern314 (u/redfern314)

redfern314 commented on After 20 years, the globally optimal Boggle board danvk.org/2025/04/23/bogg... · Posted by u/danvk

colanderman · 4 months ago

Simulated annealing [1] is mentioned but not explained in the list of modifications to hill climbing. The technique roughly is: accept modifications to the board which decrease the score, with a probability inversely related to the magnitude of the decrease, and which decreases as the search progresses. This helps avoid getting stuck in local maximae.

[1] https://en.wikipedia.org/wiki/Simulated_annealing

EDIT: Somehow I didn't see that simulated annealing was mentioned by name (but not explained), ha!

redfern314 · 4 months ago

The article actually does mention using this technique, though it doesn't explain it, so thanks for the background from someone who isn't familiar with this space!

redfern314 commented on Intuit, Owner of TurboTax, Wins Battle Against America's Taxpayers prospect.org/power/2025-0... · Posted by u/leotravis10

fracus · 4 months ago

That's a strange name for something that cost money.

redfern314 · 4 months ago

Yes, one might argue it's a little misleading, but it comes across as significantly more genuine and less scammy than TurboTax. The federal filing is completely free, no matter which forms you have, and you just pay $15 per state. They also have the standard support upsells, but they don't push them crazy hard (I think it's one prompt between the federal and state sections).

I've used them for the past several years, never had any issues. Paid for audit defense one year when my return was especially complex (luckily haven't needed it yet).

redfern314 commented on Major Flaws in 2025 Meta-Analysis on Fluoride and Children IQ Scores osf.io/preprints/osf/zhm5... · Posted by u/jandrewrogers

midtake · 5 months ago

It is still a medical treatment added to the water supply, and sets a dangerous precedent. This same power if unchecked has the potential for great harm.

As for efficacy, the same (or greater) benefits to enamel hardness can be obtained from using fluoride toothpaste anyway, I do not see the urgency for this. They've stopped fluoridating their water in Scandinavia for years now.

redfern314 · 5 months ago

In no way does it set a dangerous precedent. Fortifying flour and iodizing salt (both of which could be termed a "medical treatment") were huge successes, with universally positive results and at virtually no cost. Mandating something like this should be done cautiously (in either direction), but fluoride isn't the first, only, or last example of it.

The only difference is that it's rather harder to avoid fluorinated water than iodized salt if one is so inclined, which raises the bar for proof of efficacy and preponderance evidence that it does not cause harm (which has been provided by others in this thread).

redfern314 commented on Why rents are still rising too fast economist.com/finance-and... · Posted by u/jcartw

betaby · 5 months ago

The USA have added about 2 million people the last year.

That about the size of Houston, TX.

The USA are not building at the rate one city of Houston per year.

Source https://www.worldometers.info/world-population/us-population...

redfern314 · 5 months ago

I was under the impression it was more of a distribution problem than a quantity problem? This chart suggests we're building on the order of 1.5 million units of housing per year, which (unless all of those people are occupying a single unit each) should be sufficient in aggregate to keep up with population growth: https://fred.stlouisfed.org/series/ETOTALUSQ176N

But people are moving to the cities, which is exactly where we're not building.

redfern314 commented on Gemini Robotics deepmind.google/discover/... · Posted by u/meetpateltech

fusslo · 5 months ago

I'm a firmware engineer that's been working in consumer electronics and I feel very bleak about my future I feel so left behind. I have extremely limited robotics and computer vision experience. I have no ML experience. The only math I know has to do with basic signal processing.

When I see open roles at these companies I think the projects I'm going to work on in the future will be more and more irrelevant to society as a whole.

Anyway, this is amazing. Please delete/remove my post if it seems like this adds nothing to the conversation

redfern314 · 5 months ago

Also a firmware engineer. I see 4 career paths under the advent of AI:

1. If you can't beat em, join em - get a masters in ML or something and work at a higher level of the stack. I know several folks who have pivoted this way and are happy.

2. Double down - there will always be layers below the AI (drivers, silicon, etc). Sure, ChatGPT will continue chipping away at how much coding we do day to day, but at the end of the day, good luck to an AI trying to debug I2C bus clock stretching issues IRL. And you can bet that these robotic actuators have plenty of hardware issues to debug.

3. Pick an area of tech which is relatively immune (medical/automotive/aerospace) due to regulatory and other barriers to AI entry. You don't necessarily need robotics/CV experience to do this.

4. GTFO (I say this with no judgment) - and work in a different industry which is less likely to be automated. It would not be the most lucrative option but is certainly an option.

redfern314 commented on Turn any bicycle electric dhruvvidyut.co.in/... · Posted by u/samdung

4gotunameagain · 7 months ago

More than happy to learn something through a mistake in my calculations !

Regarding the 50%, I assumed that they stated this number because this is when the battery is in bulk charge and can suck up as much as you can give it.

For the 250W, I hadn't even seen that, good catch. Maybe 250W is the peak power that cannot be sustained for thermal or current rating reasons ? 250W for a 12.8V 10Ah battery is 2C, so that should not be the limiting factor. I do not know about the motor or the ESC

Also, for sure the maximum range is not achieved with the top speed !

redfern314 · 7 months ago

Agreed on all points! Very plausible that 250W is peak; other motors on the market vary whether they state peak or sustained so the waters are a little muddy (e.g. I know that the popular BBS02 "750W" motor can put out over 1kW peak).

redfern314 commented on Turn any bicycle electric dhruvvidyut.co.in/... · Posted by u/samdung

4gotunameagain · 7 months ago

Let's check the numbers. They claim :

  Range: 40km
  20 min pedaling charges 50%
  Top speed 25kph

If a 70kg well trained amateur cyclist can output ~200W for an hour [1], so let's guestimate 130 for an average person. That would mean the battery has a capacity of at least: 130W * 2*20min = 86.6Wh. The efficiency of the motor/ESC is not considered.

So at 15kph, it would take 2.6 hours to reach the stated 40km range. 86.6Wh / 2.6hrs = 32.5W

A model based calculator [2] says that with 32.5W you indeed cycle at 15.5kph.

LiFePo batteries have an energy density of 325Wh/L, so we would need a battery volume of: 86.6Wh/325Wh/L = 0.27L, but a quick search for an example online reveals that a commercial 10Ah 12.8V takes up 1L. That would seem to fit within the product.

I was initially doubting the claims, but it seems to check out ?

[1] https://blog.2peak.com/en/what-are-the-average-watts-of-a-go... [2] https://www.gribble.org/cycling/power_v_speed.html

redfern314 · 7 months ago

Also curious what "50%" means in their specs; the top power for the motor is 250W and top speed of 25kph would take ~100W on flat ground, which would throw off your calculations considerably. (Not that I take issue with your calculations, they just haven't published enough data to know what you'd actually be getting.)

redfern314 commented on Turn any bicycle electric dhruvvidyut.co.in/... · Posted by u/samdung

redfern314 · 7 months ago

This is an interesting alternative to existing kits where you need to replace a wheel (hub-drive) or do surgery on your bottom bracket (typical mid-drive). It also appears to not need an external charger (the charge port appears to be a universal C14, the same as a computer) which is very convenient.

On the downsides, I have severe doubts over the battery cell quality at that price point, and it looks significantly heavier than other options from the metal case alone (I don't see actual specs for weight).

Love the demo video. The mud and fire scenes made me cringe, which I'm sure is exactly what they were going for (as the motor keeps spinning regardless of the foul treatment)!

I will keep my standard mid-drive conversion kit (I've used TSDZ2 and DM-02 in the past) but always love to see alternatives coming online for other segments of the market.

redfern314 commented on Sci-fi books that you may never have heard of, but definitely should read shepherd.com/best-books/s... · Posted by u/bwb

Suppafly · 10 months ago

>the audio book is good but the book is not

I don't know how that can possibly make sense.

redfern314 · 10 months ago

It's difficult to explain without spoilers... one of the characters feels significantly more fleshed out and real because of some artistic choices in the voice acting.

I am not sure I'd go as far as GP and say that the book is not good, but this is one of the cases where the audiobook feels more like a "production" and not just a book in a different medium.

redfern314 commented on The effect of daily usage of Mouthwash on the oropharyngeal microbiome microbiologyresearch.org/... · Posted by u/_glass

robbles · a year ago

What brand of toothpaste do you use for this? I often struggle to find a toothpaste that's SLS-free but still has fluoride.

redfern314 · a year ago

Also see Hello toothpaste (not affiliated) which has fluoride but not SLS: https://www.hello-products.com/products/naturally-whitening-...

Same problem for me, constant canker sores. Switching to Hello hasn't totally eliminated them, but it has reduced them.