Posts by bobkn

Undergrad thought he had mastered Unix in weeks. Then he discovered rm -rf

Homed in, not honed. Dammit.

Virginia's datacenters guzzle water like there's no tomorrow, says FOI-based report

Gallons aren't exactly SI units, either.

I used acre feet for comparison with US agriculture. Makes the numbers for the data centers smaller, too.

Maybe the data centers could switch to closed loop cooling. I wonder how large the heat exchangers would need to be? Not pretty, I'd bet.

The water use mentioned corresponds to 5677 acre feet of water per year. (Acre feet is a commonly used agricultural term in the US.)

The total amount of water used in irrigation in the US each year is about 90 billion (thousand million) acre feet. Not much of that is in Virginia, though.

Maybe datacenter water usage is a serious local issue.

Lawrence Livermore lab repeats fusion breakthrough – yep, still kinda works

The hohlraum is 120mm long?

That's about an order of magnitude more than I'd expect.

MIT boffins build battery alternative out of cement, carbon black, water

energy desnity

The energy density for the concrete "capacitor" is 0.22Wh/l. That's three orders of magnitude below what lithium ion batteries provide.

I admit that you probably can't make a building foundation out of lithium ion batteries.

First steps into the world of thought leadership: What could go wrong?

Gender related?

I admit that the sample is tiny, but are we implicitly thinking that silly self-centered posts on LinkedIn are a female territory?

On a somewhat unrelated manner, I found that ending my LinkedIn account didn't eliminate my presence there. I kept getting link requests by email. I had to contact then to specifically request that they get rid of the profile. They really didn't want to say goodbye.

Flash? Nu-uh. Windows 11 users complain of slow NVMe SSD performance

Re: Am I missing sumfing

I dislike people who post "me, too", but...

Me too.

Devilish plans for your next app update ensure they never happen – unless you start praying

For our British friends, a bit of trivia: "whizz" (with two zeds) is usually used as a verb, meaning to piss. A "whiz" (one zed) is more like a boffin.

Humanity gazes into the abyss to get its first glimpse of a black hole

But what's the scale of the image?

Have to keep from screaming that at my monitor. I guess for some, the image is Art.

20 micro arc seconds is 0.1 nanoradians. The NY to Paris distance is very roughly 6000 km. That would give a resolution of 0.6 mm.

20 micro arc second equal 0.1 nanoradians. The distance from NY to Paris is roughly 6000 km. That would give a resolution of roughly 0.6 mm. I guess that you could read a headline with that.

Post-silly season blues leave me bereft of autonomous robot limbs

Video: a countertenor singing music from Henry Purcell?

I doubt that any of my fellow Americans would post such a link. But then, anti-intellectualism is part of the current populist environment. (Maybe most Americans, like me, also can't stand countertenors.)

NASA stalls $8bn James Webb Space Telescope again – this time to 2020

Re: It will be killed for national security reasons!

Did you read the article?

You're giving Trump credit for signing a spending bill with more science funding than what the administration requested.

I doubt that indicates a real friendliness towards funding science. We can only speculate what Trump might have done if a line-item veto existed.

Researchers solve screen glare nightmare with 'moth-eye' antireflective film

Scattter? not so much.

Moth eye antireflection coatings use very small structures (smaller than the wavelength of light). They don't scatter light in some benign direction; they don't reflect it at all (ideally).

Moth's eyes don't do this. The name comes from the appearance of the structures as seen with a scanning electron microscope; they resemble the compound eyes of moths. I believe that moth's eyes are highly reflective, but as retro-reflectors: they send the light back to the source.

That type of AR coating has been around for a long time. The earliest AR coatings, developed in the 19th century, involved "staining" glass chemically. It doesn't give a regular structure, and it isn't simply a surface pattern, but the effect is similar.

The advance here is coming up with a plastic film that could be applied to a screen, rather than patterning the glass directly (expensive).

And, yes, you wouldn't want to touch such an AR coating. Fragile, and difficult to clean without damage.