femto

29 ms·

511.
by femto 4y ago
Could one achieve PV quality silicon using zone melting? https://en.wikipedia.org/wiki/Zone_melting
512.
by femto 4y ago
Looking at the video posted elsewhere in the comments, I'd say he made his own lens by buying a large rectangular sheet of acrylic and using a (homemade?) lathe to machine correctly shaped groves on it.
513.
by femto 4y ago
Nice. I wasn't aware of KiwiSDR. It's pretty well what I was thinking about, if the samples can be streamed. The docs mention that the clock is GPS disciplined, but is it the case that the samples are timestamped in a way that c
514.
by femto 4y ago
The rx/tx separation in over-the-horizon radars (OTHR) serves to increase isolation between the transmitter and receiver. The received signal is tiny, as it has not only bounced off the target but done a double bounce off the ionosphe
515.
by femto 4y ago
A close relative worked for a company that made asbestos cement products in the day. The factory contained an automated production line, about 100m long. The first step was a room into which the raw asbestos fibre was blown. From there it
516.
by femto 4y ago
I wrote one of those books. That is, a Wikipedia article I largely wrote was plagiarised and published in a book by a scammer. Some time later my words on Wikipedia were tagged as having been plagiarised from the scammer's book. It
517.
by femto 4y ago
Thanks!
518.
by femto 4y ago
I'm not a quantum physicist either. The amplitude would have to be j or -j to get a probability of -1 (probability = amplitude squared?). Does +/-j correspond to a positron?
519.
by femto 4y ago
> Well, there's a reason you never hear the weather forecaster talk about a -20% chance of rain tomorrow -- it really does make as little sense as it sounds. Maybe negative probabilities do make sense? 1 = the event is certain to ha
520.
by femto 4y ago
There is a style of tie known as a kipper (ie. smoked herring) tie [1]. There is no escape from the numbers! :-) [1] https://en.wikipedia.org/wiki/Kipper_tie
521.
by femto 4y ago
What's lithium hydroxide used for in fusion reactors? Edit: A bit more searching turned up an answer. It's a neutron absorber. So it's used as a shield to stop the neutrons leaving the reactor?
522.
by femto 4y ago
Measuring the temperature is the same as measuring the average energy of particles in the plasma, which is the same as measuring the average speed of the particles. Basically you do that by measuring radiation, doing it in several differen
523.
by femto 4y ago
Maybe there needs to be a self-hosting association/union that self-hosters can join? It could advocate for adherence to open standards, and an equal standing for small servers. It could also be a repository of advice for current best
524.
by femto 4y ago
It's already a done thing. https://immi.homeaffairs.gov.au/visas/working-in-australia/r...
525.
by femto 4y ago
I was going to ask if anyone got a place they recognise or have been to, but then you show one that Iv'e been to. Then again it is a popular tourist destination. Here's a magical looking Scottish place it gave to me: https:&#x2F
526.
by femto 4y ago
If he's that into cuckoo clocks he's probably in touch with other people who share the interest. Talk to him now to find out who those friends are. Those are the people you offer the clocks to. It also means you get to spend tim
527.
by femto 4y ago
Next challenge: the lightest concrete bike. Concrete canoes are a thing civil engineers make for fun [1]. Weight can come in at under 10kg [2]. That's about half the weight of a typical canoe [3]. On that basis, one might be able t
528.
by femto 4y ago
That would be a non-Euclidian (ie. curved) universe? Maybe it is possible to construct a non-Euclidean universe for sound, by modifying properties of the propagation medium as a function of space or time?
529.
by femto 4y ago
To me a manual is all about engine braking. You just have to use the brake pedal less. I haven't driven an electric vehicle before, but I imagine they could deliver a similar experience if the regeneration was suitably programmed? C
530.
by femto 4y ago
https://rfid.michelin.com/what-is-rfid/ It's not a complete joke. Lots of tyres contain RFID chips for inventory control. Michelin consider it's an asset that the "Tire tag can be read even when the tir
531.
by femto 4y ago
> ...it costs more money to dye the plastic... I'd posit that the real cost is the cost of carrying more inventory. It's cheaper to carry 200 in beige than 100 in each of 10 colours. It means you're less likely to be out
532.
by femto 4y ago
I had the same thought. Perhaps the bound quarks are never far enough apart for the strong force to be constant? My understanding is that if you do manage to pull two quarks apart the energy of separation is eventually enough to form two n
533.
by femto 4y ago
Fibre cement (aka 'fibro') https://en.wikipedia.org/wiki/Fibre_cement
534.
by femto 4y ago
Then there are the mining trains that produce net energy: https://www.popularmechanics.com/science/energy/a39372219/se... If you're digging iron ore out of a mine and carting it on a one-way trip to the
535.
by femto 4y ago
If anything such overreach will lead to a loss of support for republicanism. As it is I think Australians generally see the Queen (and Governor General to a lesser extent) as being outside politics. There is a deep cynicism in the electora
536.
by femto 4y ago
Technically it is not Australia but New South Wales, the most populous state in Australia. Australia is a federation of states, with the federal government only having legislative power in certain areas. The result is a mish-mash of diffe
537.
by femto 4y ago
With a further optimisation in the batch handling of snail mail: "I have a wonderful secretary who looks at the incoming postal mail and separates out anything that she knows I've been looking forward to seeing urgently. Everythin
538.
by femto 4y ago
Also thinking about channel sounding. MIMO usually has a method of measuring the channel response with known data (or a known property of the data, such as a modulation type), then the channel is either assumed to be stationary whist the u
539.
by femto 4y ago
I guess one problem could be that the scatterers/stars are luminous, so their own emissions might overpower the scattered signal? Maybe a cluster of darker objects? Or maybe luminous objects are okay if the scattered waves are coming
540.
by femto 4y ago
I wonder if a cluster of stars can be treated as a MIMO scattering channel for more distant unknown objects? If so, it should be possible to resolve details in the unknown object. I guess the geometry would have to be such that there is a

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