Now, let's say you want to probe two things at the same time (triggered by a common signal source). You can't. And the reason you can't is because the producer took the expedient of floating the entire scope, and there's no trigger input.

In other words, they took the cheap way out by not actually building a differential probe. Related to that, this thing doesn't appear to have a step attenuator, which is why the effective resolution depends on the volts/div setting of the input.

Also, they don't specify the CMRR, which is one the main figures of merit people look for on differential probes. Any capacitive coupling between the scope and ground is going to degrade CMRR. So who knows if it can actually measure anything useful.

You can buy a scope with multiple optically-isolated channels as well as a trigger input, but those end up costing as much as a differential probe. Because it turns out that achieving good CMRR when you have multiple inputs is as hard a problem as making a good differential probe.

This is not to say the product you linked shouldn't or can't be used for anything, but it is a niche product. That's probably why it is advertised as a "power quality monitor" and not an "oscilloscope".

Well, of course not! They're corrupted by the other companies who benefit from the DSA and DMA.

If you look at that person's responses to others in this thread, that is exactly what they are doing. I do hope they have proper health and safety training for moving the goalposts so much.

BART (San Francisco Bay Area Rapid Transit), as a real world example, recently installed "evasion-proof" fare gates, and observed a 90% drop in vandalism-related maintenance expense. An overwhelming majority of fare evaders are not vandals, but apparently nearly all vandals were fare evaders. Bayes' theorem in action.

I don't have any data to back this up, but my sense is that attestation is an analogous situation.

In other words, banks and governments and other such institutions have noticed (and they probably do have data to back this up) that very few of their customers use "unapproved" devices and a very large majority of fraud comes from "unapproved" devices. They view banning unapproved devices as a high-ROI means to reduce fraud.

So, any argument predicated on "attestation is not security" is doomed to fail, just like saying "most fare-evaders aren't vandals". Yes, most people running GrapheneOS aren't trying to commit bank fraud, but the banks don't care about that if nearly 100% of fraudsters are using unapproved devices.

You might then wonder why the albedo of the poles matters (why are scientists concerned about that?). The answer to that is that the poles are very cold and black bodies radiate energy as T^4.

So you don’t want to have low albedo where it is cold and a high albedo where it is hot because then the most emissive surface isn’t emitting much heat due to low T and the places with high T have low emissivity. Obviously heat transport within the atmosphere is hugely important for this analysis, which you can’t easily approximate with napkin math.

However solar panels are most likely to be placed where it is relatively hot (because humans mostly don’t live at the poles). So that actually good because now you have more emissive surfaces with high T, which promotes global cooling.

Look up RFC 6106 (published 15 years ago). Router advertisements have carried DNS resolver info for a long time now.

Once again, the old adage “IPv6 haters don’t understand IPv6” applies.

As much as I would like hosts to use the local NTP server, most will ignore the NTP server you specify in DHCP anyway, so it’s kind of a moot point.

Edit: RFC 6016 actually supersedes RFC 5006 from 2007. That’s nearly two full decades we have had DNS info in RAs. That’s the year Itanium2 came out (any greybeards here old enough to remember that one?)

Yes, that is essentially how a gyroscopic artificial horizon works.

Consider that the local horizon changes relative to an inertial frame (the stars) as you travel across the surface of a sphere, so even if you could build a perfect gyro that remained stationary in the inertial frame you would need to update the local down as you move. The solution is to slightly weight the gyro cage to bias it to the local down.

Now, consider that, in a properly-coordinated turn, the passengers (and gyro) will feel that gravity points straight to the floor :) So the time-constant of the damping is important.

I suspect the way this usually gets started is similar to embezzlement schemes. “Oh I’ll just borrow a few dollars from the till and pay it back tomorrow” is akin to “The manuscript is due tonight so I’ll just touch up this microphotograph to look like the other one that had bad focus.”

That escalates into forging invoices on the one hand and completely fabricated data on the other. By that point they’re in too deep to stop until they get caught.

But the real question is: does the appearance of good, cheap IR sensors in combat mean that we civilians will finally be allowed to buy thermal IR cameras that don’t suck? Everything is limited to 20 Hz with potato resolution. The ITAR restriction is a joke at this point.

An even earlier version, the AIM-9R was tested in 1990 before the budget was cut as part of the Cold War wind down. That’s 35 years ago.

Even earlier than that, a Soviet missile which became operational in 1984 (40 years ago!), the R-74, inspired the AIM-9R program.

So it’s not like imaging seekers were unknown to the people designing today’s generation of fighters.

IPv4 is 32 bits. It has a hard cap of ~4 billion addresses. China and India alone have 2.85 billion people.

Add in the United States and Europe, and now nobody else gets an IP address. South America, Canada, Mexico, Australia, Africa, the middle east, the rest of Southeast Asia, etc. don't get to use the internet. That's 4 billion people who don't get to use the internet.

32 bits seemed practically infinite at the time IPv4 was created, and the whole thing started as a way for the American military-industrial-research complex to communicate with itself anyway. Why would you even want to assign addresses on your defense network to foreign adversaries?

Now that it's a commercial thing, a more equitable distribution would have, with hindsight, been a good thing.

I get the impression that this fact is fundamentally lost on a lot of the people who want a "compatible" IPv6. Like, their mental model does not distinguish between how we as humans write down an IPv4 address in text and how that address is represented in the packet.

So they think "let's just add a couple more dots and numerals and keep everything else the same"

Err... you do realize that the number of humans currently living on planet earth is twice the number of IPv4 addresses... right?

We can't all have an IPv4 address for each of our devices. We can't all even have one IPv4 address, period. But maybe they should just try not being poor, eh?

Grumble grumble. Well, there used to more than audio cards, back before the first time Apple canceled the Mac Pro and released the 2013 Studio^H^H Trash Can^H^H Mac Pro.

Then everyone stopped writing Mac drivers because why bother. So when they brought the PCIe Pro back in 2019, there wasn't much to put in it besides a few Radeon cards that Apple commissioned.

The nice thing about PCIe is the low latency, so you can build all sorts of fun data acquisition and real time control applications. It's also much cheaper because you don't need multi-gigabit SERDES that can drive a 1m line. That's why LabVIEW (originally a Mac exclusive) and NI-DAQ no longer exist on Mac.

USB-C oscilloscopes work because the peripheral contains all the hardware, so it doesn't particularly matter that the device->host latency is high. They also don't require much bandwidth because triggering happens inside the peripheral, and only the triggered waveform record is sent a few dozen times per second.

> It's not the Mac's or Apple's fault. We are actually live in the age where systems are quite independent and do not require direct installations.

It is, and we don't. Maybe you don't notice it, but others do.