ianhowson

I think the proposal suggested an orbit where the solar panels are always in sun and always properly aligned and always clean due to space gophers.

But more seriously, GPU loads are super spiky. Ground-based power grids and generators and batteries have trouble keeping up with them. You can go from 1MW idle to 50MW full power in 10ms. Unbuffered solar cells are right out.

This is the best idea to come out of this whole scheme. Space solar panels are super cheap and efficient? Prove it! Launch them and transmit the energy down.

This is orders of magnitude easier than the original proposal -- and yet still nonsensical.

I had a good laugh.

- You can't build 40MW of solar panels for $2M, even with theoretical maximum efficiency. You can't even build the cabling and regulators at that price.

- You need battery storage -- not as your backup -- but as primary source. It is going to cost more than $2M. Batteries are heavy. They are going to cost a lot to launch. This is not even solved on the ground yet.

- You need a heat transport medium to move heat into your massive radiator. Either you use water or you use air or you use heatpipes (metal). You have to pay for the cost and weight and launch expense. This is probably half the weight of the rack and I haven't bothered to do the math about how you transport heat into a 500 foot solar sail.

- Let's not even talk about how you need to colocate multiple other racks for compute and storage. There aren't any 1TBps orbital link technologies.

- Rad shielding? It doesn't work, but I'll let this slide; it seems like the least problematic part of the proposal.

- 15 year lifetime? GPUs are obsolete after 12 months.

I don't want to be the guy who shoots stuff down just for fun, but this doesn't even pass the sniff test. Maybe you can get 10x cheaper power and cooling in space. Still doesn't work.

1. They're overpriced. A quick Amazon search will show comparable kits for half of the price. You can buy a whole prebuilt ebike for the same price.

2. They're dangerous. FWD ebikes have a tendency to break traction on corners.

3. They tend to destroy the dropouts in your fork.

4. Installation is much more complex than "pop off your bike's front wheel". I can't even find the axle compatibility specs on their website. You know that there are many standards for front axles, right?

Do not recommend.

> Maybe the device was churning on error re-transmissions from the brownout

I think this is more likely. Two different routers impacted. Crappy grounding or induced noise causing high BER on the links.

Irrelevant.

1. Downstream of the mains power supply are DC-DC converters that run the router hardware. Those contain the filters and capacitance you think you're fixing. Nothing in that router actually cares about mains power quality. They absolutely do not care about perfect sinusoids.

2. If you were seeing insufficient power to the router, you would observe crashes and faults -- not slowdowns.

3. Two different routers showed the same behavior, which suggests that the fault lies outside the router+power supply and more to do with something common (e.g. network, laptop).

The dip shows a reduction in voltage, and a larger one than I would like, but without a scale on either time or voltage, it's difficult to guess if it actually matters. I would suspect not, since the device does boot successfully. Again, the voltage doesn't matter, since the router runs off its internal DC-DC supplies, not the external power supply.

I'm happy that the capacitor and new supply has fixed the issue, but I'm unconvinced by the explanation. Check grounding between inverter and laptop.

Well, there are encrypted CNIs like Weave. I've used Calico over ZeroTier to similar effect. The network is 'encrypted' and there isn't much effort required past initial configuration.

But that's not really the issue. You still have a big plaintext network with a bunch of random stuff talking, no mutual auth and no security controls other than segmentation. That's the tricky problem that mTLS and service meshes attempt to solve.

There's now FDA guidance on cybersecurity risks, but in a nutshell, it says "you must consider cybersecurity risks in your risk management plan." Manufacturers were (usually) doing this anyway but the probability and impact have been reassessed since the various lawsuits.

I don't work on pacemakers, specifically, but I'm confident you can no longer say "it has RF remote and nobody can buy the programming interface, therefore it's secure", because that's what went wrong before.

Instead, the risk management plan will look something like:

1. "magnet only with big disclaimers" (because you need the emergency cut-out switch; 'patient died because malfunction' is a worse outcome than 'maybe someone put a big-ass magnet on someone's chest and they got mostly non-life-threatening symptoms')

2. optionally, some form of 'secured' RF interface. Don't presume SSL. This is risk management, remember, so it's probably enough to say "hold a magnet on and then we enable unencrypted unauthenticated comms". Or maybe they do use SSL and just put way bigger micros in there. I don't know.

(edit: someone below who knows more than I do says "use Bluetooth", possibly triggered by magnet taps. Makes sense to me.)

Further, it's not that the magnet 'hurts' the pacemaker or device in any way. The presence of a magnetic field is used as a control signal to change the operating parameters of the device.

This is critically important for a device that may not have any remote control functionality or easy way to reprogram it other than 'cut up the patient'.

(Keep in mind that these things were designed decades ago, and 'RF remote control of pacemaker' probably introduces more problems than it solves, even today.)

I lived in the Gold Coast for a year while my job was in Sydney. I commuted by air once a week. Total commute time and housing expenses decreased.

I generally agree with you. I don't personally find eMTBs to be bothersome, and fully expect to be riding one when I'm not physically able to ride an acoustic MTB. And I definitely agree with you re. bystanders, where regular MTBs are fast enough to be dangerous.

The only point where I disagree is:

> There's nothing about eMTBs allowing people to venture in more difficult trails than with normal MTBs

If you want to go down the hill, you need to climb up the hill. This is a skill and fitness gate, normally; you're not going to tackle a difficult or extended descent if you don't think you can climb out again.

Soquel Demo Forest, one of the very popular Bay Area spots, bans eMTBs. It might be reasonable in this case due to the elevation profile. From the car park you need to climb for 20-40 minutes. You descend. You then have another long climb back to the carpark. It's a worst-case scenario for batteries, and because the area is so popular, it tends to attract people riding beyond their limits already.

I don't personally care, and I don't want to tell people not to enjoy an activity, but I can understand the reasoning in some cases.

Powertrains are much, much better.

- You can shift under load (usually)

- Shifts are a little faster

- Clutches give less chainslap

- Narrow-wide rings hold the chain freakishly well

At least here in NorCal, it's not trail damage that's the issue. It's:

* people riding beyond their ability (too fast, too technical) and getting injured

* batteries overheating and stranding the rider somewhere they can't climb out of, requiring heli rescue and risking wildfires

I also don't like to be overtaken by someone who isn't suffering as much as I am [1] and it makes me feel bad.

[1] Not really, I also ride a road e-bike which strokes my fragile ego.

It won't work with the LG Ultrafine 5k, which requires a Thunderbolt connection to run at full resolution, and behind-the-scenes is a tiled pair of DP1.2 displays.

It ought to work with a DisplayPort 1.4 5k, though there aren't many of those.

I do misunderstand. Please educate me! What makes these better than other headphones or the AirPods Pro, which are looking downright good value right now?