<rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>Hacker News: tjohns</title><link>https://news.ycombinator.com/user?id=tjohns</link><description>Hacker News RSS</description><docs>https://hnrss.org/</docs><generator>hnrss v2.1.1</generator><lastBuildDate>Wed, 30 Sep 2026 08:56:16 +0000</lastBuildDate><atom:link href="https://hnrss.org/user?id=tjohns" rel="self" type="application/rss+xml"></atom:link><item><title><![CDATA[New comment by tjohns in "The FAA's plan to fix air traffic? $875M worth of AI"]]></title><description><![CDATA[
<p>> Weather data can be published every minute and shown live as a full map over the screen<p>This already exists via FIS-B.<p>> not as random abbreviations of wind and cloud coverage<p>The abbreviations (METARs) are a feature, not a bug. There are numerical legal minimums for weather that determine whether a landing is legal or not. A graphical map doesn't tell you this. The METARs are condensed because they're easy for professional pilots to skim.<p>(Back in the days of teletypes they also saved bandwidth, but that's just a historical note at this point.)<p>Regardless, pilots already have access to both textual and graphical weather products in the cockpit.<p>> And we already know where each aircraft is, and where they took off, and where they're headed. So practically speaking the radio talk can be limited to only the important communication and emergencies, while increasing the situational awareness by at least ten fold.<p>As a pilot myself, I think you're vastly misunderstanding the nature of ATC communication. 90% of communication on the radio are time-sensitve, important things - mostly heading and altitude changes to avoid other traffic.<p>Weather and clearances (when not relayed by ACARS, FIS-B, or CPDLC) are routinely handled on dedicated frequencies and aren't really causing meaningful frequency congestion.</p>
]]></description><pubDate>Mon, 21 Sep 2026 18:03:40 +0000</pubDate><link>https://news.ycombinator.com/item?id=49790929</link><dc:creator>tjohns</dc:creator><comments>https://news.ycombinator.com/item?id=49790929</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=49790929</guid></item><item><title><![CDATA[New comment by tjohns in "The FAA's plan to fix air traffic? $875M worth of AI"]]></title><description><![CDATA[
<p>> That sounds like a system that was bound to fail, because it was kept limited to a certain range of capabilities.<p>You're always going to be limited to a limited range of capabilities. You can't run a full web browser in every cockpit - you need a standardized interface that works across different vendors, across borders, and over a low-bandwidth radio link.<p>And I don't think anybody considers CPDLC a failure. The goal was never to 100% replace voice communication.<p>> One can easily imagine a system that broadcasts the weather<p>That exists, it's called FIS-B. Everyone uses it.<p>> and clearance<p>Clearance isn't something that can just be broadcast. You need to have a conversation with the pilot to make sure the clearance is acceptable to them. The pilot needs the ability to reject the clearance and request amendments.<p>> even aircraft location data close to real-time, and provide great situational awareness to everyone involved.<p>This exists, it's called ADS-B. Everyone uses it.</p>
]]></description><pubDate>Mon, 21 Sep 2026 17:54:21 +0000</pubDate><link>https://news.ycombinator.com/item?id=49790793</link><dc:creator>tjohns</dc:creator><comments>https://news.ycombinator.com/item?id=49790793</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=49790793</guid></item><item><title><![CDATA[New comment by tjohns in "The FAA's plan to fix air traffic? $875M worth of AI"]]></title><description><![CDATA[
<p>CPDLC exists and is used. It has its limitations though - it doesn’t provide as much flexibility for pilot replies, pilots don’t always have a free hand to text with (especially in turbulence), and is generally slower and more clumsy than voice so is only suitable for routine, non-time-sensitive messages.</p>
]]></description><pubDate>Fri, 18 Sep 2026 02:04:21 +0000</pubDate><link>https://news.ycombinator.com/item?id=49749394</link><dc:creator>tjohns</dc:creator><comments>https://news.ycombinator.com/item?id=49749394</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=49749394</guid></item><item><title><![CDATA[New comment by tjohns in "Poll: Are You Aphantastic"]]></title><description><![CDATA[
<p>Yes, I can superimpose an arbitrary imagined object (in full photorealistic detail)... however it's still in a separate/parallel "channel" of my mind and I intuitively know it's not something I'm seeing physically.<p>The best way to describe it is that I'm copying what I'm seeing through my eyes into my mind's eye, and superimposing the image there. This happens in real-time, effortlessly. I then have two streams of visual information that I can chose to pay attention to, one with the superimposed object and one without. If I chose to focus on the scene in my mind's eye, it's as if I have superimposed the object into my actual visual field. I can switch back and forth between the two parallel visual streams at will.<p>I'm not sure which option this would place me in.</p>
]]></description><pubDate>Fri, 28 Aug 2026 03:34:19 +0000</pubDate><link>https://news.ycombinator.com/item?id=49474053</link><dc:creator>tjohns</dc:creator><comments>https://news.ycombinator.com/item?id=49474053</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=49474053</guid></item><item><title><![CDATA[New comment by tjohns in "England set to be one of the first countries to eliminate hepatitis C"]]></title><description><![CDATA[
<p>It's free if you don't bring up things that should technically have been a dedicated own appointment.<p>The idea behind physicals is they're considered preventative care... catching problems early, often before there's any overt symptoms. For example, checking your cholesterol and A1c levels before they progress to heart failure or diabetes.<p>Once you're showing symptoms, you've left the realm of preventative care and it's now diagnostic/treatment for a established issue.<p>(ACA only provides 100% free coverage for visits that are 100% within the "preventative care" box.)</p>
]]></description><pubDate>Tue, 11 Aug 2026 23:10:59 +0000</pubDate><link>https://news.ycombinator.com/item?id=49265740</link><dc:creator>tjohns</dc:creator><comments>https://news.ycombinator.com/item?id=49265740</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=49265740</guid></item><item><title><![CDATA[New comment by tjohns in "WorldClaw Agentic 3D open-world generation at scale"]]></title><description><![CDATA[
<p>There is no code. The GitHub repo is empty.</p>
]]></description><pubDate>Tue, 11 Aug 2026 22:56:47 +0000</pubDate><link>https://news.ycombinator.com/item?id=49265632</link><dc:creator>tjohns</dc:creator><comments>https://news.ycombinator.com/item?id=49265632</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=49265632</guid></item><item><title><![CDATA[New comment by tjohns in "England set to be one of the first countries to eliminate hepatitis C"]]></title><description><![CDATA[
<p>Actually, I would've have assumed the other way - that the NHS was better than the US system. Which was why I was shocked when you said health checkups aren't allowed before age 40. :)<p>US healthcare plans offer an annual physical exam every year at all ages. Looking at the UK NHS website, it seems to be only offered there after age 40, and limited to once every 5 years? Am I reading that right?</p>
]]></description><pubDate>Tue, 11 Aug 2026 20:51:40 +0000</pubDate><link>https://news.ycombinator.com/item?id=49264298</link><dc:creator>tjohns</dc:creator><comments>https://news.ycombinator.com/item?id=49264298</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=49264298</guid></item><item><title><![CDATA[New comment by tjohns in "England set to be one of the first countries to eliminate hepatitis C"]]></title><description><![CDATA[
<p>From a US perspective, even this seems wild to me. I've always been told that at least an annual physical exam with bloodwork is highly recommended as the standard of care for adults of all ages.<p>Not everyone chooses to get them, of course. But ACA insurance plans here offer at least one annual physical exam free of charge (considered preventative care).</p>
]]></description><pubDate>Tue, 11 Aug 2026 19:40:35 +0000</pubDate><link>https://news.ycombinator.com/item?id=49263392</link><dc:creator>tjohns</dc:creator><comments>https://news.ycombinator.com/item?id=49263392</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=49263392</guid></item><item><title><![CDATA[New comment by tjohns in "Photos of items from families in different countries with different incomes"]]></title><description><![CDATA[
<p>You have it backwards. Housing is astronomically expensive in San Francisco precisely because there are so many people with high incomes bidding against each other.<p>When you have a highly inelastic supply (constrained by zoning laws, density limits, and geographical boundaries), prices rise to the maximum margin of what the highest-income buyers are capable of paying.<p>Regarding taxes: Since taxes apply to all local high-earners equally, it doesn't change their relative purchasing power against one another in the local housing market. If taxes were suddenly halved, that extra liquidity would be priced into the next bidding war, driving home prices even higher.</p>
]]></description><pubDate>Thu, 16 Jul 2026 17:44:59 +0000</pubDate><link>https://news.ycombinator.com/item?id=48937760</link><dc:creator>tjohns</dc:creator><comments>https://news.ycombinator.com/item?id=48937760</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=48937760</guid></item><item><title><![CDATA[New comment by tjohns in "Mysteries of Telegram Data Centers (2022)"]]></title><description><![CDATA[
<p>Yes, you need to register with a phone number, but publicly you'll show up as your @username and that's how most people will interact with you.<p>And I agree, I think yours is an accurate assessment. Telegram is indeed much more community centric.</p>
]]></description><pubDate>Wed, 15 Jul 2026 20:26:02 +0000</pubDate><link>https://news.ycombinator.com/item?id=48926597</link><dc:creator>tjohns</dc:creator><comments>https://news.ycombinator.com/item?id=48926597</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=48926597</guid></item><item><title><![CDATA[New comment by tjohns in "Mysteries of Telegram Data Centers (2022)"]]></title><description><![CDATA[
<p>- Messages send quickly and reliably, even under poor and sometimes hostile network conditions. Telegram just seems to work even when other chat apps struggle.<p>- Telegram uses usernames instead of phone numbers by default, which is good if you're using it as an IRC replacement instead of an SMS replacement.<p>- You can have the client open on essentially unlimited devices simultaneously, including a web app if you need it.<p>- Messages can be edited at any point after sending with no expiry.<p>- You can schedule messages to send later, or send a message silently so it doesn't wake people up.<p>- Different group types - announcement channels, Discord-style groups with sub-channels, flexible moderator roles, etc. (I believe WhatsApp has some of this.)<p>- Support for bots, which is also very helpful for managing large communities.<p>- Community-created, sharable stickers. Seriously, people underestimate how nice these are.<p>The downside is that a lot of this requires state to be stored on the Telegram servers, so most chat's aren't E2E encrypted. (They do have an option for E2E encrypted private 1:1 chats, but you lose most of the polish by using that.)<p>Also, the official apps are open source, so you can modify them if needed.</p>
]]></description><pubDate>Wed, 15 Jul 2026 18:15:40 +0000</pubDate><link>https://news.ycombinator.com/item?id=48924947</link><dc:creator>tjohns</dc:creator><comments>https://news.ycombinator.com/item?id=48924947</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=48924947</guid></item><item><title><![CDATA[New comment by tjohns in "John Deere owners will get the right to repair equipment under FTC settlement"]]></title><description><![CDATA[
<p>While I suspect this is actually profitable for them, you can't attribute 100% of their profit to anti-repair activities.<p>At a minimum, you'd have to break out profit from equipment sales vs service contracts.</p>
]]></description><pubDate>Thu, 09 Jul 2026 01:15:59 +0000</pubDate><link>https://news.ycombinator.com/item?id=48839693</link><dc:creator>tjohns</dc:creator><comments>https://news.ycombinator.com/item?id=48839693</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=48839693</guid></item><item><title><![CDATA[New comment by tjohns in "OpenPrinter"]]></title><description><![CDATA[
<p>The tech specs say it uses HP 63 cartridges (or HP 302/803 outside the US), and that the cartridges can be refilled using a refill kit.<p>The photos clearly show HP cartridges installed.</p>
]]></description><pubDate>Mon, 06 Jul 2026 02:34:16 +0000</pubDate><link>https://news.ycombinator.com/item?id=48800075</link><dc:creator>tjohns</dc:creator><comments>https://news.ycombinator.com/item?id=48800075</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=48800075</guid></item><item><title><![CDATA[New comment by tjohns in "OpenPrinter"]]></title><description><![CDATA[
<p>On the technology side, I'm somewhat hopeful because it looks like they're using off-the-shelf HP ink cartridges for this. HP cartridges embed the printhead into the cartridge itself, and that printhead is arguably the most complicated part of the entire device. Outsource the printhead, and you're just designing a plotter with a PCL interface.<p>I agree that the bigger challenge is going to be patents.<p>It also wouldn't surprise me to see HP add DRM to cartridges to authenticate the printer itself if this catches on. (Possibly requiring a printer driver/firmware update.)</p>
]]></description><pubDate>Sun, 05 Jul 2026 21:46:27 +0000</pubDate><link>https://news.ycombinator.com/item?id=48798253</link><dc:creator>tjohns</dc:creator><comments>https://news.ycombinator.com/item?id=48798253</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=48798253</guid></item><item><title><![CDATA[New comment by tjohns in "Global review confirms mRNA vaccines are safe, effective and full of promise "]]></title><description><![CDATA[
<p>It's worth clarifying that the adenovirus-based (viral vector) vaccines that article is discussing were a completely different technology from the mRNA vaccines.</p>
]]></description><pubDate>Thu, 02 Jul 2026 02:42:45 +0000</pubDate><link>https://news.ycombinator.com/item?id=48755817</link><dc:creator>tjohns</dc:creator><comments>https://news.ycombinator.com/item?id=48755817</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=48755817</guid></item><item><title><![CDATA[New comment by tjohns in "We can still stop California's 3D printer surveillance scheme"]]></title><description><![CDATA[
<p>> Then what, ban stepper motors?<p>Don't give them ideas.<p>But seriously, given that the 3D printer movement started out with people building their own printers from scratch and there continues to be a healthy open-source hardware ecosystem within the community, I can't see this stopping anyone.<p>Unless you also make it illegal for 3D printers to print 3D printer parts...</p>
]]></description><pubDate>Fri, 26 Jun 2026 23:17:49 +0000</pubDate><link>https://news.ycombinator.com/item?id=48693267</link><dc:creator>tjohns</dc:creator><comments>https://news.ycombinator.com/item?id=48693267</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=48693267</guid></item><item><title><![CDATA[New comment by tjohns in "U.S. pulling ocean sensors a 'shock' for Canadian research as El Niño nears"]]></title><description><![CDATA[
<p>Dismantling monitoring programs which show evidence of climate change is one of the Project 2025 priorities.<p>Specifically, their plan calls for downsizing the Office of Oceanic and Atmospheric Research (Mandate for Leadership, Project 2025, p. 676), and breaking up NOAA (p. 674), because they view these agencies as a source of "climate alarmism" and that "the preponderance of its climate-change research should be disbanded."</p>
]]></description><pubDate>Tue, 16 Jun 2026 20:08:02 +0000</pubDate><link>https://news.ycombinator.com/item?id=48561261</link><dc:creator>tjohns</dc:creator><comments>https://news.ycombinator.com/item?id=48561261</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=48561261</guid></item><item><title><![CDATA[New comment by tjohns in "Waymo Premier"]]></title><description><![CDATA[
<p>An oil change is quick, like 30 minutes. If I grab a granola bar instead of sitting down for breakfast and then instead use that time to do the oil change, the time expenditure is basically a wash.</p>
]]></description><pubDate>Fri, 12 Jun 2026 21:56:30 +0000</pubDate><link>https://news.ycombinator.com/item?id=48509905</link><dc:creator>tjohns</dc:creator><comments>https://news.ycombinator.com/item?id=48509905</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=48509905</guid></item><item><title><![CDATA[New comment by tjohns in "Waymo Premier"]]></title><description><![CDATA[
<p>Oil changes cost like $35/year if you do it yourself. Decent tires last 4-5 years, so that's like $100/year (to be generous). Air filters are so cheap and need replacement so infrequently as to not even be worth counting.</p>
]]></description><pubDate>Thu, 11 Jun 2026 18:03:41 +0000</pubDate><link>https://news.ycombinator.com/item?id=48494094</link><dc:creator>tjohns</dc:creator><comments>https://news.ycombinator.com/item?id=48494094</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=48494094</guid></item><item><title><![CDATA[New comment by tjohns in "Waymo Premier"]]></title><description><![CDATA[
<p>"Incurred violations" should be effectively $0. How often are you getting a traffic ticket? I think the last time I got a ticket was a decade ago...</p>
]]></description><pubDate>Thu, 11 Jun 2026 17:55:19 +0000</pubDate><link>https://news.ycombinator.com/item?id=48493948</link><dc:creator>tjohns</dc:creator><comments>https://news.ycombinator.com/item?id=48493948</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=48493948</guid></item></channel></rss>