Glassblowing #2: Making a tungsten lamp and (bad) vacuum diode 2026-06-18 Now that I have a way to run electrodes through glass, it's time to do something with that. An old school lightbulb is rather simple: just a thin wire that gets hot enough to glow. However, to produce anything approaching white light, the wire must get to around 2500 C. While conductors like tungsten or graphite can survive those temperatures, they all burn on contact with air. To prevent this, I'll be sealing my lamp in glass under vacuum: no air, no problem. I lied. Some ceramics start conducting once heated, and being oxides, are completely unaffected by oxygen. Open air "Nernst lamps" did enjoy brief popularity in the 1890-1900s, but because of the added complexity of preheating the filament, they were replaced by filament lamps once vacuum pumps became good enough for commercial production. https://en.wikipedia.org/wiki/Nernst_lamp: those lamps. https://www.youtube.com/watch?v=-spTvp5-sf0: Using one. To start, I bent some some 0.3mm diameter tungsten wire into a "U" shape, and twisted a length of very fine 0.012 mm tungsten wire onto the free ends. I cut one side of the lead frame shorter so that the filament would sit diagonally: allowing it to be reasonably long without looping it around which could result in a short. To make the bulb, I partially inserted the lead frame into a glass tube, heated the end with an oxy-propane torch and pinched the glass onto the wires: Once one end was sealed, I connected the other to a rotary vane vacuum pump, and pumped it down while lightly heating the tube to remove moisture. After a few minutes, I headed the middle of the tube to sale the bulb, and pulled off the excess tubing. After the glass cooled, I cut the middle of the wire "U" to separate the leads: Glowing at 4 volts The finished lamp glows nicely between 200 and 400 mA (3-6 V and 0.5-2.5 W): I didn't stretch the filament tight enough and it ended up touching the glass, which creates a dim spot. The glass is borosilicate, so I'm not too worried about cracking, but it's still not ideal. I've tested the bulb up to 10 volts (~7 W), which is bright to light up a whole room, and the creates white light instead of the orange-ish color seen at low power — but it also gets very hot and won't last very long. In addition to color, the filament's temperature also affects the bulb's efficiency: a low temperature filament emits the vast majority of it's light in the infrared. A hot filament emits more visible light per watt, but tungsten evaporates faster leading to early failure. This tradeoff between lifespan and color/efficiency is why most light bulbs have rather short lifespans... or at least they did until we stopped using filaments. As an experiment, I ran a length of wire through a hole in the glass tube before evacuating it: When making seals like this, first melt a capillary tube (~1 mm) onto the tungsten wire before sealing it. This ensures good contact to the metal and protects the wire from the torch flame. The idea was to observe thermionic emission: when the filament is white hot, the atom's have enough kinetic energy to knock electrons into the vacuum. If the cold electrode is at a positive voltage, these electrons allow a small current to flow. If it's negative, the free electrons are repelled and nothing happens. While a diode isn't terribly exciting, it's the basis of more interesting devices like triodes, X-ray tubes and CRTs. ... and it's terrible: only conducting 1 uA with 700 V of bias between the filament and anode. Reverse biased, it conducts around 50 nA, mostly from the photoelectric effect. I suspect this is the result of two problems. Tungsten wire contains trapped gasses, which are released when it's heated. To avoid ruining the vacuum, the filament should be run while pumping down the tube, which I forgot to do. Second, the anode area is really small: Its ~6 mm of 0.3 mm wire, several centimeters away from the filament. Most emitted electrons will miss the anode and create a negative charge on the glass, which impedes current flow. Real vacuum diodes surrounding the filament in a metal tube, but I didn't do that because I wanted it to work as a light bulb. Just for fun, here's a photograph of my spool of filament wire, lit by the bulb made using it: Related: /projects/glass/1/: Considerations for sealing metal through glass http://www.rhunt.f9.co.uk/Glass_Blowing/Filament_Lamp_A/Filament_Lamp_A_Page1.htm: another homemade incandescent lamp

This week, politicians in the UK pushed forward with plans to eviscerate privacy and free speech on the internet by announcing a ban on social media for users under 16 that is set to take effect in Spring 2027. The UK government continues to falsely characterize this policy as a necessary response...

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Hey Community, Back in January I was visiting Shenzen and I saw these camera robots that follow skater and film . A few days a go I saw these camera robots BENI robot but since it’s not open platform it’s not an option for me . I was searching around for follow bots in china but did not find a lot :( Anyone here who knows wich one this is ? submitted by /u/Spinning-Complex [link] [Kommentare]

For a time i’ve been getting into meme coin trading. Using tools such as phantom, pump.fun, DEX, etc. Often you’ll come across people promoting their groups on discord/telegram for coins they will be trading daily. They profit by making you pay monthly ofc. What’s your opinion on them? submitted by /u/Utamira [link] [Kommentare]

Stable coins should be free to trade on an exchange. Until that happens, it will not be widely adopted by the average joe. Exchanges need to take some of that treasury interest and make it so, we can trade, sell, spend a stable at no cost to the consumer. Yeah yeah, yield, blah blah blah. That may not always be there so, we need to be able to use a stable coin like a fiat dollar. I can walk into a bank and withdraw $100 and walk away with $100, at the shitty debased worth that it is 😊 With a stable coin, we get $.98 of every dollar. How is that beneficial to us to use and exchange stable coins? Especially if clarity takes away the high yield rates? Will the exchanges change this when clarity passes? If they want to compete, they should. Guess we’ll need to watch it play out. What are your thoughts? submitted by /u/Exact_Objective546 [link] [Kommentare]

I'm considering building the Toolbox Robotics EB15 or EB300 3D-printed robotic arm and would love to hear from people who have actually built one. ​ I'm particularly interested in: ​ - Overall build experience, assembly difficulty, and total filament usage. - Motion performance: Is the arm smooth or jerky? How much backlash, vibration, or missed steps do you experience? - Real-world performance: accuracy, repeatability, payload, and long-term reliability. - Software experience (ROS, MoveIt, control software, etc.) and any modifications or upgrades you would recommend. ​ Photos, videos, build logs, or GitHub repositories would be greatly appreciated. ​ Links:- ​ https://toolboxrobotics.com/robotic-arm-eb15 ​ https://toolboxrobotics.com/robotic-arm-eb300 submitted by /u/Fals3_ [link] [Kommentare]

​ Hello I'm currently 26 I have 3 years of experience doing general IT help desk work and web development. I want to move on to having a deeper understanding of things and securing them. I have a undergrad in IT. I want to work with security but not only apps and networks yes this interests me but I'm also interested in the system or device itself how that's secured. Alternatively I am also interested in how a computer works, how to solve real problems with it, how a computer processes and sends data physically and then through a network and how to build computers themselves and as well as computers in bigger devices like robotics and how build bigger systems like a robotic arm. So I'm a little confused on if I should do my masters in computer engineering and add on cybersecurity electives or should I do computer science and on hardware or embedded systems electives. I do have the option at my school of double majoring as well but I think that would be to much work especially because if I do CE i have a big foundation to cover. ​ ​ ​ https://catalog.uhcl.edu/preview\\\_program.php?catoid=25&poid=7072 ​ ​ ​ https://catalog.uhcl.edu/preview\\\_program.php?catoid=25&poid=7074 submitted by /u/Colfuzi0 [link] [Kommentare]

tl;dr: Over the course of the past 4.5 years, I’ve taken out ~$175,000 in personal loans and 0% credit card balance transfer loans to purchase 5 Bitcoin. I've paid ~$18,000 in interest. All loans were unsecured. No risk of liquidation. As mentioned in my previous (4 year) update, all loans were paid in full. This new loan is all I have outstanding. I've been making updates every 6 months or so since the beginning. See my post history for previous updates. ************ Today, June 19th, 2026 Bitcoin is trading at $63,00 per coin, which brings the current value of my 5₿ to $315,000. The average price I paid is ~$38,600 per Bitcoin. My total cost basis is ~$193,000 for 5₿ ($175k in loans + $18,000 in interest). This comes to ~63% unrealized profit or ~$122,000 in dollar terms as of today. ************** Not much new to report other than that I couldn’t resist this recent dip so I went ahead and took out another 0% interest credit card balance transfer for $15,000 and bought 0.25BTC. This brings my total to 5 Bitcoin. I know I said I was done taking out loans, but with the price so low and the balance transfer loan at 0%, plus a 3% transfer fee, I thought to myself why not make it a clean 5 Bitcoin! I’ve been throwing just about everything I have into it for the past 5 years anyway. I recently decided to start investing in the stock market again for the first time in ages. I feel like I have enough Bitcoin now that I can move on. It won’t take me long to pay off this most recent loan, maybe 5-6 months at most. I can easily afford it. I will say this though… Bitcoin has seriously underperformed what I originally anticipated. Last years bull market was underwhelming to say the least. It really hasn’t done much better than stocks the past 5 years. Pretty much every single prediction I’ve heard about Bitcoin and institutional adoption of the past 5 years has failed to materialize. I’m sick of all the moonboys as much as I am the haters. Not to mention, the Bitcoin community has become fragmented and kind of toxic if I’m being honest. I have had to filter out and unfollow a lot of people this past year in the Bitcoin community. I still think Bitcoin is the apex asset but I’m going o be diversifying with new income moving forward. I will reassess in a 3 years time. submitted by /u/Vaginosis-Psychosis [link] [Kommentare]

Recommend some of the best modern books about probability and/or statistics to help you get that probability intuition or mindset needed to excel at ML, from beginning to advanced or separated please! submitted by /u/c_carav_io [link] [Kommentare]

I apologize for such an amateur question if someone is offended ​ I just finished my 2nd year of degree. Well, the degree was a bit slow and I did the ML course this semester as well but being a Third World Country and stuff, it doesn't really matter cause I didn't learn antg of value from them ​ I've been studying ML myself for 5-6 months, but I skipped the last 2 months cause of some issues and I've failed to get that motion back so I need a little bit of advices as where to continue ​ I know python of course and I've learned many ML algorithms, all supervised and what you'd call easy. I have understood their general concepts and maths but never went in deep. I did them in practical as well. Made a very few projects. ​ Now, I'm confused what should I learn next, I feel unsupervised learning isn't really my thing or I wouldn't be able to do it so can I just skip that? And idk what's next, so what is it? I've thought of learning Agentic AI as well but I can't do that until I'm satisfied with myself that I completely know ML and I can work on professional level. ​ And if you've any resources to learn from, certifications etc as well. I'd really appreciate it. Again I apologize for really rookie questions. submitted by /u/Negative-Guard-4487 [link] [Kommentare]