Bob Mahar - Curator, The Maharchives
@bobmahar.bsky.social
Father, husband, Dir. IT Infrastructure at Muhlenberg College, coder, micro & macro photo, old computers / books / science, making & fixing stuff, entropy remediator. Curator of The #Maharchives. More recently, amateur radiation metrologist. 🙄
From the #Maharchives: IDK, man, I just work here...
May 10, 2025 at 1:41 AM
From the #Maharchives: IDK, man, I just work here...
Bessel Functions Gonna Function, Yo! That's the way we roll at the subterranean dungeon that is my basement #Maharchives.
May 4, 2025 at 5:09 PM
Bessel Functions Gonna Function, Yo! That's the way we roll at the subterranean dungeon that is my basement #Maharchives.
It's going to be a ripple tank, God willing.
May 4, 2025 at 3:29 PM
It's going to be a ripple tank, God willing.
From the #Maharchives: IDK, something wierd I've wanted to make for a while. I TRIED super glue, but that failed. So to recoup after several failures, I used urethane foam - which was the perfect solution, but applied poorly. "The next time, it will be flawless!"
May 4, 2025 at 2:56 PM
From the #Maharchives: IDK, something wierd I've wanted to make for a while. I TRIED super glue, but that failed. So to recoup after several failures, I used urethane foam - which was the perfect solution, but applied poorly. "The next time, it will be flawless!"
From the #Maharchives Enlightened Self Promotion Department: "Finally!" You can own a thoriated lens for just $25 that has the same activity as much more expensive / rare classic camera lenses. www.ebay.com/itm/29725364...
April 27, 2025 at 2:31 AM
From the #Maharchives Enlightened Self Promotion Department: "Finally!" You can own a thoriated lens for just $25 that has the same activity as much more expensive / rare classic camera lenses. www.ebay.com/itm/29725364...
I saw this on the side of the road while biking, stopped, and picked it up. 60 second later I wrecked.
April 25, 2025 at 8:53 PM
I saw this on the side of the road while biking, stopped, and picked it up. 60 second later I wrecked.
the right of the people to keep and bear Arms, shall not be infringed
April 20, 2025 at 10:41 PM
the right of the people to keep and bear Arms, shall not be infringed
It looks like a herd of wildebeest overwintered in my back yard. I refuse to poison it, so it turns purple from the violets, and yellow from the dandelions, and red from windswept Coke Zero cans.
April 19, 2025 at 7:14 PM
It looks like a herd of wildebeest overwintered in my back yard. I refuse to poison it, so it turns purple from the violets, and yellow from the dandelions, and red from windswept Coke Zero cans.
Just found out there were thermite powered cordless soldering irons.
April 19, 2025 at 7:03 PM
Just found out there were thermite powered cordless soldering irons.
It's officially time to retire.
April 15, 2025 at 7:06 PM
It's officially time to retire.
"The Ads Made Me Do it!"
April 13, 2025 at 6:19 PM
"The Ads Made Me Do it!"
OMG! OMG! OMG!
It only took five years,
but Amy is OVULATING!
It only took five years,
but Amy is OVULATING!
April 12, 2025 at 5:14 PM
OMG! OMG! OMG!
It only took five years,
but Amy is OVULATING!
It only took five years,
but Amy is OVULATING!
Soylent Green Is PEOPLE! But who doesn't want worry free breeding?
April 8, 2025 at 7:15 PM
Soylent Green Is PEOPLE! But who doesn't want worry free breeding?
Dear God, please tell me there is a 3rd option.
April 8, 2025 at 12:59 AM
Dear God, please tell me there is a 3rd option.
From the #Maharchives: This small microfiche lens has a thoriated front element making it a bit radioactive. I used it for closeup photography for years, it's actually quite well corrected. Cost? $0 Saved from the dumpster.
April 1, 2025 at 12:27 AM
From the #Maharchives: This small microfiche lens has a thoriated front element making it a bit radioactive. I used it for closeup photography for years, it's actually quite well corrected. Cost? $0 Saved from the dumpster.
From the #Maharchives: One of my favorite #PENTAX lenses is the S-M-C Takumar 85/1.8. It's just a magical portrait lense. It's also has a thoriated front element, made with radioactive thorium to improve its optical properties. From the mount end, there is little activity.
April 1, 2025 at 12:11 AM
From the #Maharchives: One of my favorite #PENTAX lenses is the S-M-C Takumar 85/1.8. It's just a magical portrait lense. It's also has a thoriated front element, made with radioactive thorium to improve its optical properties. From the mount end, there is little activity.
"What's your return policy?"
March 31, 2025 at 11:31 PM
"What's your return policy?"
From the #Maharchives: Yes, static discharge can make a geiger counter go nuts. And don't judge the way I make my coffee.
March 25, 2025 at 8:48 PM
From the #Maharchives: Yes, static discharge can make a geiger counter go nuts. And don't judge the way I make my coffee.
But where there is sadness sometimes beauty. The idea is that like cracks in a windshield, if you use a vacuum to pull the air out, when the vacuum is withdrawn, oil can penetrate the cracks. It would never be right for spectroscopy, but might be good for counting. IDK, it's trash now. Why not.
March 22, 2025 at 4:21 AM
But where there is sadness sometimes beauty. The idea is that like cracks in a windshield, if you use a vacuum to pull the air out, when the vacuum is withdrawn, oil can penetrate the cracks. It would never be right for spectroscopy, but might be good for counting. IDK, it's trash now. Why not.
Sorta what I expected. The crystal has delaminated and cracked probably due to thermal stress. I may be able to get it in good enough condition for counting by drilling a couple small holes and flooding with silicone oil using a vacuum to purge the air and get the oil in the cracks.
March 22, 2025 at 4:21 AM
Sorta what I expected. The crystal has delaminated and cracked probably due to thermal stress. I may be able to get it in good enough condition for counting by drilling a couple small holes and flooding with silicone oil using a vacuum to purge the air and get the oil in the cracks.
Context: The aluminum thing is a 22 pound sodium iodide crystal. It's likely old and useless. After removing the photomultiplier tubes I quickly sealed it up to keep moisture out. But it seems as if this one is hermetically sealed with glass windows - so safe to inspect. We'll find out, LOL!
March 22, 2025 at 1:02 AM
Context: The aluminum thing is a 22 pound sodium iodide crystal. It's likely old and useless. After removing the photomultiplier tubes I quickly sealed it up to keep moisture out. But it seems as if this one is hermetically sealed with glass windows - so safe to inspect. We'll find out, LOL!
Apparently my package was sent to Leavenworth. It's been there for a week.
March 22, 2025 at 12:47 AM
Apparently my package was sent to Leavenworth. It's been there for a week.
From the golden age of digital learning:
March 22, 2025 at 12:43 AM
From the golden age of digital learning:
From the #Maharchives:
🎶 I got tubes, they're
photomultiplying.
🎶 And I'm losing control
🎶 'Cause the power there're supplying
🎶 It's electrifying!
🎶 I got tubes, they're
photomultiplying.
🎶 And I'm losing control
🎶 'Cause the power there're supplying
🎶 It's electrifying!
March 22, 2025 at 12:40 AM
From the #Maharchives:
🎶 I got tubes, they're
photomultiplying.
🎶 And I'm losing control
🎶 'Cause the power there're supplying
🎶 It's electrifying!
🎶 I got tubes, they're
photomultiplying.
🎶 And I'm losing control
🎶 'Cause the power there're supplying
🎶 It's electrifying!
From the #Maharchives "Please make this madness end!" Department: trying to see why a 22 pound crystal won't glow just right. Oh, the crystal is damaged by moisture, temperature change, looking at it, thinking bad thoughts around it, not thinking bad thoughts around it, ...
March 18, 2025 at 11:06 PM
From the #Maharchives "Please make this madness end!" Department: trying to see why a 22 pound crystal won't glow just right. Oh, the crystal is damaged by moisture, temperature change, looking at it, thinking bad thoughts around it, not thinking bad thoughts around it, ...