Lightsmith
@slepkov.bsky.social
Physics prof at the largest small university in Ontario, Canada. Ultrafast lasers, microscopy, microwave photonics, physics education, multiple-choice assessment. Funny is good. A pervert for nuance.
Pinned
Lightsmith
@slepkov.bsky.social
· Oct 6
Torn between a pic of food, nature, optics phenomenon, or dumb meme as my first bsky post.
I guess optics art wins. Here's polarization-filtered colouration (polage) piece I call Night Flood.
I guess optics art wins. Here's polarization-filtered colouration (polage) piece I call Night Flood.
Will the NYT please use a science dictionary?! This is getting ridiculous.
October 21, 2025 at 12:37 PM
Will the NYT please use a science dictionary?! This is getting ridiculous.
Fun stuff here in PNAS.
Static electric 'microlightning' in micro water bubbles may be the long-sought ignition mechanism for mashy will-o'-the-wisps...
www.pnas.org/doi/10.1073/...
Static electric 'microlightning' in micro water bubbles may be the long-sought ignition mechanism for mashy will-o'-the-wisps...
www.pnas.org/doi/10.1073/...
Unveiling ignis fatuus: Microlightning between microbubbles | PNAS
Will-o’-the-wisps, ghostly blue flames seen at night in marshlands and long attributed
to methane cool flames, have remained scientifically unexpla...
www.pnas.org
September 30, 2025 at 6:16 PM
Fun stuff here in PNAS.
Static electric 'microlightning' in micro water bubbles may be the long-sought ignition mechanism for mashy will-o'-the-wisps...
www.pnas.org/doi/10.1073/...
Static electric 'microlightning' in micro water bubbles may be the long-sought ignition mechanism for mashy will-o'-the-wisps...
www.pnas.org/doi/10.1073/...
What is going on with the NYT Spelling Bee. This is Canadian erasure.
September 25, 2025 at 3:10 PM
What is going on with the NYT Spelling Bee. This is Canadian erasure.
Is it just me, or is the Spelling Bee particularly frustrating for scientists?
September 18, 2025 at 12:26 PM
Is it just me, or is the Spelling Bee particularly frustrating for scientists?
Is the youth cooked?
I just found my teen daughter's desk lamp in the recycling bin. When I asked her about it she said "It's broken. I didn't do anything to it! it Just stopped working!".
LED bulbs last so long that she didn't know about bulb replacement.
I just found my teen daughter's desk lamp in the recycling bin. When I asked her about it she said "It's broken. I didn't do anything to it! it Just stopped working!".
LED bulbs last so long that she didn't know about bulb replacement.
a close up of a man 's face with the words we are so cooked below him
ALT: a close up of a man 's face with the words we are so cooked below him
media.tenor.com
September 17, 2025 at 12:46 AM
Is the youth cooked?
I just found my teen daughter's desk lamp in the recycling bin. When I asked her about it she said "It's broken. I didn't do anything to it! it Just stopped working!".
LED bulbs last so long that she didn't know about bulb replacement.
I just found my teen daughter's desk lamp in the recycling bin. When I asked her about it she said "It's broken. I didn't do anything to it! it Just stopped working!".
LED bulbs last so long that she didn't know about bulb replacement.
Happy Wordle-in-one day to me! 🎉
Time to find a new starter.
Wordle 1,538 1/6
🟩🟩🟩🟩🟩
Time to find a new starter.
Wordle 1,538 1/6
🟩🟩🟩🟩🟩
September 4, 2025 at 5:24 PM
Happy Wordle-in-one day to me! 🎉
Time to find a new starter.
Wordle 1,538 1/6
🟩🟩🟩🟩🟩
Time to find a new starter.
Wordle 1,538 1/6
🟩🟩🟩🟩🟩
Our new paper asks (and answers) whether a shallow-learning approach (decision trees) can be as useful in (hyper)spectral analysis as advanced deep-learning methods.
tldr: Yes it can. Complex ≠ better.
doi.org/10.1088/2515... via @ioppublishing.bsky.social
#photonics
tldr: Yes it can. Complex ≠ better.
doi.org/10.1088/2515... via @ioppublishing.bsky.social
#photonics
July 16, 2025 at 4:01 PM
Our new paper asks (and answers) whether a shallow-learning approach (decision trees) can be as useful in (hyper)spectral analysis as advanced deep-learning methods.
tldr: Yes it can. Complex ≠ better.
doi.org/10.1088/2515... via @ioppublishing.bsky.social
#photonics
tldr: Yes it can. Complex ≠ better.
doi.org/10.1088/2515... via @ioppublishing.bsky.social
#photonics
this is the way
July 16, 2025 at 3:59 PM
this is the way
I'm struggling to parse the moral landscape on this one. If this gambit succeeds, who has the greatest moral failing: the authors, the reviewer, or the journal editors?
"POSITIVE REVIEWS ONLY"
Researchers are hiding instructions for AI peer reviewers in their preprints. I'm almost impressed by how much some of these researchers hide within a tiny white space.
But it's far from clear how much of an impact such prompts have.
www.nature.com/articles/d41...
⚛️🧪🤖
Researchers are hiding instructions for AI peer reviewers in their preprints. I'm almost impressed by how much some of these researchers hide within a tiny white space.
But it's far from clear how much of an impact such prompts have.
www.nature.com/articles/d41...
⚛️🧪🤖
July 15, 2025 at 3:46 PM
I'm struggling to parse the moral landscape on this one. If this gambit succeeds, who has the greatest moral failing: the authors, the reviewer, or the journal editors?
Let's play Jupiter or River Scum?
June 27, 2025 at 1:03 AM
Let's play Jupiter or River Scum?
Reposted by Lightsmith
"Although fewer women apply for tenure-track jobs, those who do apply are more likely to be interviewed and more likely to get offered the job... These findings run directly counter to the claim that women are discriminated against in STEM hiring." www.stevestewartwilliams.com/p/rethinking...
May 13, 2025 at 12:00 AM
"Although fewer women apply for tenure-track jobs, those who do apply are more likely to be interviewed and more likely to get offered the job... These findings run directly counter to the claim that women are discriminated against in STEM hiring." www.stevestewartwilliams.com/p/rethinking...
Spring has now truly sprung at Trent U.
Does your campus have a riverside bench from which you might count new goslings?
@trentuniversity.bsky.social
Does your campus have a riverside bench from which you might count new goslings?
@trentuniversity.bsky.social
May 9, 2025 at 7:59 PM
Spring has now truly sprung at Trent U.
Does your campus have a riverside bench from which you might count new goslings?
@trentuniversity.bsky.social
Does your campus have a riverside bench from which you might count new goslings?
@trentuniversity.bsky.social
Reposted by Lightsmith
So here is the Heiligenschein raytracing, where we see that retroreflection with a smooth reflectorshows a clear caustic and separation between red and blue! This will be washed out with randomness in reflected angles using a diffuse reflector. @johncnaylor.bsky.social
March 10, 2025 at 6:39 PM
So here is the Heiligenschein raytracing, where we see that retroreflection with a smooth reflectorshows a clear caustic and separation between red and blue! This will be washed out with randomness in reflected angles using a diffuse reflector. @johncnaylor.bsky.social
February 14, 2025 at 4:53 PM
I hate nutritionism.
February 7, 2025 at 12:05 AM
I hate nutritionism.
Reposted by Lightsmith
Community exists, to the degree we value it. Especially now, community matters within education, and within the group engaged with the teaching and learning of Physics. I'm just hoping to support the fact that all of us, together, make a difference. #ITeachPhysics
AAPT is pleased to announce that Gabriel Spalding will serve as the President of the American Association of Physics Teachers for the coming year. Read more ➡ ow.ly/PWrA50USGsk #AAPTNews @mqmlab.bsky.social
February 3, 2025 at 9:18 PM
Community exists, to the degree we value it. Especially now, community matters within education, and within the group engaged with the teaching and learning of Physics. I'm just hoping to support the fact that all of us, together, make a difference. #ITeachPhysics
Reposted by Lightsmith
Vive le Canada ✌️❤️🇨🇦
February 2, 2025 at 2:35 AM
Vive le Canada ✌️❤️🇨🇦
We are truly in the golden age of self-learning physics. Curiosity + 10 seconds of any of of Bertolotti's digital Factlets = anabolic learning!
#TeachPhysics ⚛️
#TeachPhysics ⚛️
#PhysicsFactlet
If you put apertures of different shapes in the path of a plane wave, you get different diffraction patterns. And with a bit of experience you can say a lot about the aperture shape just by looking at the diffraction pattern.
#Physics #Optics #Photonics #ITeachPhysics
If you put apertures of different shapes in the path of a plane wave, you get different diffraction patterns. And with a bit of experience you can say a lot about the aperture shape just by looking at the diffraction pattern.
#Physics #Optics #Photonics #ITeachPhysics
January 19, 2025 at 2:36 PM
We are truly in the golden age of self-learning physics. Curiosity + 10 seconds of any of of Bertolotti's digital Factlets = anabolic learning!
#TeachPhysics ⚛️
#TeachPhysics ⚛️
Reposted by Lightsmith
#PhysicsFactlet
If you put apertures of different shapes in the path of a plane wave, you get different diffraction patterns. And with a bit of experience you can say a lot about the aperture shape just by looking at the diffraction pattern.
#Physics #Optics #Photonics #ITeachPhysics
If you put apertures of different shapes in the path of a plane wave, you get different diffraction patterns. And with a bit of experience you can say a lot about the aperture shape just by looking at the diffraction pattern.
#Physics #Optics #Photonics #ITeachPhysics
September 16, 2024 at 11:03 AM
#PhysicsFactlet
If you put apertures of different shapes in the path of a plane wave, you get different diffraction patterns. And with a bit of experience you can say a lot about the aperture shape just by looking at the diffraction pattern.
#Physics #Optics #Photonics #ITeachPhysics
If you put apertures of different shapes in the path of a plane wave, you get different diffraction patterns. And with a bit of experience you can say a lot about the aperture shape just by looking at the diffraction pattern.
#Physics #Optics #Photonics #ITeachPhysics
Any science professors in Sweden willing to answer a basic question about grad school letters of recommendation? Please message me!
⚛️🧪
⚛️🧪
January 14, 2025 at 10:24 PM
Any science professors in Sweden willing to answer a basic question about grad school letters of recommendation? Please message me!
⚛️🧪
⚛️🧪
Reposted by Lightsmith
Bad. But how bad? I once asked myself, while finding fakes in the Scientific Report @natureportfolio.bsky.social.
So I decide to "do my our research" - I took 100 articles in a row from Physical sciences that contains diffraction.
Result - 15 fakes out 100.
Details in the 🧵
#ResearchIntegrity
1/x
So I decide to "do my our research" - I took 100 articles in a row from Physical sciences that contains diffraction.
Result - 15 fakes out 100.
Details in the 🧵
#ResearchIntegrity
1/x
January 13, 2025 at 10:51 PM
Bad. But how bad? I once asked myself, while finding fakes in the Scientific Report @natureportfolio.bsky.social.
So I decide to "do my our research" - I took 100 articles in a row from Physical sciences that contains diffraction.
Result - 15 fakes out 100.
Details in the 🧵
#ResearchIntegrity
1/x
So I decide to "do my our research" - I took 100 articles in a row from Physical sciences that contains diffraction.
Result - 15 fakes out 100.
Details in the 🧵
#ResearchIntegrity
1/x
Reposted by Lightsmith
Please everyone, I beg you, abandon this talking point.
In fact 100% of the energy we use ends up as waste heat—and that's fine!
The problem with fossil fuels is not that in some esoteric sense they're supposedly less efficient. The problem is their emissions.
🔌💡
In fact 100% of the energy we use ends up as waste heat—and that's fine!
The problem with fossil fuels is not that in some esoteric sense they're supposedly less efficient. The problem is their emissions.
🔌💡
Did you know that 2/3 of all energy we use ends up as waste heat because of how inefficient our energy system is?
Yet we pay for 100% of the energy inputs.
Here’s the US as an example.
Yet we pay for 100% of the energy inputs.
Here’s the US as an example.
January 5, 2025 at 9:51 PM
Please everyone, I beg you, abandon this talking point.
In fact 100% of the energy we use ends up as waste heat—and that's fine!
The problem with fossil fuels is not that in some esoteric sense they're supposedly less efficient. The problem is their emissions.
🔌💡
In fact 100% of the energy we use ends up as waste heat—and that's fine!
The problem with fossil fuels is not that in some esoteric sense they're supposedly less efficient. The problem is their emissions.
🔌💡
I've always liked @thecure.com , but they were never in my "top 5".
But, boy, what an unexpected gift it was to get such a fantastic new album in 2024!
I'm transported to my youth. I'm overcome by the scent of my first girlfriend's bedroom. I'm haunted by longing.
But, boy, what an unexpected gift it was to get such a fantastic new album in 2024!
I'm transported to my youth. I'm overcome by the scent of my first girlfriend's bedroom. I'm haunted by longing.
January 5, 2025 at 11:22 PM
I've always liked @thecure.com , but they were never in my "top 5".
But, boy, what an unexpected gift it was to get such a fantastic new album in 2024!
I'm transported to my youth. I'm overcome by the scent of my first girlfriend's bedroom. I'm haunted by longing.
But, boy, what an unexpected gift it was to get such a fantastic new album in 2024!
I'm transported to my youth. I'm overcome by the scent of my first girlfriend's bedroom. I'm haunted by longing.
One of the best physics stories of all time. I had not appreciated the distinction between manipulating the neutron reflector shell and the Demon Core itself! ⚛️
The seam is horizontal. It is just that the core is on its axis, here. Presumably to make it easy to pick up.
The demon core screwdriver wasn't inserted between the two sides of the pit, of course — it was inserted between the two sides of a neutron reflector.
The demon core screwdriver wasn't inserted between the two sides of the pit, of course — it was inserted between the two sides of a neutron reflector.
January 5, 2025 at 9:05 PM
One of the best physics stories of all time. I had not appreciated the distinction between manipulating the neutron reflector shell and the Demon Core itself! ⚛️