Today I Learned

[OmCheeto]

Today I learned (following up something I read online) that my phone camera sees a bit of infrared. In particular, it sees the output from my TV remote control as a purple glow even though I can't see it directly. Apparently the sensors are sensitive to infrared but the camera has a thin filter which is supposed to cut most of it out.

Today I verified that I can see infrared light at 872 nm +/- 40 nm.
I have an underwater camera that I bought 10 years ago, and it has a 12 infrared led illuminator. The camera is sensitive to both visible and infrared light.
I always assumed that the lamps had a broad spectrum, as I could clearly see the light, but today I found out that they don't, with the use of diffraction grating.

There was some argument in a thread several years ago about this: Can you see IR? [2006-2008]
There was much chatter about people who could see such light being mutants, but, it looks as though it's not quite the case.
After much googling, I finally found someone who had done the experiment, and had a reasonable explanation how it works:

The human eye can see 'invisible' infrared light [phys.org Dec 2014]

"The visible spectrum includes waves of light that are 400-720 nanometers long," explained Kefalov, an associate professor of ophthalmology and visual sciences. "But if a pigment molecule in the retina is hit in rapid succession by a pair of photons that are 1,000 nanometers long, those light particles will deliver the same amount of energy as a single hit from a 500-nanometer photon, which is well within the visible spectrum. That's how we are able to see it."​

ps. I used a mercury vapor lamp as reference, as usual. [image]
8 second exposure time.

 

[NascentOxygen]

After much googling, I finally found someone who had done the experiment, and had a reasonable explanation how it works:

The human eye can see 'invisible' infrared light [phys.org Dec 2014]
"The visible spectrum includes waves of light that are 400-720 nanometers long," explained Kefalov, an associate professor of ophthalmology and visual sciences. "But if a pigment molecule in the retina is hit in rapid succession by a pair of photons that are 1,000 nanometers long, those light particles will deliver the same amount of energy as a single hit from a 500-nanometer photon, which is well within the visible spectrum. That's how we are able to see it."

Very interesting. Presumably this ability to render IR light as visible is not restricted to human retinas? So it might explain why it is that animals in the wild seem to stare towards the 'invisible' IR floodlight of a hidden wildlife IR camera and can be seen to approach warily the fringe of the invisibly floodlight circle of ground.

 

[jtbell]

Today I learned that among Donald Trump's other abilities, he has the power to add floors to an existing building.

http://www.nytimes.com/2016/11/02/nyregion/donald-trump-tower-heights.html

Or take the https://www.trumpinternationalrealty.com/property-gallery/trump-international-hotel-and-tower-new-york, the hotel and residential building on Columbus Circle that was, pre-Trump, the 44-story Gulf & Western office building. Mr. Trump improved the structure so thoroughly that it managed to stretch into a 52-story tower, even though it stayed, strictly speaking, the same height.

 

[BillTre]

Not sure what to think about this.

I used to work in a lab where we used IR of various wavelengths to illuminate biological specimens in microscopes.
The IR penetrated tissue better (deeper into a sample that is) and activated particular fluorescent dyes.

We also had two-photon confocal microscopes that used IR. I was always told that the two photon microscopes required an extremely high photon density to get two photon excitation (the two photons had to be in the same place at the same time (within some small but vague limits)). This was achieved by using pulsed lasers which concentrated the photons into a very small fraction of the overall time and focused the laser beam into a very small dot.

This makes me doubtful that a TV remote could could achieve two photon illumination very efficiently.

On the other hand, some animals can detect a wider ranges of frequencies than humans.
Pit vipers (like rattle snakes) have a unique structure that can detect IR. They don't use their eyes for this, but have sensors in pits that form a very crude pinhole camera. Information from these sensors does get mapped in the optic tectum, a midbrain sub-cortical sensory center where the optic field is laid out in 2D, but with poor resolution.

 

[OmCheeto]

Very interesting. Presumably this ability to render IR light as visible is not restricted to human retinas? So it might explain why it is that animals in the wild seem to stare towards the 'invisible' IR floodlight of a hidden wildlife IR camera and can be seen to approach warily the fringe of the invisibly floodlight circle of ground.

One problem with my experiment, and the scientist's experiment, is that something is not quite right.

"The research was initiated after scientists on the research team reported seeing occasional flashes of green light while working with an infrared laser."​

Both my camera and I, see red light. So something is not quite right.
Of course, this being the "Today I learned", I was forced to publish my findings too early, as there is no "Over the last week, my experiments have taught me" thread.

I may have to start a new thread.

 

[OmCheeto]

I used to work in a lab where we used IR of various wavelengths to illuminate biological specimens in microscopes.
The IR penetrated tissue better (deeper into a sample that is) and activated particular fluorescent dyes.

Today I learned of IR fluorescence.
For some reason, I was only aware of UV fluorescence.
I am definitely going to have to start a new thread.

 

[jim hardy]

The human eye can see 'invisible' infrared light [phys.org Dec 2014]

That's really cool.

The research was initiated after scientists on the research team reported seeing occasional flashes of green light while working with an infrared laser. Unlike the laser pointers used in lecture halls or as toys, the powerful infrared laser the scientists worked with emits light waves thought to be invisible to the human eye.

Green, light from infrared !

One wonders what else might trigger those photoreceptors.

 

[mfb]

A common way to "see" near infrared lasers in a lab are materials that absorb two photons and emit one photon at higher energy. That can be green, but it can also be at longer wavelengths (the remaining energy is then lost elsewhere).

 

[OmCheeto]

That's really cool.Green, light from infrared !

View attachment 108366

One wonders what else might trigger those photoreceptors.

Their whole study goes against everything I know about quantum physics.
Which is very close to zero, btw.
Ergo, my crackpot mind suspects: "commingled wave-functions?"

----------------
please don't ban me. please don't ban me. :(

 

[OmCheeto]

TIL that I coined a new term, as Google claims that there are; "No results found for "commingled wave functions"."

I find that odd.

But then again, I'm pretty sure those quantum mechanics probably have a much fancier term.

 

[mfb]

"entangled"?

But what you are probably looking for is nonlinear optics or higher harmonic generation.

 

[OmCheeto]

"entangled"?

But what you are probably looking for is nonlinear optics or higher harmonic generation.

Maybe.
I did some more spectral experimenting(fail!), and glossed over nonlinear optics(way over my head), last night, and decided I had a laundry list of questions.
It may take me a week to gather my thoughts on this topic.

 

[jim hardy]

Hmmmmmm going back to 1960's high school physics
Particles can stick together and combine their mass
Waves can add and combine their amplitude

so i guess whichever you consider light to be, particle or wave, it's plausible two pieces of it could team up and excite something in a retina ?

 

[BillTre]

TIL dentists have flexible Ni/Ti drill bits or drilling out curvy root canals.

 

[OmCheeto]

Hmmmmmm going back to 1960's high school physics
Particles can stick together and combine their mass
Waves can add and combine their amplitude

so i guess whichever you consider light to be, particle or wave, it's plausible two pieces of it could team up and excite something in a retina ?

Those are two of my questions.

 

[BillTre]

TIL that my sister, who does traveling displays for the Smithsonian Institute,
is working on a Star Wars display in Denver and is doing the "wiring for the Light Sabers!".

 

[jim hardy]

TIL of software called GEMS, a Microsoft Windows based election handling product
http://www.essvote.com/products/7/39/software/gems/

Global Election Management System
GEMS™ is a Microsoft Windows®-based election management and tabulation software. It allows election administrators to easily and completely control every step of the election process, from ballot layout to election reporting, all in one proven application.

GEMS automates the complete election cycle from precinct/dist

completely control ? Surely that's a mal-mot.

TIL also it tallies votes in floating point not integer. I suppose that makes sense because the numbers are so large plus it's easier for programmers to just hand numbers to a floating point processor than to do integer arithmetic on such large numbers. 300 million takes 29 or 30 bits? While floating point will result in fractional votes the errors should be very small.

But that the GEMS system is so amenable to this kind of skulduggery is disconcerting.


that video is linked from here
http://blackboxvoting.org/
headquartered near Seattle
who claim to be nonpartisan
but i don't really know for sure who they are.

see my signature
old jim

 

[fresh_42]

completely control ? Surely that's a mal-mot.

Sure? ...

 

[jim hardy]

Sure? ...

Sorry about the long video, fresh. I hope you find time to watch it.

It caught my interest because Shelby County Tenn and Dade County Fla(where i grew up) were among first to implement something called Metropolitan County Government in mid 1950's.
Color me suspicious, but the characters who pushed it in Miami had not long prior got out of Greene County Missouri(my ancestral home) just ahead of the tar and feathers.
Probably that's why i m attracted to conspiracy theories . I have to watch myself.

old jim

 

[Sophia]

TIL of software called GEMS, a Microsoft election handling product
http://www.essvote.com/products/7/39/software/gems/

completely control ? Surely that's a mal-mot.

TIL also it tallies votes in floating point not integer. I suppose that makes sense because the numbers are so large plus it's easier for programmers to just hand numbers to a floating point processor than to do integer arithmetic on such large numbers. 300 million takes 29 or 30 bits? While floating point will result in fractional votes the errors should be very small.

But that the GEMS system is so amenable to this kind of skulduggery is disconcerting.


that video is linked from here
http://blackboxvoting.org/
headquartered near Seattle
who claim to be nonpartisan
but i don't really know for sure who they are.

see my signature
old jim

MS Windows software has full control and enough reliability for this kind of project ? :-D

 

[fresh_42]

Color me suspicious, but the characters who pushed it in Miami had not long prior got out of Greene County Missouri(my ancestral home) just ahead of the tar and feathers.

Lol. Funny picture. I remember to have answered a post on FB calling Trump's accusation of a rigged election ridiculous. But on the other hand, there has been Florida, there has been the DNC and its treatment of Bernie ...

Your post just reminded me of that.

 

[nsaspook]

... many US politics sites are run by Macedonians, for money.
https://www.buzzfeed.com/craigsilve...rump-misinfo?utm_term=.xv3ZdRGnva#.fsRvzDxYOZ

Using domain name registration records and online searches, BuzzFeed News identified over 100 active US politics websites being run from Veles. The largest of these sites have https://www.facebook.com/USANewsflash/ that boast hundreds of thousands of followers.

 

[OmCheeto]

... many US politics sites are run by Macedonians, for money.
https://www.buzzfeed.com/craigsilve...rump-misinfo?utm_term=.xv3ZdRGnva#.fsRvzDxYOZ

I think that belongs in the "weird news" thread.

 

[rbelli1]

TIL of software called GEMS, a Microsoft election handling product

Except Microsoft had nothing to do with this project.

BoB

 

[jim hardy]

Except Microsoft had nothing to do with this project.

okay , i misinterpreted their phrase "GEMS™ is a Microsoft Windows®-based" , sorry about that.
Doesn't allay my unease any, though.

 

[jim hardy]

... many US politics sites are run by Macedonians, for money.
https://www.buzzfeed.com/craigsilve...rump-misinfo?utm_term=.xv3ZdRGnva#.fsRvzDxYOZ

might explain some of the insane conspiracy stuff out there ?

 

[fresh_42]

okay , i misinterpreted their phrase "GEMS™ is a Microsoft Windows®-based" , sorry about that.
Doesn't allay my unease any, though.

Yep, guess this is the price of modern times. I never have heard about hacked punched cards.

 

[mfb]

Many countries still use paper for a good reason.

 

[nsaspook]

might explain some of the insane conspiracy stuff out there ?

Money making schemes with little or no political agenda. "Never give a sucker an even break."

 

[Jonathan Scott]

I think that belongs in the "weird news" thread.

Today I realized that I haven't seen any non-weird news for a while.

 

[mfb]

Non-weird news: Construction of the James Webb space telescope is complete.

 

[rbelli1]

http://jwst.nasa.gov/webcam.html

It seems the JWST web cam is JWST-less at the moment.

BoB

 

[Jonathan Scott]

Today I learned about antiprotonic helium. If antiprotons are mixed with helium, some of them replace electrons to form antiprotonic helium atoms, which last long enough (tens of microseconds) to allow some measurements. This doesn't work for any other element.

 

[BillTre]

Today I learned about antiprotonic helium. If antiprotons are mixed with helium, some of them replace electrons to form antiprotonic helium atoms, which last long enough (tens of microseconds) to allow some measurements. This doesn't work for any other element.

So Jonathan, these antiprotonic helium atoms would therefore have an extra proton's worth of mass?

 

[Jonathan Scott]

So Jonathan, these antiprotonic helium atoms would therefore have an extra proton's worth of mass?

Yes, give or take an electron of course.