FLIR video of "cold" UFOs

[Mick West]

The above video was presented by Knuth in February:

Source: https://youtu.be/HCOlDsrjU44?t=3502


In the presentation he shows two objects fly over, the first is bright, and glare-shaped and he says it's a passenger jet showing up as warmer than -64°F

The next thing looks like a triangle of three dots.

If you go by the scale, it's about -55°

However I did some backyard experiments with my FLIR, and found that small objects against the sky show up as much colder than they are. unfortunately it's overcast here. But using this scene:

In about 75° weather, I measured the temperature of the black rubber junction above the bulb:

45°, and measuring the rubber up close, it was actually more like 80°

I'll try this again against a clear blue sky, and maybe a night sky. But I think it already shows that temperature measurements of small objects against the sky are not reliable.

 

[Ann K]

The trefoil is much sharper in resolution than the plane. Is that an artefact of the heat of the plane, or does that just signal that the object is a lot closer (and slower) than the plane?

 

[Edward Current]

Diffraction? It's more of a problem in IR because of the wavelengths. The giveaway for me is how sharp outlines in the example, like the canopy, become wide gradients. You need to be able to see a broad enough area to get away from boundaries where the rays you want are corrupted.

Regarding the UFO specifically, wouldn't we expect planes to be different temperatures depending on whether they're ascending or cruising/descending?

I'd guess the hot plane is just blurrier because of glare.

 

[Mick West]

The giveaway for me is how sharp outlines in the example, like the canopy, become wide gradients. You need to be able to see a broad enough area to get away from boundaries where the rays you want are corrupted.

Great point. Obviously the edges of the canopy here, in pink/magenta are actually the same temperature as the rest of it (the yellow). But the edges of things against the sky show up cold — and a thin or small thing is nothing but edges.

 

[Mendel]

In the presentation he shows two objects fly over, the first is bright, and glare-shaped and he says it's a passenger jet showing up as warmer than -64°

The next thing looks like a triangle of three dots.
If you go by the scale, it's about -55°

Obviously -55⁰F is warmer than -64⁰F.

Air temperature varies with altitude (higher=colder).

Article:

Layers in the ISA Standard Atmosphere 1976

Layer​	Level name​	Base geopotential altitude above MSL[5]​ h (m)​	Base geometric altitude above MSL[5]​ z (m)​	Lapse rate ( °C/km)[a]​​	Base temperature T (°C)​	Base atmospheric pressure p (Pa)​	Base atmospheric density ρ (kg/m3​)​
0​	Troposphere​	-610​	-611​	+6.5​	+19.0​	108,900 (1.075 atm)​	1.2985​
1​	Tropopause​	11,000​	11,019​	0.0​	−56.5​	22,632​	0.3639​

Source: https://en.m.wikipedia.org/wiki/International_Standard_Atmosphere

So, apart from the obvious variations (weather, season, time of day etc.), a temperature difference of 9⁰C could simply indicate an altitude difference of 9/6.5=1.4 km (~5000 ft.).

9⁰F difference convert to about 5⁰C, corresponding to 2500 ft. altitude difference.

(Note that above 37000 ft the temperature remains constant, up to start of the stratosphere at 67000 ft.)

 

[Easy Muffin]

Diffraction? It's more of a problem in IR because of the wavelengths. The giveaway for me is how sharp outlines in the example, like the canopy, become wide gradients. You need to be able to see a broad enough area to get away from boundaries where the rays you want are corrupted.

Quite possible. Diffraction, competing light sources, hardware limitations etc can all affect temperature readings if the size of the object in question is below a certain threshold, aka the spot-size effect.

That triangle reminds me of this video we had here a while back, which the bird people said were ducks. https://www.metabunk.org/threads/triangle-object-filmed-uap-or-cameraglitch.12057/