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Colour-changing magnifying glass gives clear view of infrared light

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Re: Colour-changing magnifying glass gives clear view of infrared light

#31

Post by unbanned »

londons_explore wrote: post #27

Why do scientists who seem to select gold as the ideal material for almost anything? Is it actually a better material, or do scientists just want to be able to put in a purchase order for some gold and have shiny photos on all the media reports? Yes, I know it has a low reactivity - but stainless steel is pretty good there too, as well as a bunch of other materials. It also has a high conductivity - but copper is pre…

You can use silver, or any other material with an abundance of surface electrons, but gold gives SPR signal at convenient wavelengths

Re: Colour-changing magnifying glass gives clear view of infrared light

#33

Post by Retric »

withinboredom wrote: post #24
hoseja wrote: post #23

Earlier quoted context omitted.

I think you can just back(front?)light it.

Wouldn’t that defeat the purpose of everyone within 5 miles can see your glowing eyes?

The cost difference is unlikely to be relevant for a Mach 4, air to air missile. But, if this is small and cheap enough it might get added to a lot of currently unguided weapons like bombs and RPG’s etc.

Militaries constantly make cost vs effectiveness trade offs, and new technology can very easily change the equation.

Re: Colour-changing magnifying glass gives clear view of infrared light

#34

Post by ChrisMarshallNY »

londons_explore wrote: post #27

Why do scientists who seem to select gold as the ideal material for almost anything? Is it actually a better material, or do scientists just want to be able to put in a purchase order for some gold and have shiny photos on all the media reports? Yes, I know it has a low reactivity - but stainless steel is pretty good there too, as well as a bunch of other materials. It also has a high conductivity - but copper is pre…

Gold is an awesome conductor, and, more importantly, it is nearly impervious to corrosion.

That’s why it’s used in circuit board solder points and various types of plugs.

I think that platinum may be slightly better, but it is even more expensive.

Gold electroplating is not for the faint of heart. They use cyanide as a catalyst. At one of the companies I worked for, they had 50-gallon drums of cyanide, down in the electroplating lab.

Re: Colour-changing magnifying glass gives clear view of infrared light

#35

Post by the__alchemist »

Question re this: > Although the development of mid-IR (MIR) sources is evolving, a bottleneck con- tinues to be producing low-noise room tem-perature detectors

How do these relate to the relatively cheap IR cameras available? Eg, both commercial IR cameras, and military NVGs work at room temperature (Using different technologies). For example, are the devices lamented about in the article high-precision scientific instrument that can detect very fine differences in freq?

edit: This may be the key: > The noise-equivalent power of hybrid nanocavity- molecular detectors is predicted to be 100-fold lower than commercial uncooled detectors.

Re: Colour-changing magnifying glass gives clear view of infrared light

#36

Post by toss1 »

CamperBob2 wrote: post #5
edrxty wrote: post #2

This will almost certainly be used for weapons in short order. Currently if you want thermal imaging or very low light capability you have to use very expensive substrates. Being able to use CMOS detectors for MWIR/LWIR would instantly increase available resolutions by an order of magnitude at any given price point, assuming these filters are actually relatively cheap.

Yep, if it works at all, ITAR will slap it with a "Don't even think about using this for anything" label.

No, if they slap a label on it, it isn't "Don't Use It", it is "Don't even think about exporting this without permission.". It may have been relaxed, but regular IR cameras that we can buy and use here everyday in the US may land you in jail for selling them in eBay and shipping them to a customer in China or Iran. But we can buy, sell, and use them freely.

Re: Colour-changing magnifying glass gives clear view of infrared light

#37

Post by HideousKojima »

withinboredom wrote: post #24
hoseja wrote: post #23

Earlier quoted context omitted.

I think you can just back(front?)light it.

Wouldn’t that defeat the purpose of everyone within 5 miles can see your glowing eyes?

The Russian T-90 tank uses infrared emitters as countermeasures, looks like a pair of angry eyes: https://www.army-technology.com/wp-content/uploads/sites/3/2...

Re: Colour-changing magnifying glass gives clear view of infrared light

#39

Post by Karliss »

londons_explore wrote: post #27

Why do scientists who seem to select gold as the ideal material for almost anything? Is it actually a better material, or do scientists just want to be able to put in a purchase order for some gold and have shiny photos on all the media reports? Yes, I know it has a low reactivity - but stainless steel is pretty good there too, as well as a bunch of other materials. It also has a high conductivity - but copper is pre…

Stainless steel still corrodes under harsh conditions.

One of the mechanisms for why stainless steel is has low reactivity is through passivation. The elements mixed into stainless steel alloy quickly form a thin oxide layer in normal atmosphere which prevents further corrosion similar to aluminum or titanium. That's good enough for structural use but not the same as actually chemically inert elements.

There is also aspect of what happens in more conditions like being pulverized to the nanoparticle size or vaporized and deposited at few atom thin layer.

Silver and copper actually have better thermal and electric conductivity than gold, but they don't have the other good properties gold has.

Also it's at the bottom of periodic table (usable part) which might be important for certain interactions and correlates with extremes of multiple properties. There is one more row lower, but most of those elements are radioactive, not occurring naturally or both, which eliminates almost any practical use, complicates research and introduces new weird properties.

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