An infrared light that makes a stamp on a the hand visible

In summary, the conversation discussed a type of identification system that uses an invisible stamp on a person's hand, which can only be seen under an infrared light. The system has been around for at least 40 years and there was some confusion about whether the light used is infrared or ultraviolet.
  • #1
partialfracti
22
0
I read about a type of identification system in which a person's hand is stamped with some sort of ink or substance that is invisible to the naked eye. This normally invisible stamp on the human hand is visible under an infrared light. I remember that an infrared camera sees things that give off heat. Apparently infrared radiation is heat radiation.

I don't think the stamp makes the hand hotter. How would the invisible stamp on the human hand be made visible by infrared light?
 
Science news on Phys.org
  • #2
Are you certain that is is not ultraviolet light? Such stamps/scanners have been around for at least 40 years.
 
  • #3
Perhaps what I read about is ultraviolet light.
 

What is an infrared light?

An infrared light is a type of electromagnetic radiation with a longer wavelength than visible light. It is typically used for heat detection and communication purposes.

How does an infrared light make a stamp on the hand visible?

When an infrared light is shone on the hand, it reflects off the ink used in the stamp and the light is then detected by a camera or sensor, making the stamp visible.

What is the purpose of using an infrared light to make a stamp visible?

This method is often used for security purposes, such as verifying entry into a restricted area or identifying individuals for access control. It can also be used for entertainment purposes, such as glow-in-the-dark stamps at events.

Is an infrared light harmful to the skin?

No, infrared light is not harmful to the skin. Infrared radiation is a natural form of energy that is present in sunlight and is also emitted by our own bodies.

Can an infrared light be seen by the naked eye?

No, infrared light is not visible to the human eye. It falls outside of the visible light spectrum and can only be detected by specialized equipment such as cameras or sensors.

Similar threads

I How is IR ink able to be seen with specialized filters?
    • Optics
Replies
3
Views
777
Cameras detecting Infrared and making it visible
    • Optics
Replies
17
Views
2K
Optical DIY Privacy Shades: Make Your Own IR-Blocking Sunglasses
    • DIY Projects
Replies
2
Views
2K
Why does infrared light produce more heat than visible light?
    • Optics
Replies
24
Views
6K
B Infrared Detectors & The 2nd Law of Thermodynamics
    • Thermodynamics
5
Replies
152
Views
5K
I Can visible light cause fluorescence in colorful objects?
    • Electromagnetism
Replies
13
Views
1K
Changing Visible Light into IR and then back
    • Optics
Replies
1
Views
3K
I Blackbody radiation and the cosmic microwave background
    • Classical Physics
Replies
29
Views
2K
I Mach-Zehnder interferometer, but with an entangled beam?
    • Quantum Physics
Replies
33
Views
2K
How does radiation become heat?
    • Thermodynamics
Replies
20
Views
9K

Hot Threads

Recent Insights

Back
Top