Infrared Remote Controls & Red Light: How Fast Does It Need To Go?

[genq]

What happens if an infrared remote control is pointing and coming at your eye really fast while transmitting... would the frequency of the em waves increase? If so, how fast would it need to be traveling in order to appear red?

 

[collinsmark]

How angry is the boyfriend/girlfriend that is hurling the remote control at your face?

 

[collinsmark]

Seriously though, the angriest of all angriest boyfiends/girlfriends could not cause enough Doppler shift to cause the infrared light to appear visible simply by hurling it at your face, without some sort of mechanized launching apparatus such as a highly sophisticated rail-gun or some such, which is beyond our present technology. On the other hand, a very angry boyfiend/girlfriend, might be able to hurl a well aimed remote control at your head such that you see red after the fact.

 

[Weissritter]

Seriously though, the angriest of all angriest boyfiends/girlfriends could not cause enough Doppler shift to cause the infrared light to appear visible simply by hurling it at your face, without some sort of mechanized launching apparatus such as a highly sophisticated rail-gun or some such, which is beyond our present technology.

:grumpy: Hey! I wanted to make a Doppler roller-coaster, with humans having enough speed to see the same colors through all the trip while the light itself did change. :grumpy:

Anyway, the easiest way to use Doppler's is for sound, not light. If you research enough the topic of light you could end up getting a Nobel or banned from PF :rofl:

 

[pmacias]

I can provide an explanation for the relationship between infrared remote controls and red light. Infrared remote controls use infrared (IR) light to transmit signals to electronic devices. This IR light falls within the electromagnetic spectrum, which includes all types of electromagnetic radiation, including visible light.

The frequency of electromagnetic waves, including IR light, is directly related to their speed. The faster the waves move, the higher their frequency. As the frequency increases, the wavelength decreases. This means that if an infrared remote control is moving towards your eye at a high speed while transmitting, the frequency of the IR waves would increase.

However, the speed at which an infrared remote control would need to travel in order to appear red is not a straightforward answer. This is because the color of light is not solely determined by its frequency, but also by its wavelength. Red light has a longer wavelength compared to IR light. Therefore, even if the frequency of the IR waves increases due to the high speed of the remote control, it would not necessarily appear red to the human eye.

Furthermore, the perceived color of light is also affected by the sensitivity of the human eye. Our eyes are more sensitive to certain wavelengths of light, which is why we can see visible light but not other types of electromagnetic waves such as radio waves or X-rays. Therefore, even if the frequency of the IR waves increases and falls within the visible light spectrum, it may not appear red to our eyes.

In conclusion, the frequency of IR waves would increase if an infrared remote control is moving towards your eye at a high speed. However, the speed at which it would need to travel in order to appear red is not a simple answer and is dependent on factors such as wavelength and human eye sensitivity. It is important to note that it is not recommended to point an infrared remote control directly at your eye, regardless of its speed, as it can still cause potential harm.