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## NASA

### Course: NASA>Unit 2

Lesson 4: Spectroscopy

# Infrared waves (1800)

Created by NASA.

## Want to join the conversation?

• Why does the figure at around show Africa much cooler than the other areas even though it is near the equator?
• My guess is rainforests, since South America is cooler in that place too. But I'm not sure.
(1 vote)
• Why these three colours are more than others? why?
• How do gamma rays travel at the same speed as radio waves? If gamma rays have a much higher frequency then wouldn't they have to travel a lot further distance compared to radio waves or any other form of EMT? I was under the impression they all traveled at light speed.
(1 vote)
• I am not an expert on this, or even moderately good at this. So, don't take this seriously. Might be wrong.

I believe that it's the amplitude you're talking about. Speed is always the same with the light spectrum, but amplitude is what changes. It'd take the same amount of time for a certain peak of gamma rays to reach a point as a peak of visible light. It's not speed, it's height of the waves and the closeness.

Hope this helped. Like I said, I'm not an expert on this, so this might be drastically wrong. If it is, I'm sorry. I did the best I could. Anyway, I hope this helped. And, if no one can get it, you can always Google it. :P
• Why is the temperature in infra-red region warmer than that in visible region?
The frequency of visible light is greater than that of infra-red rays. So, the energy of infra red rays will be lesser (E=hv :-Plank's relation) and hence the temperature too.
(1 vote)
• Why is it that a wall (or hand) can block an infrared signal from a remote control to the TV whereas a radio wave (which has lower energy) can pass through a wall with no problem? I was under the impression that the higher the energy of a wave (ex. x-ray) the more easily it can 'penetrate' stuff...
(1 vote)
• From the video, it says that lower-wavelength rays are less absorbed and scattered when going through dense things like galaxies. X-rays cannot go through lead, which is very dense. I assume radio waves can, but I have no idea.
(1 vote)
• so is music infrared light?
(1 vote)
• No, they're sound waves. :) Sound waves are vibrations, not radiation.
(1 vote)
• Is there a scale for nanometers?
(1 vote)
• Yes - there are 25,400,000 nanometers in an inch! Your fingernails grow 1 nanometer every day, and a human red blood cell is 6,000-8,000nm across.
• Is infrared hottter than visible light
(1 vote)
• Infrared light is of a lower energy than visible light.
(1 vote)
• 2;12 does our body give off inferred waves?