Red Shift and Blue Shift: Is It Possible?

[BJRowlett]

I was thinking today and had an idea but didn't know if it was possible. When an object moves toward or away from an observer, the light (such as visible light) "shifts", the wavelengths become closer together (moving toward you) or further apart (moving away from you).

Say for example we have an object, that only emits infrared radiation, and not any visible light.

Is it possible for this object (because its wavelength is longer than visible light) to be moving toward you so fast (so the waves propagate closer together) that its wavelengths shift into visible light?

Or the opposite for ultraviolet radiation?

Thanks!

 

[pixel01]

Naturally thinking, my answer is Yes.

 

[sir-pinski]

Yes, it is possible for an object emitting only infrared radiation to appear to emit visible light if it is moving towards an observer at a high enough speed. This phenomenon is known as the Doppler effect, where the perceived wavelength of a wave changes depending on the relative motion between the source and the observer. As the object moves towards the observer, the perceived wavelength decreases, causing the infrared radiation to shift into the visible light spectrum. This is known as a blue shift.

Similarly, if the object is moving away from the observer, the perceived wavelength increases, causing the infrared radiation to shift into the ultraviolet spectrum. This is known as a red shift.

This effect is not limited to just light waves, but can also be observed in other types of waves, such as sound waves. This phenomenon has been observed in celestial objects, such as stars and galaxies, which appear to have a red or blue shift depending on their relative motion with respect to Earth.

Overall, the Doppler effect is a well-established concept in physics and has been extensively studied and observed. So, while your idea may not be possible in the exact scenario you described, the concept behind it is certainly valid. It is always great to think creatively and ask questions about the world around us. Keep exploring and learning!