Eli5: What is the difference between cosmic microwave radiation and the microwaves made from my kitchen?


I know that there are microwaves in space as a remnant from the Big Bang. The microwave oven in my kitchen also makes microwaves. Is there a difference between the two? And how come my microwave oven can heat up food, but the temperature of space is almost absolute zero?

In: 4

There is a huger diffrent in frequency. Microwaves are at 2.4 GHz but the CMB peek at 160gGHz

The heating effect is one of intensity. Compare it to visible light that is just electromagnetic waves like microwaves. The light from a small flashlight on your skin does not heat up you a lot compared to sunlight. Sunlight heat you up less than sunlight concentrated with a magnifying glass which will result in burn damage in a few seconds.

The CMB will deliver less power per area unit than a small flashlight and microwave that have a higher power density than sunlight.