Re: Could this be faked
Not an astrophysicist, but it seems to me the frequencies wouldn't be a problem (just microwaves). The location however... CMB comes from all directions in the sky. To fake it you'd need a source that could blanket the entire sky to an extraordinarily high resolution that is better than the best radio and microwave telescopes down here (so I dunno... micro-arc seconds between sources maybe?).
Trillions of point sources? Quadrillions? More...? The material costs and launch logistics alone prohibit it.
And even if you could source enough material, and loft it, couldn't be too close to Earth or it'd be visible.
Then you have an occlusion problem where your orbiting cluster of quadrillions of microwave sources visibly blocks what's behind them. Suddenly the rest of the solar system and beyond vanishes from view? Think someone might notice...
Short answer: No, can't be faked
Biting the hand that feeds IT
