Verified answer

No. It doesn't work that way.

Let's imagine instead of talking about cosmic things you just talk about your refrigerator. Let's say your refrigerator is at a frosty 275 K (just over freezing). If you put water in at 20 C, the temperature of the water doesn't jump to 295 C. That would be instant hot steam. Temperature is not a thing that adds that way. Water doesn't heat up when you put it in a refrigerator.

<QUOTE>If the temperature here is 70° F, would it really be 65° if not for the CMB?</QUOTE>

That's nonsense. Let me give you an example: paper burns at about 210 degrees Celsius, and that doesn't depend on the ambient temperature. If you burn paper in the Winter, that doesn't mean that paper will burn at a lower temperature.

However, it does mean that it'll cool off faster -- because it's in contact with a thermal bath (the air at ambient temperature) with a lower temperature. Somehow, I think you're confusing the temperature at which things occur with the ambient temperature -- or "baseline temperature" as you call it.

<QUOTE>2.725° K isn't the average temperature, it's the base temperature.</QUOTE>

That is the temperature of the RADIATION thermal bath -- the annihilation photons left over from the coupling with matter. That's the temperature at which matter thermalizes if it's not in contact with other heat sources and is allowed to lose heat (by radiation, for example) for a VERY long time. But that doesn't mean that being in contact with such thermal bath "raises the zero point" at which you count temperature.

Think of it as matter being immersed in a thermal bath. It doesn't change the "real temperature" -- that's nonsense.

By the way, the thermal bath of relic neutrinos is lower than 2.7 Kelvin -- it's actually 1.9 Kelvin,

http://en.wikipedia.org/wiki/Cosmic_neutrino_backg...

because neutrinos decoupled from matter sooner, so they didn't get "fed" by more energy from interactions with matter (mostly from annihilation/pair production) and cooled off more. As you can see, it makes no sense considering the CMBR temperature as the "zero point".

I don't think it works that way. Earth's temperature is a balance between heat lost to a 2.725 K cold sink and the heat gained from the 6,000 K heat source of the Sun. So it is more like the Sun being 6002.725 K instead of 6,000, which is not much difference.

LOL!!!! No, please wait, I'm laughing so hard it's hard to type. It's 70 degrees F because of the Sun and it's affect on the atmosphere and water and Coriolis forces and weather, or your thermostat is set at 70 degrees F. That 2.73 degrees Kelvin is just the AVERAGE temperature of the ENTIRE Universe. Take a statistics course. Extrapolating from statistics, which can be manipulated pretty easily, can be dangerous. ROFL!