2.725 kelvin
2.725 KTemperature · definition
Celsius and Fahrenheit have shifted zero points. Differences are useful; “twice as hot” in °C or °F is not a physical temperature ratio.
Temperature
Just how hot is 2.725 kelvin?
Deep cold
2.725 K
2.725 kelvin
Celsius and Fahrenheit have shifted zero points.
2.725 KTemperature
0 K · absolute zero
Cosmic microwave background
The cosmic microwave background is faint thermal radiation filling the universe, left over from the early stages after the Big Bang.
2.725 KTemperature
0 K · absolute zero
Celsius and Fahrenheit zero points are offsets. Compare temperature differences, not ratios in °C or °F. The kelvin axis starts at absolute zero.
A little perspective
2.725 kelvin is the same as the temperature of the cosmic microwave background.
Measurements, assumptions & sources +
2.725 kelvin
Temperature: 2.725 K; definition.
Celsius and Fahrenheit have shifted zero points. Differences are useful; “twice as hot” in °C or °F is not a physical temperature ratio.
Cosmic microwave background
Temperature: 2.725 K; approximate.
The temperature of the nearly blackbody relic radiation. It is not the temperature of every object in space.
The marked temperature is calibrated. Unmeasured illustration details are representative.
Measurement details
Why these numbers?
Compare 2.725 kelvin with the temperature of the cosmic microwave background. The notes below explain how each value was chosen.
Cosmic microwave background
2.725 KTemperature · approximate
The temperature of the nearly blackbody relic radiation. It is not the temperature of every object in space.
- Comparing
- Temperature ↔ Temperature
- Relative size
- We compare temperatures using a difference in kelvins, not a ratio.
How to read the visual
The diagram uses the recorded measurements. Details outside the marked spans do not set the scale.
- The temperature of the cosmic microwave background: This is an estimate; check the notes for its rounding and uncertainty.
Compare temperature differences in kelvins; Celsius and Fahrenheit ratios are not meaningful.
-270.42 °Cdegrees Celsius
-454.77 °Fdegrees Fahrenheit
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