A researcher is studying two identical brass blocks, X and Y.
Block X has been heated in an oven to 120∘C120^\circ\text{C}120∘C.
Block Y is at room temperature, 21∘C21^\circ\text{C}21∘C.
Identify which block emits thermal radiation at a higher rate and explain your answer.
Explain why both blocks look identical to the researcher, despite being at different temperatures.