Kevin Swint

“Figure 3.3: Since it takes time for distant light to reach us, looking farther away means looking farther back in time. Beyond the most distant galaxies, we see an opaque wall of glowing hydrogen plasma, whose glow has taken about 14 billion years to reach us. This is because the same hydrogen that fills space today was hot enough to be plasma about 14 billion years ago, when our Universe was only about 400,000 years old. (Credit: Adapted from NASA/WMAP team)”
― Max Tegmark, Our Mathematical Universe: My Quest for the Ultimate Nature of Reality