2 verifications about Circadian Rhythm Circadian Rhythm ×
“A study led by Yadan Li at Southwest University in Chongqing found that exposure to frightening images and sounds at night (20:00) produced greater increases in skin conductance, heart rate, and blood pressure than the same exposure during the day (08:00), regardless of room lighting conditions.”
Li et al. did find stronger skin conductance and heart-rate responses to frightening stimuli at night versus day, but the study did not measure blood pressure, did not report 20:00/08:00 as the test hours, and did not establish that the effect is independent of room lighting. These unsupported additions materially overstate the original findings.
“Watching the sunset supports the human circadian rhythm by promoting sleepiness.”
The evidence does not support the claim that watching the sunset promotes sleepiness through circadian mechanisms. Peer-reviewed research consistently shows that light exposure in the evening delays circadian timing and pushes sleepiness later, while melatonin—the key sleep-onset hormone—rises under dim or dark conditions, not in response to light. The claim conflates the fact that sunset wavelengths influence circadian brain centers with the unsupported conclusion that sunset viewing actively induces sleepiness. Any benefit is indirect and depends heavily on context.