Internal Time Quotes

“when two strains compete for the same resources, the strain with an internal timing system that is most adapted to its temporal environment has the greatest advantage.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“A systematic pattern on weekends appears: early types become sleep deprived on free days as a consequence of the social pressure exerted by their owlish friends, who are the majority.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“Once enlightened, they started to understand themselves (and others) much better, began to appreciate their own individual time, and were suddenly relieved of the weight of prejudice ridiculing their temporal habits: for example, being called lazy if you don't wake up fresh as a daisy by seven o'clock in the morning; or being called a boring person only because you don't enjoy going out with friends after ten at night.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“Your internal time is produced by your own body clock. It varies from individual to individual just as body height, eye color, or personality varies, and it interacts with sun time and social time. In spite of internal time being probably the most important to our health and well-being--more important than sun time and certainly more important than social time--it has been thoroughly neglected.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“The phase of an individual’s body clock in relationship to a zeitgeber is a biological phenomenon and not a matter of discipline.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“Only about 60 percent of conceptions actually lead to a birth. The number of natural abortions of unrecognized pregnancies during their first weeks might even decrease this rate.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“The journey of these algae during their vertical migration is quite extraordinary, considering their size. A change of depth by ten meters is equivalent to us walking eighteen kilometers. We know that algae and other plankton can travel considerably more than fifty meters during their vertical migration down and back up, which would mean that we would have to travel 180 kilometers every day. The small creatures do not swim these large distances actively. Instead, they make themselves lighter or heavier than water by filling their cell with gas bubbles or getting rid of them. 6”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“You see, this book is about larks and owls from beginning to end!”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“Once the day-active birds had firmly established their dominance in the air, some of them switched to night activity. The lark is a good example of the former and the owl is a good example of the latter.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“All our ancestors must have been night-active (most mammals still are), but we and some other mammals have reconquered the day.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“During the day our mammalian ancestors could hide in a dark and cool burrow and during the cold nights they could roam around, dodging dangerous but now potentially sluggish reptiles.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“While birds are the end product of an evolutionary line that conquered the airspace, the ancestors of mammals conquered the night.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“Humans are primates, and primates are mammals. The first mammals appeared on earth between 200 and 250 million years ago—a very short time in evolutionary units. To put that figure in perspective, the first primitive unicellular organisms appeared roughly 4,500 million years ago; the first cell with a proper nucleus appeared about 1,500 million years ago;7 and the first animals with bones inside their body appeared on land only 380 million years ago.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“You probably guessed the rationale behind the pink glasses, the filter sheets, and the special light bulbs. After dusk and before dawn, they aimed to shield Gerry and Barbara from that part of the light spectrum that reaches our timing system most effectively (the blue parts of the light spectrum).”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“But our internal clocks are only effective if we provide them with sufficient information: with sufficient differences in daily light and darkness, or with sufficient contact to changing photoperiods and temperatures.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“It is quite remarkable how many aspects of our lives are influenced by industrialization and its consequences, isolating us increasingly from natural signals.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“The farther from the equator that humans live, the higher the overall rate of suicide, and the larger the difference in suicide rates between summer and winter.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“In addition, patients who suffer from bipolar depression and die by suicide do so during their manic phase and rarely during their depressed phase.7 The actual act of suicide (and not merely the thought about it) takes a level of energy that depressed individuals cannot muster during their most depressed times of year.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“Its entire mainland territory, which extends over almost a sixth of the earth’s circumference, is fused into one single time zone referenced to Beijing sun time.9 When people in western China look at their watch and see that it is 10:00 P.M., it is actually only 7:24 P.M. by sun time, and if they had to get up at six in the morning to go to work, it would by local sun time be only 3:24 A.M. I have been told that the western Chinese population actually doesn’t orchestrate social life by Beijing time. For example, when they come together for an early evening meal (say at around 7 P.M. local sun time), they would arrange to meet at 11 P.M.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“As you read in the introduction, time-zone time is the temporal reference that people have lived by since the late nineteenth century, when the world was subdivided into twenty-four time zones. Before that, the temporal reference was local sun time. It is quite remarkable that we find—in the first part of the twenty-first century—that our body clocks still live very much like those of our ancestors, namely by sun time, while our entire social life has to conform to a different schedule.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“The numbers connecting smoking with social jet lag are striking: among those who suffer less than an hour of social jet lag per day, we find 15 to 20 percent are smokers. This percentage systematically rises to over 60 percent when internal and external time are more than five hours out of synch.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“A recent Danish project has eliminated timetables entirely and left the decision about when to arrive at school to the students.6 One of the teachers of this school in Copenhagen recently pointed out in a television interview that schools should be regarded as service centers, and so they are required to offer the best possible service to their customers, meaning the optimal environment for achieving the best education possible. Allowing students to sleep and work at their optimal times should definitely be part of this service.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“Despite these barriers, the number of schools trying out other timetables for adolescent students is rapidly increasing in several countries, from Switzerland to the United States.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“Early to rise and early to bed makes a bird healthy, wealthy, and dead.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“The fact that many early types actually use an alarm clock (despite always waking up before it rings) must lie in some unfounded paranoia about not waking up in time for work.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“It is quite remarkable how firmly belief and conviction stand in the way of reasoning.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“It is quite remarkable how firmly belief and conviction stand in the way of reasoning,”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired

“But if there is something to the relationship of being a late type and being able to endure and "sleep in," then late types are better night-hunters than early chronotypes. The lateness of teenagers in our modern industrial age may be a remnant of a skill that accompanies the age of peak physical condition.”
― Till Roenneberg, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired