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Examining the Big Questions of Time

Make the time to really sit and think about what all these years, months, days, hours, minutes, seconds, and nanoseconds mean for us.
Examining the Big Questions of Time is rated 3.9 out of 5 by 38.
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Rated 2 out of 5 by from Not an easy lecturer to follow The speaker reads her presentation and speaks very fast. Quantum string theory is not easy to follow, so my wife and I have struggled to keep up. On the other hand, we have been inspired to read some books by physicists such as Brian Green, and will then return to these lectures to see if they make more sense to us.
Date published: 2022-01-25
Rated 3 out of 5 by from rounded view of time so, a little physics,, some philosophy, neurology, brain studies, even the workings of clocks themselves; if you like an interdisciplinary approach to topics then you may like this course, the instructor speaks well, although I wish she would get off the chair and walk around a bit to not make it seem she's looking at the teleprompter. There were a couple of things I couldn't wrap my head around but overall the lecture were understandable for someone with just a general passing knowledge like me. the visuals were good and I think the 12 lecture format was adequate. I would recommend the course as long as you weren't looking for a study of time concentrating only from a single approach.
Date published: 2022-01-23
Rated 4 out of 5 by from Examining the Big Questions of Time Very interesting. Only a few spots where the technicalities behind the discussion got too scientifically hard to follow.
Date published: 2022-01-22
Rated 2 out of 5 by from Not what I expected I only watched the first few lectures. It just didn’t hold my interest. It seemed like the lecturer was reading a script unlike other courses I’ve taken. The first lecture was so elementary. Maybe at a later date I’ll try again skipping to lectures that sound more interesting.
Date published: 2022-01-17
Rated 2 out of 5 by from No continuity A discontinuous collection of lectures. No common thread. Like reading SA articles.
Date published: 2022-01-15
Rated 3 out of 5 by from Scientific American Comes To The Great Courses Not the usual type of course (in most Great Courses the lecturer leads you through a series of steps to the summit of the course). This one is a conglomeration of ideas around time covering philosophy, physics, psychology, biology there's no easy steps from one lecture to the next be prepared to mentally jump about. Your bound to find one lecture which stimulates you
Date published: 2022-01-07
Rated 5 out of 5 by from Examining the Big Questions of Time. I am not a physicist just a regular person that loves the wonderment of science. Laura Helmuth did a fantastic job of laying out the material in a logical manner that I could understand. She spoke clearly and enthusiastically as she enjoyed the wonderment of science too.
Date published: 2021-12-18
Rated 1 out of 5 by from the two on line. the price on line is 50% higher than the magazine price . !! I didn't buy ..
Date published: 2021-11-26
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With the help of "Scientific American" magazine, dive into one of the biggest scientific explorations of the last few centuries to uncover the realities of time and how much-and how little-we truly understand about it.


Laura Helmuth
Laura Helmuth

I hope you’ll join me on this fascinating tour of what science has discovered.


Scientific American

Laura Helmuth is the editor in chief of Scientific American. She earned a PhD in Cognitive Neuroscience from the University of California, Berkeley, and a graduate certificate in Science Communication from the University of California, Santa Cruz.

Laura has served as the health, science, and environment editor for The Washington Post; director of digital news for National Geographic Partners; science and health editor for Slate; science editor for Smithsonian Magazine; and editor for Science. She is currently on the advisory boards for Spectrum, an autism news website, and SciLine, an organization that helps journalists find the best scientific sources. She also serves on the board of directors for High Country News, a magazine that covers the American West. She is a member of the National Academies of Sciences, Engineering, and Medicine’s Standing Committee on Advancing Science Communication and was previously president of the National Association of Science Writers.

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A Matter of Time

01: A Matter of Time

While most of us measure time in hours or days as we plan our activities, these units are not nearly small enough—nor large enough—for those who work at the edges of discovery. Explore how some scientists use attoseconds and others use billion-year increments to study the often baffling revelations of spacetime.

27 min
The Myth of the Beginning of Time

02: The Myth of the Beginning of Time

Just a few decades ago, scientists were absolute in their determination that time began with the Big Bang. But that’s all been turned on its head with the rise of string theory and other fascinating developments in theoretical physics. Learn how those advances brought the pre-Bang universe to the forefront of cosmology.

30 min
That Mysterious Flow

03: That Mysterious Flow

Right now, you are reading these words. True enough, right? But all that certainty erodes when we look at the concept of “now” through the lens of modern physics. Although we perceive “now” as being unique—our present moment always seeming to separate the knowable past from the unknowable future—you’ll learn why “now” slips from our grasp when we try to actually define it.

21 min
Is Time an Illusion?

04: Is Time an Illusion?

While we’ve all heard that time is money, the two terms might turn out to be more similar than we ever knew. Could time, like money, be just an invented convenience with no fundamental existence in the natural world? Discover the many ways in which philosophers have helped physicists grapple with this question—and the answers they’ve come to so far.

31 min
Time Travel and the Twin Paradox

05: Time Travel and the Twin Paradox

In a thought experiment called the twin paradox, Einstein illustrated that two observers moving at different speeds would experience different durations between the same two events. See how this time dilation has been proven and measured since Einstein’s life, and why your GPS wouldn’t work without accounting for it. Time travel, anyone?

23 min
A Chronicle of Timekeeping

06: A Chronicle of Timekeeping

From the ancient Egyptians to the 13th-century inventors of the mechanical clock to the atomic clocks of the last century, people keep striving to measure time more accurately. Understand why accuracy in timekeeping was important for the agriculturists of the Nile and why it still matters for those of us today who use navigation systems, cell phones, and electricity from the power grid.

29 min
Atomic Clocks

07: Atomic Clocks

Modern timekeeping has allowed us to measure differences in the passage of time as affected by motion and gravity to such a degree that relatively itself can now be measured in the lab. Learn about the development and precision of atomic clocks—and the myriad ways they benefit us—and about the optical clocks that can keep time to within one second in roughly 3.7 billion years.

27 min
Times of Our Lives

08: Times of Our Lives

Our circadian rhythm is hardwired into every cell in our bodies. Even under constant lighting, human cells in a petri dish will continue to follow 24-hour cycles of gene activity, hormone secretion, and energy production. Explore neurologists’ latest thinking about the brain’s internal timekeeping systems, and how those systems affect our health.

28 min
Remembering When

09: Remembering When

While our internal clocks regulate our physical processes, our mind has a clock of its own. Explore what scientists mean by “mind time,” and how we organize our thoughts about events in the passage of time. Uncover how mind time is linked to our ability to make and store memories, and reveal the interesting differences between anterograde and retrograde amnesia.

21 min
Inconstant Constants

10: Inconstant Constants

Almost all our scientific knowledge is possible because we rely on a few very basic constants—such as the velocity of light and the mass of the electron. Discover how string theory brings the possibility of a vast number of other worlds with different self-consistent laws and constants, and whether or not those worlds could possibly include biological entities like ourselves.

25 min
Atoms of Space and Time

11: Atoms of Space and Time

In the field of quantum mechanics, physicists have suggested for almost a century that light is made of energy packets that can behave like both a particle and a wave, a phenomenon known as photons. But could gravity also be made of discrete packets—gravitons? Explore the concept of loop quantum gravity and learn how physicists use spin networks to gain a deeper understanding of our universe.

29 min
Could Time End?

12: Could Time End?

As we experience life, time never ends. Even after death, our molecules will be recycled, and both time and matter will continue. But if time can slow down and speed up—as Einstein predicted, and later confirmed by observation—could it also end? Explore what the equations of modern physics tell us about the possibility of an end with no rebirth.

25 min