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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 4.0 out of 5 by 51.
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Rated 1 out of 5 by from Meh Another new series with an "expert" that hasn't actually done anything relevant to the topic being presented; is quality control just not a thing anymore or have the goal posts moved?
Date published: 2024-03-02
Rated 2 out of 5 by from Big Question.... Unwatchable. Plodding and off topic on many occasions
Date published: 2023-12-01
Rated 5 out of 5 by from Time, space, gravity, quantum theory, relativity. Dr Helmuth, in a relaxed and confident style, guides us through the "inter-relatedness" of the most current research/ideas of time, space, quantum theory, string theory, and relativity. This series will be satisfying fuel for casually scientific/philosophical mind, as well as those hoping for deeper substantive cuts. Thank you Dr. Laura Helmuth.
Date published: 2023-05-12
Rated 5 out of 5 by from Mind boggling My take away is that infinity and the infinitesimal do not exist in nature. Maybe useful in math though. Even math that is useful in explaining nature.
Date published: 2023-01-31
Rated 5 out of 5 by from An important course This is an example thought provoking set of discussions of a basic issue
Date published: 2022-06-20
Rated 5 out of 5 by from Very entertaining! This is not a "learning" course. It's a series of lectures based on articles in Scientific American that have some aspect of TIME as a subject. Not just physics, but biology, perception, philosophy, etc. I never realized how deep the subject is - each chapter gives you lots to think about. It's an excellent course!!!
Date published: 2022-06-09
Rated 5 out of 5 by from An approachable survey of the implications of time The subject of time has troubled a great many minds, and has been an excuse for the unthinkable. The presenter offered a survey time , hitting the old chestnuts, but also presenting recent thinking on the topic. I needed the notes for this one for sure. Often I felt I was skating on the surface, but that is how I learn.
Date published: 2022-05-31
Rated 5 out of 5 by from Fascinating, mind-boggling concepts and ironic Dr. Helmuth was an excellent presenter of a subject that is both fascinating and often mind-boggling. The irony I found was that throughout the dozen lectures on time, there was a broken clock behind her that always showed the same time.
Date published: 2022-05-19
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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

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. She has served in various editorial positions, including for The Washington Post, Smithsonian magazine, and Science. 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