Podcast Summary
Scientists question if time is a fundamental property of the universe: Scientists are exploring the possibility that time may not be a constant, but rather a complex concept in the universe, challenging our understanding of reality. Our daily synchronized time comes from atomic clocks, but the true nature of time remains a mystery.
The time we experience in our daily lives is not the same as the fundamental concept of time in the universe. The BBC, as a trusted source of information, helps us explore these complex ideas. NPR's Jeff Brumfield explains that scientists are questioning if time is a fundamental property of the universe. This idea has been hinted at for decades, but it challenges our understanding of reality. During a visit to the National Institute of Standards and Technology, Jeff discovered how our daily synchronized time comes from atomic clocks. However, the true nature of time and its role in the universe remains a mystery. The best stories, like those from the BBC, make us think about these intriguing questions.
The illusion of absolute time: Atomic clocks challenge the notion of time as an unyielding force, suggesting it might be more complex and subjective than perceived
Our understanding of time, particularly the concept of it being an absolute and consistent entity, may be an illusion. During a visit to a lab, the speaker discovered the intricacies of atomic clocks, which count time to an unimaginable precision. However, the commitment to this continuous counting comes with a catch: if the counting is ever stopped, time itself ceases to exist. This concept challenges the common perception of time as an unyielding force. Theoretical physicist Chanda Prescott Weinstein adds to this idea, suggesting that the idea of absolute time is a construct perpetuated by the government to maintain order. Instead, she proposes that time may be more complex and subjective than we've been led to believe. The atomic clock system is a remarkable achievement, but it also highlights the intriguing possibility that our perception of time might not be as straightforward as we once thought.
Time is a relative concept influenced by gravity and the universe's expansion: Time is not absolute, it bends in strong gravitational fields and passes slower in the distant universe, reflecting the dynamic nature of space-time and the universe's evolution
Time, as we commonly experience it, is not an absolute concept but rather a relative one that can be influenced by factors such as gravity and the expansion of the universe. According to the general theory of relativity, time and space are intertwined in a concept known as space-time. This means that time can bend and curve, and its flow can be affected by gravity. For instance, time flows slower in stronger gravitational fields, such as near the Earth's surface or in the vicinity of massive objects. Furthermore, the universe's expansion, which began with the Big Bang, also affects the flow of time. In the distant universe, time passes more slowly for us as we observe events taking longer to unfold. This is not because the events themselves are happening more slowly but because time is literally ticking more slowly from our perspective. In the early universe, scientists focus on the energy density instead of time as a marker for the passage of events. Space-time and energy density are closely related concepts, and both are essential for understanding the universe's evolution. Ultimately, our perception of time is shaped by various factors, and it's essential to recognize that time is not an unchanging constant but a dynamic concept that can be influenced by the physical world around us.
Challenging the fundamental nature of time: Some physicists propose removing time from certain calculations for simpler and more accurate results, but implications and replacements are unclear
Some physicists, including Neema Arkani Hamed, are questioning the fundamental nature of space and time in the universe. They suggest that these concepts might not be as foundational as previously thought, and that removing the concept of time from certain calculations could lead to simpler and more accurate results. This idea, known as time-symmetric quantum field theory, is still a work in progress, and it's unclear what, if anything, would replace time in these calculations. The implications of this theory could be profound, as it challenges long-held assumptions about the nature of reality. It's important to note that this is a complex and ongoing area of research, and many questions remain unanswered. However, the possibility that time might not be as fundamental as we once believed is an intriguing and thought-provoking idea.
Exploring new geometric shapes to describe collisions without time: While scientists ponder the replacement of space and time in the universe, time remains a real concept at human scales, and the exploration continues
While a physicist is exploring new geometric shapes to describe collisions without using time, the fundamental understanding of what replaces space and time in the universe remains elusive. These shapes, though intriguing, are just mathematical concepts. Despite the uncertainty, even scientists acknowledge that time is a real concept, and something that would still need to exist at human scales, no matter what is more fundamental. The exploration of the nature of time continues, and we'll keep learning as new discoveries are made. This was discussed in a conversation between Gina and Jeff, as part of NPR's Shortwave podcast. The episode was produced by Burleigh McCoy, edited by Gabriel Spitzer, fact checked by Abi Levene, and edited for broadcast by Amina Khan. The audio was engineered by Natasha Branch. To share your thoughts on the show, email shortwave@npr.org. This podcast is supported by Easycater, helping companies solve food needs, and The Bid, BlackRock's podcast on market insights and challenges.
