Is Time Travel, Especially Into the Past Possible? | Matt Szydagis | TEDxSchenectady
TEDx Talks・18 minutes read
Time travel is a captivating concept with historical and media examples of incorrect predictions, despite physics limitations. Einstein's theory of special relativity and the twin paradox illustrate time's plasticity, while the feasibility of past and future time travel remains uncertain due to complex mathematical extrapolations and the need for advanced technology.
Insights
- History showcases the fallibility of experts, as seen in the New York Times' retraction of a rocket statement in 1969, challenging the perceived impossibility of time travel despite physics constraints.
- The convergence of quantum mechanics and relativity is essential for understanding time travel feasibility, with potential avenues like Tipler cylinders and wormholes requiring advanced technology and theoretical frameworks to navigate the complexities of time manipulation.
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Recent questions
Is time travel possible?
Yes, time travel is a captivating concept that has been explored in various forms of media and historical events. While physics currently deems time travel impossible, history has shown that experts have been wrong before. Theoretical frameworks like Einstein's theory of special relativity and the twin paradox illustrate time's plasticity and the potential for traveling to the future with advanced technology. Traveling to the past involves complex mathematical extrapolations from special relativity and concepts like the Tipler cylinder from general relativity. The idea of wormholes as shortcuts through space-time presents challenges due to the need for negative mass and instability. Quantum mechanics also plays a role in exploring the possibility of time travel by examining interactions of particles. Overall, while time travel remains a theoretical concept, advancements in physics could potentially make it a reality in the future.
What is the twin paradox?
The twin paradox is a thought experiment that demonstrates time's plasticity and the effects of special relativity. It involves one twin staying on Earth while the other travels through space at near-light speeds. When the traveling twin returns, they find that less time has passed for them compared to their twin on Earth. This paradox highlights the concept that time is not absolute and can be experienced differently based on relative motion and gravitational fields. The twin paradox is fundamental in understanding the implications of time travel and the complexities of spacetime.
How does general relativity relate to time travel?
General relativity plays a crucial role in discussions about time travel, particularly in exploring potential avenues for traveling to the past. Concepts like the Tipler cylinder, which involves rotating cylinders to create closed timelike curves, offer theoretical frameworks for past time travel. While these ideas are still speculative and face challenges, general relativity provides the mathematical and theoretical foundation for understanding the complexities of spacetime and the potential for manipulating it to achieve time travel.
What are some time travel paradoxes?
Time travel paradoxes are theoretical conundrums that arise from the possibility of altering the past or creating closed loops of information without a clear origin. Examples include the grandfather paradox, where a time traveler prevents their own existence, and the ontological paradox, where information or objects exist without a discernible origin. These paradoxes highlight the complexities and potential consequences of time travel, raising questions about causality, free will, and the nature of reality.
Why haven't we seen time travelers?
The lack of robust evidence for time travelers among us can be attributed to the limitations imposed by general relativity. Even if time travel were possible, the theory suggests that individuals could not travel back before the creation of the time-traveling mechanism. Additionally, the complexities and challenges posed by current physics understanding, including the need for a full theory of everything combining relativity and quantum mechanics, contribute to the absence of visible time travelers. While the speaker optimistically predicts the potential feasibility of time travel for subatomic particles in the future, serious research and development efforts are currently lacking in this area.
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Summary
00:00
Exploring Time Travel: Concepts and Possibilities
- Time travel is a captivating concept, evident in various forms of media and historical events.
- Notable instances of incorrect predictions include the New York Times retracting a statement about rockets in 1969.
- Despite the perceived impossibility of time travel due to physics, history shows that experts have been wrong before.
- Einstein's theory of special relativity is fundamental to understanding time travel discussions.
- The twin paradox, illustrated by atomic clocks, demonstrates time's plasticity.
- Time is not absolute, and individuals experience time differently based on their circumstances.
- Traveling to the future is theoretically possible with advanced technology and fuel sources.
- Attempting to travel to the past involves complex mathematical extrapolations from special relativity.
- General relativity, particularly the concept of a Tipler cylinder, offers potential avenues for past time travel.
- The idea of wormholes as shortcuts through space-time presents challenges due to the need for negative mass and instability.
15:37
"Quantum Mechanics and Time Travel Possibilities"
- Quantum mechanics explains the world of the very small, including particle physics, and raises questions about the possibility of time travel by examining interactions of particles like protons, electrons, and photons.
- The combination of quantum mechanics and relativity is necessary to determine the feasibility of time travel, as there is currently no single set of equations that can explain the entire universe, encompassing gravity and particle physics.
- Various paradoxes related to time travel, such as the grandfather paradox and the ontological paradox, highlight the complexities and potential consequences of altering the past or creating closed loops of information without an origin.
- Proposed explanations for time travel paradoxes include parallel universes, predestination, and the concept of the universe becoming a Möbius strip, leading to the coexistence of multiple timelines and individuals being both dead and alive simultaneously.
- The lack of robust evidence for time travelers among us is attributed to the limitations imposed by general relativity, which suggests that even if time travel were possible, individuals could not travel back before the creation of the time-traveling mechanism.
- Despite the numerous challenges and limitations posed by current physics understanding, the speaker optimistically predicts that once a full theory of everything combining relativity and quantum mechanics is achieved, time travel may become feasible for subatomic particles within the next 100 years, although serious research and development efforts are currently lacking.
