Have you ever felt like time is flying by? Well, according to physics, time might actually be moving slower! A hundred years ago, people thought time was the same for everyone and everything. It was believed that time moved forward in a straight line, with each second being the same as the last.
In 1919, Albert Einstein changed how we think about time with his theory of special relativity. He showed that time is relative, meaning it can slow down or speed up depending on how fast you’re moving compared to something else. For example, when you travel faster, time moves slower for you. NASA has to consider this when dealing with satellites that orbit Earth at 29,000 km/h. The clocks on these satellites tick slower than clocks on the ground by about 38 microseconds each day. A microsecond is one-millionth of a second!
This difference might seem tiny, but GPS systems need to be incredibly precise, down to the nanosecond. If we didn’t adjust for these time differences, GPS would become inaccurate very quickly, leading to errors of about 10 kilometers per day. Without these adjustments, GPS wouldn’t work for navigation!
The closer you get to the speed of light, the slower time moves for you. Imagine two identical twins: one stays on Earth, and the other travels in a spaceship at 99.99999% the speed of light. After 80 years, the twin on Earth would be an old man, while the twin in the spaceship would have only aged one day!
Our universe is expanding, and it’s doing so at an increasing speed. The farther away something is from our galaxy, the faster it’s moving away. Eventually, these distant objects move so far away that we can’t see them anymore. The light from these galaxies will never reach us here on Earth.
You might wonder if our galaxy reaches the speed of light, could time freeze? Maybe this is why time feels like it’s speeding up. If time were slowing down, more events could happen in shorter intervals. We see rapid advancements in technology, knowledge, and even evolution. Could this be evidence that time is actually slowing down? What could this acceleration lead to?
If you’re curious about Einstein’s theory of relativity, you can explore it further on Brilliant, a website that helps you think like a scientist. Brilliant offers a special relativity course that breaks down complex ideas into easy-to-understand pieces. You can learn by solving fun and challenging problems, making the process enjoyable.
Visit brilliant.org/afterschool to start learning for free. The first 200 people will get 20% off their annual premium subscription. Remember, knowledge is power, and learning should be fun. For more interesting content, don’t forget to subscribe!
Conduct a simple experiment to understand time dilation. Use a stopwatch and measure time intervals while walking and running. Compare the results and discuss how speed affects time perception. This will help you grasp the concept of time slowing down at higher speeds.
Engage in a role-playing activity where you and your classmates act out scenarios involving time dilation. One student can be an astronaut traveling near the speed of light, while another stays on Earth. Discuss how time would differ for each character and relate it to Einstein’s theory.
Use an online simulation to explore how GPS systems account for time differences due to relativity. Analyze how satellite clocks differ from those on Earth and why these adjustments are crucial for accurate navigation.
Participate in a debate about the expanding universe and its implications on time perception. Discuss whether the universe’s expansion could be linked to the feeling that time is moving faster and what this means for future advancements.
Write a short story from the perspective of someone traveling at near-light speed. Describe their experiences and how time differs for them compared to people on Earth. This will help you creatively explore the effects of relativity on time.
Here’s a sanitized version of the provided YouTube transcript:
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Is time moving faster? We’ve all heard the cliché phrase, but according to physics, time is actually moving slower. 100 years ago, we believed that time was the same for everyone and everything; we were all participating in the same ticks of the clock. Every interval of time was the same as the one before and moved forward in a linear, uniform progression.
However, in 1919, Albert Einstein demonstrated that time is relative with his theory of special relativity. He discovered that time slows down or speeds up depending on how fast you move relative to something else. For instance, we know that when you travel faster, time moves slower. This is something NASA has had to account for in their satellites, which move around the Earth at 29,000 km/h. The clocks onboard each satellite tick slower than identical clocks on the ground by about 38 microseconds per day. Each microsecond is one millionth of a second.
This may sound small, but the high precision of the GPS system requires nanosecond accuracy, and 38 microseconds is 38,000 nanoseconds. If these effects were not properly taken into account, a navigational fix based on the GPS constellation would be inaccurate after only two minutes, and errors in global positioning would continue to accumulate at a rate of about 10 kilometers per day. The whole system would be ineffective for navigation if we were not able to adjust for relativity.
The closer you travel to the speed of light, the slower time moves according to the theory of relativity. If two identical twin babies were part of an experiment where one baby goes into a spaceship that blasts off at 99.99999% the speed of light, and the other baby stays on Earth, the babies would experience time in very different ways. After 80 years, the baby on Earth would be an old man, while the baby in the spaceship would have only aged one day.
As it turns out, we are moving faster; the universe is expanding, and this expansion is happening at an accelerated rate. The farther something is from our galaxy, the faster it is accelerating away from us. Eventually, these distant objects move so far away that they fall off the visual cliff and are no longer part of the observable universe, at least from our perspective. The light from the galaxies beyond the visual edge will never reach our telescopes here on Earth.
You might be wondering if our galaxy reaches the speed of light, could time freeze? Perhaps this is why time feels like it’s accelerating. If time were slowing down, more events could happen in shorter intervals, and we are witnessing a rapid rise in technology, knowledge, understanding, evolution, and extinction, all accumulating at an exponential rate. Could this acceleration of events be evidence that time is actually slowing down? If so, then what is this acceleration leading to?
This is a complicated idea for another video, but if you’re curious to learn more about Einstein’s theory of relativity, check out Brilliant, a problem-solving website that teaches you to think like a scientist. You get to master concepts by solving fun and challenging problems, making learning enjoyable. Brilliant’s thought-provoking special relativity course breaks down complex ideas into bite-sized, understandable chunks that lead you from curiosity to mastery.
See how Einstein bested Newton, ponder about throwing clocks, and play relativistic laser tag. Learn more about Brilliant by going to brilliant.org/afterschool to start learning for free. The first 200 people will get 20% off their annual premium subscription. Knowledge is power, and learning should be fun. For more interesting videos like this one, please subscribe.
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This version maintains the original content while removing any informal language and ensuring clarity.
Time – The continuous progression of existence and events in the past, present, and future, often considered as a fourth dimension in physics. – In physics, time is a crucial factor when calculating the speed of an object.
Physics – The branch of science concerned with the nature and properties of matter and energy. – Physics helps us understand how the universe behaves through concepts like force, motion, and energy.
Relativity – A theory in physics developed by Albert Einstein that describes the interrelation of time and space. – According to the theory of relativity, time can slow down or speed up depending on how fast you are moving relative to something else.
Light – Electromagnetic radiation that is visible to the human eye and is responsible for the sense of sight. – Light travels at a speed of approximately 299,792 kilometers per second in a vacuum.
Universe – The totality of known or supposed objects and phenomena throughout space; the cosmos. – The universe is vast and contains billions of galaxies, each with millions of stars.
Satellites – Objects that orbit around planets or stars, often used for communication or observation. – Satellites orbiting Earth provide us with weather data and enable GPS navigation.
GPS – Global Positioning System, a network of satellites that provides location and time information anywhere on Earth. – GPS technology relies on satellites to help determine precise locations on Earth.
Speed – The rate at which an object covers distance, calculated as distance divided by time. – The speed of light is the fastest speed at which information can travel in the universe.
Earth – The third planet from the Sun, and the only astronomical object known to harbor life. – Earth rotates on its axis, causing the cycle of day and night.
Acceleration – The rate of change of velocity of an object with respect to time. – When a car speeds up, it experiences acceleration, which can be calculated using physics formulas.
