Time is the apparent progression of events from the past to the future. Although it is not possible to fully define the nature of time, we all share many common experiences bound up with time: causes naturally lead to consequences, we remember the past but not the future, and the evolution of time appears to be continuous and irreversible.
Is time related?
Einstein’s special theory Relativity The experience of the flow of time revealed that it was relevant to the viewer and their situation. Previously, Isaac Newton’s mission assumed that there was a “master clock” that kept synchronized time throughout the universe. This clock was not supposed to actually exist, but the concept allowed Newton’s equations to work. The main idea is that all viewers can agree at the same time, According to the Internet Encyclopedia of Philosophy (Opens in new tab).
However, to build work before him, Einstein Found that time is relevant. In special relativity, moving clocks run slow; The faster you move in space, the slower you will progress over time. The closer you get to the speed of light, the greater the effect.
In the decades since Einstein first proposed this concept, physicists have made numerous measurements that prove this effect. The atomic clock in the jet plane ticks at a slower speed than it does on the ground. A subatomic particle called a muon does not last long enough to travel through the atmosphere, when it forms. Cosmic rays Air molecules hit the ground. But because mions travel close to the speed of light, they seem to last longer in our view, thus allowing them to complete their journey.
When Einstein developed his theory of general relativity, he expanded this notion, which is “Extension of time“To the circumstances involved Gravity. Strong gravitational force shortens the reserve time, so the clock in a strong gravity well (for example, near the Earth’s surface or near a black hole) will tick faster than the clock in the middle of space. Physicist Christopher S. According to Byrd (Opens in new tab).
Related: In real life Einstein’s theory of relativity can be found in 9 ways
Is time travel possible?
Time travel for the future is not allowed – it is mandatory. In fact, with every passing moment, we are all moving towards our own future. The future is inevitable, inevitable. But the reality of relativity makes it clear that “jumping” at the right time is perfectly acceptable.
If a twin rocket launches and travels at the speed of light for a few years, when they return to Earth, they will be much younger than the twins that will go to Earth. Even if a few years have passed in the spacecraft, it may have taken decades or even centuries on Earth, depending on how fast the rocket traveled. According to Cosmos magazine (Opens in new tab). In a real-life example, NASA astronaut Scott Kelly enjoyed a few milliseconds less time than his double mark (Scott is also six minutes younger), traveling at a speed of about 17,500 miles (28,100 km) thanks to spending more time in space. / h), According to the LiveScience sister site Space.com (Opens in new tab).
But time travel seems to have been restricted within the past – at least in all trials and tribulations. For one, it raises all sorts of embarrassing issues as the possibility becomes popular Grandfather conflict Asks what happens if you go over time and kill your own grandfather: you will not be, so you cannot travel over time to do that act.
Second, there is no known mechanism in physics that allows us to travel backwards over time. Although specific time-travel conditions can be structured in general relativity, those conditions do not seem to exist in our universe (such as objects with negative mass or countless elongated cylinders).
However, physicists do not now have a full understanding of why time travel has been banned in the past.
Can the time be changed?
All the rules and equations used by physicists to understand the natural world are symmetrical. That is, they can be reversed without changing any results. For example, if you watch a video of the ball rising and falling in the air without any other context, you cannot tell whether the video is moving forward or reversing.
However, one aspect of physics seems to value time flow: the concept of entropy, which measures the disorder in a system. As stated in it The second law of thermodynamicsEntropy always rises in a closed system, and this evolution cannot be reversed.
Physicists do not know whether the development of entropy appears to be the “arrow” of time or whether it is a coincidence. Stanford Encyclopedia of Philosophy (Opens in new tab).
Is time unique or continuous?
Almost all theories of physics consider time as a continuum, which is how we perceive the flow of time. There is no such thing as a small “unit” over time. All events will run smoothly without interruption or hiccups.
However, the theory of quantum gravity, called the loop quantum gravity, assumes that there is a small potential unit. Space time. This unit represents the smallest extension of the interval and period. In this theory, what we consider to be smooth, continuous time is actually a stumbling, stop-and-move progression from the past to the future. But because it’s happening for an incredibly short period of time, it seems like a series of film frames coming together, according to a 1998 article by physicist Carlo Rowelli. Life Reviews of Relativity (Opens in new tab).
Is time real?
Scientists, philosophers and others have wondered about the nature of time. And although we learn a lot about time, such as the fact of time extension and the possible relationship between time and entropy, we have not been able to come up with a complete explanation of what time is.
Some philosophers and physicists have argued that what we experience over time is just an illusion, an artifact of our consciousness. In this view, the passage of time is not real; The past and future are already at their full extent, as well as the whole space is already there. What we perceive as time flow is an adjunct to the way our brain functions when it processes sensory information from our environment. According to physicist Sean Caroline (Opens in new tab).
Byrd, CS (2013, June 24). Does time go faster on the top of the building compared to the bottom of it? Science questions with amazing answers. https://www.wtamu.edu/~cbaird/sq/2013/06/24/does-time-go-faster-at-the-top-of-a-building-compared-to-the-bottom/ (Opens in new tab)
Calendar, c. (2021, June 8). Thermodynamic asymmetry at time. Stanford Encyclopedia of Philosophy. https://plato.stanford.edu/entries/time-thermo/ (Opens in new tab)
Carol, s. (2013, October 18). Is time real? https://www.preposterousuniverse.com/blog/2013/10/18/is-time-real/ (Opens in new tab)
Hunter, J. (nd). Time travel. Internet Encyclopedia of Philosophy. Retrieved April 5, 2022 https://iep.utm.edu/timetrav/ (Opens in new tab)
O’Connell, c. (2021, August 3). Time Travel: Five Ways We Can Do It. Cosmos. https://cosmosmagazine.com/science/physics/five-ways-to-travel-through-time/ (Opens in new tab)
Rowelli, c. (1998). Loop quantum gravity. Living Reviews on Relativity, 1(1) https://link.springer.com/article/10.12942/lrr-2008-5 (Opens in new tab)