What is “Time” and how exactly does it work?



What is “Time” and how exactly does it work?

In: Physics

Time is the phenomenon created by combining mass and energy. As energy is added to mass, the time phenomena increases. When mass is not moving time relative to it is both instantaneous and infinite. Our current concept of time is created by moving 2.1 million km/hr.

Source: I am high.

Sean Carroll has a really great video on this. If you don’t feel like sitting through an hour, search for Minkowski Diagrams.

Lets think about a standard 2-D graph. Along the vertical axis you have time, along the horizontal axis you have distance.

You can draw a line through any two points on this graph.

That line will represent the relationship between space and time, also called velocity.

The greater the angle of the the line, the greater the velocity, the faster you move through the time axis. The lower the angle of the line the lower the velocity, the more you move through space and less through time.

It’s not the most intuitive thing, but I hope this helps.

I would highly recommend that you read The Order Of Time by Carlo Rovelli. It is so far my favourite book about how time technically doesn’t exist and will lead you down a rabbit hole of further reading. Pretty easily digestible too, considering the subject


they’re hard to answer, because the two theories we have about how the universe work. treat time differently.

According to Special Relativity (which successfully explains virtually everything we know about huge astronomical bodies), time is one dimension of 4-dimensional *spacetime*, and different bodies can move through it at different speeds depending on their motion through the 3 spatial dimensions.

According to quantum theory (which successfully explains virtually everything we know about particle physics), time is just a background measuring stick that ticks by at a set rate always.

These two understandings of time aren’t compatible with each other, and neither theory can work with the other definition of time. So, time is one of the basic elements of existence that’s still really really hard to figure out. Honestly, I know links are discouraged here, but the wikipedia article for Time might blow you mind with how little we understand it.

Time is a dimension, along with the three dimensions of space, that gives you a particular location in space and time. Asking how it works is sort of like asking how the y-dimension of up and down works. In the spatial dimensions, things can move in any of the directions of that dimension so long as they do not go faster than the speed of light. This is similar with time, but for some reason we don’t seem to be able to move backwards in time. This concept is often referred to as the “arrow of time” and it is an unsolved general physics problem. Another thing worth noting is that as we move faster through space relative to a stationary observer, the observer will measure our time as moving slower than their’s. The reasons for why all of these things happen get complicated and are sometimes still unsolved, but they are studied in field like special and general relativity, cosmology, and quantum mechanics (among other fields).

There is no experiment that can be done to prove or disprove the existence of time. Time could be something we believe in that doesn’t exist or it could exist. Time may or may not exist however what does exist is measurable actions that can be interpreted as taking a set amount of time such as the rotation of the Earth.

What is time then, basically it’s the duration between two points based on how long the Earth takes to rotate. So the duration between starting this comment and finishing can be measured against the Earths rotation and given a value which we call time.

time is the space between the beginning and the end… and… it works like this… in the beginning was division… God seperated… the first act in thinking… making distinctions… sorting things out.. segregating things… in the beginning was expansion and contraction… which beget… division… addition… multiplication… and… subtraction… therefore… accretion… the gradual build up over time… bit by bit…

Time is the monitoring of change and change only happens with energy. Time exists because energy exists but I think it is descriptive instead of prescriptive to an existential mind that can care about time’s being. The less energy the longer time takes (?). I am an amateur so don’t take what I’m saying as dogma. A crude analogy is being nuclear bored at work and time drags so, so slowly.

Time is a measurement that lets you compare different amounts of energy to each other. Ignore most of these answers about quantum theory, quantum theory has lots of time involved in it and it means the same thing. The fact is that temperature, energy of a beam of light, work done on physical objects, can all be compared to each other by using tile to normalize comparisons.

It’s the stretching of the glue that was holding the fabric of reality together that was blown apart by the big bang.

I think Einstein was wrong that time is relative to motion. There must be a single & central present moment of NOW that applies equally to everywhere and everything that currently IS, no matter it’s relative motion or positioning in “spacetime”. In relativity, no such frame of reference (one NOW) exists. That’s absurd, isn’t it?

Time does not exist in the way we think. It’s not a line; that’s an oversimplification. Throw away any concept of linear time you have and try to see the world you navigate in as millions of small atoms. The movement, decaying and transformation of those atoms (and all other particles) is what we can call time, but it’s not bound to a global ‘timeline’. It all happens locally.

It seems this process seems to go slower when close to heavy objects (like Earth).

So in general when we zoom out, all across the earth the decaying / transformation process is about the same rate to our perception (although we do need to correct this on a low level sometimes in machines).

Most of these responses seem to be attempts at physics based explanations so here is a philosophical perspective: Aristotle defined time as the measurement of motion with respect to the before and after. In this sense time is a numerical value that describes how far apart the beginning and end of a motion (or more generally any change) are. As distance is the measurement of a given length, so time is a measurement of a motion across that length not counting the length itself. 🙂

“Time” is a measurement of change. In 3D space, you can measure distance and find the position of something. How do you then describe the period between measuring an object at different points? “Time” is the measurement that describes the period between two events.

“Time” is not fixed, it depends on a rate of change. Basically, the clock of “time” can run faster or slower. What changes how fast time flows is “mass.” A more massive object slows “time” as it “flows” past the object. The exact “why” is unknown, but this means that “time” slows down when near massive objects.

So what is it? It’s a measurement of change that can be affected by mass. Why mass slows “time,” we don’t fully know. The best way to understand is a river analogy. “Time” is some part of our universe that keeps flowing like a river. And like a river, they both slow down near the riverbank or “mass.” We use that flow to measure, we can see how the flow changes near mass, but we don’t know *exactly* what it is.

Asking two different physicists what time is and how it works is like asking a Hindu priest and a Presbyterian minister what “God” is and how god works. Both have probably spent a lifetime studying and thinking about that very question. They have very thought-through ideas about it that many many others believe as well. They may really believe that they have the one true answer. But the truth is that no one knows for sure. That’s not a very satisfying answer, but that’s how it is.

Here are the two most popular ideas:

Imagine an ant on the floor of an elevator. The ant can move left, right, forward, backward–any direction it wants, but only on the floor. To the ant, the floor is the only thing that exists. The elevator is moving up at a constant speed, and has been moving in that direction and at that speed for the ant’s entire existence, so the movement isn’t something it feels or notices. The two main ideas say that

1. the elevator floor is rigid and flat. The rocks and loose change on the floor just sit on top of the tiles. If the ant moves 1 tile left as fast as it can, the elevator has gone the same fixed distance up as when the ant moves its fastest a tile forward, back, etc.
2. the elevator floor is spandex with tiles printed right on the fabric. The rocks and loose change on the floor stretch it out where they’re sitting. Because the tiles aren’t all the same size and shape when they’re being stretched, if the ant moves its fastest one tile left, the elevator won’t have gone the same distance up as if the ant had gone one tile right. How much the elevator has gone up while the ant moves across a single tile depends on if/how stretched that tile is.

Time is the elevator shaft.

Edit: Thanks for the award!

Its analogous to potential energy plus kinetic energy trade off of a ball on a hill. If the ball is at the top of the hill it has no kinetic energy but lots of potential energy, once the ball rolls down to the bottom and is moving fast it has no potential energy but lots of kinetic energy. Apparently time and space distance have a similar inverse relationship. While sitting still you have lots of time and no space distance, while moving really fast, like close to the speed of light, you have lots of space distance but hardly any time. Thats why time slows down when you go faster.


🤔⚡☀️”Time” is a measure of magnitudes. The magnitudes change depending-on: position and observation. Ken Wheeler speaks to this concept on His Youtube: “Theoria Apophasis”. Many ‘Theories’ view “Time” as an object, removing the Observer as prime measuring Aspect.

I like the Twilight Zone concept of time – it’s a train of dioramas. To travel through time, you hop off the train and walk (run?) to the car (time) you want. Like, the time stamp of my life 20 minutes ago (20 cars back) has me getting coffee. But fast forward 20 cars from now and you would see me brushing my teeth. Alternate timelines would be different trains.

This is similar to thinking of time as the 4th dimension. 1st dimension is a line – a collection of points. 2nd dimension is a plane – a collection of lines. 3rd dimension is our reality – a collection of planes. 4th dimension is time- a collection of momentary realities.

The problem with this image is that time is continuous – we don’t actually have a way to chop it into pieces. Yet? We say this second or this minute, but our starting point is kinda arbitrary. We have been able to coordinate with other people on our definition of time units by using natural phenomenon, but there is no time particle that we can count.

In my physics of space and time class (decades ago), there was a delightful image of time as a straight line going in one direction, until it reaches now – time zero. From there, it becomes a cone of possibility- do I continue sitting on the couch? Do I get up and brush my teeth? Do I hop in the car and go to the airport and board a flight to China? There is no option for me to suddenly be in China next – that event falls outside of the cone of possible events, into the area known as elsewhen.

I CAN be in China, later, but I can’t jump outside the cone to be in China now. I CAN go to Mars, but I’m gonna have to track the edge of that cone for a long time.

Not sure that answers the question, but it seemed relevant. If my professor couldn’t really give the answer to that question (and he was the editor of the Journal of Theoretical Physics, and at some point in the class smirked a bit and said, “This is MY contribution,” so I’m pretty sure he knew what he was on about), I’m not sure the answer is out there.

Time is a gift, precious and rare, that helps you have the time you need to have the time of your life.