What are space and time?

It’s a commonly-asked question; being humans, we’re especially fond of difficult questions and absolutely prone to defining things. As our collective perspectives of the world change and develop, many of us find ourselves deeply questioning the nature of space and time. We seek knowledge and understanding, and often we confuse ourselves with strange concepts.

I’ve been passionate about physics since I left high-school, and the cruciality of space and time has caused the two concepts to graze my consciousness in an almost unrelenting fashion. I’ve come across both mind-blowing and disappointing ideas about the subjects and finally have an idea that I feel is concrete enough to share with those less-informed.

So, is time an illusion? Can time be defined?

The short answer is, no, time is not an illusion; yes, time can be defined.

In fact, while the Oxford definition may not be so state-of-the-art, another simple definition of time could be as follows: “A measurable difference between things.”

In this sense, the measurable difference between waking up and going to work would be about two hours. The difference between a full cup of coffee and that same cup empty would be about 15 minutes. And for a final example, the difference between the dog sitting on the carpet and the owner watching it would be zero — kind of.

So that’s an introductory definition to time, but there’s much more to it than that, especially when considering its implications and the possibility of abstracting time as an object.

What about space?

Intuitively, space is the same as time in that they’re both measurable differences between things. Perhaps a better definition of each would be to say that they’re measurable differences distinct from one another. However, you remember that thing in the back of your mind that says something about Einstein and them both being connected, right?

Einstein worked extensively on the subject of space and time, or spacetime, as we now think of and refer to it. The work involved ‘invariance’ — Einstein wrote his most famous paper on things that don’t change, namely the speed of light. Represented commonly by the letter ‘c’, the speed of light is a fixed measurement of nearly 300,000,000 metres per second. Light waves, despite travelling with different frequencies that correspond to different energy levels, will always travel at (a little bit less than) that speed.

So, what has this got to do with space and time? Well, the speed of light is measured in metres per second, units of space per unit of time. Einstein’s theories took into account the fact that light — more generally electromagnetic (E.M.) radiation — mediates the events that we’re familiar with. For us to be aware of anything around us, E.M. radiation must transmit information.

The mathematics involved in calculating the measurements of events relative to one another gave rise to a new perspective on time. Much like how measurements of distance can be different for different observers, measurements of time can be different for different observers as well. This makes time and space essentially more closely related than we thought, and the conversion factor for telling the two apart is the speed of light. Space and time are known to physicists as dimensions.

So, by now I’m sure that you can see space and time are just necessary definitions for helping us understand the world around us. They’re no more false or illusory than anything else that exists, and describing them takes surprisingly little effort. But now let’s address the elephant in the room.

How about that ‘c’ thing, ey?

The speed of light is the universal speed limit; it tells us something phenomenal about how space and time relate to one another. At a fundamental level, everything that we know that’s moving slower than the speed of light is being inhibited by a documented force. This lends itself to the theory that all particles in the universe are figuratively trying to move at the speed of light.

So, why specifically 300 million metres for every second? Why not some other relation or speed? Nobody currently knows the answer to this, but the answer may have something to do with the other dimensions. You see, while space and time are dimensions that can be measured, there are other possible dimensions that exist. Charge and mass are two that you’re probably familiar with, things (events) have ‘rest mass’ and charge, properties that differ between different things. There are other possible dimensions too that are obscure to the public. In fact, words like ‘spin’, ‘hyperspin’, ‘charm’, and ‘strangeness’ all relate to measurable quantities that could be perceived as dimensions.

Ultimately, the fact that we have quantified in some way the relationship between space and time means that we are one step closer to understanding the true nature of dimensions. Understanding this nature could lead to innovation beyond our wildest dreams. Time-travel, teleportation or even mass generators could be on the horizon! As I’m a fan of science and the prospects it offers, I must finish by advocating my support for scientists around the world.

Thanks for reading!

This was a guest post, but feel free to visit my website if you’re curious about where it came from! Unique Philosophy