The block universe theory states that time doesn’t exist how we generally perceive it. In reality, the past, present, and future co-occur, making time a clever illusion. According to the theory, this means your birth, death, and every moment in between exist somewhere in space-time.
The block universe theory says that the universe consists of a massive block containing every event and place. So, this would mean time doesn’t occur linearly but in a spiral.
In a block universe, time and place are relative concepts, as Einstein stated in his theory of relativity. According to that theory, time passes at varying rates for people or objects moving relative to each other. So, an event one person observes might happen at a different time for someone else.
If you’re confused, we will break things down a bit for you. Picture a three-dimensional rectangle with three spatial dimensions, length, width, and height. Now, imagine this rectangle as the  universe, containing all events that will ever happen. Let’s add a fourth temporal dimension to the block – time.
Next, think of an event that happened in your life, such as your most recent birthday. This particular day in the cube represents its location in the space-time continuum. All other events also exist inside this block and are intricately linked.
Below, we will go over the block universe theory in greater detail.
Physicist Explains The Illusory Nature of Time With Block Universe Theory
Dr. Kristie Miller, the joint director for the Centre for Time at the University of Sydney, said that time doesn’t pass. When you talk about the present, you describe your location right now. And, this location frequently changes, making it seem as though the present changes also.
To us, it appears that time flows or passes linearly. In other words, today marks the present, yesterday was the past, and tomorrow represents the future.
However, according to the block universe theory, a specific present moment doesn’t exist, and the past and future are relative. So, someone moving relative to you might exist in your past, meaning you’re in their future. In the block universe, this means that the other person exists earlier than you, and you’re located later than them.
So, in this mode of thinking, any moment in the past represents events occurring earlier than your location. And future means any times or events that happen later than your location.
In an article published on ABC Science, Miller describes the theory in this manner:
“So, suppose Bert the dinosaur is located earlier than Sally the dog. That relation between Bert and Sally holds, regardless of whether we are located earlier than Bert or later than Sally.”
In summary, the block universe theory states that you exist relative to all other phenomena. In space-time, every event occurs simultaneously at later and earlier locations within the giant “block.”
Does This Make Time Travel Possible?
You would think so since time represents another dimension. Dr. Miller says we can hypothetically travel in time, but not with our current technology. For starters, we would have to build space crafts capable of reaching the speed of light. Traveling that fast would result in the time dilation phenomenon, where it slows down enough for us to arrive in the future.
We can also theoretically travel into the past by using wormholes as a shortcut through space-time. However, Miller said that we couldn’t change the past even if we had the technology to time travel. She explained that this would cause a contradiction in the present and future. Since the past, present and future are the same in the block universe theory, nothing we do can alter them.
Everything occurs relatively, meaning that the past to us represents someone else’s future. By traveling to the past, we change our location in space-time, not the events that occur.
Dr. Miller said: “I’ll act, in the past, in the sorts of ways I act in the present. But I won’t be changing the past. Just as when I eat cornflakes instead of toast tomorrow, I am not changing the future, I’m just making the future the way it is, when I travel to the past I don’t change it, I just make it the way it is, and always has been.”
A Recap of the Block Universe Theory
To clarify, traveling to the past would only set off a predestined chain of perpetual events in the block universe. And, what we do there wouldn’t affect the future since it’s co-occurring.
Miller explained further: “The events in the block are there for all time: they do not change. So, as a time traveler, it’s not as though I suddenly appear at a past time. It’s always been the case that I am located at that past time.
“Nothing a time traveler does changes anything in the block. Instead, what the traveler does at any time makes that time, and later times, the way they are,” she said.
However, remember that we haven’t yet proven this theory, which would only be possible by traveling through time. Another idea known as growing-blockism states that the block universe grows continuously, meaning the future doesn’t yet exist. Proponents of this theory believe that as time passes, more of the universe comes into being based on present actions.
Hopefully, we will one day travel through space-time to learn the mysteries of our universe.
Final Thoughts on the Block Universe Theory
The block universe theory says that the past, present, and future co-occur. Nothing we do can alter events in space-time because they already exist. For instance, if we could time travel, it wouldn’t change anything happening in that period. It would simply trigger phenomena predestined to occur at that particular point.
Dr. Miller doesn’t dismiss the idea that these travelers may already exist. She said that perhaps they shaped the past, present, and future. We will need a special machine to test the block universe theory, but maybe we have already created one in the future.
