Could we one day travel through time like the Avengers? Here’s why the answer matters to each of us personally
Usually I’ve been posting about pretty serious topics, often controversial political topics, so I thought it was about time to explore something less serious and more fun, but that still has some surprising implications on our faith.
A few days ago, I saw the latest Avengers movie, Endgame. It was really good, and I would highly recommend seeing it, though you should probably watch its prequel Infinity War to understand what’s going on. I won’t give away any real spoilers, but the plot of Endgame centers around the heroes using time travel to attempt to defeat the villain Thanos.
If you’re a regular movie watcher, no doubt you’ve seen the concept of time travel explored in movies many times before. You’ve probably seen some of the classic time-travel paradoxes, such as the grandfather paradox and the butterfly effect, show up as plot devices. But is time travel really possible? Is the fact that we can’t travel through time just a matter of us not having discovered the right technology yet? And if it is possible, what implications does that have on our faith in God?
The dimension of time
It’s been said that our universe exists in four dimensions: three of space and one of time. It’s a little counterintuitive for us to think of time as a dimension in any way similar to the three spatial dimensions, but we do know that time is a physical thing that can be manipulated. This is most noticeable in areas of high gravity, because gravity warps both time and space. Someone experiencing a strong gravitational pull will actually experience time at a slower rate than someone who is not, a phenomenon known as gravitational time dilation.
The effects from the gravity of most astronomical bodies, like planets and stars, is very small. The gravity of the Earth causes a time lag of 0.007 seconds every six months for astronauts on the International Space Station. But around a black hole, with gravity so strong not even light can escape, the time dilation is significant. If you traveled close enough to the event horizon of a black hole, where its gravity pulls you down at nearly the speed of light, spent a few minutes there, and then returned, you might find that while only a few minutes had passed for you, hundreds of years had passed on Earth.
Velocity has a similar effect. The closer you get to the speed of light, the slower time will run for you relative to everything else. If you left today on a year-long round-trip to and from Earth at 99.9% of the speed of light, you’d return to find Earth calendars reading 2044 and your friends on Earth 25 years older, even though only one year passed for you.
This much is firmly established scientifically. But there is a big difference between distorting a subject’s experience of time and actually traveling through time. For that, we must ask: What is time? The way many movies and books portray time is as something like a 1-dimensional line, with each point in time being a location on that line. With the right technology and know-how, one could theoretically travel back and forth on that line. Accessing even higher dimensions could even allow you to see alternative timelines branching off of the “main” one, similar to how a straight 1-D line on a paper can branch off into other lines once you add the second dimension of width. But is time really like that — a traversable line? If you watch science-fiction movies and even read the science section of the mainstream media sites, you might think this is basically a given. But it’s only one theory of the nature of time.
Do the past and the future exist?
There are two basic categories of theories of time. One theory, known as the A-theory of time (or the “tensed” theory), is that the way we intuitively perceive time is correct: The past is what once was, and the future is what will be, but the past and the future do not currently exist. We may perceive and even experience the passage of time differently, but two objects cannot simultaneously exist at different points in time. You cannot travel to the future or the past, because they do not exist. Only the present exists, so there is nowhere to travel to.
The other theory, known as the B-theory (or “tenseless” theory) of time, is the theory that science fiction runs on. It says that time is a traversable dimension just like our three spatial dimensions, and if we can just figure out how to travel through that fourth dimension, we can move back and forth through it freely. As mentioned above, it basically pictures time as a timeline. On the B-theory, the past and the future do exist, and are just as real as the present; they are just on different points of the timeline. Time travel is only even theoretically possible if the B-theory of time is true.
But B-theory, while it is definitely the more interesting theory and makes for much better stories, also has some rather weird and disturbing implications. And they’re even stranger than the time-travel paradoxes that show up in the movies.
Disturbing implications of B-theory: You are mostly dead (and a worm)
Again, B-theory views time as a line, analogous in some ways to a spatial line. To see what this means for us, we can use a spatial line to illustrate, such as a tape measure. If you were to lay out a tape measure in front of you, and then stand up and put your feet on that tape measure, you would see that your feet aren’t just occupying one point on that tape measure. They are occupying several inches’ worth of space, covering several dozen marks on the tape measure. You don’t exist at just one point on the tape measure at a time; you are at all those points simultaneously.
So let’s imagine ourselves in a universe where time is like that tape measure, like a timeline. In such a world, the past and the future are just as real as the present. Therefore, just as your feet exist at multiple points on the tape measure when you stand on it, you exist at multiple points in time, not just this one, and the you at all those past and future points is just as real as the you at the present point. In other words, at another point on the timeline, you are a 5-year-old. Go in the opposite direction, and you have (hopefully) reached an old age. Go even further along the line, and your body is a corpse in the grave, and your soul is in the afterlife. Going further along the line, your body exists only as a corpse until the resurrection, however far in the future that may be. Just as your foot exists at all those points on the tape measure, you exist in all of these states: a child, an adult, an elderly person, and a corpse. You are both alive and dead, both young and old. In fact, chances are that prior to the resurrection at the end of this age, the vast majority of you is dead. What you are right now is just an ultra-thin slice of the real you. The real you covers the whole time of your temporal existence, from now until eternity. On this basis, some philosophers who subscribe to the B-theory of time have called us, along with all other objects, four-dimensional “worms” that stretch out along the line of time.
This would apply to everything in history as well. King Nebuchadnezzar is in the process of conquering Jerusalem elsewhere on the timeline — we’re just not at that point on the line and don’t know how to get there. George Washington is leading his army across the frozen Delaware River. The Cleveland Indians are winning the World Series. Isaac Newton is formulating his theory of gravity. Adam and Eve are enjoying an idyllic, sinless paradise in Eden. You are doing the worst thing you’ve ever done. Jesus Christ is dying on the cross for that thing, and all the other sins of the world. All these things are happening, but we’re just not at the right location on the timeline to see them.
What a universe with time travel would mean for faith
As you can see, a world where time travel is possible creates some wild and theologically uncomfortable paradoxes. The world is fallen into sin at some locations on the timeline, and unfallen at others. We are doing evil at some locations on the timeline, and good at others. We are in eternity at some locations, and in our earthly lives at others. In Revelation, when God declares that he is making all things new, he is only making things new past a certain point on the timeline — not all things that exist. When Hebrews 9:26 says that “[Christ] has appeared once for all at the end of the ages to do away with sin by the sacrifice of Himself,” it wouldn’t really mean he died once for all, because he would be still perpetually suffering and dying — just at another point on the timeline.
These strange and uncomfortable implications don’t mean the B-theory of time is false, of course. We’ve found far too many times that the universe is far more complicated than we could hope to understand, and things that seem like contradictions to us can still be true.
I know the Bible isn’t a science book. The Bible usually speaks from a human perspective in human terms. It isn’t meant to reveal to us the mysteries of the material universe. So I am not trying to use the Bible to prove the A-theory of time is true. However, this isn’t just a scientific question; it’s also a philosophical one. So I think it’s valid to also make philosophical and theological observations about the nature of time, as I have been doing. And the Bible is an authority in those areas.
I’m also not saying that what the Bible says is incompatible with a B-theory of time. God can do things we can’t even fathom. He can make all the promises of Scripture a reality no matter what the nature of time is. But I think the A-theory of time is the most consistent with Scripture and with logic. I think it’s the most consistent with the hope Scripture presents.
Encouragements in a world without time travel
If it turns out the A-theory of time is true, some of us science fiction enthusiasts might be disappointed. But I think this can also be great news. It gives us freedom from the past and hope for the future. Why? Because of what Paul says in 2 Corinthians 5:17. “If anyone is in Christ, he is a new creation. The old has passed away. Behold, the new has come!”
God is truly with us here and now, sharing our experience. If the A-theory of tone is true, it would follow that God does not exist “outside of time” as some Christians say, but that when he created the universe, he entered into time with us and interacts with the events of the universe as they happen. He is not standing distantly above the universal timeline, constantly experiencing all times at once. In real time, he shares with us in our grief and joy and trouble and thankfulness, and he hears and answers our prayers as we speak them. Of course, he has complete knowledge of what will happen in the future, what has happened in the past, and what is happening in the present, and he acts based on that knowledge. But when God is hearing your prayers today, he is not also watching you do the worst thing you ever did years ago. He’s not there; he’s here. When we are with him in heaven, he won’t still be back there in the past as we commit our worst actions. We can know God is with us now, and fully shares in our experiences.
The old is truly gone. Who has never been plagued by bad things in their past? Whether it’s things you did or things that were done to you, there are all things in the past we would like to escape. On a B-theory of time, it could be said that there is a growing distance between you now and the you that did or experienced those things. They still exist, but are getting farther away from where you are now, and in that sense they are passing away. But on an A-theory, Paul’s statement is much more powerful, because the past is not only gone but annihilated. Those things literally do not exist. Soon God will bring about justice for all the evil done to us, redeem our mistakes, make everything new, and what is good will remain or be restored, while what is bad will remain annihilated.
The new has come. Each moment is new. It did not exist before it arrived, and it will no longer exist after it leaves. Because the old is truly gone, annihilated, you can truly be made new. It’s a long, slow process on this Earth as we struggle and sometimes resist. But eventually, when this present age comes to an end and God brings his kingdom to earth, all the old things will be completely annihilated, obliterated, nonexistent. And bit by bit, the hurts of your past are being annihilated now.
Everything we learn can enhance the truths we know
Unless you’re a science teacher, science-fiction enthusiast, or have curious children who ask lots of questions, you may never actually make practical usage of this information. But each bit of information we learn helps shape the way we think, and the way we think shapes our relationship with God and others. You may never hear or even think of the A-theory and B-theory of time after you finish this post, but you will certainly recall parts of your past that you want to escape.
If you are a Christian, you know that your sins are forgiven and that God is healing your hurts. But maybe, if you find yourself agreeing with the perspective I’ve presented here, you can begin to also recall that our past misdeeds don’t exist; they have been annihilated. They are escapable. Our past hurts will not last forever; their effects may continue, but in the end they, too, will be annihilated. God is with you in the present here, not watching that stuff back there. Maybe this will help us all have a little more confidence in God’s close presence, and in his grace to wipe out all evil and consign it to nonexistence, while bringing us into what is new.
