Time: Do the past, present, and future exist all at once? | Big Think

Time: Do the past, present, and future exist all at once?
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Everything we do as living organisms is dependent, in some capacity, on time. The concept is so complex that scientists still argue whether it exists or if it is an illusion.

In this video, astrophysicist Michelle Thaller, science educator Bill Nye, author James Gleick, and neuroscientist Dean Buonomano discuss how the human brain perceives of the passage of time, the idea in theoretical physics of time as a fourth dimension, and the theory that space and time are interwoven.

Thaller illustrates Einstein's theory of relativity, Buonomano outlines eternalism, and all the experts touch on issues of perception, definition, and experience.

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TRANSCRIPT:

MICHELLE THALLER: Is time real or is it an illusion? Well, time is certainly real but the question is what do we mean by the word time? And it may surprise you that physicists don't have a simple answer for that.

JAMES GLEICK: Physicists argue about and physicists actually have symposia on the subject of is there such a thing as time. And it's also something that has a traditional in philosophy going back about a century. But, I think it's fair to say that in one sense it's a ridiculous idea. How can you say time doesn't exist when we have such a profound experience of it first of all. And second of all we're talking about it constantly. I mean we couldn't get, I can't get through this sentence with out referring to time. I was going to say we couldn't get through the day without discussing time. So, obviously when a physicist questions the existence of time they are trying to say something specialized, something technical.

BILL NYE: Notice that in English we don't have any other word for time except time. It's unique. It's this wild fourth dimension in nature. This is one dimension, this is one dimension, this is one dimension and time is the fourth dimension. And we call it the fourth dimension not just in theoretical physics but in engineering. I worked on four dimensional autopilots so you tell where you want to go and what altitude it is above sea level and then when you want to get there. Like you can't get there at any time.

GLEICK: Einstein or maybe I should say more properly Minkowski, his teacher and contemporary, offers a vision of space-time as a single thing, as a four dimensional block in which the past and the future are just like spatial dimensions. They're just like north and south in the equations of physics. And so you can construct a view of the world in which the future is already there and you can say, and physicists do say something very much like this, that in the fundamental laws of physics there is no distinction between the past and the future. And so if you're playing that game you're essentially saying time as an independent thing doesn't exist. Time is just another dimension like space. Again, that is in obvious conflict with our intuitions about the world. We go through the day acting as though the past is over and the future has not yet happened and it might happen this way or it might happen that way. We could flip a coin and see. We tend to believe in our gut that the future is not fully determined and therefore is different from the past.

DEAN BUONOMANO: If the flow if time, if our subjective sense of the flow of time is an illusion we have this clash between physics and neuroscience because the dominant theory in physics is that we live in the block universe. And I should be clear. There's no consensus. There's no 100 percent agreement. But the standard view in physics is that, and this comes in large part from relativity, that we live in an eternalist universe, in a block universe in which the past, present and future is equally real. So, this raises the question of whether we can trust our brain to tell us that time is flowing.

NYE: In my opinion time is both subjective and objective. What we do in science and engineering and in life, astronomy, is measure time as carefully as we can because it's so important to our everyday world. You go to plant crops you want to know when to plant them. You want to know when to harvest them. If you want to have a global positioning system that enables you to determine which side of the street you're on, from your phone you need to take into account both the traditional passage of time that you might be familiar with watching a clock here on the Earth's surface, and the passage of time as it's affected by the...

[bigthink]

Have questions for one of the experts featured in this video? Let us know! We'll keep them in mind for our next video.

[BrettyPOV]

Time is a useful tool but I can't help feel I had a more healthy relationship with time as a child, when it wasn't associated with so much anxiety of the future and regret of the past. As a child I lived in the present and experienced much joy and also struggles. This new concept of time passed down to us seems to come with drawbacks, as useful as it is.

[QuestionEverythingButWHY]

"I am just a child who has never grown up. I still keep asking these 'how' and 'why' questions. Occasionally, I find an answer."
― Stephen Hawking

[locwpqj]

I’ve been thinking about this a lot since my husband died, that time is an illusion——if everything is happening all at once he still exists! As do I when I was young! I wish I could visit that dimension whenever I wanted!

[jackmorgan]

A long, long time ago I read the following, paraphrasing of course, in Mad Magazine:
“To the past, the present is the future. To the future, the present is the past. If the present is both future and past, then we live in all dimensions simultaneously.”
I've yet to see all this discussion of "time" stated more succinctly.

[williamolenchenko]

Perhaps a good analogy is a movie on a DVD disc. The entire movie already exists on the DVD, but you observe only the "present" while the movie is being played. The observer creates the illusion of past, present and future by having a memory of the past, and an expectation of the future.

[moonshine]

Time is all about your state of consciousness and perception. If you sit in a empty room for 5 hours with just a clock to look at. Time will take FOREVER because you are actively aware and observing of it's passing. Now say you are in the same room except it's with your friends playing video games. 5 hours will pass in the blink of an eye. The amount of time is no different but your consciousness and perception of it is.

[JorgeMartinez-xbks]

So free will is just an illusion. The whole script or movie of our life was already filmed and we are just watching the show second by second. Amazing, no need to cry.

[behamut]

I remember once I was at a music festival. It was a rock festival and I was about to see one of my favorite bands of all time, I have been waiting for HOURS under the cold rain for them to show up, almost to the point of giving up and going home. It was so weird to feel so miserable and happy at the same time once they finally started to play.

And I remember that I started to think ''tomorrow all these sensations will be just a memory, they won't exist anymore, it will all disappear and it will feel like a dream'' and that just felt so weird to me. I couldn't understand why that moment had to disappear if it felt so real and it was so powerful. The rain, the cold, the tiredness, the excitement. Why was it more ''valid'' there than the day after?.

4 years have passed since that day, and still sometimes I stop and remember that moment, remember the rain falling on my coat and me and my friend huddled together trying to endure it, and it feels like I'm still there, waiting for my favorite band to come up.

It was a revelation to know that Einstein had a similar way of thinking as well.

[jondunmore]

Try telling your boss that time is an illusion.

[wufspyder]

Since I was 10yrs old, I'm over 60 now, I've always understood that: Time was the measurement of matter's movement through space. And that all aspects of it (ie. Past, Present and Future) exists simultaneously. Based on where you, as an individual are, relative to your position in that movement.

[RANDOM_PERSONx_x]

Time basically comes to a standstill at the speed of light. It's such a huge clue, yet no one can figure this out. The universe is so amazing and inspirational. I'm completely blown away right now!

[tonytonguetied]

She described space time better than anyone I’ve ever heard!!! I don’t even think I understood that concept until now, but I’ve heard it for years.

[poppopN]

"i didn't say that"-Albert Einsten

[hayleyb]

I love Michelle Thaller!!! I seem to have an easier time comprehending concepts if she's explaining them. Something about her voice & inflection really resonates.
Love from Texas ♡

[dankydiecast]

I had a Science teacher in 8th grade tell us kids something that has stuck with me all these years. Imagine a planet millions of light years away but they have a very special telescope that receives pictures from other distant worlds. They point it at Earth but they are so far away, they are only just now getting pictures of dinosaurs walking around on our planet.

[MrVikingsandra]

Wow, I find this topic so fascinating, I'm reading quite a few books about it. Mrs Thaller is such a brilliant teacher I find, the way she explained these concepts was super clear and to the point. Thank you for sharing your knowledge with us 😃

[hashashin]

I'm in a very boring French lesson right now, time is not moving here.

[donjohnstone]

I think time is change (fundamental dynamic movement). Everything in the known universe is constantly undergoing change and time is one of the conceptual tools we use to measure the process of change. If nothing changed then time would not exist.

[wonderingheights]

Time is the 4th dimension. Gravity allows us to experience it. That’s why the fabric of space/time bends around certain objects, and why certain objects bend space/time bc of their mass.

When people have NDEs, they mention that time doesn’t exist. Time is an illusion. But we use time to grow, to live, to experience our human experience on earth.