What is Time? - AlwaysAsking.com

What is time? Few things are so familiar and mysterious. Time is the most common noun in the English language. Our lives are governed by time, and yet we have so little understanding of it.

In this episode, we consider what science has to tell us about time. We find that it is stranger than anyone could have imagined, at least, anyone before Einstein.

Beginning: 00:00
Episode start: 00:25
The miracle year: 01:45
Special relativity: 03:37
Overturning tradition: 04:16
Strange predictions of special relativity: 05:30
Confirmations of special relativity: 07:36
Is the speed of light constant: 08:44
Ranging the moon: 10:05
Measuring time: 11:34
Atomic clocks: 12:53
Time dilation: 14:26
Testing time dilation: 15:53
Twin paradox: 17:32
Time dilation and GPS: 19:03
Significant time dilation: 20:25
Particle accelerators: 21:42
Length contraction: 23:27
Atmospheric muons: 23:44
Interstellar travel: 25:42
Length contraction on atomic scales: 27:30
Length contraction on astronomical scales: 28:39
Understanding special relativity: 29:33
Spacetime: 29:54
Spacetime and length contraction: 31:04
Spacetime and twins: 33:21
Clock desynchronization: 34:39
Relativity of simultaneity: 36:59
Events in spacetime: 40:41
Evidence of four-dimensional spacetime: 41:40
Interchangeability of time and space: 43:15
Messages from the future: 45:02
The future has already happened: 47:17
The Andromeda paradox: 48:44
Understanding the Andromeda paradox: 51:25
Conclusions: 53:34
Implications for reality: 54:25
Four-dimensionalism: 55:09
Is change an illusion: 57:04
Why is the future unknowable: 59:20
Time's arrow: 01:00:08
Implications for self: 01:00:08
Do we have freewill: 01:01:52
Religion and special relativity: 01:03:06
Relativity of viewpoints: 01:03:17
Existence of all times and events: 01:03:43
Eternal life: 01:04:50
Caesar still lives: 01:05:15
A tenacious illusion: 01:08:40

Other formats:

[vblake]

Your explanation of this topic is a thing of beauty.

[mattyoung]

I will say that I've been watching various things, like documentaries on YouTube, and spend several years at uni studying physical sciences, and quite often I'll watch different docos, but on the same topic. This wasn't because I'm just crazy about these topics, it's because they do interest me, but I find it quite hard to understand. So each time I watch something. I may learn a little something extra, but have never come across a single production that has managed to allow me to better understand so much of this stuff.

Then I watch your video ... and it's a combination of your explanation being so clearly put forth ... you don't dumb it right down, but you spend quite a bit of time explaining everything. So now, with the bits I've learned over the years, and your video here, it's like so much has just clicked. I'm so stoked, and thankful. 😁❤️ thank you!! I am not saying I'm a subject matter expert now, but this video has been so very helpful 😁 you have my sub, and I look forward to more videos. I hope you can get some good monetisation going with these videos! Our future needs these types of videos to be prioritised over much of the other crap out there! Cheers mate!

[NameRequiredSoHere]

The quote about how "now" is analogous to "here" finally made relativity understandable for me. I also find it much more comforting than the religious idea of heaven since it is a theory that is a demonstrable possibility. I've had so much grief as I've had to deal with the death of close friends and family. It's a comfort to imagine that from some other perspective, in another "here and now" they are still part of my universe.

[YogSoth]

Please come This channel is so good. I would gladly support this channel financially if it came back.

[MrTheguy]

This is an amazing watch. This is the best video I have seen on this topic. Thank you!

[DoesNotGiveAF]

If you continue making content like this you will definitely grow. Aside from those who genuinely enjoy this content many others like these "long" interesting videos at night to unwind and fall asleep with. It takes a lot of work to put something like this together so thank you for your effort and even though you deserve compensation I greatly appreciate the lack of ads.

[donaldkupczyk]

When I was 12 years old I saw Madonna doing a show (on our old black and white tv) the only thing is she was 30 years old, and yet she was born 1 month before me..How do you think that was possible ?..

[richardnelson]

In fact, the future does not exist EVER. The past is what the present no longer is. The future is what the present isn't yet. If all 3 existed simultaneously, you would yourself have to exist in all 3 at the same time, and talk about strange paradoxes, nothing would make any sense at all. Even the laws of physics would become meaningless. Example. In the present an object has motion, but in the future it has no motion. Combine the 2, and what is the object doing ? It can't both be in motion and motionless at the same time. This is only the tip of the iceberg in disproving that all 3 can exist simultaneously. By saying that the future already exists, is also saying that the universe already existed when it didn't. What in the world are these people smoking ? I'd like to try some

[TheZooman]

This was a very comprehensive video about space-time. I look forward to watching many more.

[LiveArtPresents]

It's eight o'clock. I've got it written down on a piece of paper.

[AbhishekKumar-dbom]

You deserve more subscribers.I just stumbled upon you channel.
Really appreciate how you try to reply to a comment with great knowledge. You yourself seems to be a passionate and knowledgeable person.

Keep it up buddy. Love from India.

[nitrofan]

This episode is so informative and confusing at the same time. Great work!

[andreybogoslowsky]

Most ridiculous part about this universe is-“cause and effect”
I can’t get used to it for over 50 years.
Take for example, if I shampoo my hair twice, my hair stays clean longer.
Or as soon as I clean my gutters it will start pouring storming.
I can bring endless examples about how future can be changed by actions in the present.
Since I have nothing to do since early childhood, I keep myself busy painting, drawing
I paid for my children’s college. I don’t need anything else.

[wbiro]

Time is a concept that has been misunderstood ever since Einstein's former professor came up with the term 'spacetime'. Since then, everyone has been believing in Voodoo Time - time as a mystical physical medium that you can physically move through (hence the erroneous notion of backwards time travel).
Wherever you hear 'time' in this video, remove it and correctly insert CHANGE, which is the actual phenomenon of interest, and the voodoo disappears (as well as the Grandfather Paradox, which should have been a red flag that your thinking was wrong), and your backwards travel engineering efforts are correctly refocused on 'change' (from Voodoo time to the reality of change).
What is time? Nothing mysterious, it is a tool that we invented to quantify one dimension of change (space being another tool for another dimension of, change, with its invented spatial units, heat being another, then entrophy, etc. etc.).
If you want to go backwards in time, just run your clock backward. It will not affect any other aspect of change.

[Villinos]

I've read tons of stuff trying to grasp the concept of spacetime and get an idea about the theory of relativity. I haven't studied physics, I am a medical doctor and I am only familiar with the basics in this field. Your video (and the texts in your site) is the best material I've read so far. Explaining these concepts so clearly and effortlessly and in such a natural order, is a rare talent. Having the knowledge isn't enough to make these things understandable to the non specialist reader. I consider your work invaluable for anyone wanting to expand their knowledge. Thank you!

[acpeji]

Is it really proven that we live in a block universe and that the past, present and future is happening at the same time?

I am always thinking about this because it is really mind-blowing to know that our future is already decided...

[fredkelly]

At least with an esoteric fanbase you get to answer all the comments.

[credterfe]

Time is the freedom to have or to arrange an order of events. Order if left to itself will ultimately be consumed by entropy the default state, and with the loss of order, time stands still. Time as an ever-increasing calendrical series cannot continue. Space is also mentioned here, as the freedom of celestial or any physical object to move about without collision or external hindrance. Space so understood is also ultimately consumed by gravity as objects collapse on each other at the CoG of the universe. In this state there is zero space due to overcrowding and extreme gravitational attraction. So zero time and space ultimately if things are left to themselves.

[KpxUrz]

I plan on living Forever! --- and, so far, so good...

[ikaeksen]

It is not peridolia, but do you see the image of a girl with a yellow handbag in middle of galaxy? she allmost as big as galaxy is top to bottom. But to see her easier you need to not be too close to your tv or monitor.