Comments on: What is Time?

By: rchapra

rchapra — Wed, 19 Dec 2012 14:38:29 +0000

What we call time is the process by which we organize our perception of movement.

By: roadfood

roadfood — Tue, 18 Dec 2012 16:28:59 +0000

“Time. Time. What is time? Swiss manufacture it. French horde it. Italians want it. Americans say it is money. Hindus say it does not exist. Do you know what I say? I say time is a crook.”

 –Peter Lorre  in the movie “Beat the Devil”

By: BillyJoe7

BillyJoe7 — Mon, 17 Dec 2012 09:59:56 +0000

Maybe it was the iPad autocorrect function. Let’s see:
Jarred
Nope, must have been a typo, sorry.

By: Jared Olsen

Jared Olsen — Mon, 17 Dec 2012 08:15:29 +0000

Nice link, BillyJoe. Inspirational. The little girl talking about filled electron shells…wow. Not a helluva lot of deep abstraction though, which I think would be required for the ‘time’ question.
BTW Jaded? Was that a typo??

By: selfification

selfification — Sun, 16 Dec 2012 16:42:50 +0000

“Let us say that you had the ability to view the entire universe at once. As you watched it, you make not of the randomness or the messiness of the universe. We say that “positive time” has passed if your see more randomness overall (like milk mixing in water to become a uniformly watered down mixture). We say that “negative time” has passed if you see less randomness overall (like a broken vase re-arranging itself). We use devices called clocks that give us a measuring stick so that we may talk to one another about amounts of time. Now, we know that how quickly you are running around, where you and how close you are to other big objects and things affects how a clock works. There is no standard clock – everything is based on your own clock. But for people on earth, the changes are tiny and we still manage to mostly get along with crude measurements like seconds, minutes and hours.”

By: BillyJoe7

BillyJoe7 — Sun, 16 Dec 2012 11:03:18 +0000

Jaded,

There is a retired high school teacher in Australia, who has gone back to teach physics to primary school children in grades 3 and 4. He uses diagrams and models and the kids seem to be engaged and interested. At another school in Western Australia, children in grades 5 and 6 are being taught relativity.

http://www.abc.net.au/7.30/content/2012/s3647537.htm

By: Jared Olsen

Jared Olsen — Sun, 16 Dec 2012 09:39:38 +0000

I’m inclined to agree with quen_tin on this one. The best Einstein could do was “what a clock reads”, as quoted above. If anyone really knows what time is, I think explaining it to a child is next to impossible. Why not ask ‘what is quantum entanglement?’. That being said, I think it is a fruitful exercise, if not for the askers, then at least for the answerers (as the posts above show ).

By: BillyJoe7

BillyJoe7 — Sat, 15 Dec 2012 20:41:37 +0000

Tyro,

That was a pretty clever response and entirely accurate. Everything in the universe travels through spacetime at the same rate in all reference frames. That includes light. In fact, it is the reason that the speed of light is the same in all reference frames. The time dimension of light’s spacetime is zero, so all of it’s spacetime is taken up in the space dimension. This also shows why the constancy of the speed of light is not really all that special.

By: tyro

tyro — Sat, 15 Dec 2012 17:17:37 +0000

I’ll be very interested to see what sort of answers people come up with. For flames, the forces and particles involved are accessible to children and there are day-to-day analogues. As Feynman once said about magnets, some forces don’t have any analogies and have to be taken as they are and intuitive understanding may be elusive. I think that despite the simplicity of the question, time doesn’t have any analogues so it simply isn’t something that can intuitively understood. I suspect the best answers for children will have to emphasize the complexity and our lack of (non-mathematical) understanding.

By: tyro

tyro — Sat, 15 Dec 2012 17:12:24 +0000

@Blair T

No movement, no time. No time, no movement.

As I understand it, the reason that we have time dilation and other weird GR effects is that our movement through time and space is always a constant, c (the speed of light). When our movement through space is 0, our movement through time is at a maximum. That’s why when particles are moving through space close to the speed of light, their movement through time is very low. So ironically, as intuitive as your statement sounds it’s actually backwards.