# Proper time change

• B
When helium 4 becomes a super fluid does the proper time change, can this be detected?

Ibix
Proper time is the time measured by a clock travelling with something - so your proper time is measured by your wristwatch. I'm not sure why you think phase changes in helium has anything to do with proper time (and proper time of what? The whole volume of helium? One atom? You?). Can you tell us where you got this idea from?

russ_watters and Ripperooster
My understanding of proper time:
Every point in space is affected differently by time and gravity so has a different relative time, this goes for the 1st floor and the 50th or my toe and my eyebrow.

My question: does the proper time of a substance change the when you change a substance into a superfluid.

I don't know where I got the idea from, but I couldn't find a clear answer, which usually sends me down the rabbit hole..

Orodruin
Staff Emeritus
Homework Helper
Gold Member
2021 Award
My understanding of proper time:
Every point in space is affected differently by time and gravity so has a different relative time, this goes for the 1st floor and the 50th or my toe and my eyebrow.
This understanding is not correct. There is nothing such as a unique way of identifying a "point in space" as that would be coordinate dependent. Proper time is an invariant quantity related to a clock following a particular world line.

Ibix
Proper time is boringly predictable. It ticks by at one second per second - it's a things own measure of its own passage of time, so it cannot be any other way. Where you start to get unusual (to everyday intuition) effects in relativity is when you try to compare two clocks that are not at the same place, or have followed different routes through spacetime. This is not, or at least not solely, to do with proper time (note that the word "proper" has drifted in meaning in English - it's used here in its Latin sense of "one's own", the root of the word property).

There is, at least in principle, a slight difference in the tick rate of a clock sitting in a jar of liquid helium compared to one sitting beside the jar, due to gravitational time dilation from the mass of helium. It's on the order of one part in 1030 (give or take a few orders of magnitude depending on the mass of helium and the distance between the clocks), if my mental arithmetic is right - so one second difference every hundred thousand billion billion years or so (recall the universe is only thirteen billion years old).

I am not aware of any reason why a phase transition would have any effect on an already unmeasurably small difference.

Thank you,

The question came from reading about the effects of bubbles, wall climbing and friction of the super fluid.

I understand the immeasurable diffences of my head and feet but I'm sure differences in relative time have been shown at the top and bottom of a skyscraper.

Can the relative time of a superfluid be proven to be constant though it's change or phase change as you put it.

phinds
Gold Member
2021 Award
Can the relative time of a superfluid be proven to be constant though it's change or phase change as you put it.
You started off talking about proper time and now you have switched to relative time. Time relative to WHAT? Do you mean the proper time throughout the life of the material? If so, that question has already been answered.

Ibix
I understand the immeasurable diffences of my head and feet but I'm sure differences in relative time have been shown at the top and bottom of a skyscraper.
I believe tick rate differences have been measured at height differences as low as 1m, so differences between your head and toes are detectable. But this is the gravitational field of the Earth. My number above is a back-of-the-envelope estimate of the equivalent effect due to the gravity of a jar of liquid helium (or, indeed, a jar of water) and sounds optimistic on reflection. Its gravity just isn't important to anything.
Can the relative time of a superfluid be proven to be constant though it's change or phase change as you put it.
As phinds says, relative to what?

I can't think of a reason why helium would have any relativistic effects that another chunk of matter wouldn't have. Its peculiar properties are a form of self-organising behaviour, at least in my limited understanding, not related to kinematics or gravity.

Dale
Mentor
2021 Award
I don't know where I got the idea from, but I couldn't find a clear answer, which usually sends me down the rabbit hole..
The clear answer is “no”. So you can come on up out of the rabbit hole