Easy Questions?

[Griffin NoName]

Does Einstein's Theory of Relativity explain why time appears to speed up the older you get? If so, how?

[Aggie]

I don't think so, but here's how I look at it:

The perception of time is relative to your age, because a given unit of time is measured as a proportion of your total lifetime (lived-time).  So, when you're six years old, a two-month summer holiday seems extraordinarily long, because it's a significant proportion (2.8%) of your total life* of 72 months. By the time you're sixty, those same two summer months only represent 0.28% of your life, or roughly 6 days of 6-year-old time.

_{*Say you're born at the start of September, so the end of the school holiday coincides with your 6th birthday}

I'm sure it's not all as clean and proportionate as that, but that's the gist of why I think time speeds up with age.

Or perhaps our brains record less information (in the sense of frames per second) as we age.  It could be that we're exposed to less new things and learning experiences over time, and our brain perceives long-time** based on this type of marker.  When you're young, new and critical experiences happen all the time, but older people have already been exposed to nearly everything they ever will be.

_{**I can't say that I've noticed a change in the duration of a second or a minute compared to when I was young (short-time), but definitely feel like the weeks and months go by much more quickly (medium- to long-time). I haven't yet noticed a change in how fast the years pass; in fact, although a month feels short, the last year feels very long when I compare who I am now with who I was then. It was a pretty big year for personal growth and change, even though I didn't really 'do' much compared to some years. This may support the latter conjecture regarding experience and time.}

The weirdest time-distortions I've experienced were when I was working out of town for extended stretches, and back for short stays.  I perceived the two halves of my life as being on different timelines.  It was as if the event-time of city life was based on the days I was there, while field-time corresponded with the calendar.  

Sometimes I'd think that I'd seen a particular friend or visited a particular restaurant quite recently (say, two weeks ago) because it had been roughly that amount of city-days since it had happened, but would then realize that it was actually closer to two months in realtime. It was as if my time out of town had been cut out of my city timeline entirely.

[anthrobabe]

I have begun to feel that it has something to do with my perception of my mortality.   

[Sibling Zono (anon1mat0)]

Statistically speaking I should be a bit above my half life yet time does pass significantly faster now.

Somewhere I read something on the subject but I don't remember where or what.

Perhaps I'm suffering from Alzheimer? 

[Griffin NoName]

Interesting. I was hopng someone would propose that the particles streaming through us become worn and less resistant to light passing through, or something.

I don't go for the x% of our age theory because personaly although I remember time being very slow as a child, I no longer know what that actually felt like so I can't compare. It may be that we do actions slower as we grow old, therefore the same amount of activity fills more minutes/hours so our perception is that time has speeded up. eg. it used to take me about 10 minutes to rise froom bed, dress, coffee and out the house. Now it takes nearer two hours.

[Aggie]

I'll agree that how frantic our days are contribute to our sense of time; when you are a child, there seems to be more moments of boredom, and inactivity seems to be more painful (can't sit still). However, as adults, it seems like time goes remarkably fast for the busy as well.

I look at the relative value of time as we age (the x% theory) as similar to our perception of money.  When we've not experience large amount of money, small amounts seem more significant.  A dollar to a 6-year-old who might have a piggy bank with $20 in it is a much bigger amount of the total than to that 60-year-old with $200,000 in the bank.  I've always been amazed at how much one's perception of money changes as one accumulates larger sums (that first $1 in pennies, then $10, $100, $1000 once you've started your first job, $10000, $100000....). A thousand bucks certainly doesn't mean the same thing to me now as it did when I was half this age.

[Griffin NoName]

Time is money

The odd thing for me is that there are many days when I do nothing except rest in bed. I would have assumed this would mean hours and hours of total boredom passing very slowly. The opposite has happened. When I was healthy and frantically busy, time was nowhere near as fast as now.

[anthrobabe]

Y'all I have a daughter who will be 28 on March 1st.
In 3 years I will celebrate the 20th anniversary of my 29th birthday.
My baby daughter will be married 3 years in April.

Halt time! Halt I say!

[Aggie]

oh wiki on danny boy :  Some listeners have interpreted the song to be a message from a parent to a son going off to war or leaving as part of the Irish diaspora.

But still only some.

I've been thinking on this (as we're performing it on three consecutive days at the moment) and the parent connection comes to mind. Otherwise, if a man was going off to war, wouldn't he (the soldier) be more likely to end in a grave than the beloved from whose perspective the song is written? It makes more sense from the perspective of an elderly/sickly parent.

[Griffin NoName]

It makes more sense from the perspective of an elderly/sickly parent.

Yes, that makes sense. I think it's the only scenario that does. Especially if they are already booked to go to Switzerland. 

I have always wondered why the sweetheart at home dies first. Answer, it isn't a sweetheart.

Now what if Danny Boy were replaced by Patsy Girl, since we now allow female soldiers to fight. LoL.

[Swatopluk]

How do the contents of a container behave in zero gravity that is mostly filled with water but has maybe 10-15% air? If it is the other way around the liquid forms globules floating in the air but with 90% liquid that would not be possible. Does the liquid stick to the walls of the container or does the air form spherical bubbles? A few big ones or many very small?
Does it matter what liquid is used (water, water with a detergent, mercury...)?

[Griffin NoName]

Which way up is the container?

[Swatopluk]

7-up 

[Sibling Zono (anon1mat0)]

If someone should be able to answer that is you Swato...
---
I'd expect capillarity to apply to the liquid (ie, hugging the container) and the gas as bubbles but I don't have the math to support that, and I assume it would greatly depend on the nature of the fluids themselves and capacity to interact with each other. I understand the math for bubbles is particularly complex, and have no idea how solubility would apply in this case. 

[Aggie]

Surface tension will be important (i.e. detergent would change things), but I would think that most of the liquid in the case of pure water would stay connected-ish. A single spherical bubble might be expected in an equilibrium (& zero acceleration/force) state where the adhesion of the liquid to the container was larger than the surface tension of the liquid, as this will give the lowest surface area of interface for the smallest volume of air.