# It’s just a question of time

Yesterday, I had to sell my soul and due to time pressure bring my children to the hamburger place. We ordered one of those happy meals. That led me to do a quick study of time and what kind of time units we have in our universe… Some of this is also reflected in a Wiki post.

For example, I’ve never heard about the Chronon. A proposed quantum of time which implies that we are talking about a discrete-time university and not a continuous-time one. This time unit is something like 7 x 10-24 s.

I have looked at the Planck time before (and still I am very puzzled by the huge orders of magnitude between different time units). The Planck time is miniscule compare to the Chronon, some 5 x 10-44 s. Quite a lot of plancks in a chronon.

A notable time unit is the Jiffy which turns up here and there. Personally, I do not like the jiffy definition as 1/50 s or 1/60 s (Europe vs America). To inconsistent. Let’s stay with the physics definition: the time it takes for the ligt to travel one femtometer: 3 x 10-24. So, we have two-ish jiffies on one chronon.

In one of the above mentioned wikipedia pages they have tabulated units and also made a logarithmic scale to represent them. We have more examples:

I’ll let you do the rest of late-night-wiki-reading.

It’s just a question of time

So, illustrating this in the figure above (in a logaritmic scale). We have from the left, Mr. Planck at the 10^-44 level. Then the Jiffy-Chronon pair at some 10^-24.

We recognize picoseconds, nanoseconds from our designer’s world. Nanoseconds imply the typical time period of our clock/signals. Picoseconds helps us discuss the rise- and fall-times.

The m/c indicates the time it takes for the light to travel 1 meter. Effectively that order of magnitude for our electrical waves to travel across a PCB. This helps us understand the need for termination, transmission lines, etc.

The second itself, is our common reference, and is the expected time your supervisor wants an answer on his e-mails.

We can see the year (10^7) which helps us understand the time from the design of a chip to the acceptance of a journal paper.

The age of University (10^17) is the bigger candidates and estimates the time it takes for you to get accepted in the IEEE community.

So, getting to the point. What is then the HMET?

That’s my definition of the “Happy Meal Excitement Time”. It is the expected time of paid interest from a four-year old in the happy-meal box and the toy that follows it. The time is measured from when the child screams “I want a toy” and pulls your clothes until it has received the box and opened it and lost interest of the toy. Sort of…

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