Wednesday/ physics memories

Yes, it’s a 1996 issue and possibly missing a few notes on quantum mechanics and particle physics, but hey: $8. (That’s a French train on the cover).

I picked up this physics handbook at a secondhand bookstore today.  What in the world do I want to do with it? Well, it is very similar to one that I had as a freshman engineering student, and it brings back happy memories.

The first chapter has tables that illustrate the orders of magnitude in time, mass and length that physics deal with. The rest of the book is packed with pictures and diagrams.

Whoah. It’s an unimaginable long way to the edge of the observable universe (the last entry in the table). A light year is roughly 10^16 m, so that 10^26 is equal to 10 billion light years.
The age of Earth and the age of the universe are an order of magnitude apart, rougly speaking. In more precise terms, the age of Earth is 4.6 billion years and that of the universe 13.8 billion years.
This table tells me that Earth is roughly 100 times the mass of the moon, and the Sun is roughly 100,000 times heavier than Earth. I think I read somewhere that if Earth was the size of the head of a match stick, the Sun would be a soccer ball!

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