When did you go to school?
I went to school long enough ago that Pluto was considered a planet. The solar system then had nine planets. Now it has eight.
If you had learned about the solar system before 1930, astronomy did not even know Pluto existed.
Since 2006 Pluto hasn’t been considered a planet, but that may change again as an effort is being made to restore its status as a planet.
Numismatics also has its moments of change.
When the 1969-S doubled-die Lincoln cent was first discovered in 1970, the Treasury declared it counterfeit and confiscated all those it could grab. Hobby experts disagreed.
After a lengthy period of a decade or so, the coins were called genuine and the doubled-die is now one of the rarities of the Lincoln series that can be found in circulation.
It is listed in the guide books.
When I studied economics in college in the 1970s the term “euro dollar” meant a dollar deposit at a bank outside the United States.
When the euro currency was introduced by the European Union in 1999, too many people primed by their educations kept putting dollar after euro simply out of habit.
But the currency is the euro – period.
Yesterday I read an online report with mixed up euro terminology. Other than revealing the writer’s time of education and that he hasn’t updated it in his working knowledge, no real harm is done.
But all these little changes add up over time.
That is why it is important for all collectors to continue to educate themselves by staying informed of current events, getting new editions of the guide books and occasionally reading them.
I write “occasionally” because even I need the refreshers.
I was looking up something in Indian cents yesterday and I noticed yet more minting varieties in the listings that I had not realized were there.
How long they have been there, I am sure an Indian cent expert can tell me, but I found myself repairing a gap in my knowledge.
We all are prone to those gaps because new information keeps coming.
The kind of gaps might show to the world just when you last updated your working knowledge. You never know when the subject might come up.
Buzz blogger Dave Harper is winner of the 2014 Numismatic Literary Guild Award for Best Blog and is editor of the weekly newspaper "Numismatic News."