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Norman Sperling
2625 Alcatraz Avenue #235
Berkeley, CA 94705-2702

cellphone 650 - 200 - 9211
eMail normsperling [at] gmail.com

Norm Sperling’s Great Science Trek: 2014

San Luis Obispo
Santa Barbara
Palm Springs
Death Valley
El Paso
Corpus Christi
Baton Rouge
Key West
Winter Star Party, Scout Key

MARCH 2014:
up the Eastern seaboard

APRIL 2014:
near I-40, I-30, and I-20 westbound

MAY 2014:
near US-101 northbound
May 17-18: Maker Faire, San Mateo
May 23-26: BayCon, Santa Clara

California till midJune

JUNE 2014:
Pacific Northwest

JULY 2014:
Western Canada, eastbound

AUGUST 2014:
near the US/Can border, westbound
August 22-on: UC Berkeley

Speaking engagements welcome!
2014 and 2015 itineraries will probably cross several times.

The Metric Light Year

© Norman Sperling, October 24, 2011

My friend John Westfall, an astronomer and geographer, points out that astronomy uses several non-metric units, most prominently the "light year". Officially, that's the distance that a beam of light travels, at the speed of light, in a year's time. In metric units, that's 9,460,730,472,580.8 km (about 9.5 Pm), according to Wikipedia.

While the light year is more than 5% shorter than 10^16 meters, no celestial object more than 20 light years away has its distance known within 5%. Uncertainties out there begin at 15% and quickly grow worse than 25%.

So, as far as anyone can measure, there is no difference between "100 light years" and "10^18 meters". Let's call 10^16 meters a "metric light year".

The Journal of Irreproducible Results
This Book Warps Space and Time
What Your Astronomy Textbook Won't Tell You

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