Archive for January 4, 2017

Wednesday, January 4, 2017

The Leap Second

Jack Forster:

UTC used to be based on the rotation of the Earth around its axis, as observed at Greenwich. Once upon a time – a simpler, happier time – the second was exactly 1/86,400 of a day. By the mid-1950s, however, clocks had gotten accurate enough that we’d figured out that the Earth’s rotation on its own axis was irregular, so in 1952, the International Union Of Astronomers decided to define the second as a fraction of one orbit of the Earth around the Sun: a second would now be 1/31,556,925.9747 of a tropical year.

However, the year turned out to have the same basic problem as the day; it’s irregular, changing slightly in length from one year to the next. (This is different, by the way, from the problem that requires the insertion of an extra day in a Leap Year; the Leap Year is inserted to keep the Gregorian Calendar in sync with the seasons, but the reason for the Leap Year, is that there isn’t a whole number of days in a year, not that an astronomical year varies slightly in length from one year to the next.)

[…]

As it turns out, atomic clocks are much more stable than the Earth’s rotation around its axis, or its orbit around the Sun, and it soon became clear that while an atomic clock-based time standard (UTC) was great to have, it meant that there was going to be a cumulative difference between UTC, and observed mean solar time. While both the astronomical day, and year, are irregular, the day overall has been getting slightly longer for at least the last few centuries. To keep UTC and mean solar time in sync, a Leap Second is occasionally added to UTC.

Via Nick Heer:

Accurate time is also essential for things like HTTPS certificates and, apparently, Cloudfare’s CDN services.

Previously: Intercalation.

Getting a New 2013 Mac Pro in 2017

Chris Adamson:

Waiting isn’t really an option, with my 2008 machine not supported by Sierra.

I think my needs, for development and especially for video work (Motion and Wirecast, mainly) are best served by the Mac Pro. Even the pathetic, three-year-old Mac Pro, because what I want is lots of cores, silent operation, and expandability of RAM and storage, something the iMac and MacBook Pro can’t offer.

[…]

If Marco’s right, then the choice is either today’s Mac Pro, or no Mac Pro.

[…]

I’m honestly not sure Apple is even a consumer electronics company anymore. I’m starting to think they’re more a fashion and luxury goods company instead. […] The whole reason I bought AAPL in the first place was from reading Motley Fool back in the day (on AOL even! yes, I’m old!), whose emphasis on buying single stocks came from knowing what a company did and how it could be profitable doing that. I understood Apple in the 90s and believed that if they kept doing the right thing, they would succeed. They did, and I was rewarded handsomely for believing in them. But now, what the heck am I supposed to think when they’re maybe making a car, or making $300 coffee table books to celebrate how great they are? This makes no damn sense to me, so it’s time for me to be out.

I’m always amazed at just how small the Mac Pro looks in photos.

Previously: How Apple Alienated Mac Loyalists.

Update (2017-01-11): See also: The Talk Show.

OWC DEC MacBook Pro Dock

Juli Clover (via Paul Haddad):

Other World Computing today announced the OWC DEC, an attachment designed to snap onto the bottom of a 2016 MacBook Pro to add additional functionality to the machine.

The OWC DEC adds 4TB of storage, an SD Card Slot, USB Type-A ports for using standard USB devices, and a Gigabit Ethernet port. According to OWC, additional features will be introduced at a later date.

OWC:

When installed, the OWC DEC and MacBook Pro will be as thin as a 2012 MacBook Pro, allowing this advanced solution to retain the attractive light weight design that users favor.

Previously: New MacBook Pros and the State of the Mac.