## Leap seconds

2012 was a leap year, 2016 will be too, as will 2020 – you get the picture.

Every four years, the Gregorian calendar observers what is known as a leap year, a year with one day extra than the previous three years, or than the next three. This is because the solar year (how long it takes the earth to complete an entire orbit of the sun) is almost 6 hours longer than the standard 365 days calendar year.

### Solar vs Gregorian Time

There is however a small issue with leap years. The original rule of adding a leap day every fourth year ever so slightly overcompensates for the time difference, as the solar year is 365.2422 days long. With leap years the average year has 365.25 days, which is 0.0078 days too many! Also, our planets spin is slightly irregular, meaning that some [solar] days are slightly longer [as in milliseconds!] than others, whilst others are slightly shorter.

You might think that there really isn’t any point in worrying about 0.0078 days, as it would take over 128 years before all those tiny bits of days added up to make an entire day. However if we ignored the 0.0078 days, in 23,376 years we would have lost so much time, the seasons would have completely reversed, as there would be a huge 6 months of time distortion!

To solve the problem, clever scientists have worked out that if we miss out three leap days (omitting three leap years) every 400 years, then the average calendar year becomes 365.2425 days long. However this still leaves a 0.0003 day (or 25.92 second) difference each 400 year cycle – 0.0648 seconds every year. A relatively insignificant amount, but all the same, we want to be accurate, so a solution has been found!

### Leap Seconds

Every so often we also get a leap second. Due to the irregularity of the movement of the earth, it is impossible to construct a precise schedule for these seconds.

Leap seconds are added in as and when they are needed, so the Gregorian measure of time should never be more than one second out of sync with the measure of time linked to the earth’s orbit.

Sometimes leap seconds are positive, meaning they add to time, and they can also [in theory] be negative.

Leap seconds are usually added to the end of the day, at the end of a year, or half year period. The most recent leap second was on July the 30th 2012, where one second was added to time, so it didn’t become the 1st of June the second after 23:59:59, it instead became 23:59:60.

### Problems With Leap Seconds

Leap seconds are brilliant from a scientific perspective, as they help to keep time and the environment in almost perfect constant sync, year after year. However from a technical perspective, they pose some huge problems!

Remember the huge fuss about the Millennium bug, the problems the turn of the century was [thought] to cause and the money that was thrown at it? Ultimately, nothing major happened. Leap seconds pose a similar sort of technological issue, but the threat much more real.

The most recent leap second, caused major technical issues for firms all around the world. Just before the leap second, there was a solar storm, which disrupted technology, especially websites, needless to say this didn’t help the leap second scenario in the slightest!

One of the most high profile victims of the June 2012 leap second was social network Reddit. Due to the nature of its activates Reddit relies heavily on synchronised operations, as do Foursquare, LinkedIn, Gawker, and StumbleUpon, who were all also affected. When the time on the servers of these services was thrown out of sync by one second with the time Apache Cassandra and Java were displaying, their technical systems went into meltdown!

After a few hours, most of the technical blackout was over, and the majority of services were back up and running.

Six months notice is given prior to a leap second, and for many firms they are not a problem. Measures do need to be put in place, however if they are, there are [usually] no issues.

### Should We Abolish The Leap Second?

From a scientific perspective, the leap second is a fantastic idea; it keeps time perfectly synchronised. However from a technical perspective it is a bit of a costly annoyance.

In January 2012, there was a meeting by the ITU, who discussed whether or not to drop the leap second. We could just ignore these time adjustments altogether, or we could add a leap hour every few hundred years. Despite hopes, the ITU were unable to reach a consensus, so have put off making a decision until 2015 – at the earliest.

## SD10 Bluetooth Stereo Headset – Review

Previously I have reviewed the Pocket Boom, a cool little device which can turn virtually any device into a speaker. Recently the same people asked if I wanted to review a SoundWear SD10 Bluetooth Stereo Headset, so here I go!

Please note, like with the Pocket Boom Review, all the opinions in this article are mine, and are completely honest – I am not being paid to write this review.

The SoundWear SD10 Bluetooth Stereo Headset is a device which provides wireless headphones, which can synchronise with almost any Bluetooth device. This means that when you are out and about, you can take calls, and listen to music, without the limits of wires.

### Ergonomics

The headset very cleverly folds away quite neatly, which does mean that they can fit into your pocket without much of a problem, meaning they are portable, like you need them to be.

The headphones when they are folded up would fit in your pocket

So, are the headphones comfortable to wear? My answer would be it depends who you are. I have tried them on, and I have got other members of the team and some of my friends to try them on, and the responses you get are mixed. Some people have no trouble whatsoever, the headset fits snugly onto their head, and are very comfortable to ware. Other people have tried them on, and they do fit, they are just a bit more awkward. Maybe that’s something you might want to consider – especially as they are not retractable/adjustable.

### Ease of Use

Like with the Pocket Boom, if you don’t read the instructions, you aren’t going anywhere very fast! Read what the small A5 (ish) sheet of paper tells you, and things become pretty simple.

With some phones you need to fiddle with some settings either with Bluetooth, or on audio tracks to get them to work properly with calls and music, but it does work!

### Sound Quality

Obviously one of the most important things with all headphones is the sound quality. You can get the most amazing headset, but if it has poor sound quality, then there is little point to it.

So what about the quality of the audio stream produced by the SD10 Bluetooth headset? Well it is actually very good! The headphones fit very snugly around your ears, reducing any noise interference, and the audio quality is very respectable.

Obviously noise cancelling headphones, or recording studio ones would be better, but the quality is very respectable, especially as it is coming from a wireless stream. For the average music listener, I don’t think there is any need to worry about poor sound quality.

### Instructions

The headphones do come with instructions, which are clear, and just require a small amount of common sense and logic to use. They are helpful, but could contain a little more info – possibly room for an FAQ’s section.

The headset, along with packaging, instructions and USB lead

### Power

From what I have seen of the headset, it seems to last a reasonable amount of time between charges. You don’t start listening to a tune, and then a call comes in, by which time the headset has given up and is needing a charge. The battery life seems to be pretty good, so no need to worry about that.

The issue I have with power is the way you charge the headset – via USB. You can only charge it via USB, and there is no alternative, no batteries you can replace etc. This can be a little inconvenient, especially as it doesn’t come with a USB plug adaptor, but I am sure it will work okay with the one I use for my iPod, or the one I use for my camera. Don’t take my word for that, I wouldn’t want to blow your headset – if you have one or are getting one!

### Value for Money?

Here comes the killer question: is the SoundWear SD10 Bluetooth Stereo Headset value for money? I try to evaluate every product I review using value for money, so it is a good test. The headset retails at £24.99, which is reasonable, but I think it depends what you need it for. If you are going to be making calls wireless and listening to music, go for it. If you just want to listen to music (like me) then I am not so sure. There are different headphones more suited to music listeners, but this set does give you the added bonus of being able to make calls.

Interested in buying a set, or just want to read a bit more? Check out the SoundWear SD10 Bluetooth Stereo Headset on Mobile Fun’s website.

As I said at the beginning of the article, this product has been sent to Technology Bloggers to review. Our thanks to Mobile Fun who provided us with the headset.

## Understanding iCloud

The latest release in the cloud computing world, and the replacement for Apple’s old MobileMe service is Apple iCloud. The new software is designed to work seamlessly between various apple hardware such as iPods, Apple laptops and desktops, and the iPad. There are several applications available with the iCloud software, ranging from ‘Find my Device’, which allows an internet connected device such as the iPhone to be remotely tracked, to Photo Stream, which makes ‘streamed’ photos available on any connected device.

The first, Find My Device, was initially a MobileMe application, which has been migrated to the iCloud software package. Using the service, a user can view the rough location of their device over-layed on a scalable map of the area, as well as a circle indicating the margin of error on the tracking. Along with remote tracking, the program also allows the user to change the password, display a message on the device, or play a sound (even if it is set to silent). A final feature of the program makes use of the cloud storage technology and allows the user to temporarily delete the contents of the device, storing them to the cloud server until told to return to their original location.

Not quite cloud computing!

Photo Stream directly utilizes the cloud storage technology to share pictures between devices. When a picture is taken from an iphone with Photo Stream enabled, the picture will automatically be uploaded to the cloud server, where it will be available to any of the user’s other Photo Stream enabled machines. According to Apple, the service will soon be integrated with their Apple TV box, which would allow users to view any pictures in icloud on TVs connected to Apple TV.

While only currently available in the US, iTunes Match is one of the most popular uses for the virtual computing abilities of the iCloud software. iTunes Match allows users to ‘scan’ their music in any compatible device (even if the music is not purchased from iTunes), and upload it to the iCloud virtual servers, ready to be downloaded to any of the user’s other Apple products in a DRM free format.

‘Back To My Mac’ and iOS Backup are two more erstwhile MobileMe program migrated to the iCloud package. The first is essentially a remote access program, allowing the user to remotely log into any device with the same Apple ID and the program active. The second is a backup program, which allows the user to back up the data and settings on their device to the virtual servers, and restore the device or access the data remotely as needed.

While the iCloud software is very slim as far as system resources, it requires a fairly current OS to run properly. Creating an account requires iOS 5 or later, or for desktops, OSX Lion. For PCs, Windows Vista or later is required to properly sync. iCloud can also sync to Outlook 7 or later for calendars and contact info.

The cost of the iCloud software varies with the amount of services the user chooses to sign up for. Data storage starts at 5 gigabytes free, and added storage can be purchased in increments of ten gigabytes, for \$20 per ten gigabytes per year. At the moment, the maximum storage amount available is 50 gigabytes, however Apple has said it is possible for that to go up in the future. Apart from storage costs, the iTunes Match service is a yearly fee of \$25.

With the iCloud software, Apple has taken full advantage of the evolving cloud storage technology to bring a wide variety of programs to Apple users, and an increased connectivity between Apple hardware.