Category: Miscellany

Update on contact lenses

In short, I gave up.

In the first post I mentioned that I felt OK with the single vision lenses but that I hadn’t tried driving with them in. As soon as I did, I started to notice problems.

The main one was that I couldn;t focus on vehicles following behind using the internal mirror: it just stayed blurred. The other, more troubling, artifact was dazzling at night and coronas around car lights. The first time out at night I had to pull over and take them out. It was downright dangerous.

After a further consultation it became apparent that I am actually left eye dominant whereas the optician (and I) previously thought I was right eye dominant. That explained the problem with the mirror: the left eye had a distance vision lense. After some discussion, we moved to varifocal toric lenses. However these were monthly’s and took 10 days to obtain.

I really tried to get on with these, but the night vision problems remained and my vision just wasn’t as good as with glasses. Eventually I admitted defeat until something new comes along.

Day One with contact lenses

I’ve been wearing glasses for about 15 years now. I have classic Presbyopia: also known as short arms 🙂 My distance vision is still nearly perfect in one eye and not much worse in the other. My close up vision has been deteriorating for about 16-17 years though.

I moved over to Varifocals years ago because I was fed up with having to take my glasses off to look at somebody across a table and then having to put them back on to read a laptop screen. More recently I’ve had to add dedicated reading glasses and mid-vision computer glasses for when I’m at home and using two big monitors. I’ve been considering switching to contact lenses for some time, and after a friend of mine also made the change and reported back that was all was well, I decided to stop hovering and to jump in.

My prescription was pretty current, so it was simply a matter of talking it through with the optometrist in Boots; trying out some test glasses; and saying yes. Pretty painless so far.

I’ve got single-use mono-vision lenses. The right hand one is optimised for distance and the left hand one is a compromise between reading and computer work. I had them fitted yesterday and spent a couple of hours with them in.

I had no major difficulties putting them in or taking them out. Once I had got used to handling them it was straightforward. It appears that I don’t mind touching my eyeball, so that’s good.

It was strange for the first few minutes but then my brain started to adjust for the differences, and by the end of the two hours I could see clearly and focus at all distances. I didn’t drive and I didn’t try the computer monitors though. That’s a job for today.

“Perpetual” motion, maybe?

I know “perpetual” is over egging it, so don't shoot me down. However, this is a fascinating example of how long a well balanced object can oscillate.

I've always been fascinated by those instances where simple objects can oscillate for ages with no external input of energy. I've seen it with a bunch of keys; where one is in the lock and others are hanging from the ring. The bunch oscillates for ages, rather than being damped quickly, as one would expect.In this case, I was making the morning tea and was attracted by the tiny ringing of one spoon on the other. If you listen closely, you can hear it, and you can see the left hand spoon is oscillating in sympathy as it is excited by the larger spoon. Actually it's two spoons on one ring.Apologies for the clock in the background.

 

iPhone 5S? – No thanks

It’s time to get off the continual upgrade treadmill for a while

iPhone

For as long as I’ve had a mobile phone, I’ve always been on a contract. In the past this has been great as it meant that I’ve been entitled to a regular upgrade. However, this entitlement has come at a cost and I’ve now decided to change behaviour.

The contract that has just expired was an iPhone 4S from Vodafone for 12 months at a cost of £36 per month. When I last upgraded, from an iPhone 4, I was able to sell the ‘4’ for more than I needed to put up front for the 4S, but it still locked me into paying £36 per month. That’s £432 per year.

I know there’s been the iPhone 5 out for some time, and now there’s the ‘5S’ but do you know what? My ‘4S’ is all that I need. So, I’ve decided to let the contract lapse and move on to a SIM-only contract at £9 per month: a saving of £324 over the year. Even if I only do this for a year and then go back on a contract, or buy a new phone outright, I’ll still be better off given the likely resale value of the ‘4S’.

The only current unknown is being able to tether with a SIM-only contract. Advice is varied on this. Vodafone CS says no, but forum.vodafone.co.uk says yes. We’ll see.

update

The upgrade has completed and was completely invisible. I thought I’d need a new SIM, but apparently not. Also, tethering worked without me needing to do anything other than enable it on the phone. I used it to prove it did work. That’s removed the sole remaining reason for jailbreaking the phone now.

Image courtesy of blakeburris and Wikimedia Commons

Day one on Nokomis

Adventures on the river

For some time now, my brother in law’s friend has been suggesting that Varina and I take Nokomis away for a few days. Nokomis, named after Hiawatha’s grandmother, is a 49 foot narrow boat based on the River Nene near Wellingborough. It used to be a house boat but now sits idle for most of the time.

This year, we decided to take them up on the offer and plan to pootle down the river as far as Peterborough, visiting various places along the way.

Nokomis is moored at Wollaston lock, and after loading a mass of gear, food and booze, we got way about 1:30. The Nene is a lovely river, but public moorings are few and far between, so we opted to go only the short distance into Wellingborough on day one as we wanted to take a look round the town and visit a couple of pubs.

We only needed to navigate two locks on day one, Wollaston itself and Wellingborough Upper. The latter was interesting as there were two dead sheep floating in the entrance; one of which preceded us into the lock and got trapped behind one of the lower gates. This made the exit a bit tricky, particularly as it was stuck behind the port side gate and the ladder was also on that side. Varina was working the lock and had to hop aboard from that ladder.

No matter, we got to Wellingborough and moored up just after the bridge. We are on the bend, so only the stern is alongside, but that’s OK. We had been warned about the occasional pranks of the locals, mainly casting off boats in the middle of the night, so we are chained up as well.

After spending some time getting organised, we had a few drinks, a nice leisurely meal and played a few board games before having an early night. So far so good, until we were rudely awoken by one of the CO detectors going off. The boat is old and uses gas for heating water and cooling the fridge. The fridge is temperamental at the best of times and I put the problem down to that. We turned off all the gas, opened the windows and went back to sleep. Oh, we also removed the batteries from the detector. Bad boy!

As we awoke refreshed and alive, I assume we were OK. I know it’s probably not the best course of action, but I reasoned that the source was removed and the windows were open to clear any residue.

Unfortunately, the weather had taken a turn for the worse overnight and there was rain in the air. Ho hum.

Why are they going in backwards?

A couple of years ago, my daughter gave me a bee house as a Christmas present. I put it up in a sunny part of the garden and waited. I can see it from my office window.

It’s had a few solitary bees buzzing about it and even a couple of Bumble Bees, but this year it seems to be Honey Bees that are attracted by it.

I was watching them all buzzing around and then noticed a strange behavioural pattern. If you look closely at about 0:30 you will see a bee go forwards into one of the holes, then reverse out, turn around, and go back in backwards.

I’ve seen this happen many times but I can’t see a reason. I think these are worker bees. As far as I know they only forage, they don’t build new combs.

Goodbye Posterous

Well, that was an interesting interlude.

As most will be aware, Posterous is closing down at the end of April. As a result, I’m back here for a while.

I suspect I won’t be here long as the hosted version of WordPress is too restrictive: I can’t add plugins. However , it will do until I can set up a WP installation on my own hosting service at EZPZ Hosting.

How does the shortest distance between two points become so short?

Imagine two streets at right angles to one another and imagine that a pedestrian wants to get from point A on one street to point C on the other. One can construct a right-angled triangle ABC with hypotenuse AC. Imagine two streets at right angles…

Triangle

Imagine two streets at right angles to one another and imagine that a pedestrian wants to get from point A on one street to point C on the other. One can construct a right-angled triangle ABC with hypotenuse AC.

Imagine two streets at right angles to one another and imagine that a pedestrian wants to get from point A on one street to point C on the other. One can construct a right-angled triangle ABC with hypotenuse AC.

Now consider that there is no direct route from A to C and no other roads. The route to be travelled will be A – B – C and the distance travelled will be AB + BC, rather than the straight line distance AC = SQRT( AB*AB + BC*BC).

Now consider that there is actually an intermediate road parallel to BC between A and B, intersecting AB at point D. Further consider that there is a similar road parallel to AB intersecting BC at point E, and that these two new roads intersect at point F.

The pedestrian now has the alternative route A – D – F – E – C with distance AD + DF + FE + EC. However AD + DE = AC, and DF + EC = BC, thus the distance walked is still AC + BC.

One can extend this arrangement, introducing extra roads into the matrix, but at all times the distance travelled is the same as the route A – B – C. As the number of roads increases, so the inter-road distance diminishes, but the total route remains the same; so how is it that at the limit, where the number of extra roads is infinite, and the inter-road distance approaches zero, and thus the route from A to C approximates a straight line, the total distance becomes SQRT( AB*AB + BC*BC)?

I know I’m obviously missing something here, but for the life of me I can’t see what.

 

There’s sooo much space in my office now

Little Miss Organiser works wonders again. Whilst I was away in Scotland walking in the mountains, wild camping, sailing and climbing; Little Miss Organiser was busy re-organising the Home Office I have down the bottom of the garden. Previously, i…

Little Miss Organiser works wonders again.

My Office

Whilst I was away in Scotland walking in the mountains, wild camping, sailing and climbing; Little Miss Organiser was busy re-organising the Home Office I have down the bottom of the garden.

Previously, it was very cramped and extermely messy. After her wonder touch, it’s now all tidy (I can see the floor!) and there’s probably room for two people now.

As well as being my office, I also use this space as my amateur radio shack and for indulging in my penchant for designing and building odd bits of electronics. So it’s amazing that there’s now so much space.

(disclaimer: Little Miss Organiser is my wife, Varina. That said, she’s bloody good at her job)