One of my challenges as Primary Caregiver to two young kids is shoving enough nutritious food down them each day to keep them healthy and growing. And I think I’ve worked out now that it’s all a matter of packaging.

For instance, (ignoring my version of the food pyramid for a moment) we all know that your typical healthy diet should include some vegetables. Okay. And we all know that most kids believe that vegetables are the foulest substance in the known universe. But there are exceptions. Potato is a vegetable (well, just) and hot chips are made of potato.

So will my kids eat chips? Absolutely - what kid wouldn’t? Will they eat mashed potato? Not really, no. It’s not on their list of detestable food items that must be removed before it contaminates everything else on the plate, but they won’t take more than a nibble. It’s the packaging. It’s not chip-shaped. So far, no amount argument that "it’s the same stuff that’s in chips" has worked.    

Will they eat tomato? No way. Tomato sauce on things? Yes. To my utter surprise, they’ll even happily eat (or is it drink?) tomato soup.

Fish? I don’t think so, not in its natural (but cooked) state at least. Fish fingers? Yep. Even fish fillets, as long as they have the required batter and/or breadcrumbs on them.

In case my mum is reading this, rest assured, they haven’t caught scurvy yet, but the experimentation continues…

For those of you following my domestic adventures, early on Monday morning, L came back to Melbourne. She’d rung a few days earlier and said she’d be coming back. We met up with her for a little while on the way home from the airport.

I suppose it was to be expected - I knew she’d eventually miss the kids, and I’d thought from the beginning that the whole idea of resuming a ten year old relationship with Monsieur Le Frog was flawed. She’ll be staying at a friend’s house for a bit while she sorts herself out and finds a job, and we’ll figure out the permanent arrangements later.

• Refresh your minds about what happened in March

We celebrated Isaac’s fifth birthday with chocolate cake, presents and lots of running around in the park. Then we somehow managed to pack up all our gear back into the backpack and headed (over the bridge once again, naturally) to the airport.

There was no queue at all for check-in, and we had to double-check the signs to make sure we hadn’t inadvertently stumbled upon the queue for "Frequent Business Flyer Lick-Your-Boots Executive Class", instead of the "Scum Class" that we were flying. But we were apparently in the right queue, so we got our stuff checked-in, had some lunch, then said our goodbyes to my sister and boarded the plane.

There were plenty of spare seats, and the flight staff told me so many times that we could spread out that I’d have felt guilty if we hadn’t, so we did. They cheerfully handed over extra snacks for the kids (mmmmmmm…. Tim Tam….)

We flew back into Melbourne, collected the car, which set me back $53 for parking, but that’s the convenience of the Short Term carpark, and avoiding having to use the Shuttle Bus.

Just passing through Town Hall station again… with a good view of people’s feet Those Sydney Cityrail people just don’t like any fun Luna Park Sydney: is there an amusement park anywhere in the world with a better view?

We headed back into central Sydney, bound for the totally awesome Powerhouse Museum. It’s a mish-mash of exhibits about various clever technological things and the people behind them; a kind of opposite to the Natural History Museum in London, if you like. If it moves, lights, flies, generates, turns, computes or pollutes, it’s in the Powerhouse Museum, and as a bonus there’s plenty of stuff for little kids to muck around with too. Isaac was particularly interested to notice that there was a robot who shared his name.

I always thought museum and zoo food outlets were required by law to sting you for as much money as possible for food, but our lunch there was quite reasonable. Afterwards we left the museum and walked over the bridge to the Sydney Light Rail station, where we caught what purports to be a Light Rail Vehicle, but looks awfully like a tram (complete with conductor; oh what a nostalgia trip) to Sydney’s Central Station, which isn’t actually particularly central, but is a station.

We caught a northbound train, which took us over the Harbour Bridge once again, though the view was a little underwhelming because we were on the lower deck of the train carriage. But we did manage to get a glimpse of the top of the Opera House. We got off at Milson’s Point station, from where there is yet another great view of the bridge and the harbour, and we strolled down the hill to Luna Park.

A difference between Luna Park in Melbourne and Luna Park in Sydney is that in Sydney they keep closing it, renovating it, re-opening it, and then closing it again. Which is why it appears most Sydneysiders have no idea if it’s open or closed. We had seen the ferris wheel operating the previous day from the ferry, which meant unless they’d closed it overnight, it should be open.

Which thankfully it was. But another difference between Melbourne and Sydney was that you can walk into the Melbourne Luna Park for free, then pay for the rides you want. In Sydney, you pay up-front and get the rides for free, and with all of us, it worked out to $52. I admit, I had to think about it, but as my sister pointed out, we were on holiday, so we coughed up and went in. And in the end, we went on enough rides to make it worthwhile.

After one last dodgem-cars ride, we walked back out of Luna Park’s gaping mouth, up to the bus stop, and boarded a 227 bus, driven by the crankiest bus driver I’ve encountered in quite a while: he was impatient to us passengers who weren’t quite sure where we were going, and he swore at other drivers. Maybe his radio had broken down and he couldn’t listen to the easy listening station anymore.

But no matter, he delivered us back to my sister’s place and we settled down to a totally awesome rendition of that old (and normally quite staid) favourite bangers and mash.

The standard tourist piccies - Sydney Harbour Bridge and Opera House The monorail, which goes round… and round… and round… Riding the ferry back to Neutral Bay - Susannah, Isaac, me and Jeremy

We got up bright and early to go to the airport. Our destination: Sy-d-ney, to stay with my sister, Susannah, for a few days.

It was an 8:30 flight. An 8:30am flight means getting to the airport by about 8am to check-in. Getting to the airport by 8am means leaving the house by 7:15am. And leaving the house by 7:15am, when you’ve got yourself plus two small children to get organised, means waking up close to around 6am. And getting up at 6am is not a lot of fun, if you ask me.

But we managed it, and by 9:40 (about ten minutes early) were touching down in Sydney. Susannah and her boyfriend Adrian were there to meet us, and drove us back to their flat in North Sydney, taking us over the Harbour Bridge in the process, for maximum sightseeing points.

After being given the customary guided tour of the new flat, we spent a few minutes in the park across the street, before heading out on an excursion. First stop, the ferry wharf at the end of an alarmingly hilly street in Neutral Bay, for a ferry ride across the harbour to Circular Quay. Which isn’t circular, but is a quay. We strolled around and looked at the Opera House and the Harbour. Sydney Harbour on a sunny day really does warrant full marks for picturesqueness.

Then we went up into the station and caught a train to Town Hall. We walked a block down bustling, busy Park Street (which for some unknown reason reminded me of New York - not that I’ve ever been to New York, but you see enough of it watching Seinfeld or Letterman…) to the monorail station, which was undergoing renovations, and boy, you could tell, it was a mass of uncovered messy concrete and signs apologising for any inconvenience. In fact most of the inconvenience was caused by the signs apologising for any inconvenience being in the way. But no matter: Isaac had been dying to go on the monorail, and we caught it all the way around, then headed by train and ferry and car back to the flat.

During the afternoon, I’d made and received an inordinate number of phone calls about arrangements for dinner, and having got these finalised, I went off to dinner with friends for the evening (and amazingly, didn’t even get at all lost along the way), leaving Susannah to handle babysitting the kids, which she did admirably.

If you can have "domestic science", which I am fast becoming experienced at, then why can’t you have domestic science experiments? Well you can.

One day last week I was curious to answer once and for all the question of whether or not the fridge light goes off when you close the door. After neglecting it for some time, I had just fitted a new light to the inside of the fridge, and was wondering if the door light switch was triggering properly. (Yeah sure, that’s just my excuse).

So I got the video camera, turned it on, and put it in the fridge. This is the result:

1. Put the camera in	2. The door closes…	3. The door has shut, but for a moment the light stays on	4. The light goes out
5. Darkness remains…	6. The door opens, and the light goes on again. The camera auto-focus has trouble err… auto-focussing	7. Door fully open, and the camera has focussed itself.	See it in hastily encoded RealVideo format! (Get the Real Player here - Ignore the one that costs money, and look for the tiny link to the free "basic" one)

Have you done anything this futile ever? Feel free to tell the world in the site guestbook.