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Australian Squirrels

Thursday, November 4th, 2021

I was doing some research for lecture preparation the other day and learned something I never knew: Australia has had squirrels! And there’s a small chance the country still does…

Grey squirrels (the same ones common in our backyard!) were introduced into botanical gardens in Melbourne in 1880, and Ballarat in 1937. They spread into surrounding suburbs and gardens but were never truly successful, and apparently died out within a few decades. It’s possible the last remaining grey squirrel in australia was a pet which lived for 9 years (and was fed breakfast cereal)! I can’t find much information about why they died out but it may have been a combination of a small initial colony, lack of suitable food, competition from possums and natural predation (including from lizards and birds).

Needless to say this experiment will never happen again, as grey squirrels (along with all non-native mammals) are prohibited from import into Australia.

The case of the Indian palm squirrel is a little more surprising. Along with several other species (including fish and birds) these little guys were introduced into Perth in 1898 to make the area more livable for colonists. Almost none of the introduced species survived, but palm squirrels established a thriving colony in the grounds of Perth Zoo.

There they lived for over 100 years, being popular with visitors and a tasty snack for the zoo animals (there are accounts of the squirrels being eaten by monkeys, brolgas and leopards). The squirrels slowly spread out from the zoo into neighboring suburbs, a golf course and a high school and it has been estimated that the colony contained at its peak about 1000 squirrels. Some were even imported east to set up a similar colony in Taronga Zoo (in 1920) but these died out within 50 years due to predation and because the squirrels were frequently caught in the traps set up to control rats.

By all accounts the squirrels in Perth were quite popular – especially at the school – and well known by the locals. But the squirrel was eventually deemed a threat to native wildlife and agriculture, and about a decade ago an eradication program was initiated. This was very successful (apparently they’re easy to catch) and within three years the squirrels were reduced to ‘undetectable levels’

It’s not known if they’re truly extinct in Australia, but if any still live their numbers are likely too small to allow the colony to survive.

So there you have it! Australia did have squirrels, and for over 100 years at that!

Now about the reports of errant ghost kangaroos in the USA…

Posted in Animals, Australia, Nature, Science, The Unknown | 2 Comments »

The Sky Is Falling

Friday, May 14th, 2021

Back in July 1979, I feared that I might die because of Skylab falling on me.

Skylab was the first ‘space station’, built and operated by the USA for 10 months from mid 1973 until early 1974. When the final crew departed they put Skylab into a higher orbit with the intention of leaving it in space until 1983 when the (in development) Space Shuttles could service it. Ultimately nature had other ideas and by 1979 it was clear Skylab would fall to Earth.

NASA’s calculations suggested it would land in the eastern Indian Ocean somewhere. But they didn’t know precisely where or when, and in Australia we were very aware there was a chance it would land smack on us! I can still recall schoolyard doomsayers predicting it could land on someone’s house, and to 7-year old me this was (very briefly) the new big scare to replace King Kong snatching me out of a window one night.

On July 11, 1979, during its 34,981st orbit, NASA made a last minute adjustment to prevent Skylab from falling on the USA. Later that night it entered the atmosphere and while most of it burned up as it fell some parts eventually rained down on remote areas of the western Australian outback.

It didn’t fall on our house, or anyone’s house for that matter. At best it may have given a kangaroo a bit of a start.

The madness quickly transitioned from ‘Skylab will fall on you!’ to ‘If you find Skylab pieces you’ll be a millionaire!’ and treasure hunters of all stripes descended on the outback to find what remained of the space station.

Some were successful, finding many pieces including some very large ones. Much of it is on display now in a museum in the town of Esperance, but some made its way into private collections. While the USA claimed that Skylab was still its property, it never made any attempt to claim debris. Quite the opposite actually: president Carter apologized to Australia and NASA gave memorial plaques to those that found the first pieces of debris!

In the end Skylab was a successful mission, the falling to earth didn’t hurt anyone, and everyone emerged smiling. The world moved on.

There have been many more cases of spacecraft raining down in the years since, and every time it happens (as recently as last week) the media reminds us once again that they might land on our houses! Let’s hope, like Skylab, that when our space trash does fall back to Earth it’s careful enough to land far away from any of us 🙂

Posted in Australia, Blog, History, Retro, Science | Comments Closed

Gimbals & Tic-Tacs

Tuesday, December 17th, 2019

Back in 2004 sailors on the USS Nimitz that was at the time doing training exercises reported sightings of UFOs. This is not highly unusual: there is a rich history of UFO sightings by fighter pilots and near military assets. What makes this encounter strange is that it was recorded, and you can watch it yourself:

This video was leaked by a sailor many years after and the incident became part of an effort by interested parties to obtain more UFO information from the Navy.

You may have heard of one of the results of such efforts: the Navy has now legitimized UFO sighting reporting, and personnel are encouraged to come forward rather than keep silent in fear of recrimination.

It’s also led to other videos being released, which last month the Navy confirmed as unidentified. Quite literally, these videos show UFOs.

This is the so-called ‘gimbal’ UFO. Watch it rotate at the end:

And here is footage of the ‘go fast’ UFO, which as with all these others was filmed by fighter pilots:

When the news that the navy had changed its tack on UFO reports emerged earlier this year there were a few pilots coming forward with astonishing stories of sightings, and the official admission a few weeks ago that yes, navy pilots have seen (and recorded) UFOs will likely lead to more pilots speaking out. It seems, after 70 years, the military is finally acknowledging strange things in the sky.

But what are they? As I’ve said here before I absolutely believe in extraterrestrial life, but I find it hard to accept living beings making interstellar journeys. The vastness of space also makes finding other civilizations no easy task. So the odds seem stacked against them being alien or from parts unknown. I’d love to be wrong though.

For now I’ll accept the navy definition. These are unidentified. This simply means we don’t (yet) know what they are, not that we claim them to be anything specific 🙂

Posted in Science, The Unknown | Comments Closed

Lunar Module

Sunday, November 24th, 2019

As soon as I saw the above in the LEGO store window I had to have it.

It was built in three stages; the lunar surface first:

Of course I had ‘help’ 🙂

The descent stage was next, and was a lot of fun to build including a lot of ‘metallic’ parts.

It also contains lots of little details, including a tiny model laser reflector, which I often use in examples during one of my lectures!

The finished Lunar Module:

It’s a fantastic kit, and one of the most fun LEGO builds I’ve ever done. I give this my highest LEGO score 🙂

Posted in Blog, Collecting, Crafts, Miscellaneous, Models, Otaku, Science, Toys | Comments Closed

Infinite Ape Simulator

Thursday, November 14th, 2019

I’ve been thinking about the Infinite Monkey Theorem, which postulates that an infinite amount of monkeys banging away on keyboards randomly forever would eventually produce the works of Shakespeare. You can read about this in detail here.

I thought to myself, rather than use dirty monkeys to reproduce Shakespeare (which has been attempted), why not use a machine brain? So I turned to an actual honest-to-goodness computer and wrote a simulation.

My machine was the Commodore 64, and I wrote a simple piece of code to randomly generate three letters in order and test to see if they spelled ‘act’, the first word of Hamlet. I was testing the water, so to speak, instead of diving right into a full reproduction of the entire play.

Now it’s fairly simple statistics to calculate that of the 17576 possible three letter words, only one is ‘act’. But I started by looking for words that started with ‘a’ (ie. of the form a–) of which there are 676, and then words starting with ac-, of which there are 26. I timed my result to see if – as expected – each successively correct letter took approximately 26 times as long to generate as the previous.

Here’s my code alongside one example output looking specifically for ‘act’:

The time is in seconds, and I ran 12 searches each for a– and ac- and 5 (due to the time required) for act. Here are the average times to generate each type of result:

A–: 3 seconds
AC-: 84 seconds
ACT: 2027 seconds

These numbers are close to 26x multiples of each other as expected, and I imagine were I to do enough tests they would converge to that value. From these results we can speculate how long it may take for my C64 to recreate Hamlet…

But first some facts: Hamlet has 132680 letters and 199749 characters in total including spaces and seven punctuation signs. Including these but ignoring case, there are 34 potential candidates for each character and 199749 characters need to be generated. My predictions that follow are based on times equal to 34/26 of those listed above.

The expected (ie. 50% chance) time it would take my C64 to randomly generate Hamlet would be 34^199746 times 1908 seconds which is (approximately) 34^199739 million years. The minimum time is about 1.7 hours ( if it got it right on the first go) and the maximum is of course infinity.

But – given our universe is only less than 14,000 million years old – this means I’m confident in saying my C64 would never randomly generate Hamlet. In fact were I to expand the sim to look for the sequence ‘Act 1’ I would expect the average successful attempt to take about one month. If I extended the sim all the way to the first spoken word – over 100 characters in – I’d expect the Earth would be consumed by the sun before my C64 did it.

Some of you say “that’s just a C64!”, which is primitive compared to the device you’re reading this on. But even if your fancy phone or laptop is a trillion times more powerful, this is nothing compared to a factor of ~10^200k.

It’s pleasant to think of infinite typing apes (or computers) randomly spewing out a work of art, but it would never happen 🙂

(Incidentally and somewhat related; the world is still awaiting the results of B’s testing of this!)

Posted in Blog, Miscellaneous, Science, The Unknown | 2 Comments »

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