π is wrong, long live ტ

? is often given an almost mythical status, so I found it very refreshing when I was made aware of the ? movement that argue that ? = 2? is a much more natural constant.

There are lots of good arguments in favour (do follow the link above), and I’m definitely a convert.

However, as Stewart Russell pointed out to me on Facebook, physicists already have other uses for ?, so perhaps a better symbol could be chosen.

I would propose the Georgian letter ? (pronounced tari), which doesn’t seem to have any uses in maths or physics.

Are we related to people born before 1575?



Babbitt Family Tree
Originally uploaded by FrodoBabbs

While sampling some nice beer in Århus earlier this year with my good old friend Thomas Mailund, we had an interesting discussion about how long our genes live on for.

I was reminded of this discussion when I managed to find my great-great-great-great-great-great-great-great-great-great-great-grandfather on Google. His name was Georg Widmann, and he was born around 1532 in Heiningen in Württemberg.

However, as I discussed a few years ago, we get half our genes from our father and the other half from our mother; we therefore get 25% from each grandparent, 12.5% from each great-grandparent, etc., so when do we reach a point when there’s nothing left?

According to Wikipedia, the “haploid human genome contains ca. 23,000 protein-coding genes”. 23,000 can be halved 14.49 times, which equals around 435 years (at a generation length of 30), and this means that any ancestor born before the year 1575 is likely to have contributed less than one gene to our genome. (Georg is of course an exception – ignoring the possibility of adultery and mutations, my Y chromosome is an exact copy of his.)

One can look at the numbers differently, too. Genes are defined by the “2.9 billion base pairs of the haploid human genome”. 2,900,000,000 can be halved 31.43 times, taking us back 943 years to the year 1157, but that will include ancestors who have only contributed junk DNA.

The “human genome contains vast regions of DNA the function of which, if any, remains unknown. These regions in fact comprise the vast majority, by some estimates 97%, of the human genome size.” 3% of 2.9 billion base pairs is 87 million base pairs, which would take us back 791 years to the year 1219.

However, the “nucleotide diversity between humans is about 0.1%, which is 1 difference per 1,000 base pairs.” That would take us down to 87,000 base pairs that actually matter, and that number can be halved 16.41 times, which would take us back 492 years to the year 1608.

To conclude, I’m not absolutely sure what the cut-off point should be. There’s definitely no point in doing genealogy further back than the year 1157 (except for pure patrilineal and matrilineal descent), but there are good arguments also for stopping in 1219, 1575 or 1608.

Ammonite hunters



An ammonite and I
Originally uploaded by viralbus

Marcel, Charlotte and I left Phyllis and the wee ones on the sandy beach in Lyme Regis and walked over to the Jurassic cliffs on Manmouth Beach.

We had heard it was a good place to find ammonites, so I was hoping to find an incomplete chunk or two.

What I didn’t expect was to find the beach littered with huge, complete ammonite shells like the one on the photo!

On the other hand, we didn’t find any small ones we could take home. Whether that was because they had already been removed by other fossil hunters, or whether only the big ones fossilise well, I don’t know.

What I do know is that we met several other people with big hammers that they used to split the stones with. We had to restrict ourselves to chucking the stones onto the hard ground, which is not quite as efficient.

So next time, we’ll bring hammers, chisels and a sturdy rucksack!

Myanmar/Burma and the US against the rest of us

According to this map (click on it for more information), there are now only two countries in the world that haven’t adopted the metric system: Myanmar/Burma and the US.

It’s a bit strange to see that the UK has been allowed the colour blue – perhaps they should have assigned a different colour to countries that have changed over officially, but where people still use different units in practice.

I just wish there was a way to make the US go metric, too – so long as the largest English-speaking country is using imperial measures, it will be really hard for the UK to let go completely.

Anĝaĝinax̂



Unangax Aleut Dancers
Originally uploaded by javacolleen

Danish newspapers are reporting that Danish scientists have decoded the DNA from an individual from the Greenlandic Saqqaq culture (which died out completely).

According to their results, they were most closely related to the Aleut people.

If this is the case, I don’t quite understand why they called the individual Inuk (“person” in Greenlandic), rather than an?a?inax?, which is the modern Aleut word.

Hmmm, I wonder whether the Aleuts could demand to get Greenland back from the Inuits? 😉

Unlikely intelligence



Aliens
Originally uploaded by [Soren]

The Independent reports that professor Conway Morris has claimed that “alien biospheres will be strikingly similar to the terrestrial equivalent and that in such biospheres intelligence will inevitably emerge”.

From statements such as this one, one would have thought that intelligence had developed many times during the history of this planet.

For instance, it’s reasonable to assume that life on planets with similar gravity and air density will have quadrupeds, bipeds and flying animals, and that eyes and ears and brains are all likely to develop.

Just think about how similar the body shapes of fish, dolphins and ichthyosaurs are, although they have very different origins.

However, it doesn’t seem to be the case that human-level intelligence has ever developed before on Earth.

This makes me wonder whether there’s something about high intelligence that makes it almost impossible as an evolutionary strategy.

I think I read somewhere that there is genetic evidence that the human race almost died out before it really got started (cannot find the link just now), so although we were eventually very successful, it was hard to get there.

Another way of looking at it is that there has only been human-level intelligence for approximately 100,000 years out of the past 500,000,000 years (the time of the Cambrian explosion), or 0.02% of the time.

I wish somebody could explain to me why high intelligence never appeared before. Surely evolution could have produced it many times, and much sooner, if only it had been a successful evolutionary strategy.

Laboratory Earth



Sun
Originally uploaded by jalalspages

It appears that there are many more scientists who think our civilisation is heating our planet up more than would have been the case otherwise than there are qualified people thinking otherwise, and I therefore do think it’s foolish to avoid taking strong measures to combat global warming.

However, as the recent Copenhagen summit showed, the evidence is not yet so overwhelming that all of humanity can be convinced, and it’s therefore very hard to achieve any meaningful emission cuts.

We therefore need to get more evidence and refute all major competing theories.

One of the alternative favourite theories cited by the opponents of global warming is solar activity.

I therefore found this article (written before the current cold spell began) very interesting:

But how to prove this? During the 20th century, solar activity rose steadily, as did the amount of industrial gases being pumped into the atmosphere. With both quantities rising, it has been impossible to distinguish between them. Now, that has all changed.

In the past 12 months solar activity has fallen to levels unseen since the 1920s. Sunspots have become rare sights and for three quarters of this year the Sun has been spot-free. According to one study if the trend continues at its current rate, the Sun will lose its ability to produce sunspots by 2015. That would take it back to its condition in the latter 17th century, when hardly any sunspots appeared for 70 years — and Northern Europe underwent the worst years of the so-called Little Ice Age.

Winter scenes from this period were romanticised by artists such as Brueghel painting frost fairs and hunting scenes. But was the 17th century sunspot crash responsible for the Little Ice Age or a coincidence? Could we now find ourselves plunged into a similar freeze if the sunspots do not return?

I’m well aware that the current cold spell doesn’t disprove global warming in the slightest. One possible consequence of global warming could be the Gulf Stream moving or stopping completely, and that would make the British Isles even colder than they are at the moment.

It will be interesting to see if the solar activity theory can be complete refuted within a few years, though.