Supernova month!

Supernovae are like buses: there’s nothing for ages, then two of them turn up at once.

Earlier this month a supernova was discovered in M82, also known as the Cigar Galaxy.

Over the past couple of days, another supernova has been confirmed in M99. (M99 has already had three supernovae since its discovery in 1781. This new supernova makes the count four.)

Two stars explode in the same month? Signs and portents!

On the other hand, a great cosmic coincidence?

The galaxy M82 is 12 million lights years away, and M99 is 60 million. At some point, 60 million years ago, a massive star at the end of its life lost its delicate balance between the gravity from its mass and the force from its nuclear furnace, and exploded.

48 million years later, and 55 million light years away, two stars in orbit around each other were completing an eons-old dance. A large star was being stripped of gas by its white dwarf companion. The white dwarf’s mass reaches a critical limit, and explodes.

12 million years later, the light from both of these events reach us.

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I like to think of it as ever expanding bubbles, as the light from both explosions moves through the universe, and intersects where (and when) we are.

Appendix: Getting Numbers

Wolfram-Alpha constantly surprises me in its power, particularly interpreting my prattlings.

“distance to m99”

“distance to m82”

“distance between m99 and m82”

And my favourite surprise: “angle between m99 and m82”


If you’re in the Northern Hemisphere right now, there is a star currently exploding the M82, the Cigar Galaxy. (Sometimes a galaxy is just a galaxy, y’know.)

There’s some good visuals in this video:

Though, I agree with my friend Alan Duffy who baulks at the soundtrack. Here’s my suggestion: turn down the music of the above video and play the following instead:

Ah, Tijuana!

Easy Easel

In previous Rough Science stage shows, I’ve used an easel to display diagrams, old-school.

Rough Science 2012

For Rough Science: LIFE in Adelaide, I need not only one easel, but five. Five. At around eighty bucks a pop, I need something much, much cheaper. On top of that, they need to be light, collapsable, and transportable so I can fly them in February.

I am a very big fan of PVC pipes and connectors, having used them for previous science interactives and activities. After spending a quarter hour in the PVC plumbing aisle at the hardware store, I came up the the Quick and Dirty Easel.

You will need:

o Three (3) 100cm lengths of PVC pipe;
o Three (3) 60cm lengths of PVC pipe;
o Two (2) 3cm lengths of PVC pipe;
o Two (2) T connectors;
o Two (2) L connectors;
o One (1) coupling;
o Three (3) caps;
o One (1) bolt and wing-nut.

All the parts

In the ends of the 60cm pipe, I drilled holes for the bolt. In two of them I made an elongated hole so that the legs could spread.

Holes in pipes

Connect the 3cm lengths to the L connectors. These will hold up the card/diagrams/Sunflowers by Van Gogh.

Picture holder

The bolt goes through the drilled holes. The elongated holes face inwards.

Bolted ends

Connect the pipes to the T connectors and coupling. From here, it’s like Lego. Or Mechano. Or K’Nex.

Finished easel

It is lightweight and strong enough to hold a stack of card.


Now to spray paint it!

(Don’t forget the correct PPE.)

Spray painting PPE

UPDATE: Replace the caps with rubber stoppers to make the easel non-slip.

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Chimpanzee vs Human DNA

The history of comparing chimpanzee and human DNA similarities begins in 1975. King and Wilson estimate 99% similarity between chimpanzee and human DNA. PDF of Evolution at two levels in humans and chimpanzees by King and Wilson.

On the same note, The fickle Y chromosome compares the Y chromosome in chimps to the Y chromosome in humans.

In summary: The Y chromosome in the Chimp is very, very different to the Y chromosome of Humans. This is interesting because the rest of the genome is very, very similar. There are probably two reasons for this:
Reason The First: The Y chromosome doesn’t have a partner during cell devision, so over time the DNA can be subjected to large change.
Reason The Second: The Y chromosome is in charge of sperm production, and because of the mating habits of chimps (where they have many, many partners, and lots and lots of sex) means that it’s a hotspot (so to speak) of selective pressure. Basically: the better your sperm, the more likely it’s going to reach the egg before someone elses.