Not the bar kind.

As has become customary for me, on Friday I try clean up browser tabs I’ve left open holding an interesting article. It’s my end-of-the-week clean-up and blog links for readers.

The scale of the universe (Those not interested in astronomy or the scale of things may wish to skip to the next section.)

Chris McDowall posted this morning several videos showing the scale of things. I toyed with posting one of those videos a while back myself, and did post a link to an infographic showing the scale of intracellular life.

They’re great to view, but I personally find that presentations that zoom to show scale, impressive as they are, don’t really convey to me good impression of the scale of anything that’s more than a couple of ‘zoom steps’ apart.

I prefer a series of static pictures with explanation, like those in Ethan Siegel’s excellent recent presentation on the scale of the unobservable universe.

A comparison uses Voyager 2. A twitter feed currently reports that Voyager 2 is a smidgen over 13 hours of light-travel time from earth. Our observable universe is ~93 billion light years across, roughly 93 * 365 * 24 = 814680 billion hours of light-time travel. That’s 62667.7 billions times further than it’s travelled so far.

Voyager 2 is travelling at ~150,000 km/h and been at it 33 years. At it’s current rate, it’d take over 2 million billion years to travel the width of observable universe.

Read Siegel’s article for more on the unobservable universe. It’s lot bigger.

My favourite presentations of the scale of universe, which leave out all the small things that the videos Chris presents show, are variations on Gott et al’s pocket map of the universe (big PDF file) from their research paper. I’ve shown a smaller copy to the left.

You need to have a handle on log-scale graphs, though. Each major step on the graph is covers ten times the distance the previous one did. Start at the bottom and mentally inflate each segment ten times the height (= distance) of the one before it.

Bring Back Babbage The name Babbage will be familiar to those with a computing background. Jennifer Ouellette at Cocktail Party Physics alerts us to that there are fresh plans to raise funds to finally build Babbage’s Analytical Engine, giving a brief history of the machine’s design. There’s more at the computer history website. (I’ve a copy of Doron Swade’s excellent book on the Difference Engine on my shelves, describing his work to build the Difference Engine. This proposed Analytical Engine project has obvious parallels.)

China guns for large-scale genome sequencing Steve Hsu posted a short article reporting a claim that the Beijing Genomics Institute (BGI) will soon have the capacity to sequence 1000 human genomes a day. Given their labour costs are likely to be lower than in other centres, they could be a major force in this area. Even if you debate the numbers, they’re clearly putting a big effort in.

What did you do for geek cred? I’m going to steal a line from Alice Bell’s exploration of geekery and geek cred. (Some of the comments there are worth reading, too.) So… what did you do for geek cred? Go on, tell us!

Other recent articles on Code for life:

Paul Nurse on ‘anti-science doubters’ and the blogosphere

Another one bits the dust: Goodbye Walkman

Vaccine promotion – the medium matters too