Mostly empty

My researches show that the average densiity of the universe is about one atom per cubic meter. 

 That isn't very much, is it? I mean, there's an awful lot of atoms in a galaxy and there are an awful lot of galaxies. In that case there must be awful awful lot of very empty space.

 Then I got to thinking, how do you measure the density of the universe anyway? 

 Oh yes. First you measure its volume then you weigh it. Simples.

Comments

Post a Comment

Popular posts from this blog

Wicker dam

Image
Well this is typical of Britain. We used to do things well. Sheffield steel was the envy of the world, people would queue round the block for the chance to buy a nice nylon shirt from Marks and Spencer or a brand new Vauxhall Velox. And now? Now we try to keep lake water in place with a pair of wicker fences.  It is this sort of woolly thinking that could lose us our Empire. You mark my words.
Read more

What's This?

Image
What's this little thing then eh?   Well, let me tell you a story... We changed cars recently. The replacement car is awfully modern and features a USB port.   A USB port.. really? What is that for, do you charge your phone on it? No, in fact you connect your iPod* to it. However it will also accept a standard memory stick and play mp3 music files from folders directly. Now that is a cute trick, as I don't own an iPod*. However, I wouldn't want a conventional memory stick poking out of the car for all to see, so I set off in search of the smallest stick I can find. Here it is, a Busbi Mini 4GB stick. In the background are just some of the CDs and tapes I transferred to it. Even this version looks like it will hold about 40 albums, which is all we will need in the car. So, this leads me to a nostalgic moment. In order to convert the tapes to mp3, I had to record them on the PC, cut 25 minutes of audio into individual tracks and export as W...
Read more

Pompeii

Image
No trip to the Bay of Naples is complete without a visit to Pompeii. This vast 270 acre site is almost too much to take in, particularly in the scant two hours we had with our coach guide. Here's a view of the Auditorium near the end of the visit. A chance to sit down and relax for a moment.  As always, click on the image for the full size version.   The plaster casts of the victims are a chilling and sombre sight in amongst all the ruins For a more relaxed and informative experience, I suggest Herculaneum, on the other side of Vesuvius. Unlike Pompeii, this was covered in volcanic ash and mud which created a anaerobic layer that led to the  preservation of wood and similar materials. Here is a panorama of the buried town that shows how far below the current ground level it is. Most of Herculaneum is under the more recent town. It was lost for centuries: Historians agreed the it and Pompeii were on the coast, but they were digging in t...
Read more