Personal Blogs

It's easy now

Living with a bunch of ghosts

Except when it rains.

Old man

Why do you still keep the big plates for the winter feast?

Time.

After the rain

The stickleback

Came back up the stream again

And the hedgehog to the lane.

I dislike the booted

gardener crushing snails.

But applaud the thrush.

Spring

First blossom petals,

On my remaining hair.

Spring again!

A  You got it!  Same middle name.

 

Now here are Netrebko and Villazon in a famous performance.  I wish I'd been there.

The connection with my post before last is - same singing gene.

And that's why birds sing too, and we think of it as song.

But do mice laugh?  Did tyrannosauruses sing?

Did you know that mice sing, a bit like birds?  Of course they are very high sopranos, higher than bats, so for us to hear them the song has to be artifically lowered in pitch.

Click here
Audio player: audioS1.mp3

(needs Quicktime)

Read more here

 

 

Take a stick of spaghetti.  Grasp the ends, one in each hand, and bend the stick until it breaks.  How many pieces?

Go on, try the experiment, was that what you expected?

[You may decide not to try the next variation in your own home though.]

What about a sheet of lasagne?

Last night it was very cold and clear here, near Cambridge UK. I looked up and saw the star Betelgeux, in Orion, and every time I see this star I remember seeing a TV programme long ago - maybe 'The Sky at Night' - where we were told Betelgeux is red giant and if you at even with the naked eye you can see it is red. We all ran outside to look and yes! It is visibly red. So next time you see the stars during winter months look for Orion - a bit like a giant letter H and see Betelgeux, the one at top left, is red.

In a cross-country run, Sven placed exactly in the middle among all participants.

Dan placed lower (i.e. did worse than Sven), in tenth place, and Lars placed sixteenth.

How many runners took part in the race?

(This is another mini-classic, I'll try to recollect where it was first published.)

Hello stardust

For that's what you are, reader.  Here's the story, please read it, it concerns you and I.  Sorry it is a bit long but it took billions of years to happen, so it is hard to squeeze into one blog post.

Long long ago when the universe first began there was only hydrogen.  Later some helium formed.  Then some lithium and probably a little beryllium. Even a little carbon.  But nothing very heavy.

After quite a while some large stars formed.  In the heart of these stars helium was forged from hydrogen and the change threw off lots of energy. The helium could even form other elements by combining and this too produced energy. This energy flow kept the stars inflated, although gravity was trying to make them contract.

Over time these stars began to run out of hydrogen and helium, and eventually they collapsed.  This is what causes a supernova!  The star implodes violently in a short time -- days only -- but then as it smashes in on itself all sort of new elements are formed by the pressure -- including many necessary to life.  Before the implosion there might have been a little carbon perhaps but no iron for blood, or oxygen for breathing.

Now this explosion blew the heavy elements formed out at great velocities and over billions of year the atoms ended up with some other dust, and some hydrogen and helium, and gravity made it swirl together.  This formed a new star and some planets.

But some of the little planets were too small for their gravity to hold on to all the hydrogen and helium they began with. Part of their hydrogen combined with oxygen to make water, which has remained.  But mostly what was left was heavier elements -- think rocks. Still all the same the wet bits on the surface acted a home for the evolution of life.

Of course this life used many heavy atoms from supernovas billions of light-years away and billions of year before.  You and I would not exist without the dust from those ancient stars.

Literally stardust.

 

 

 

 

Here's a red dwarf, courtesy of Swinburne University. Such an object might be stable for as long as a trillion years.

http://astronomy.swin.edu.au/cms/astro/cosmos/R/Red+Dwarf

How many red dwarf stars are there in the observable universe (very roughly) and what is their combined mass (even more roughly)?

(Only estimates required but we want to see you working!  Well roughly.)