Michael Flynn's Blog, page 84

The Möbius, the Merrier

Putting on My Top Hat

A comm box reply on the earlier topology post repeated the old canard that a topologist cannot tell the difference between a donut and a coffee cup. That is absurd.

This is a donut:

And that was a coffee cup.
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For those who don't like donuts, there is always


The Möbius bagel. www.georgehart.com/bagel/bagel.html

Musica sphaerarum

The String Theory of the Middle Ages

Humphrey over at Quodlibeta ponders the advances of physics in the Middle Ages:

One of the things the Middle Ages had inherited from earlier cultures was a tension between Ptolemaic views of cosmology and Aristotelian physics. The basis of this was that Aristotle was really interested in the causes of motion and the ways in which the universe functions in a physical way. According to Aristotle, the earth has to be in the centre because that is the low...

Search patterns

Today's Headline

The Wall Street Journal ran this:

It's Always in the Last Place You Look

• "Missing Aussie Found at Pub"--headline, News.com.au, Dec. 7


But we think they got it wrong. Would a pub not be the first place you would look for a missing Aussie?

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Copy & paste from character map does this:

Ø

so I got my null set handy now.

A Blast from the Past, continued

Putting on My Top Hat

I warned you. Nostalgia is a terrible force. Could we but harness it, our energy problems would be solved. Ah, the good old days...

Topologies

Topology is a branch of mathematics concerned with whether or not two points are close together, and how this closeness is affected by mappings from one space to another. On what basis can we say that two point a and b are "close"?

A topology on X is a family of subsets that constitute the "open" subsets of X. The familiar op...

m_francis @ 2009-12-06T15:55:00

Against Motion

Chastek has an interesting post about absolute motion in physics versus biology.

Einstein tells us that there is no way to sense the difference between motion and rest, because in some frame of reference, any moving body is at rest. For example, the earth is at rest in a reference frame centered on the earth, but in motion in a reference frame centered on the sun (or anywhere else, for that matter). Since no reference frame is "privileged," that settles that. Of course the p...

Undreamt of in your philosophy, Horatio.

You Can't Make This Stuff Up

Would-be Chavezista Morales administration in Bolivia accepted money from Iran to build a hospital. Came with strings attached. All the nurses at the hospital have to wear hijab. When the pictures ran on Bolivian TV, there was much public outcry, and the ruling MAS socialists split.

Mathematica Antiqua

A Blast from the Past

Last week I received a comment on this blog from my old topology professor, Doug Harris. This has sent my brain on a stroll down memory lane. I wrote a master's thesis under him that resulted in an original theorem or two. I have always taken great pride in the fact that they were of no practical use whatsoever. It appears now that the field of function space topologies has now become a hot new topic, and so the danger has arisen that someone somewhere may actually ci...

The Weather Outside if Frightful

Let It Snow, Let It Snow, Let It Snow

Today marked the second snow-fall and first accumulation of the season. One to three inches are predicted.

I blame global warming.

Sound and fury

Alle Menschen Werden Brüder

That old deaf guy sure played a mean pin ball

This is Kool, too

Super Squirrel versus the Dog Monster!

www.dailymail.co.uk/news/worldnews/article-1230489/Squirrel-attacks-dog-Hero-squirrel-saves-baby-eaten-dog.html

this dog certainly got more than it bargained for after pouncing on a baby squirrel it found on the ground.

Moments before the hapless baby would have been torn apart, these images show its mother appearing to leap off a nearby tree and attacking the surprised dog.

1. The dog has baby squirrel; mama spots the situation from the tree.

2. Mama...