Author Archives: Bob Welbaum

How Big Can Black Holes Grow?

If I were smart, I’d stay away from this one, because it gets complicated, but I just ran across this topic on the EarthSky News. The short answer to how big a black hole can get is 50 billion suns before the food that powers them crumbles into stars. (Like I said, it’s complicated.) The

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Happy Winter Solstice

It’s all downhill from here. The winter solstice   —  officially the first day of winter, although I have my own definition — is the shortest day and the longest night of the year.  Of course that’s in the Northern Hemisphere; in the Southern Hemisphere it’s just the reverse.  Depending upon your time zone, the

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Is It Christmas?

You never know what you’ll find on the Internet. The most unusual website I’ve ever found is https://isitchristmas.com/ It answers the question “Is it Christmas?” in a very direct way.  Be sure to check it on Christmas, although you will probably be disappointed.

Printing Your Clothes

You’ve heard a lot about 3D printers, but will there ever be the day when we can use them to print our clothes? A young lady named Danit Peleg thinks that day will be here soon.  In a recent TED talk, she explains how a fashion school project let her to degisn and print some

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