Imagine a grain of fine beach sand. What’s its size? Classification scales vary, but let’s say less than a tenth (0.1) of a millmeter (mm). A grain of table salt. Same question. Maybe ~0.3 mm. In either grain there are a gazillion molecules. Now imagine something a thousand (1000) times smaller – a micrometer-sized grain.… Continue reading Tiny grains tell a stellar story
Who would have expected the Hubble Space Telescope (often referred to as HST or Hubble) to still be in operation after being launched into low Earth orbit in 1990? So, NASA/ESA kickstarted its 30th anniversary with some majestic galactic photos. Wiki: Five Space Shuttle missions have repaired, upgraded, and replaced systems on the telescope, including… Continue reading Celebrating Hubble – 30th anniversary year
Ask people on the street “What are X-rays?” and you’ll likely get a variety of replies. About medical and dental X-rays. Stories about Superman’s X-ray vision. (Why does lead block X-rays?) Invisible particles that allow us to see through stuff. Technical explanations about electromagnetic radiation. So, street surveys typically reveal levels of understanding, which I’ll… Continue reading Levels of understanding – what are X-rays?
Have yourself a merry little Christmas Let your heart be light From now on, our troubles will be out of sight Have yourself a merry little Christmas Make the Yuletide gay From now on, our troubles will be miles away Here we are as in olden days Happy golden days of yore Faithful friends who… Continue reading Santa in space
[“Quantum foundations” series] A physicist walks into a bar, and asks the bartender, “What time is it?” The bartender is about to reply but then recognizes the customer. “You’re a physicist, correct? So, it’s a trick question.” So, what’s with time? A venerable philosophical question. A foundational question in physics. We have electronic devices, extremely… Continue reading Whence the arrow of time?
You’ve probably heard the saying, “We will sell no wine before its time.” While most of us rarely think about the topic when buying retail wines, the more adventurous might go for age-worthy bottles – immature wines which can taste quite better at their peak. How long do you wait? Is there a mathematical model for… Continue reading Wine before time itself – stars older than the universe?
Yesterday the buzz started about the announcement of the 2019 Nobel Prize in physics. Here’re some samples of articles on the joint award to three scientists. A testimony to research on the cosmic microwave background radiation (and understanding of the universe’s evolution) and advances in observational astronomy. • Washington Post > “Nobel Prize in physics… Continue reading 2019 Nobel Prize in physics — our place in the universe
[“Quantum foundations” series] [Updated December 2019] Introduction to this topic If Murray Gell-Mann was right that Niels Bohr brainwashed a generation of physicists to accept the Copenhagen Interpretation, either his influence has waned or he didn’t do a very good job in the first place. For in an informal poll conducted at an international meeting… Continue reading Quantum reality, quantum worlds – new book explores quantum foundations
I generally get the difference between matter particles (leptons and quarks) and “force carrying” particles (bosons). But I still do not understand how the “exchange” of fundamental / elementary bosons (e.g., photons and gluons) bind or ‘glue’ matter particles together as well as repel matter particles — as in attraction of oppositely charged particles and… Continue reading A boson by any other name would …
I just added another “big science” ground telescope to my Experiments page — the GMT. Astronomers claim that the images from these giant telescopes will be better than those sent to earth by the Hubble space telescope. Yet another in Chile. Then I recalled recently reading about Chile as an astronomer’s paradise. Here’s a sampling… Continue reading An astronomer’s paradise — Chile