During the NASA newser Thursday, I asked whether the latest Kepler data offered any new insight on the abundance of Earth-like planets around sun-like stars (the shorthand for this formulation is “eta-Earth”), and then followed up with an e-mail to NASA. Batalha, an astrophysicist who is the mission scientist for the Kepler telescope, e-mailed her answer:
Previous estimates of eta-Earth suggest that 15-25% of stars host potentially habitable planets. These estimates are based largely on discoveries of planets orbiting the cooler stars called M dwarfs. These new discoveries suggest that the statistics for sun-like stars are roughly in-line with estimates from the cooler M-type stars. So how does that translate to the number of planets in the galaxy? M, K, and G dwarfs comprise about 90% of the stars in the galaxy. Conservatively speaking, if 15% of stars have a planet between 1 and 1.6 times the size of Earth in the Habitable Zone, then you’d expect 15% of 90% of 100 billion stars to have such planets. That’s 14 billion potentially habitable worlds.
M type stars are the most common in the galaxy comprising about 70% of the population of Main Sequence stars. Here’s how the star types break down for the solar neighborhood within 33 light-years:
357 stars total
248 of those are M dwarfs
44 K dwarfs
20 G dwarfs
That means “only” about a billion of the 14 billion I mentioned above are orbiting G stars. Ha!
Thank you, Dr. Batalha! Keep in mind, she is using conservative estimates. So 1 billion may be a little low.
Sir Arthur had hoped we’d find intelligent life elsewhere in the universe. We may be inching toward that goal today.
Many of us are familiar with a variety of audio media — cassettes, vinyl records, CD’s come to mind. Older folks remember 8-tracks and reel-to-reel tapes, yet younger people can hardly remember audio CD’s. Most of us enjoy the modern conveniece of taking your music with you — all of it, neatly indexed/organized on one device, generally an iPod.
What about other media?
8mm film (or Super-8), RCA videodiscs, VHS, Beta or even floppy disks for computers — they’re still around but the playback equipment may not be. Most video media have been replaced by the DVD or Blu-ray disk, and some are seeing even that making way for video streaming via Netflix or other on-demand service. The same applies to photographic film. The quality of an old 35mm color slide is wonderful, which is what you may conclude is you see one on your monitor, after it’s been converted to a digital format.
As the content found on these media get converted to digital, they’re easier to find, store and play back anywhere via the Internet, using a convenient little device or laptop. If you don’t have a connection, perhaps you’ll have a copy saved locally. Now, what happens if that scheme changes and/or deteriorates? We’ve all seen old newspapers fall apart, but we’ve also seen 100-year-old books preserved at home or libraries for others to share and enjoy.
Where will our media be in 100 years? The iPod has overwhelmed audio in less than 15 years. The VHS tape has gone from dominant to relatively obsolete in roughly 25 years. Solid-state flash memory is poised to replace magnetic disks in computers and laptops — or will it be replace by optical storage of some kind? Continue Reading →
Tuesday morning, the New Horizons space probe zipped past Pluto going 30,000 miles per hour. It carries the ashes of the man who discovered the dwarf planet, along with several spectrometers to analyze Pluto’s surface and one telescopic camera.
That camera has been busy for the past decade, snapping hundreds of photos of Jupiter first, and then Pluto. Those images were stitched together to create this video. The words that accompany the video come from Ray Bradbury, who read his poem “If Only We Had Taller Been” at a celebration of a NASA mission to Mars in 1971.
According to Fred Ordway, the spacesuits used in the film 2001: A Space Odyssey, were made in England: “we had our space helmets built, from our designs, at the MV Aviation Co., Ltd of Maidenhead [and] our spacesuits at the Air Sea Rescue Division, Victoria Rubber Works of the Frankenstein Group, Ltd. of Manchester.”
Having come across a frank and candid report from a test pilot about the Joint Strike Fighter Program’s F-35 inability to compete with an older F-16 jet in a “dog fight” had us reflecting on a short story written by Sir Arthur in 1951.
The fantastic and haunting short story “Superiority,” written by the science fiction visionary Arthur C. Clarke in 1951, warns us about the opportunity cost of getting into a cycle of developing ever more complex and costly weaponry while sacrificing more numerous and proven systems in the process. It is an essay on numerical advantage, over-optimistic design goals, wanting to believe manufacturer excuses and the internal threat posed relying solely on exceedingly complex systems.
I first read this story in high school back in the late 1990s, and I remember my teacher saying it was mandatory reading at some of the best engineering colleges in the world. I had since forgotten about it until I was reminded of its existence a few years back from an Aviationintel reader. In retrospect I have a feeling that it may have influenced my thought processes more than I like to admit in regards to my writing.
We welcome you to read the story and come to your own conclusions…
Superiority – by Arthur C. Clarke
IN MAKING THIS STATEMENT – which I do of my own free will – I wish first to make it perfectly clear that I am not in any way trying to gain sympathy, nor do I expect any mitigation of whatever sentence the Court may pronounce. I am writing this in an attempt to refute some of the lying reports broadcast over the prison radio and published in the papers I have been allowed to see. These have given an entirely false picture of the true cause of our defeat, and as the leader of my race’s armed forces at the cessation of hostilities I feel it my duty to protest against such libels upon those who served under me. Continue Reading →