Coffee House Musing

vimesey writes: i was ignorant and first saw a simple addition of an 'm' in Elpis turned it into a phrase, "Science is Simple, backwards."but then i googled it and found a cite that studies cells....
mea culpa. oh well...

Another Milestone! Webb Space Telescope Completes First Multi-Instrument Alignment

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The sixth stage of aligning NASA’s James Webb Space Telescope’s mirrors to its scientific instruments so they will create the most accurate and focused images possible has concluded. While the Mid-Infrared Instrument (MIRI) continues its cooldown, optics teams have successfully aligned the rest of the observatory’s onboard instruments to Webb’s mirrors. Previous alignment efforts were so accurate that the team concluded no additional adjustments to the secondary mirror are necessary until the seventh and final stage, which will involve MIRI when it has fully cooled.

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“As a general rule, the commissioning process starts with coarse corrections and then moves into fine corrections. The early secondary mirror coarse corrections, however, were so successful that the fine corrections in the first iteration of Phase Six were unnecessary,” said Chanda Walker, Webb wavefront sensing and control scientist, Ball Aerospace. “This accomplishment was due to many years of planning and great teamwork among the wavefront sensing team.”

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Throughout the majority of the alignment process, Webb’s 18 hexagonal mirrors and secondary mirror were focused into alignment to the Near-Infrared Camera (NIRCam) instrument only. Upon completing this most recent step, the observatory is now aligned to the Fine Guidance Sensor (FGS), the Near-Infrared Slitless Spectrograph (NIRISS), and the Near-Infrared Spectrometer (NIRSpec) as well as NIRCam.

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I have seen several articles about gravitational wave astronomy recently but this one had some nice diagrams of the gravitational spectrum defined by wavelength and what events cause various length waves. There are also some video simulations that illustrate what a complex region of spacetime surrounds orbiting blackholes, especially super-massive blackholes. NASA’s Fermi Space Telescope Hunts for Gravitational Waves From Monster Black Holes

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Our universe is a chaotic sea of ripples in space-time called gravitational waves. Astronomers think waves from orbiting pairs of supermassive black holes in distant galaxies are light-years long and have been trying to observe them for decades, and now they’re one step closer thanks to NASA’s Fermi Gamma-ray Space Telescope.

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Fermi detects gamma rays, the highest-energy form of light. An international team of scientists examined over a decade of Fermi data collected from pulsars, rapidly rotating cores of stars that exploded as supernovae. They looked for slight variations in the arrival time of gamma rays from these pulsars, changes which could have been caused by the light passing through gravitational waves on the way to Earth. But they didn’t find any.

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While no waves were detected, the analysis shows that, with more observations, these waves may be within Fermi’s reach.

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“We kind of surprised ourselves when we discovered Fermi could help us hunt for long gravitational waves,” said Matthew Kerr, a research physicist at the U.S. Naval Research Laboratory in Washington. “It’s new to the fray – radio studies have been doing similar searches for years. But Fermi and gamma rays have some special characteristics that together make them a very powerful tool in this investigation.”

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The results of the study, co-led by Kerr and Aditya Parthasarathy, a researcher at the Max Planck Institute for Radio Astronomy in Bonn, Germany, were published online by the journal Science on April 7.

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When massive objects accelerate, they produce gravitational waves traveling at light speed. The ground-based Laser Interferometer Gravitational Wave Observatory – which first detected gravitational waves in 2015 – can sense ripples tens to hundreds of miles long from crest to crest, which roll past Earth in just fractions of a second. The upcoming space-based Laser Interferometer Space Antenna will pick up waves millions to billions of miles long.

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Kerr and his team are searching for waves that are light-years, or trillions of miles, long and take years to pass Earth. These long ripples are part of the gravitational wave background, a random sea of waves generated in part by pairs of supermassive black holes ­in the centers of merged galaxies across the universe.

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To find them, scientists need galaxy-sized detectors called pulsar timing arrays. These arrays use specific sets of millisecond pulsars, which rotate as fast as blender blades. Millisecond pulsars sweep beams of radiation, from radio to gamma rays, past our line of sight, appearing to pulse with incredible regularity – like cosmic clocks.

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As long gravitational waves pass between one of these pulsars and Earth, they delay or advance the light arrival time by billionths of a second. By looking for a specific pattern of pulse variations among pulsars of an array, scientists expect they can reveal gravitational waves rolling past them.

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Another 101F day predicted for today. It's the second 100F+ day this week.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
And summer is still two months in the future.

We got up to 80 last Wednesday, but snow flurries here yesterday. Further north in Portland/Vancouver area they have gotten lots of wet snow and hundreds of trees and powerlines are down.

We've manages quite a few power outages just from scattered thunderstorms.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
But then it's Texas and Texas decided to let the whole power grid simply go to pieces rather than maintain or upgrade things.

You have become our heat sink.Here in the Valley of the Sun, mid-April, hovering just above 90°F the last two weeks, now, today, we aren't predicted to hit 75. And this is going to go on another couple days. Hope you can put up with our heat, and, btw, thank you. These next few days are going to be a return to perfect Phoenix winter splendor.Edited by AZPaul3, : No reason given.

We are at about 18 hours with temps above freezing. We probably will be back under tonight.Edited by Theodoric, : Punct

I gotta admit I loved living in Phoenix in the late 1960s.Had an apartment at 44th. St and E. Thomas Rd. Back then it was in an orange and date grove.

It's just about time to pull the dragonfly eggs I collected in Wisconsin last September out of the refrigerator so they can continue development.

Holy crap time flies. Hard to believe it's been 32 years.I remember those first days of utter despair when we learned that the mirror was ground incorrectly, but look at us now with one of the most successful orbital observatory missions. It turned out to be pretty well designed to allow servicing and repairs.And JWST infrared sensors are at operating temperature, I hope they show us something really spectacular first! We deserve it!

My dad insisted, before it was launched, that Hubble would be a 10 orders of magnitude increase in our seeing power and a 100 orders of magnitude increase in our knowledge. JWST should be the same.Edited by AZPaul3, : No reason given.

And THAT was what really blew my mind at the time. To think that a half century ago (when the Hubble design project started) folks were thinking "So how we gonna check the tire pressure and wipe the windscreen on that sucker" at a time when just getting shit up and keeping it there was still a major issue was mind blowing stuff.

Enjoy the day.

I have been pleased with my experiments in vaping cannabis oil. The cartridges last 2-3 weeks and a charge on the battery lasts more than a week. The battery pens for $10 or a bit less have some quality control issues. Several just never worked after being charged and a couple more quit after a couple charges. and the power setting function crapped out too. I finally bought a 1300 mah with a power setting dial on the base and a single power on button that works perfect and also gives me a better high per toke. More economical than smoking bud and less combustion by-products.Enjoy the day yourself!