dust
esiegel | December 11, 2013"Where you used to be, there is a hole in the world, which I find myself constantly walking around in the daytime, and falling in at night. I miss you like hell." -Edna St. Vincent Millay
It was just a little while ago that we were all speculating wildly -- and optimistically -- about Comet ISON, as it plunged towards the Sun from its origins in the very, very distant Solar System. As its perihelion date (the moment of closest approach to the Sun) drew near, you may have noticed something interesting about photos of the comet: it's tail appeared to get longer and longer!
Image credit &…
esiegel | September 5, 2013"One sees qualities at a distance and defects at close range." -Victor Hugo
A couple of weeks ago we took a look at the most distant galaxy (so far) in the known Universe, a galaxy so far away that it takes exclusively infrared observations from our most power space telescopes (Hubble and Spitzer) in order to detect it. What's perhaps even more remarkable is that the light we do detect from it -- the light we detected in the infrared -- was actually emitted in the Ultraviolet part of the spectrum!
Image credit: NASA, ESA, Garth Illingworth (University of California, Santa Cruz) and Rychard…
esiegel | August 21, 2013"I am undecided whether or not the Milky Way is but one of countless others all of which form an entire system. Perhaps the light from these infinitely distant galaxies is so faint that we cannot see them." -Johann Lambert
When we look out at the Universe, our view is pretty consistently dominated by the stars within our own galaxy. Although we know that many interesting things lie beyond -- globular clusters, individual galaxies, and rich clusters and superclusters of galaxies -- being in the Milky Way makes it very hard to see beyond it.
Image credit: Richard Payne, of Arizona…
esiegel | November 7, 2012"It's a brilliant surface in that sunlight." - Neil Armstrong
Indeed, all that glitters so brilliantly in the cosmos does so because of the stars that have formed throughout it.
Image credit: NASA, ESA, and the Hubble SM4 ERO Team.
Over the 14 billion-or-so years that our Universe has been around, we've formed hundreds of billions of stars in our galaxy alone.
Image credit: ESO / Serge Brunier (TWAN), Frederic Tapissier.
Given that our galaxy is just one of at least hundreds of billions in the observable Universe, the number of stars that have formed over our Universe's history is a…
egrossman | September 28, 2011by Elizabeth Grossman
Why some people who inhaled the airborne contaminants unleashed by the destruction of the World Trade Center on September 11, 2001 became sick for only a short time, why some have become chronically ill, and others terminally ill, may never be known. What is known, however, is that the dust and aerosols released in that disaster contained a potentially treacherous mix of everything that was in those enormous buildings and in those aircraft. What is also known is that, as Paul J. Lioy, professor and vice chair of the Department of Environmental and Occupational Medicine…
egrossman | September 23, 2011by Elizabeth Grossman
It's now ten years since the streets of lower Manhattan roiled with clouds of toxic dust and debris from the horrific events of September 11, 2001, but it was clear from discussions and presentations at the September 16 conference hosted by the New York Coalition for Occupational Safety and Health (NYCOSH) that the dust has not yet settled when it comes to issues of protecting worker and community health from environmental hazards of a disaster - nor from the ongoing impacts of 9/11. In the course of the day-long meeting held on lower Broadway a few blocks from the World…
egrossman | June 1, 2011by Elizabeth Grossman
"With what's on the table in Washington now, you may think the technical phrase is 'job-killing OSHA standards' but standards save lives," said David Michaels, Assistant Secretary of Labor of Occupational Safety and Health, in his address to the American Industrial Hygiene Association meeting in Portland, Oregon on May 18th. "OSHA doesn't kill jobs. OSHA stops jobs from killing workers."
To occupational health and safety professionals, this is not news - and it's a message that Michaels has taken on the road over the past year - but in the current anti-regulatory…
esiegel | May 5, 2010It will shine still brighter when night is about you. May it be a light for you in dark places, when all other lights go out. -J.R.R. Tolkien
The night sky is no stranger to most of you. Once the Sun goes down in the west, the sky darkens, turning ever-deeper shades of blue until it approaches blackness, and stars and planets begin to come out against the fading backdrop.
Many things pollute the darkening sky, and can obscure your vision of the dimmest objects in the sky. Getting away from the city and light pollution is important, as is having clear skies without too many clouds in them.…