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Comment: Re:swinging and spinning (Score 1) 162

by michaelwv (#35084324) Attached to: Low Budget Air Space Photography
The payload is suspended from the balloon and is essentially a pendulum. Any buffeting or motion takes a while to damp down. Just the simple motion of the balloon itself might be enough (I don't know the damping function well enough to figure out what frequencies and amplitudes of forcing functions are relevant).

Comment: Re:I'm confused. (Score 1) 506

by michaelwv (#35075988) Attached to: Universe 250+ Times Bigger Than What Is Observable
In the Big Bang theory, the Universe did not start out as an extremely compact volume. The theory states that it started at an infinite density and temperature. If the Universe is infinite, then it was also quite possibly infinite at the beginning. As other posters have mentioned, it's also the case that spacetime is allowed to expand faster than the speed of light.

Comment: Re:Distant Galaxy Now even Further (Score 1) 225

by michaelwv (#35037600) Attached to: What Exactly Is a Galaxy?
My understanding of general relativity, special relativity, and cosmological expansion are perfectly fine. But my ability to explain things clearly and unambiguously are probably more suspect. I was trying to explain why there were perfectly reasonable reasons to talk about several different definitions of distance.
"In our frame of reference, it really currently is 13.2 billion light years away"
We have to precisely define "currently" and "away"? There are several reasonable and different definitions for each of those. What would you like to mean by those words? Once we define that, then we can calculate whatever distance is the appropriate one for those definitions.

Comment: Re:Distant Galaxy Now even Further (Score 2) 225

by michaelwv (#35037044) Attached to: What Exactly Is a Galaxy?
It's not really about preferred frame of reference, it's the different meanings of distance that arise in general relativity. In this case there are two meanings being discussed:
1) How long has that photon been traveling to get to Earth ("light travel time")? 13.2 billion years
2) How far away is that galaxy right now ("proper distance"). I.e., if each galaxy had a clock that counted seconds since the Big Bang and could instantaneously extend a long ruler to the other galaxy and the ruler was sent and received at the same time has measured by those clocks, how long would that ruler be? 32 billion light years

There are other definitions, and you can make this arbitrarily more complicated by considering moving reference frames.
Moon

Microwave Map of Entire Moon Revealed 82

Posted by samzenpus
from the quickest-route-mode dept.
Zothecula writes "The first complete microwave image of the Moon taken by Chinese lunar satellite Chang'E-1 has been revealed. Chang'E-1 is China's first scientific mission to explore planetary bodies beyond Earth and the on-board Lunar Microwave Radiometer has made it possible for the first time to globally map the Moon in microwave frequencies. Radar observations of the Moon are unable to provide thermal information, and microwave observations taken from Earth cannot reach the far side of the moon. So Chang'E-1's (CE-1) orbit was conducted at an altitude of 200km (124 miles) and allowed it to observe every location of the moon with a nadir view and at high spatial resolution."

Comment: Re:Needs a caption (Score 2, Informative) 154

by michaelwv (#33381728) Attached to: Video Showing Half a Million Asteroid Discoveries
Discoveries are observations. Most discoveries are near opposition. It's only for special reasons that some surveys have been looking in other directions: either things like WISE that are in the infrared and so have special restrictions about where they can point, or targeted searches for near-Earth objects. In you click on the video you can read all about it in the caption. http://www.youtube.com/watch?v=S_d-gs0WoUw
Medicine

Rare Sharing of Data Led To Results In Alzheimer's Research 159

Posted by Soulskill
from the never-forget dept.
jamie passes along a story in the NY Times about how an unprecedented level of openness and data-sharing among scientists involved in the study of Alzheimer's disease has yielded a wealth of new research papers and may become the template for making progress in dealing with other afflictions. Quoting: "The key to the Alzheimer's project was an agreement as ambitious as its goal: not just to raise money, not just to do research on a vast scale, but also to share all the data, making every single finding public immediately, available to anyone with a computer anywhere in the world. No one would own the data. No one could submit patent applications, though private companies would ultimately profit from any drugs or imaging tests developed as a result of the effort. 'It was unbelievable,' said Dr. John Q. Trojanowski, an Alzheimer's researcher at the University of Pennsylvania. 'It's not science the way most of us have practiced it in our careers. But we all realized that we would never get biomarkers unless all of us parked our egos and intellectual-property noses outside the door and agreed that all of our data would be public immediately.'"
Mars

SpaceX Unveils Heavy-Lift Rocket Designs 248

Posted by timothy
from the now-comes-the-wedding-night dept.
FleaPlus writes "At the recent Joint Propulsion Conference, SpaceX's rocket development facility director Tom Markusic unveiled conceptual plans for how its current Falcon 1 and Falcon 9 commercial rockets can be evolved into heavy-lift rockets, ranging from a Falcon X capable of lifting 38,000kg to orbit, up to a 140,000kg Falcon XX (more than either the Saturn V or the 75,000kg shuttle-derived rocket Congress currently plans on having NASA spend >$13B building). SpaceX presentations also discuss a new Merlin 2 heavy-lift engine, solar-electric cargo tugs, adapting their current engines for descent/ascent vehicles fueled by Mars-derived methane, and a desire for the government to take the lead on in-space nuclear thermal propulsion while commercial focuses on launchers. In a recent interview, SpaceX CEO/CTO Elon Musk expressed his goal of lowering the price of Mars transportation enough to enable early colonization in 20 years, and his own plans for retiring to Mars."
Security

ReCAPTCHA.net Now Vulnerable to Algorithmic Attack 251

Posted by timothy
from the bless-you! dept.
n3ond4x writes "reCAPTCHA.net algorithms have been developed to solve the current CAPTCHA at an efficacy of 30%. The algorithms were disclosed at DEFCON 18 over the weekend and have since been made available online. Also available is a video demonstration of random reCAPTCHA.net CAPTCHAs being subjected to the algorithms." There's probably an excellent Firefox plugin to render this page's color scheme more bearable. Note: the PowerPoint presentation linked opens fine in OpenOffice, and the video speaks for itself.

What the world *really* needs is a good Automatic Bicycle Sharpener.

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