[Jabberwalker]

How about a liquid helium geyser?

[stratos]

Jabberwalker Jabberwalker:

How about a liquid helium geyser?

Would it be that big that it would show up in the pic. like it does?

[Jabberwalker]

Reptilian forward base, then?

[stratos]

Jabberwalker Jabberwalker:

Reptilian forward base, then?

OMG we're going to be invaded. Someone send all the Democrats there to negotiate our surrender.

[Jabberwalker]

Wasn't it the Republicans who wanted nothing to do with WWII before Pearl Harbour?

[stratos]

Jabberwalker Jabberwalker:

Wasn't it the Republicans who wanted nothing to do with WWII before Pearl Harbour?

Actually most of America wanted nothing to do with WWII prior to Pearl Harbor. We were very isolationist during this time. I do think the republican congress put in bills and laws to prevent arms being sent to England or anyone, but as we know F.D.R found ways around those laws.

[Jabberwalker]

I do think the republican congress put in bills and laws to prevent arms being sent to England or anyone (like us)

[stratos]

Jabberwalker Jabberwalker:

I do think the republican congress put in bills and laws to prevent arms being sent to England or anyone (like us)

I just don't know if it was republican dominated congress or not during this time without researching it.

[DrCaleb]

$1:

Ask Ethan #72: The timeline of the Universe

We claim to know the Universe’s history to incredible precision. But is this justified?

$1:

“The only reason for time is so that everything doesn’t happen at once.”
-Albert Einstein

We’ve reached the end of another spectacular week, which means it’s time to go to the mailbag for Ask Ethan. Each week, you send in your questions and suggestions, and I choose my favorite to showcase a little something about the Universe. Or in today’s case, a big thing! Today’s all-encompassing question comes courtesy of Scott Robbins, who wants to know:

$1:

I am confused about the timeline of the Big Bang. When scientists talk about the beginning of the universe, the formation of the elements and the creation of galaxies, etc. they cite extremely specific time intervals in which these things occur… Where do they get these numbers? There is no way to have them be empirically confirmed, and yet they are given to extreme degrees of accuracy (and with confidence). How can scientists be so confident in these times, and where are the numbers coming from?

He includes a link to a helpful image to illustrate this. (Reproduced here.)



This image is mostly correct (but not entirely), and it leaves out something that I would consider very important: error ranges. There are uncertainties on all of these, but nonetheless, the general picture is true, and the uncertainties are relatively small.

How do we know? There are three things that conspire together:

We understand how the Universe expanded, and hence, what its physical size-and-scale is as a function of time.
We understand how the temperature (and hence, energy) of the particles in the Universe depends on the expansion history.
We understand — to varying degrees — the physical processes that determine each of these steps, and how they evolve.

Let’s take a glimpse at each of these, individually, and then put the full story together.

https://medium.com/starts-with-a-bang/a ... 870d1b8f52

A long article, but well worth the read as it not only goes over what we know, but the things we are also uncertain about.

[DrCaleb]

$1:

Ten new Rosetta images that reveal comet 67P in all its glory

In August 2014, the European Space Agency’s Rosetta spacecraft arrived at comet 67P/Churyumov-Gerasimenko. Once in orbit, it swooped as low as 10 kilometers to get unprecedented data from the comet (and to drop off its short-lived Philae lander). Today, Science is publishing a suite of new papers detailing some of the mission’s first findings, including discoveries from Rosetta’s main science camera, OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System). Images like these reveal 67P to be a far more diverse place than anyone expected.

http://news.sciencemag.org/space/2015/0 ... -its-glory

[DrCaleb]

$1:

Unseen Galaxies of the Universe Detected

"This object is a unique example of what is suspected to be an abundant, underlying population of small and faint galaxies at about 500 million years after the Big Bang," explained Adi Zitrin of the California Institute of Technology. "The discovery is telling us that galaxies as faint as this one exist, and we should continue looking for them and even fainter objects so that we can understand how galaxies, and the Universe, have evolved over time."
Using the NASA/ESA Hubble Space Telescope astronomers have made what may be the most reliable distance measurement yet of an object that existed in the Universe’s formative years. The galaxy is one of the faintest, smallest and most distant galaxies ever seen and measuring its distance with this accuracy was possible due only to the incredibly detailed mapping of how giant galaxy clusters warp the space-time around them.

Astronomers often use gravitational lensing — the magnifying power of galaxy clusters — to find distant galaxies. However, when it comes to the very early Universe, distance measurements can become inaccurate as the objects are so dim. Now, a team of astronomers has combined a traditional method of distance measurement with some clever reverse engineering to vastly improve accuracy. Galaxy clusters are so massive that their gravity deflects light passing through them, distorting the images of the distant objects behind them and sometimes magnifying and brightening them in gravitational lensing.

The lensing power of the mammoth galaxy cluster Abell 2744, nicknamed Pandora's Cluster (image at top of page), focussed the light from the faraway galaxy that was being studied, making it appear about ten times brighter than it otherwise would have been, and allowing astronomers to see it. The lensing also produced three magnified images of the same galaxy.

"We were able to spot the galaxy's multiple gravitationally-lensed images using near-infrared and visible-light photos from Hubble," explained study leader Zitrin. "But at first we didn’t know how far away it was from Earth."

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6a00d8341bf7f753ef01b8d0c7fb51970c.jpg [ 88.15 KiB | Viewed 412 times ]

0:

6a00d8341bf7f753ef01b7c73e748f970b.jpg [ 88.57 KiB | Viewed 77 times ]

http://www.dailygalaxy.com/my_weblog/20 ... -bang.html

[DrCaleb]

$1:

Lensless space telescope could be 1,000 times stronger than Hubble

The Hubble space telescope has given us decades of incredible images, but it's reaching the end of its service life and the question is, what will come after? One possibility is the Aragoscope from the University of Colorado Boulder, which uses a gigantic orbital disk instead of a mirror to produce images 1,000 times sharper than the Hubble's best efforts.

The Aragoscope is named after French scientist Francois Arago who first noticed how a disk diffracted light waves. The principle is based on using a large disk as a diffraction lens, which bends light from distant objects around the edge of the disk and focuses it like a conventional refraction lens. The phenomenon isn't very pronounced on the small scale, but if the telescope is extremely large, it not only becomes practical, but also extremely powerful.

When deployed the Aragoscope will consist of an opaque disk a half mile in diameter parked in geostationary orbit behind which is an orbiting telescope keeping station some tens to hundreds of miles behind that collects the light at the focal point and rectifies it into a high-resolution image.

http://www.gizmag.com/aragoscope-lensle ... ope/35761/

[DrCaleb]

$1:

Gamma-ray bursts are a real threat to life

A new study confirms the potential hazard of nearby gamma-ray bursts (GRBs), and quantifies the probability of an event on Earth and more generally in the Milky Way and other galaxies. The authors find a 50% chance that a nearby GRB powerful enough to cause a major life extinction on the planet took place during the past 500 million years (Myr). They further estimate that GRBs prevent complex life like that on Earth in 90% of the galaxies.

GRBs occur about once a day from random directions in the sky. Their origin remained a mystery until about a decade ago, when it became clear that at least some long GRBs are associated with supernova explosions (CERN Courier September 2003 p15). When nuclear fuel is exhausted at the centre of a massive star, thermal pressure can no longer sustain gravity and the core collapses on itself. If this process leads to the formation of a rapidly spinning black hole, accreted matter can be funnelled into a pair of powerful relativistic jets that drill their way through the outer layers of the dying star. If such a jet is pointing towards Earth, its high-energy emission appears as a GRB.

The luminosity of long GRBs – the most powerful ones – is so intense that they are observed throughout the universe (CERN Courier April 2009 p12). If one were to happen nearby, the intense flash of gamma rays illuminating the Earth for tens of seconds could severely damage the thin ozone layer that absorbs ultraviolet radiation from the Sun. Calculations suggest that a fluence of 100 kJ/m2 would create a depletion of 91% of this life-protecting layer on a timescale of a month, via a chain of chemical reactions in the atmosphere. This would be enough to cause a massive life-extinction event. Some scientists have proposed that a GRB could have been at the origin of the Ordovician extinction some 450 Myr ago, which wiped out 80% of the species on Earth.

http://cerncourier.com/cws/article/cern/59937

[DrCaleb]

$1:

Citizen scientists lead astronomers to mystery objects in space
Scientists analyzed the “yellow balls” that appeared in Spitzer data and figured out that they are a new way to detect the early stages of massive star formation.

Sometimes it takes a village to find new and unusual objects in space. Volunteers scanning tens of thousands of starry images from NASA's Spitzer Space Telescope, using the Web-based Milky Way Project, recently stumbled upon a new class of curiosities that had gone largely unrecognized before — yellow balls. The rounded features are not actually yellow, they just appear that way in the infrared, color-assigned Spitzer images.

"The volunteers started chatting about the yellow balls they kept seeing in the images of our galaxy, and this brought the features to our attention," said Grace Wolf-Chase of the Adler Planetarium in Chicago. A colorful, 122-foot (37 meters) Spitzer mosaic of the Milky Way hangs at the planetarium, showcasing our galaxy's bubbling brew of stars. The yellow balls in this mosaic appear small but are actually several hundred to thousands of times the size of our solar system.

"With prompting by the volunteers, we analyzed the yellow balls and figured out that they are a new way to detect the early stages of massive star formation," said Charles Kerton of Iowa State University in Ames. "The simple question of 'Hmm, what's that?' led us to this discovery."

The Milky Way Project is one of many so-called citizen scientist projects making up the Zooniverse website, which relies on crowdsourcing to help process scientific data. So far, more than 70 scientific papers have resulted from volunteers using Zooniverse, four of which are tied to the Milky Way Project. In 2009, volunteers using a Zooniverse project called Galaxy Zoo began chatting about unusual objects they dubbed "green peas." Their efforts led to the discovery of a class of compact galaxies that churned out extreme numbers of stars.

In the Milky Way Project, volunteers scan through images that Spitzer took of the thick plane of our galaxy, where newborn stars are igniting in swaths of dust. The infrared wavelengths detected by Spitzer have been assigned visible colors we can see with our eyes. In addition to the yellow balls, there are many green bubbles with red centers, populating a landscape of swirling gas and dust. These bubbles are the result of massive newborn stars blowing out cavities in their surroundings. The green bubble rims are made largely of organic molecules called polycyclic aromatic hydrocarbons (PAHs), cleared away by blasts of radiation and winds from the central star. Dust warmed by the star appears red in the center of the bubbles.

http://www.astronomy.com/news/2015/01/c ... s-in-space

[DrCaleb]

$1:

NASA's Europa Mission to Hunt Down Life's Niches

As NASA applauds its boosted White House budget request for 2016, scientists at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., are excited to see a robotic mission concept to Europa take a big step towards being launched in the mid-2020s.

During a conference call to reporters on Monday, NASA chief financial officer David Radzanowski said the US space agency is requesting $30 million for preliminary studies into a mission to Europa for the year that begins Oct. 1. This is in addition to the $100 million Congress added to NASA’s budget to begin design work for a Europa mission last year.

In response to this news, and after 15 years exploring Europa mission concepts, JPL senior research scientist Robert Pappalardo said that most mission concepts have either been too small, too big or just too expensive, but “we believe we have now found the one that is just right.”

“We call this concept the Europa Clipper,” he said.

The Clipper concept has been an idea undergoing preliminary studies for some time, consisting of a Jupiter-orbiting spacecraft that will make multiple flybys of the Jovian moon Europa over a 3 year period. The spacecraft will dive deep into Jupiter’s radiation belts to fly over Europa’s surface approximately 45 times during its primary mission.

NASA’s Cassini spacecraft, which is currently orbiting Saturn, has carried out similar flybys of moon Titan, constructing a comprehensive map of its surface and measuring the moon’s thick atmosphere. The Europa Clipper will be focused on Europa in an effort to understand its habitable potential.


A model of the Europa Clipper mission concept displayed at NASA's Jet Propulsion Laboratory, Calif., on Feb. 2, 2015. The spacecraft's 'vault' is shown in red.

http://news.discovery.com/space/alien-l ... 150202.htm