Board index » Word on the Street... » News & Debate




Post new topic Reply to topic  [ 460 posts ]  Go to page Previous  1, 2, 3, 4, 5, 6, 7, 8 ... 23  Next
Author Message
 Post subject: Re: our universe is so rad
PostPosted: Mon Apr 07, 2008 1:57 pm 
Offline
Faithless
 Profile

Joined: Tue Apr 19, 2005 12:34 am
Posts: 2623
A little closer to home, but when I first learned about honeybee communication it blew my fucking mind:

http://en.wikipedia.org/wiki/Waggle_dance
http://users.rcn.com/jkimball.ma.ultran ... ances.html
http://gears.tucson.ars.ag.gov/ic/dance/dance.html

The ability of honey bees to share information about floral patch feeding sites breatly helps their colonies achieve efficiency in foraging. Whenever a scout bee discovers a new rich food source, she recruits nestmates to it and thus helps ensure that her colony's forager force stays focused on the richest available patches. The majority of this recruitment is by the waggle dance, a unique form of animal behavior in Apis, in which the returning forager seems to perform a miniaturized "reenactment" of her recent journey. Other bees attending these dances somehow (just how they do is not known) learn the distance, direction, and odor of the flower patch and can translate this information into a flight to the original flowers. The waggle dance has been acclaimed as a truly symbolic message, one which is seperated in space and time from both the actions on which it is based, and the behaviors it will guide. Our understanding of this system is due mostly to the pioneering work of the late Karl von Frisch (shared a Nobel Prize for these studies) and his students and colleagues, research which now spans 70 years.

The round dance is performed for food sources close to the colony (less than 50-80 m) and the waggle dance used for distant floral sites. Round dances elicit flight and searching (by olfactory and visual cues) behavior for flowers close to the hive but without respect to any specified direction.

The waggle dance has two components:

* a straight run — the direction of which conveys information about the direction of the food
* the speed at which the dance is repeated which indicates how far away the food is.

The graph shows the relationship between the speed of the dance and the distance to the food. It is based on data collected by the German ethologist Karl von Frisch. It was he who discovered much of what we know today about honeybee communication (and was honored with a Nobel Prize in 1973).

Image Image

By itself, the knowledge that food is 6 kilometers (3.7 miles) away is not very useful. But von Frisch also noted that the direction of the straight portion of the waggle dance varied with the direction of the food source from the hive and the time of day.

* At any one time, the direction changes with the location of the food.
* With a fixed source of food, the direction changes by the same angle as the sun during its passage through the sky.

But

* The sun is not visible within the hive.
* The scouts dance on the vertical surface of the combs.

How, then, do they translate flight angles in the darkened hive? The image shows how:
Image

When scouts remain in the hive for a long period, they shift the direction of the straight portion of the waggle dance as the day wears on (and the direction of the sun shifts). But they cannot see the sun in the darkened hive. Evidently, they are "aware" of the passing time and make the necessary corrections.

In addition, von Frisch also discovered that scouts (and foragers) don't actually have to see the sun to navigate. As long as they can see a small patch of clear blue sky, they get along fine. This is because sky light is partially polarized, and the plane of polarization in any part of the sky is determined by the location of the sun.


Top
 
 Post subject: Re: our universe is so rad
PostPosted: Mon Apr 07, 2008 8:14 pm 
Offline
User avatar
Stone's Dutch Bitch
 WWW  Profile

Joined: Mon Nov 19, 2007 7:47 pm
Posts: 303
Location: Right There
Gender: Female
These kind of threads make my head burst ....ai! :roll:

_________________

http://reducetosilence.blogspot.com


Top
 
 Post subject: Re: our universe is so rad
PostPosted: Wed Apr 09, 2008 5:18 pm 
Offline
User avatar
Interweb Celebrity
 Profile

Joined: Sun Oct 17, 2004 12:47 am
Posts: 46000
Location: Reasonville
http://www.foxnews.com/story/0,2933,348189,00.html

Life-From-Space Theory Gets Unexpected Boost


Lefties are just 11 percent of the world population. But take a close look at anyone's amino acids, which are protein's and thus life's tiny building blocks, and left-handers rule.

Left-handed amino acids are mirror images of their right-handed buddies, and though similar, the mirrored molecules are chemically different. For some reason, nearly every single organism exclusively relies on lefties. Why does life discriminate on a molecular level?

Neutron starlight might have zapped amino acids riding on comets and asteroids into a bias, and a little water might have concentrated them after they crashed into Earth, a team of scientists now say.

If so, our planet's first inhabitants would have little choice other than to rely on the lefty acids.

"People have been exploring this question for years, and I think we've put some pieces together that make it not so puzzling," said Ronald Breslow, a chemist and biologist at Columbia University in New York.

Selective destruction

In nature, chemical reactions that make amino acids form equal amounts of lefties and righties, which is why the extreme bias for the left-handed molecules on Earth is such a mystery.

Breslow said scientists have discovered ancient amino acids that hitchhiked onto Earth on meteorites in the past, but no one could adequately explain why there were five to 10 percent more of the left-handed types in the chunks of rock.

"The molecules are loaded with heavy isotopes, so we knew they came from space," Breslow said. "What is so mysterious is that there isn't a 50-50 mix of right- and left-handed versions."

But Breslow explained that neutron stars — super-dense, fast-spinning remnants of supernovas — could be the culprit as they emit circularly polarized light, sort of like a laser.

High-energy beams coming out of one pole are polarized in a right-handed way, while the other pole shoots out left-handed rays.

While right-handed light breaks apart some of both versions of amino acids, it preferentially zaps more of the righties because their molecular structure better absorbs the light energy. (The process is comparable to how dark objects heat up quicker in the sun than light objects.)

If amino acid-peppered asteroids or comets soaked up more right- than left-handed neutron starlight before they smacked into Earth, Breslow said it could explain why the space rocks show a bias for the lefty molecules.

From concentrate

Add a little desert heat and occasional water to meteorite debris, Breslow said, and the story gets more interesting.

As the water dries up, the amino acids crystallize and leave behind a concentrated residue of lefties.

"Amino acids like to stack up one right-handed molecule to one left-handed," Breslow said. "It's as if you had a big pile of gloves with a few more left gloves. If you pair them up, pretty soon you've just got the lefty gloves."

Nobody knows how amino acids and other chemistry mixed or was zapped to become life.

But the lefty acidic concentrate would have been the feeding stock for Earth's first organisms, the thinking goes, as most of the right-handed versions would be locked up in crystallized form.

Breslow said our proteins might have been made of all right-handed amino acids if we were in another neck of the cosmic neighborhood.

"The take-home lesson is that the universe doesn't have any great preference for left-handed amino acids," Breslow said. "Our solar system just happens to be getting more light here that preferentially destroys right-handed stuff. Who knows — there could be life out there that is a mirror image to us on a molecular level."

The research was funded by the National Science Foundation.

Breslow presented it April 6 at the American Chemical Society national meeting in New Orleans.

_________________
No matter how dark the storm gets overhead
They say someone's watching from the calm at the edge
What about us when we're down here in it?
We gotta watch our backs


Top
 
 Post subject: Re: our universe is so rad
PostPosted: Thu Apr 24, 2008 4:06 pm 
Offline
User avatar
Interweb Celebrity
 Profile

Joined: Sun Oct 17, 2004 12:47 am
Posts: 46000
Location: Reasonville
Test your knowledge of all things celestial in the first TierneyLab astronomy quiz.

http://www.nytimes.com/interactive/2008 ... BQUIZ.html

i scored a 5/10.

_________________
No matter how dark the storm gets overhead
They say someone's watching from the calm at the edge
What about us when we're down here in it?
We gotta watch our backs


Top
 
 Post subject: Re: our universe is so rad
PostPosted: Thu Apr 24, 2008 4:11 pm 
Offline
User avatar
Interweb Celebrity
 Profile

Joined: Sun Oct 17, 2004 12:47 am
Posts: 46000
Location: Reasonville
http://www.foxnews.com/story/0,2933,352439,00.html

Dozens of Galaxies Collide in Dramatic Space Images

Image

A huge set of new Hubble Space Images show galactic collisions in action and the variety of peculiar forms that merging galaxies can take.

The series of 59 new photographs, released Thursday on the 18th anniversary of the Hubble Space Telescope's launch, are the largest collection of Hubble images ever released together.

Galaxy mergers are now known to be more common than was previously thought.

They were even more common in the early universe than they are today. The early universe was smaller, so galaxies were closer together and therefore more prone to smash-ups. Even apparently isolated galaxies can show signs of past mergers in their internal structure.

Our own Milky Way contains the debris of the many smaller galaxies it has brushed against and devoured in the past. And it hasn't stopped munching away at its neighbors: It is currently absorbing the Sagittarius dwarf elliptical galaxy.

The Milky Way isn't the top predator though, as our giant neighbor, the Andromeda galaxy, is expected to devour the Milky Way in about two billion years. The future resulting elliptical galaxy has already been dubbed "Milkomeda."

Although colliding galaxies rush towards each other at hundreds of miles per hour, the interactions can take hundreds of millions of years to complete.

This game of celestial bumper cars is driven by the gravitational pulls that galaxies exert on one another.

Typically, the first sign of a collision is a bridge of matter connecting two galaxies as gravity's first gentle tugs tease out dust and gas. As the outer reaches of the galaxies begin to interact, long streamers of gas and dust, called tidal tails, sweep back to wrap around the galactic cores.

As the cores approach each other, the conflicting pull of matter from all directions can result in shockwaves that ripple through interstellar clouds.

Gas and dust are siphoned off to fuel bursts of star formation that appear as blue knots of young stars. Given the vast distances between stars in a galaxy — the nearest star to us is 4.3 light-years away — stars rarely collide when galaxies merge.

The Hubble images capture galaxies in various stages of the collision process and show the variety of new and unusual shapes the mergers can create, including mergers that look like an owl in flight and a toothbrush.

Photo Essay: http://www.foxnews.com/photoessay/0,4644,3830,00.html

Image

This image made by the Hubble Space Telescope and released by NASA Thursday, April 24, 2008, displays a beautiful pair of interacting spiral galaxies with swirling arms. The smaller of the two, dubbed LEDA 62867 and positioned to the left of the frame, seems to be safe for now, but will probably be swallowed by the larger spiral galaxy; NGC 6786, right, eventually. There is already some disturbance visible in both components. A supernova was seen to explode in the large spiral in 2004. NGC 6786 is located in the constellation of Draco, the Dragon, about 350 million light-years away.

Image

This image made by the Hubble Space Telescope and released by NASA Thursday, April 24, 2008 , shows a Hubble view of Arp 272, a remarkable collision between two spiral galaxies, NGC 6050 and IC 1179, and is part of the Hercules Galaxy Cluster, located in the constellation of Hercules. The galaxy cluster is part of the Great Wall of clusters and superclusters, the largest known structure in the Universe. The two spiral galaxies are linked by their swirling arms. Arp 272 is located some 450 million light-years away from Earth.

Image

This image made by the Hubble Space Telescope and released by NASA Thursday, April 24, 2008, shows NGC 520, the product of a collision between two disc galaxies that started 300 million years ago. It exemplifies the middle stages of the merging process: the discs of the parent galaxies have merged together, but the nuclei have not yet coalesced. NGC 520 is one of the brightest galaxy pairs on the sky, and can be observed with a small telescope toward the constellation of Pisces, the Fish, having the appearance of a comet. It is about 100 million light-years away and about 100,000 light-years across.

Image

This image made by the Hubble Space Telescope and released by NASA Thursday, April 24, 2008 shows Arp 148, the aftermath of an encounter between two galaxies, resulting in a ring-shaped galaxy and a long-tailed companion. The collision between the two parent galaxies produced a shockwave effect that first drew matter into the center and then caused it to propagate outwards in a ring. The elongated companion perpendicular to the ring suggests that Arp 148 is a unique snapshot of an ongoing collision. Arp 148 is nicknamed Mayall's object and is located in the constellation of Ursa Major, the Great Bear, approximately 500 million light-years away.

_________________
No matter how dark the storm gets overhead
They say someone's watching from the calm at the edge
What about us when we're down here in it?
We gotta watch our backs


Top
 
 Post subject: Re: our universe is so rad
PostPosted: Thu Apr 24, 2008 5:18 pm 
Offline
User avatar
Interweb Celebrity
 Profile

Joined: Sun Oct 17, 2004 12:47 am
Posts: 46000
Location: Reasonville
Image

Looking east from a location southwest of Ireland, an astronaut took this nighttime panorama of population centers in Ireland and the United Kingdom.

http://earthobservatory.nasa.gov/Study/CitiesAtNight/

_________________
No matter how dark the storm gets overhead
They say someone's watching from the calm at the edge
What about us when we're down here in it?
We gotta watch our backs


Top
 
 Post subject: Re: our universe is so rad
PostPosted: Wed Apr 30, 2008 7:20 pm 
Offline
User avatar
Interweb Celebrity
 Profile

Joined: Sun Oct 17, 2004 12:47 am
Posts: 46000
Location: Reasonville
sandler, you seem to be stuck on this: i do not claim to have the answer to the existence of the universe! nobody as the "answer" right now.

_________________
No matter how dark the storm gets overhead
They say someone's watching from the calm at the edge
What about us when we're down here in it?
We gotta watch our backs


Top
 
 Post subject: Re: our universe is so rad
PostPosted: Wed Apr 30, 2008 8:06 pm 
Offline
User avatar
Father Bitch
 Profile

Joined: Fri Oct 22, 2004 12:20 am
Posts: 5198
Location: Connecticut
Gender: Male
corduroy_blazer wrote:
sandler, you seem to be stuck on this: i do not claim to have the answer to the existence of the universe! nobody as the "answer" right now.



I'm stuck on this?

CB, this is perhaps my favorite thread you've ever started. It's awesome. I love astronomy.

Anyway, if you think I'm stuck on finding an answer or having one of you give one to me, then please reread my posts. I have stated many, many times that nobody has the answer. Nobody.

All I've said is that you shouldn't claim that someone's belief about the origins of all this is wrong if you can't prove it's wrong and don't have a different answer. Even the smartest scientists can prove anything right now. Of course nobody knows. If they did, we'd all be on the same page. We are all believers in something, whether that be God, accidents, or just plain nothing. That's all. I don't think for a second that we'll have the answers at any point in any of our lifetimes, so really I don't even think about it other than when reading this forum. Even then, I've been posting because I've felt like debating it.

Awesome pics you posted last week. I hadn't noticed until today.

_________________
...


Top
 
 Post subject: Re: our universe is so rad
PostPosted: Tue May 20, 2008 9:03 pm 
Offline
User avatar
Interweb Celebrity
 Profile

Joined: Sun Oct 17, 2004 12:47 am
Posts: 46000
Location: Reasonville
Cities at Night, an Orbital Tour Around the World


_________________
No matter how dark the storm gets overhead
They say someone's watching from the calm at the edge
What about us when we're down here in it?
We gotta watch our backs


Top
 
 Post subject: Re: our universe is so rad
PostPosted: Tue May 20, 2008 9:28 pm 
Offline
User avatar
Supersonic
 WWW  Profile

Joined: Mon Oct 18, 2004 3:09 pm
Posts: 10839
Location: metro west, mass
Gender: Male

_________________
"There are two ways to enslave and conquer a nation. One is by the sword. The other is by debt." -John Adams


Top
 
 Post subject: Re: our universe is so rad
PostPosted: Fri May 23, 2008 4:41 pm 
Offline
User avatar
Interweb Celebrity
 Profile

Joined: Sun Oct 17, 2004 12:47 am
Posts: 46000
Location: Reasonville
Sandler wrote:
All I've said is that you shouldn't claim that someone's belief about the origins of all this is wrong if you can't prove it's wrong and don't have a different answer. Even the smartest scientists can prove anything right now. Of course nobody knows. If they did, we'd all be on the same page. We are all believers in something, whether that be God, accidents, or just plain nothing. That's all. I don't think for a second that we'll have the answers at any point in any of our lifetimes, so really I don't even think about it other than when reading this forum. Even then, I've been posting because I've felt like debating it.


i hadn't spotted this post. my bad.

nobody can prove how the universe came to be right now, so wouldn't you say it's irrational to firmly state you know how the universe began if nobody knows?

let's take someone who says they know a creator did it. we can't know they're wrong, because we can't operate on the unprovable. there's a chance, of course, that they're right but they don't know. i'm not telling you a creator definitely didn't create the universe, because that's a possibility -- i'm telling you it's irrational to believe one did until you really know.

of course, science can speak to some facets, like the age of the earth, and intelligent design being a bunch of baloney.

_________________
No matter how dark the storm gets overhead
They say someone's watching from the calm at the edge
What about us when we're down here in it?
We gotta watch our backs


Top
 
 Post subject: Re: our universe is so rad
PostPosted: Tue Jun 03, 2008 4:09 pm 
Offline
User avatar
Interweb Celebrity
 Profile

Joined: Sun Oct 17, 2004 12:47 am
Posts: 46000
Location: Reasonville
http://www.nytimes.com/2008/06/03/science/03dark.html

Dark, Perhaps Forever

Mario Livio tossed his car keys in the air. They rose ever more slowly, paused, shining, at the top of their arc, and then in accordance with everything our Galilean ape brains have ever learned to expect, crashed back down into his hand.

That was the whole problem, explained Dr. Livio, a theorist at the Space Telescope Science Institute here on the Johns Hopkins campus.

A decade ago, astronomers discovered that what is true for your car keys is not true for the galaxies. Having been impelled apart by the force of the Big Bang, the galaxies, in defiance of cosmic gravity, are picking up speed on a dash toward eternity. If they were keys, they would be shooting for the ceiling.

“That is how shocking this was,” Dr. Livio said.

It is still shocking. Although cosmologists have adopted a cute name, dark energy, for whatever is driving this apparently antigravitational behavior on the part of the universe, nobody claims to understand why it is happening, or its implications for the future of the universe and of the life within it, despite thousands of learned papers, scores of conferences and millions of dollars’ worth of telescope time. It has led some cosmologists to the verge of abandoning their fondest dream: a theory that can account for the universe and everything about it in a single breath.

“The discovery of dark energy has greatly changed how we think about the laws of nature,” said Edward Witten, a theorist at the Institute for Advanced Study in Princeton, N.J.

This fall, NASA and the Department of Energy plan to invite proposals for a $600 million satellite mission devoted to dark energy. But some scientists fear that might not be enough. When astronomers and physicists gathered at the Space Telescope Science Institute recently to take stock of the revolution, their despair of getting to the bottom of the dark energy mystery anytime soon, if ever, was palpable, even as they anticipate a flood of new data from the sky in coming years. When it came time for one physicist to discuss new ideas about dark energy, he showed a blank screen.

The institute’s director, Matt Mountain, said that dark energy had given this generation of astronomers a rare opportunity, and he admonished them to use it wisely.

“We are placing a large bet,” Dr. Mountain said, “using our credibility as collateral, that we as a community know what we are doing.”

But many stressed that it was going to be a long march with no clear end in sight. Lawrence Krauss of Case Western Reserve University told them, “In spite of the fact that you are liable to spend the rest of your lives measuring stuff that won’t tell us what we want to know, you should keep doing it.”

Scuffling in the Dark

Through myriad techniques and observations, cosmologists have recently arrived, after decades of strife, at a robust but dark consensus regarding a cosmos in which stars and galaxies, as well as the humans who gawk at them, amount to barely more than a disputatious froth. It was born 13.7 billion years ago in the Big Bang. By weight it is 4 percent atoms and 22 percent so-called dark matter of unknown identity — perhaps elementary particles that will be discovered at the Large Hadron Collider starting up outside Geneva this year. That leaves 74 percent for the weight of whatever began causing the cosmos to accelerate about five billion years ago.

As far as astronomers can tell, there is no relation between dark matter, the particles, and dark energy other than the name, but you never know. Some physicists are even willing to burn down their old sainted Einstein and revise his theory of gravity, general relativity, to make the cosmic discrepancies go away. There is in fact a simple explanation for the dark energy, Dr. Witten pointed out, one whose tangled history goes all the way back to Einstein, but it is also the most troubling.

“Dark energy has the somewhat unusual property that it was embarrassing before it was discovered,” he said.

In 1917, Einstein invented a fudge factor known as the cosmological constant, a sort of cosmic repulsion to balance gravity and keep the universe in balance. He abandoned his constant when the universe was discovered to be expanding, but quantum physics resurrected it by showing that empty space should be foaming with energy that had the properties of Einstein’s constant.

Alas, all attempts to calculate the amount of this energy come up with an unrealistically huge number, enough energy to blow away the contents of the cosmos like leaves in a storm before stars or galaxies could form. Nothing could live there.

Dr. Witten and other physicists used to think this conundrum “would somehow go away.” Something was missing in physicists’ understanding of physics, the logic went. The constant was really zero for deep reasons that, when revealed, would lead physicists closer to an understanding of what they call “the vacuum,” that is to say, the structure of reality.

“It seems now that the answer is not really zero,” Dr. Witten said.

Einstein’s constant is the most economical explanation for dark energy, Dr. Witten said. The others, involving new force fields or tinkering with Einstein’s gravity, are hard to make work and raise more questions than they answer. But if dark energy is the cosmological constant, it is smaller than predicted by a shocking factor of 1060. No fundamental principles can explain why Einstein’s constant, or any physical parameter, could be so small without being zero, Dr. Witten said. Zero can be a fundamental number, he said, but not a 1 with 59 zeroes between it and the decimal point.

As a result, he said, maybe physicists should give up trying to explain that number and look instead for a theory that generates all kinds of universes, a so-called multiverse.

That idea has been given mathematical form by string theory, which portrays the constituents of nature as tiny wriggling strings, an elegant idea that in principle explains all the forces of nature but in practice leads to at least 10500 potential universes.

This maze was an embarrassment for string theory. As Dr. Witten, one of the leaders of the field, said, “I am tempted to say this was an embarrassment of my youth.”

“Who needs that mess?” he recalled thinking. “There is just one world we live in.”

Now, Dr. Witten allowed, dark energy might have transformed this fecundity from a vice into a virtue, a way to generate universes where you can find any cosmological constant you want. We just live in one where life is possible, just as fish only live in water.

“This interpretation of string theory might be close to the truth,” Dr. Witten said. But that truth comes at a cost.

“Before the discovery of the dark energy, quantum physicists tended to assume that the ‘vacuum’ we live in has some deep meaning that reflects nature’s deepest secrets,” Dr. Witten said. But if ours is only one of a zillion in a haystack, there is nothing special about it, no secret to be found.

It could still turn out that dark energy is some as-yet-undiscovered “fifth force,” say, or the result of not understanding gravity. In that case, Dr. Witten said, “All the old viewpoints would be correct,” and physicists could go back to dreaming of a final theory.

“I’d be happy if that happened,” he said. “Our reward would be to go back to where we were, not understanding the cosmological constant.”

The notion that there are a zillion universes, whose individual properties are just a cosmic dice throw, is a story that has been told before and “raises the blood pressure of many physicists seriously,” as Dr. Livio put it. But the idea has rarely been mentioned by Dr. Witten, who is seen in the community as a symbol of the old Einsteinian ideal.

Dr. Witten said he was just doing his duty to explain what dark energy meant to physics.

“As for how I feel personally, I am not sure what to say,” he said in an e-mail message. “I wasn’t terribly enthusiastic the first, or even second, time I heard the proposal of a multiverse. But none of us were consulted when the universe was created.”

Astronomy of the Invisible

The trouble started in 1998 when two competing teams of astronomers, one led by Saul Perlmutter of the Lawrence Berkeley National Laboratory in California and the other by Brian Schmidt of the Australian National University, discovered that the expansion of the universe was inexplicably accelerating.

Both teams were using a kind of exploding star known as a Type 1a supernova as standard candles — objects whose distance can be inferred from their apparent brightness and a few other tricks of the trade — to investigate the history and fate of the universe. They found, on the basis of a few dozen of these stars, that the more distant ones were dimmer than expected, meaning that they had been carried farther away by the cosmic expansion than expected, meaning that the universe was speeding up. The car keys were streaking for the ceiling.

The groups quibble about who saw and said what first, but they have shared in a cavalcade of awards and prizes, among them the $1 million Shaw Prize in 2006 and the $500,000 Gruber Cosmology Prize, awarded last fall at Cambridge University in England, where Dr. Perlmutter and Dr. Schmidt lectured jointly, trading sentences.

Since then myriad collaborations have joined in the hunt for these exploding stars. In Baltimore, Dr. Perlmutter reported on a new analysis of “the world’s data set,” more than 300 supernovas observed by various groups, which he said would provide the tightest constraints on the nature of dark energy “for at least the next 15 minutes.”

Dr. Perlmutter’s results, along with all the others that were presented over the next four days, were consistent with Einstein’s cosmological constant, plus or minus 10 percent, but with just about everything else the theorists can throw into the pot, as well.

Nor is there any solid evidence yet that dark energy is or is not varying with time — if it is not constant, it cannot be Einstein’s constant. Adam Riess of the Johns Hopkins space telescope institute, a key member of Dr. Schmidt’s team, said, “The biggest thing we could learn is by ruling that out.”

He added, “We have a suspect, but we’re not ready to convict anyone yet.”

Dr. Perlmutter said, “The challenge is to make dramatic improvements in the quality of the data,” adding, “The next decade should be a very fertile time.”

Astronomers have developed a smorgasbord of other ways of tracking the effect of dark energy. They have learned how to map the growth of clusters of galaxies, by analyzing how their gravity distorts the light from galaxies far behind them. Gravity makes the clusters grow; dark energy holds them back.

“We can see dark matter, and in principle even invisible clusters,” said Henk Hoekstra of the University of Victoria in Canada.

Another technique is to simply count the clusters at different times in the cosmic past, the way one might count trees to gauge the growth of a forest. Yet another method is to use sound waves from the hot, early days of the universe, which have left an imprint on the distribution of galaxies today — a 500-million-light-year “bump” — as a cosmic yardstick for measuring the universe as it grew.

Each of these methods has its own strengths and weaknesses, and experts agree that it will be necessary to marry the results from many methods to zoom in on the properties of dark energy. They also agree that the best place to do that is in space.

The Big Bake-Off

Last year a committee from the National Academy of Sciences recommended that a dark energy observatory be the next mission in an astrophysics program called Beyond Einstein.

There are now three competitors angling for the job: Dr. Perlmutter’s SNAP, for Supernova Acceleration Probe; Adept, or Advanced Dark Energy Telescope, led by Charles Bennett of Johns Hopkins; and Destiny, for Dark Energy Space Telescope, led by Tod Lauer of the National Optical Astronomy Observatory in Tucson.

Also in the works, just to add spice, is a European mission known as Euclid, which could fly in 2017, if it is approved by the European Space Agency. NASA and the Department of Energy, working together, expect to make a final selection for the dark energy mission — known colloquially as J-dem for Joint Dark Energy Mission — next spring and launch it in the middle of the next decade.

That sounds like progress, but some astronomers, including the former members of the academy committee itself, have complained that $600 million is less than half of the $1.2 billion to $1.5 billion the academy committee estimated was necessary to do the job. In a recent letter to Michael Salamon, NASA scientist in charge of the project, 11 of the committee members, including both of its chairmen, urged NASA to raise the cost cap on the mission, writing, “Cutting the budget in half would probably make the attainment of these goals impossible.”

NASA’s $600 million does not include the cost of launching the satellite, so the discrepancy is not as big as it looks. But in Baltimore, Jon Morse, director of astrophysics at NASA headquarters, warned that if the astronomers wanted to spend a billion dollars, some other astronomy mission would have to come off the table.

NASA has to live within its means, Dr. Morse said in an interview.

“Otherwise,” he said, “Beyond Einstein becomes beyond reality.”

A Hole in the Future?

Whatever proposal is eventually selected, the dark energy satellite will return a tidal wave of data about the universe and its weird denizens, both visible and invisible. This data is likely to transform astronomy in unpredictable ways, but there is no guarantee that it will nail the mystery of dark energy.

Both alternatives to the constant — some weird energy field in space, or a modification to Einstein’s theory of gravity — could vary wildly over the course of history. But Paul Steinhardt, a theorist from Princeton University, argued that they would tend to mimic the cosmological constant so closely that the different models cannot be distinguished within the projected error limits, of a few percent.. He called this blur of ignorance “the J-dem hole.” The specter of the J-dem hole dominated a panel discussion later in the week devoted to the question, “How well do we have to do?”

The answer, said Dr. Krauss of Case Western, was “better than you will be able to do.”

The only real job, he said, is to distinguish dark energy from the cosmological constant. “If we don’t answer that question, we won’t have learned a thing,” Dr. Krauss said.

He compared the present situation with the development of quantum mechanics, the paradoxical sounding rules that govern inside the atom, which overturned science in the 1920s.

That revolution, he pointed out, stemmed from theorists’ inability to explain the so-called black body radiation emitted from a hot glowing object. The solution did not come from more and more precise measurements of the black body spectrum, but rather from the heads of people like Niels Bohr and Werner Heisenberg, who envisioned new ways that atoms could work and weird new laws of nature.

“We really need new theory, and we have none,” Dr. Krauss said.

In the meantime, astronomers could get lucky. Despite Dr. Steinhardt’s analysis, measurements of dark energy’s strength could converge on a value not quite the same as Einstein’s constant. Or it could turn out that it has changed over cosmic time and is not constant. Einstein and Dr. Witten would be off the hook.

Michael Turner, a University of Chicago cosmologist who coined the term “dark energy,” said you could measure the health of a field by the big questions it takes on, and addressing Dr. Morse of NASA, who was moderating the discussion, as well as his colleagues, he said, “You have a job, to go knock on everyone’s door and say this is the opportunity of a lifetime.”

Dr. Krauss said, “It would be crazy to talk ourselves out of this.”

He added: “You have to do what you can. You would be crazy not to look.”

_________________
No matter how dark the storm gets overhead
They say someone's watching from the calm at the edge
What about us when we're down here in it?
We gotta watch our backs


Top
 
 Post subject: Re: our universe is so rad
PostPosted: Thu Jun 26, 2008 8:55 pm 
Offline
User avatar
Interweb Celebrity
 Profile

Joined: Sun Oct 17, 2004 12:47 am
Posts: 46000
Location: Reasonville
anyone know anything about this book, or this specific topic? corduroy_blazer wants.

Image

Quote:
What shape is the universe? Is it curved and closed in on itself? Is it expanding? Where is it headed? Could space be wrapped around itself, such that it produces ghost images of faraway galaxies? Such are the questions posed by Jean-Pierre Luminet in The Wraparound Universe, which he then addresses in clear and accessible language. An expert in black holes and the big bang, he leads us on a voyage through the surprising byways of space-time, where possible topologies of the universe, explorations of the infinite, and cosmic mirages combine their mysterious traits and unlock the imagination. The Wraparound Universe is a general-audience book about the overall topology or shape of the universe. The central question addressed is whether it is possible that the universe is wrapped around in an interesting way, and what impact this would have on astronomical observations and our understanding of cosmology. Along the way many of the general features and much of the history of the modern picture of cosmology are discussed.

_________________
No matter how dark the storm gets overhead
They say someone's watching from the calm at the edge
What about us when we're down here in it?
We gotta watch our backs


Top
 
 Post subject: Re: our universe is so rad
PostPosted: Thu Jun 26, 2008 9:42 pm 
Offline
User avatar
See you in another life, brother
 Profile

Joined: Mon Apr 18, 2005 7:01 pm
Posts: 13165
Gender: Male
Random question. Probably the first of many more.

So our galaxy appears to rotate clockwise. At least that's how it appeared in the Cosmic Collisions show at the Natural History Museum. So my question is Why? Do all galaxies (that we know of) rotate in the same manner?

_________________
"Socialism never took root in America because the poor see themselves not as an exploited proletariat but as temporarily embarrassed millionaires."
-- John Steinbeck


Top
 
 Post subject: Re: our universe is so rad
PostPosted: Fri Jun 27, 2008 6:38 pm 
Offline
User avatar
Reissued
 WWW  Profile

Joined: Sun Oct 24, 2004 3:38 pm
Posts: 20059
Gender: Male
corduroy11 wrote:
A little closer to home, but when I first learned about honeybee communication it blew my fucking mind:

http://en.wikipedia.org/wiki/Waggle_dance
http://users.rcn.com/jkimball.ma.ultran ... ances.html
http://gears.tucson.ars.ag.gov/ic/dance/dance.html

The ability of honey bees to share information about floral patch feeding sites breatly helps their colonies achieve efficiency in foraging. Whenever a scout bee discovers a new rich food source, she recruits nestmates to it and thus helps ensure that her colony's forager force stays focused on the richest available patches. The majority of this recruitment is by the waggle dance, a unique form of animal behavior in Apis, in which the returning forager seems to perform a miniaturized "reenactment" of her recent journey. Other bees attending these dances somehow (just how they do is not known) learn the distance, direction, and odor of the flower patch and can translate this information into a flight to the original flowers. The waggle dance has been acclaimed as a truly symbolic message, one which is seperated in space and time from both the actions on which it is based, and the behaviors it will guide. Our understanding of this system is due mostly to the pioneering work of the late Karl von Frisch (shared a Nobel Prize for these studies) and his students and colleagues, research which now spans 70 years.

The round dance is performed for food sources close to the colony (less than 50-80 m) and the waggle dance used for distant floral sites. Round dances elicit flight and searching (by olfactory and visual cues) behavior for flowers close to the hive but without respect to any specified direction.

The waggle dance has two components:

* a straight run — the direction of which conveys information about the direction of the food
* the speed at which the dance is repeated which indicates how far away the food is.

The graph shows the relationship between the speed of the dance and the distance to the food. It is based on data collected by the German ethologist Karl von Frisch. It was he who discovered much of what we know today about honeybee communication (and was honored with a Nobel Prize in 1973).

Image Image

By itself, the knowledge that food is 6 kilometers (3.7 miles) away is not very useful. But von Frisch also noted that the direction of the straight portion of the waggle dance varied with the direction of the food source from the hive and the time of day.

* At any one time, the direction changes with the location of the food.
* With a fixed source of food, the direction changes by the same angle as the sun during its passage through the sky.

But

* The sun is not visible within the hive.
* The scouts dance on the vertical surface of the combs.

How, then, do they translate flight angles in the darkened hive? The image shows how:
Image

When scouts remain in the hive for a long period, they shift the direction of the straight portion of the waggle dance as the day wears on (and the direction of the sun shifts). But they cannot see the sun in the darkened hive. Evidently, they are "aware" of the passing time and make the necessary corrections.

In addition, von Frisch also discovered that scouts (and foragers) don't actually have to see the sun to navigate. As long as they can see a small patch of clear blue sky, they get along fine. This is because sky light is partially polarized, and the plane of polarization in any part of the sky is determined by the location of the sun.


This is crazy/amazing shit right here.

_________________
stop light plays its part, so I would say you've got a part


Top
 
 Post subject: Re: our universe is so rad
PostPosted: Fri Jul 18, 2008 7:55 pm 
Offline
User avatar
Of Counsel
 Profile

Joined: Sun Oct 17, 2004 1:14 am
Posts: 37778
Location: OmaGOD!!!
Gender: Male
http://www.theonion.com/content/news/hu ... s_evidence

Image
Images from the kaleidoscope reveal that the Crab Nebula actually looks totally, like, freaky and everything.

Hubble Kaleidoscope Finds Evidence Of Space Looking All Crazy

July 16, 2008 | Issue 44•29

BALTIMORE—Astronomers analyzing the first images captured by the new Hubble Space Kaleidoscope, which went online Tuesday, announced that they've acquired the first concrete evidence that the universe is in a constant state of total weirdness.

"With their unprecedented resolution, the latest images from the new kaleidoscope reveal that space, once thought to be isotropic, is actually continuously expanding, unfolding, and rearranging in a series of freaky patterns," said astronomer Douglas Stetler, head of the Space Kaleidoscope Science Institute in Baltimore. "It's an exciting time for the field of astrokaleidoscopics, or anyone interested in the vast, wacked-out nature of space."
Enlarge Image Hubble Kaleidoscope

Image
Hubble Kaleidoscope

At $200 billion, the HSK, as scientists designate it, is the most expensive kaleidoscope ever built. Orbiting 300 miles above the Earth, the high-powered, 12-ton optical device has revealed unexpected discoveries at the farthest reaches of the universe, including a multitude of brilliantly colored interlocking and rotating diamond things never before observed by scientists.

HSK features three fine-guidance optical control sensors, a wide field and planetary camera, a faint object spectrograph, and three primary rectangular plane mirrors inside a rotating 30-meter titanium tube. The object chamber, located on the end that gathers and focuses incoming light from the visible part of the electromagnetic spectrum as well as the infrared and ultraviolet continua, is filled with 10,000 pounds of marbles, costume jewelry, beads, and the largest bits of colored glass ever produced.

"This new data will forever change how we look at the cosmos," said Stetler, who admitted he was "amazed" to learn that all galaxies rotate in a counterclockwise direction and never look the same way twice. "Before this, we couldn't even see the Lagoon Nebula, but now we are capable of detecting up to 254 constantly changing fractal versions of it at once. The further we probe the depths of space, the better we might understand just how vastly bonkers it looks."

Construction of the Hubble Space Kaleidoscope involved incredible technical challenges. According to NASA head engineer Nathan Howard, assembling components for the object chamber was particularly exacting, since it was necessary to create baubles that would still remain pretty despite the harsh environment of space. The project also faced controversy over fears that the device would be unable to record the continuously changing symmetrical forms of solar masses, after early calculations predicted that the $898 million in trinkets would not tumble properly in a zero-gravity environment.

"Despite those setbacks, the project is an unqualified success," Howard said. "The completed Hubble Kaleidoscope allows researchers to view the sharpest, most refracted displays of light, color, and shape to date."

Looking at a kaleidoscopic image of a dwarf star, Howard added, "Oooooo!"

Unlike the Hubble Telescope, which has allowed astronomers to view remote objects millions of light years away, the orbital kaleidoscopic observatory has taken humankind's knowledge of the cosmos one step further: Scientists now have access to clear images of the multicolored polygons and sparkling glitter now believed to cover up to 99.999 percent of the known universe.

The new data have challenged nearly every assumption about astrophysical phenomena.

"When we trained the powerful kaleidoscope lens on the massive eye of Jupiter, we expected to see a swirling behemoth of red and orange gas," said Dr. Mae Ling-Turlington, who works at the observatory. "What we found instead was a dazzling hexagonal array of variegated prismatic configurations, changing our very understanding of the atmospheric patterns there on the solar system's spikiest-looking planet."

Their findings are so startling, in fact, that kaleidoscopists are calling for standard models of the structure of the universe to be revamped. According to the new data, the so-called asteroid "belt" is actually an asteroid squiggle; and Mars is only red "some of the time," vacillating between purplish-blue, orange, and turquoise with specks of green as it moves along its six separate orbits around the sun.

Despite excitement over the discovery that space is all crazy-looking, a number of legislators have threatened to cut funding for NASA's kaleidoscopic program. An outspoken critic of the agency, Sen. Susan Collins (R-ME) said she hopes NASA scientists don't just use the kaleidoscope a few times and then lose interest and never touch it again, like they did with the Brookhaven Neutrino Spirograph, Fermilab's Particle Slingshot, and the Very Large Slip 'n Slide Array in New Mexico.

_________________
Unfortunately, at the Dawning of the Age of Aquarius, the Flower Children jerked off and went back to sleep.


Top
 
 Post subject: Re: our universe is so rad
PostPosted: Fri Jul 25, 2008 2:33 am 
Offline
User avatar
Interweb Celebrity
 Profile

Joined: Sun Oct 17, 2004 12:47 am
Posts: 46000
Location: Reasonville
whoa, that was cool.

Image

This photo shows the aurora borealis as seen from the Kola Peninsula in Russia on Feb. 10, 2008. Scientists studied this particular event using five recently launched satellites. The unexpected flashes of the northern lights spark when magnetic field lines that trail Earth as it orbits the sun reconnect with each other, scientists report.

_________________
No matter how dark the storm gets overhead
They say someone's watching from the calm at the edge
What about us when we're down here in it?
We gotta watch our backs


Top
 
 Post subject: Re: our universe is so rad
PostPosted: Sat Aug 09, 2008 6:54 pm 
Offline
User avatar
Interweb Celebrity
 Profile

Joined: Sun Oct 17, 2004 12:47 am
Posts: 46000
Location: Reasonville
http://sciencenews.org/view/generic/id/ ... mmon_Earth

Simulation shows the solar system could only form under rare conditions

Goldilocks isn’t the only one who demanded everything to be “just right.” The Earth and its fellow seven planets also needed perfect conditions to form as observed, and those right conditions occur rarely, a new computer simulation shows.

The new simulation, described in the Aug. 8 Science, is the first to trace from beginning to end how planetary systems form from an initial gas disk encircling a baby star.

“The really striking result of the new model is how chaotic and even violent the average story of a planet’s birth is,” says Edward Thommes, an astrophysicist now at the University of Guelph in Ontario, Canada.

The process is typically a big mess. “Planets get into each others' ‘personal space,’ gravitationally scattering each other. They compete with each other for gas from the disk that gives birth to them and lots of planets are lost along the way,” he says. “It's almost like reality TV.”

All this violence and cutthroat competition seems to reduce the chances of forming a sedate solar system similar to the one in which the Earth lives, Thommes and his colleagues from Northwestern University in Evanston, Ill., conclude in the new study.

The simulation, based on data from the 307 exoplanets discovered to date, finds that initial gas disks last for a few million years — up to 10 million, at most. During that time, gas planets such as Jupiter and Saturn grow into giants, and rocky planets and icy planets coalesce too.

Modeling the growth of the planets and the gravitational interactions between them showed that if the disk that nurtures the planets has lots of gas, the system comes out containing a high number of “hot Jupiters,” which are similar to Jupiter but bigger and more gaseous. These extra-giant planets also tend to have eccentric, or extremely oblong, orbits, a result that matches current observations of exoplanets. Such orbits are not typical of planets in the solar system. Too little gas in the disk will produce nothing bigger than Earth-like planets, or possibly a few Neptunes, “ice giants” with little gas.

“An amount of gas in between those two is where there’s a relatively narrow range where systems like ours are the end result,” Thommes says. But, he cautions, although analogues to the solar system are less common, the team did still see a handful of them after 100 simulations.

“Although we may be weird, we’re by no means unique,” he says.

Shigeru Ida, a Tokyo Institute of Technology astrophysicist who models planetary formations, agrees. “This simulation has a good potential to be a powerful tool to explore the origin of extrasolar planetary systems and our solar system,” he says.

But planet formation consists of many different processes that leave many uncertainties in the theoretical modeling of these events, says Ida, who was not involved in the new research. Therefore, “it is too early to draw a statement such as ‘the solar system is special,’ ” he says.

_________________
No matter how dark the storm gets overhead
They say someone's watching from the calm at the edge
What about us when we're down here in it?
We gotta watch our backs


Top
 
 Post subject: Re: our universe is so rad
PostPosted: Thu Dec 18, 2008 2:30 pm 
Offline
User avatar
Interweb Celebrity
 Profile

Joined: Sun Oct 17, 2004 12:47 am
Posts: 46000
Location: Reasonville
http://blogs.discovermagazine.com/badas ... s-of-2008/

Top Ten Astronomy Pictures of 2008

Number 10: Mercury

Image

Mercury is a tough planet to observe. It orbits so close to the Sun that in our sky it never seems to get very far from our nearest star, meaning you can only get clear views of it when it’s near the horizon, before the Sun rises or after it sets. Our own murky atmosphere distorts the image, so to study it, we really need to send probes.

Mariner 10 mapped some of Mercury in the 1970s, but due to the vagaries of orbital mechanics only got to see half the planet. And while it was ground breaking at the time, the images it returned were not very high-resolution.

Enter MESSENGER. This new spacecraft has to swing by the tiny planet three times before it can settle into an orbit, but in the two passes it’s done so far it’s already transformed out knowledge of Mercury. There were so many images to choose from; I considered this detailed overview showing tons of features, or this incredibly feature-laden crater rim segment, or this oblique view of a triply-concentric-crater, or these phenomenal rays blasting out of a young impact feature, or this beautiful view of sunset at a double crater where you can see the mountain shadows on the crater floor.

But in the end, it was the overview of Mercury showing the rays from impact craters blanketing the entire planet that made me sit back in wonder. It was taken as MESSENGER departed the planet for the second time, when it was nearly 28,000 km out. There is something about a large-scale yet detailed image that is truly pleasing to the eye; there is beauty and science together here (and in my mind, the two are nearly indistinguishable).

Number 9: Methuselah Moon

Image

We’re mostly used to seeing the Moon as a fat crescent in the sky, because it’s up right after sunset, a time when people might notice it. Or maybe when it’s full, since it’s bright and obvious.

But a thin crescent Moon is a sight to see! It can be a challenge to spot, in fact, struggling against the brightness of the early evening or morning sky. The closer it is to the Sun, the harder it is to spot: it’s thinner, of course, and the bright Sun washes it out.

Which is why this next image is so incredible: it was taken just 10 minutes before the Moon was closest to the Sun in the sky, when it was a mere five degrees away. It was taken by Martin Elsässer, a gifted astrophotographer. It’s hard to imagine this record will be broken… and no one will be able to shave more than 10 minutes off it anyway!

Number 8: Spitzer spies the heart of a nebula

Image

Most stars in the galaxy are born in vast gas clouds, stellar nurseries that bear stars of all masses. In the center, the most massive, hottest, and brightest stars flood the gas with ionizing ultraviolet radiation. This causes the gas to glow (similar to the way a neon sign does). This radiation, together with the massive winds of subatomic particles blown off the stars, carve out monster cavities in the clouds light years across.

The results can be incredibly beautiful objects like the nebula W5. It’s easy to tell which stars are doing the work: look to where the "fingers" are pointing. Around the edge of the cavity are light-years long fingers of material caused by the erosive winds, a bit like sandbars in stream. They point directly upstream to the source of the winds.

W5 is one of my picks because it’s beautiful, it’s interesting, and c’mon, it’s heart shaped! The gas is even reddish, and since this image was taken with the Spitzer Space Telescope, we’re seeing it in the infrared… because it’s warm. I wish I could have originally posted this on Valentine’s Day, but you take what you can get. The original image is even larger, and boasts more detail of this vast creche as well.

Number 7: The galaxy that ate too much and got gas

Image

It’s been known for a long time that galaxies are not picky eaters. In fact, they’re cannibals.

Yes, they eat each other. If a little galaxy gets too close to a big one, the gravity of the beefier of the pair will rip the littler one apart, and the contents of the loser get absorbed into the winner. Most big galaxies show evidence of this, and our own Milky Way is eating at least one galaxy right now, and has probably swallowed down dozens before it.

But we’re pikers compared to NGC 1132, a monster elliptical galaxy over 300 million light years away. In visible light it’s 20% bigger in diameter than the Milky Way, and may outmass our galaxy by a factor of ten! It’s truly gargantuan. This Hubble image reveals the enormous extent of the galaxy, but even that’s only a part of the picture; most of the mass of this galaxy is in hot X-ray emitting gas and invisible dark matter.

Still, there is beauty in this overwhelming visible-light picture. Besides the obvious and pleasing smooth profile of the galaxy itself, there are also thousands of galaxies in the background, making the high-res original image well worth your time to download and peruse.

Number 6: kaBLAM!

Image

Regular readers know how much I loves me my gamma-ray bursts (GRBs). These are the most titanic blasts in the known Universe, second in bangs only to the Big one. They can occur in two ways, as far as we know. One is when the core of a supermassive star collapses, forming a black hole. Within milliseconds, a flat dense disk of material begins to swirl around the hole, and there is a vast and mighty brew of forces that focuses twin beams of energy and matter which blast out of the star’s heart. They tear through the star and scream across the Universe, and for thousands of light years, anything they touch, they kill.

The other way to get a GRB is when two orbiting superdense neutron stars merge. The end result is similar to that of a massive star collapse; a black hole forms, the beams are focused, and death ensues.

If one were to form less than about 7000 light years from the Earth, and were aimed at us, it would be lights out. If one were 100 light years away, it would almost literally set the planet on fire.

Happily, GRBs form a long, long way away. Still, their power is unbelievable, and that’s why I picked two GRBs for the Number 6 slot. Pictured above, on the left, is GRB080319B which was 7.5 billion light years away and yet was bright enough to be seen with the unaided eye. It lasted only seconds, but had you been looking in the right spot at the right time, you would have seen an explosion that took place halfway across the Universe!

On the right is GRB080913, which is the most distant GRB ever detected, at a numbing 12.8 billion light years away. In other words, when the star died to create this explosion, the Universe was less than a billion years old… and when it reached Earth, the light from this ancient detonation had been crossing the reaches of space almost 13 billion years, since before the Earth was born, before the Sun formed, before there was even a Milky Way Galaxy.

Both images are from NASA’s Swift satellite. GRB080309B is an X-ray image, and GRB080913 is a combination of X-ray and ultraviolet imaging. These are examples of images that are not much to look at, until you truly comprehend what you are seeing. Both these objects are so far away that our brains cannot comprehend the numbers, and the energy released in a few seconds by either explosion was comparable to the Sun’s entire ten-billion year lifespan output.

Now look at the pictures again. You are gazing upon death writ large, energies vast and titanic, almost beyond our ken.

Almost. Remember, while there are mysteries abounding with GRBs, we do have a decent understanding of how they work. We’re clever, we humans.

Number 5: Sic (Luna) Transit Gloria Mundi

Image

Once a month, the Moon makes one complete orbit around the Earth. Stuck here on the surface as we are, we see the Moon moving across the sky as it orbits. Sometimes, rarely, its path intersects that of the Sun, and we see a solar eclipse. A little more common is a lunar eclipse, when the Moon enters the Earth’s shadow, and again we’re stuck on the ground, so we see the Moon darken and sometimes turn blood red.

But we never see the moon pass in front of the Earth, because we’re on the Earth. However, our spacecraft are not so disadvantaged.

The Deep Impact mission was launched in 2005, and later that year successfully slammed a copper block into a comet. The spacecraft itself sailed on, and the mission was retooled (and renamed to EPOXI) to observe other scientific events. Some smart person at NASA realized that if they turned the probe’s telescopes around they could see some drama unfolding back home. They did so, and what they got totally blew me away: the Moon transiting the Earth.



There has never been a generation of humans in all of history who could see such an event. If you ever get a little depressed, or lonely, or think like there’s nothing going on that’s interesting any more, think on that for a moment or two. A thousand generations of people could only imagine such a thing, but we can actually do it.

Number 4: Spiral Art

Image

Sigh. Spiral galaxies. Sigh.

This beauty is NGC 7331, and it’s about 50 million light years away. The incredible spiral pattern is caused by gravitational traffic jams in the disk; gas and dust pile up where the gravity into those arms, forming new stars. In a sense, the arms are an illusion, they don’t have that many more stars in them then in the between-arm space, it’s just that that’s where all the massive, bright, short-lived stars are, making the arms easier to see. Those barn-burner stars don’t live long enough to leave the arms, so between the arms it looks darker… but plenty of more modest stars (like the Sun) live there.

This image was taken by Vicent Peris using the 3.5 meter telescope at the Calar Alto Observatory in southern Spain. In full resolution it is beautiful beyond words.

Number 3: Marsalanche!

Image

I’ll admit it. I’m prejudiced. When I think of Mars, I think of an arid, cold, dead planet. If Mars ever had a heyday, it was a billion years ago when it may have been warmer, wetter, and possibly even harboring microbial life.

But those days are long dead, and since then Mars has remained entombed by time, changeless and dull.

Cripes, I can be an idiot sometimes.

That, me droogs, is a Martian landslide caught in the act! Awe. Some.

Number 2: The Mote in Sauron's Eye

Image

For hundreds of years, it was a rare event to discover a new planet. Herschel found Uranus, Adams and Leverrier uncovered Neptune, Tombaugh stumbled on Pluto (only to have its status reduced decades later). Are there more planets in the solar system? Maybe, but they’ll be forbidding and remote. Still, there are worlds to be found orbiting other stars. The first were detected in 1992, orbiting the burned-out cinder of a massive star. Then in 1995, the first planet orbiting a sun-like star was found, and the floodgates opened. To date, over 300 have been found… but none seen directly in visible light. They have all been inferred by their affect on their parent star (either through the Doppler effect or by dimming its light during a transit). One was seen directly in infrared light, but that’s still somehow not satisfying. We’re humans; we want something we can see with our eyes!

That wish came true in November of this year. Using the Hubble Space Telescope, and aiming toward the bright southern star Fomalhaut in 2004, astronomer Paul Kalas took visible light images which turned out to contain a small blip of light. He waited two years, and took more images. The blip of light moved, and moreover moved with the star… almost. The overall motion with the star indicated it was gravitationally bound to Fomalhaut, but the excess motion betrayed that orbital motion itself.

Kalas had discovered a planet.

The image itself is incredibly dramatic; Fomalhaut is a young star, barely 200 million years old. It is still surrounded by a ring of dust, circling it at a distance of 17 billion kilometers. The ring is off-center and has a sharp edge, both indicating the presence of a planet, probably in an elliptical orbit.

And there it is, just where it should be. A planet with about three times the mass of Jupiter, taking 870 years to orbit Folmalhaut. Its gravity sculpts the rung, and its distance from Fomalhaut allows us to see it against the fierce background glare of the star.

For all of history we’ve wanted to be able to gaze upon an alien world, and there it is.

Number 1: The Descent of Man

Image

When I first wrote about this picture, I called it the Best. Image. Ever.

And it still is. It's my #1 Astronomy Picture of 2008.

This is the Phoenix lander as it descends underneath its parachute… to the surface of Mars. The picture was taken by the phenomenal HiRISE camera on board the Mars Reconnaissance Orbiter. I first saw it on The Planetary Society blog written by my friend Emily Lakdawalla.

Why did I pick this one? Because it is direct evidence of humans reaching out to another planet. Not only that, it's taken by another spacecraft we had sent there, a robotic emissary that was already in orbit taking high resolution images of the Red Planet. Showing incredible skill and foresight, the engineers here on Earth told HiRISE where to point, and at the right moment they snapped this proof that our grasp sometimes equals our reach.

I love this picture. It's simple enough, just a few pixels showing the fuzzy shape of the lander and its drogue. If you look carefully, you can see the shroud lines, too, and make out the shape of the parachute. I think that's why this image speaks to me so profoundly: it's not grand, it's not gloriously colored, it's not presupposing, yet the depth of its meaning is colossal.

A more visually interesting shot was taken as Phoenix descended past a crater, and it's a remarkable image as well... but I like the other one better. It's simple, straightforward, and drives the point home that we are no longer a single-planet species.

Viking, Sojourner, Spirit, Opportunity, Phoenix. MRO, MGS, Mariner 8 and 9, Odyssey, Express. We send our emissaries to Mars because we want to learn, we want to explore. We want to know more about Mars so we can know more about Earth, but we also just want to know more. That’s the nature of humanity, and it’s something we should praise. It’s kept us alive for hundreds of millennia, and it may yet ensure the survival of our species as well.

_________________
No matter how dark the storm gets overhead
They say someone's watching from the calm at the edge
What about us when we're down here in it?
We gotta watch our backs


Top
 
 Post subject: Re: our universe is so rad
PostPosted: Thu Dec 18, 2008 5:37 pm 
Offline
User avatar
Of Counsel
 Profile

Joined: Sun Oct 17, 2004 1:14 am
Posts: 37778
Location: OmaGOD!!!
Gender: Male
Images didn't work for me.

_________________
Unfortunately, at the Dawning of the Age of Aquarius, the Flower Children jerked off and went back to sleep.


Top
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 460 posts ]  Go to page Previous  1, 2, 3, 4, 5, 6, 7, 8 ... 23  Next

Board index » Word on the Street... » News & Debate


Who is online

Users browsing this forum: No registered users and 17 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
It is currently Thu Mar 28, 2024 8:00 am