And these extremely powerful gamma ray bursts, seemingly directed at our Solar System, just happen to be coming from Messier Object #1, aye.

Let me go calculate the odds....

'Cause crabs got big boobs?

No, seriously, the weblike splay of the remaining gas does look rather similar to the web of blood vessels visible in a mammogram.

Perhaps there is a deeply mysterious fractal symmetry between boobs and supernovas!

That's sarcasm, right? An injection of humour?

If it was, it was a really lame one.

WOW!! John, a puny little old gamma ray burst caused ALL that? LMAO!!

A Gamma Ray burst close enough could effect the earth.

I understand that Shawn, I even know if it was directed directly at earth we'd be fried. It's just this guy sees EVERYTHING as a climate change issue...

We're screwed blued and tattooed. The end is here repent, repent!

Ah, OK - now I get the gist.

Gamma ray bursts (GRB) are produced when a super-massive main-sequence star goes supernova. The progenitor star that created the Crab Nebula is no longer a main-sequence star; it went supernova almost a thousand years ago. The left-over "embers" of the supernova explosion is a neutron star.

EVEN IF there was some mechanism that a dead star could produce a GRB, and EVEN IF the GRB happened to be pointed right at us (they are very directional), at an estimated 6500 light years away the Crab Nebula is way too far away to have impact what so ever on Earth.

(6500 light years = 38,180,000,000,000,000 miles = 38 quintillion miles away. Or, if you prefer, "really REALLY far away".)

There is no star of the right type anywhere around Earth which may be a GRB threat. Such stars are very rare, and widely scattered through the Galaxy. They are very big, and very bright, and hence very easy to find and chart.

Other than making for some really nifty pictures that we can all enjoy (and a lot of very cool science that we can learn), there is nothing the Crab Nebula and environs can do that could have any impact on Earth.

Michael, I hate to quibble, but that's quadrillions, not quintillions.

I did'nt catch this type of event when Al Gore last apoke.....

How can I repent if I have not yet pented?

thanks for the quibble on quad or quint, Mike. I'm a scientific notation kinda guy; it seems that my translation went one "q" too far!

According to a cool episode of History Channel's "The Universe" there were two large stars within 8,000 light-years that might generate a gamma-ray burst: Eta Carinae and WR 104 . It was even thought WR 104's axis might be "aimed" at earth so that a GRB would hit head-on, but after doing some checking we should be off-axis enough to be a miss anyway. Still, made for some exciting documentary-tv!

I thought Eta Carinae has already burst-ed. That's why there's pictures like this.

edmgeno, nice pic!

Imagine that Eta Car is a refinery; the image you link to is a really big fire at that refinery. Very big, very impressive.

Then one of the major storage tanks explodes - THAT is the supernova. Except, the SN will be much, MUCH bigger. When a star goes supernova it is, it is (for a few days) as bright as the combined light of every other star in the galaxy combined. A supernova is as bright as 100 billion stars.

A number of really cool lesser reactions occur in the star prior to the final supernova, which slough off layers of the star's atmosphere - as seen in your linked image. This is the "refinery is on fire, it's gonna blow, better pull the firefighters back" stage.

The further off-axis from something like that, the better.

Although not impossible that's highly improbable. Almost to the point of not worth being considered. As was stated with our very limited understanding of how Supernovas actually work it's highly likely this is the result of a process within the nebula we don't fully understand.

Or Vader finally found an Empire officer who managed to get the Death Star up and online and now he's making life a living hell for the Rebel Alliance!

Luke, where are you?! The Force needs you!

Brian from S.C.:hahahahha

K Man-629118: Fail

possible, though not probable. worth a look though!! good job there Six string!!

Two blasts in six months... That's a pretty slow way to transmit morse code...

Maybe cause 2 letters completes the message... FU

Seriously, what if it does contain something decodable?

Well, OK, seriously, if we keep watching it, and the bursts do keep happening and we do indeed detect some of "decodable" signal in the pattern, that would indeed be amazing. It would in fact be a first time ever event.

The SETI project has trying vainly to find some sort of meaningful signal for decades. Still nothin'. Of course, that doesn't mean we shouldn't keep lookin'...

Yeah but what if radio isn't the preferred way of transmitting across the galaxy? Perhaps bright light pulse that stands out as odd will get the attention of a civilization.

There was a similar episode a few months ago, with light from a star lasting unusually long, and was theorised to be cause by a star falling into a black hole. That's 2 "mysterious" events from the heavens this year.

FU = "Fed Up?"

Yeah but what if radio isn't the preferred way of transmitting across the galaxy? Perhaps bright light pulse that stands out as odd will get the attention of a civilization.

There was a similar episode a few months ago, with light from a star lasting unusually long, and was theorised to be cause by a star falling into a black hole. That's 2 "mysterious" events from the heavens this year.

2 "mysterious" events from the literally billions upon billions of possible sources up there. Hardly worthy of any sort of speculation, especially since we know so little about the processes behind supernovae, blackholes, etc.. Assumption by people on events such as these is the height of ignorance and our always mystifying ability to somehow assume we have a basis for forming a rational opinion on something we know nothing about is amusing.

Not being an ass or anything and you might have posted in jest but it does bring to light the fact that regardless of how much we learn there's always something that is going to throw us for a loop. Gotta love nature.

pw, I know and understand more than you think. Physics today is based on known laws, and our understanding of the universe is based on those laws. Throw in an event that breaks that understanding and it requires further study. The next great thinker and evolutionary will come from someone who doesn't think inside the box. Hawking was laughed at when he said that matter disappears inside a black hole. Though many theories have come about trying to explain what happens, no one has conclusively found an answer. Until anyone can explain it all, I don't see how anyone can call any theory ridiculous. I don't care if someone claims it must be from Aliens, having no way to disprove it, I cannot say they are wrong.

Michael, Yes must be an Alien race Fed Up with their own and hoping there are more intelligent beings out there.

Tony, yeah wasn't trying to be a jerk and in fact events like this are quite compelling on their ability to make us wonder what in fact is going on. Just pointing out our ability to place our world at the center of the universe. Kind of amusing, really. Don't take offense though, you contribute well rationed and thought out posts on here all the time, keep it up. :)

The communication we are having today is via data packets being transmitted over electrical waves converted from analog to digital. Mine as it were are being transmitted via fiber optic light, and decoded into digital format on your computer screen. Today this light transmission is via physical medium. It will not be long before we can transmit optical data via airwaves. Matter of fact in quantum mechanics, teleportation hasalready been achieved. That implies that tomorrow's computers will be able to transmit data about as fast as our brains can think. Who is to say that another civilization didn't accomplish this eons ago, and that something out there isn't able to transmit light signals embedded with data over vast distances?

What if it wasn't a two letter message? Maybe in the first blast they transmitted their version of War and Peace? We just cannot decode that much info in that short of a time.

And their version of the Gettysburg Adress is such a small blip that we never notice it.

Either way, they've waited about 6500 years for a reply. By the time we reply that light blast would be ancient technology to them. lol

(I love it when it is "Tony Time"... It's Tony Squared!)

Attack of the Tonys. T2, you will be assimilated.

Aahhh, you're mixing your sci-fi, my head hurts.

But it's not unlike Mike and Michael, you know?

We don't have two Mob's, do we?

Only one Mob per Universe. It's a rule.

I thought I saw Mob post on another article earlier. I know no other.

I did over do the sci-fi reference. My mind is racing.

I like that rule, 1 mob per universe.

Please BW, edify us. a detailed explanation would be MOST appreciated!! One proviso, if you start ANY sentence with the word....god... forget it!

hey guys did any one else notice that this guy posted some B.S. then never posted again to back it up?

You know, I was going to ask him to please enlighten us as well on what the real answer is. You wrote that before just as I was about to. I too am waiting for the truth.

effect, or affect?

Maybe Affleck or Aflac?

Ahh yes, the AFWACK duck!

Yes, this would have happened 6500 years ago. The telescopes are not physically closer to the nebula, so they have to wait for the energy to get here just like we do. Think of it as a magnification.

Astronomy is a form of time travel. The speed of light is an absolute limit. No matter how powerful the telescope, every photon of light that we examine is a record of a past event.

The Crab is an estimated 6500 light years away (probably a pretty good guesstimate, but the error bar is +- about 10%), so if you look at it tonight you are seeing it as it was 6500 years ago.

It's kinda cool that those are really old photons, which have been traveling for thousands (or even millions) of years, that have found their way across space and time to your eyeball.

If we DIDN'T have the speed of light as a factor, and the resulting "time travel" factor, we would not be able to figure out the distance to anything in the Universe.

So, not only is the speed of light, cool, IT IS THE LAW. (Or is that Judge Dredd's line?)

Oops - sorry to step on your post breakingglass; the phone rang half-way thru my response, and when I was done your +1 answer was already there.

Heh, no problem Michael. Your response was more artful than mine, to be sure.

Johnny, even the most powerful telescopes cannot alter the speed of the light which they detect. As AstronomyMike explains, we must sit here and wait for it to come to us. The amazing thing is that even though the speed of light is incredibly fast (186,000 miles a second or 700 million miles an hour), it still takes the light from this ancient explosion 6,500 years to get here so we can then see it.

One light year (the distance that light travels in one year), is about 5,900,000,000,000 miles or about 6 trillion miles and mutiplying that by 6,500 years, you get a distance of about 38 quadrillion miles away. Or in other words, that's pretty fricken far away.

It's kinda cool that those are really old photons, which have been traveling for thousands (or even millions) of years, that have found their way across space and time to your eyeball.

Yes, but if they travel at the speed of light, do photons actually age ?

Ohh good question edmgeno. I'd like to know that too.

If a beam of photons passes through the cosmos and there is no one there to see them, do they make an image?

If time stops at the speed of light, can a photon age?

ok, lets look at this. do you mean age as in changing state due to time/deterioration? Then the answer is no. Photons are photons. Do you mean age in the sense of when were they created? then yes, they are at least 65,000 light-years old. (or whatever that # that Michael posted)

If I hold a flashlight 10 feet from you, and another person holds a flashlight 50 feet from you, the second person's light will look dimmer. Why? Wouldn't it just take a very slightly less time for the light to get to you, but would be the same amount of light?

Inverse square law. 5x distance = 1/25 the light recieved.

My struggle right now, going by the photons not aging, is what happened to the rest of the light then? Did it dissipate? Photons not aging implies they travel forever, or is that not right?

As far as a photon is concerned, time seems to move at a normal rate for the photon, but everything around the photon not within its inertial reference frame (moving at the same velocity) seems to have come to a stop, including time.

So the answer is location, location, location.... Where are you relative (Einstein's relativity) to the photon?

They travel forever until they are absorbed (like say your retina). They just spread out, unless they're cohesive, i.e. lasers.

If I hold a flashlight 10 feet from you, and another person holds a flashlight 50 feet from you, the second person's light will look dimmer. Why? Wouldn't it just take a very slightly less time for the light to get to you, but would be the same amount of light?

photons absorbtion and scattering are always indicators that although a source might be farther away and actually brighter (or at least the same brightness as a closer object) it doesn't mean we will always receive the same amount of light regardless of where we are. Sort of the same with sound waves. Wave propogation tends to degrade the original signal over distance.

.

If photons did not decay it would be a violation of THE ONCE AND POWERFULLY OBSTINATE einstiens' greatest foundation. but to keep the confusion on the grand scale at which it is, and apparently so by the oh so many arrogant posts.... http://www.nature.com/nature/journal/v277/n5698/abs/277633a0.html

I do not know what the grb's are, surely they are yet another great phenomenom of which most average blokes believe the words of their high school physics teachers and the odd wikipedia article to be of the only valiant qualified answer....phooey....when metals collide x-rays are given off, so to, it may be conjectured, are gamma rays...ehem...as well, the effect could be more localized than anyone every imagined, to wit the great plasma field now invading our heliosheath from where no one is proof positive..not even michael...yet other theories abound as well, the most probable answer is that WE DO NOT KNOW...pretty easy to find truth in science..it just makes it hard to get a big nsf grant with no hypothesis, 2 data sets and not a clue of a direction for a conclusion...I note the proximity to the end of the gbr graphic...maybe this is the echo of the first great flash? yea, I know it sounds funny...at least you now know that photons may, just possibly, decay....which makes sense if you buy into the equivalence principle...I don't...we have no real physical data about the space in between terra firma and the crab nebulae....personally, I think we gotta get some more imperial probes out there!! gamma ray bursts are not cool, if they are forming locally we gotta figure that out and take the necessary reactive steps...(cue the bruce willis silly flick now)....

..not even michael...

Not even l'il ol' me?

yea, I know it sounds funny...

No comment - too easy.

...the [gamma ray burst] effect could be more localized than anyone every imagined, to wit the great plasma field now invading our heliosheath from where no one is proof positive...

We have "proof positive" that gamma ray bursts (GRB's) are not originating from the heliosheath, or anywhere near the Solar System. We can accurately and directly measure the distance of an astronomical object out to a distance of 500 light years using the simple surveying process of parallax. (The heliosheath is only .002-ish light years away - really close on the scale of things.) No GRB has ever yielded a measurable parallax.

GRB's were discovered in 1967. There is a global GRB alert system in place so that when one fires off telescopes around the world (optical, radio, X-ray, on the ground and in orbit - everything and the kitchen sink) quickly swing around and zoom in. GRB's have been all tracked to distant galaxies.\

not picking on ya michael, but I had to refute the proof positve stuff, small grb have been detected near earth have they not?...in fact are we not just now realizing that the at the top of the atmosphere, the resultant energy release of an electric discharge is in fact a gammar ray burst?..to wit, is not the current hypothesis that an anti electron or anti-proton being created and subsequently anhilated yeilding the previously undetected gramma ray source? and with extension, could not the very same process be hard at work in the now infamous "spokes" around saturns rings?...please, no proof positve, there is too much we DO NOT KNOW...the article states the boffins referenced do not know, I can only as well that collectively we do not know, and certainly would be silly not to posist that other theories may in fact have validity...we may dissect them one by one but once again we are on the same precipice, absence of evidence is not evidence of absence....we have detected gamma rays emananting from the apparently region of the crab nebula, some 6500 LY away...we have no way ap verifying that some other reaction has not created the gamma ray burst closer than that, nor farther than that, rather we suspect the usual suspect, ie the crab nebulae...logical, but not deductive logic, rather inductive logic, we have induced the hypothesis into the conclusion without substantiative data to support the induction. Period. Not really saying anything else.

not picking on ya michael, but I had to refute the proof positve stuff, small grb have been detected near earth have they not?

They have not. Not one GRB - as the term is used by astronomers - has been detected locally.

Gamma ray bursts (GRB's) are not the only source of gamma rays.

Lightning can create gamma rays. This is not the same as GRB's, which are detected from ABOVE our atmosphere by satellites (such as Swift and Fermi), and then localized to emanate from a distant galaxy by Hubble, Chandra, Herschel, other space telescopes (not affected by atmospheric gamma), and a fleet of ground-based scopes across several continents (who could not all be impacted by the same lightning produced gamma).

Saturn is not a gamma source, so I don't see where you are going with the spokes in it's rings.

Yes, the article states that the boffins don't know a whole lot. But there is much that can be ruled out. Gamma rays are the very most energetic form of light; it makes X-rays look like a flickering candle. If the Crab was a GRB source we'd know it.

Lightning can create gamma rays.

Here's a recent article on the subject.

so you are saying that without an observer, there is no image.

The image is there regardless of whether we see it or not. I'd like to hear a reason why it wouldn't be. You personally wouldn't see it but it's there regardless.

Correct-- but this does NOT mean the photons are not "passing thru the cosmos", just, we ain't there to see 'em!!

Incorrect PW, light(photons) are NOT an image until they "hit" something. jmho.

I guess that depends on what an image really is.

What if it's an image of an egg? Would it still be a chicken?

Do people reflect photons? If so is that why some people hurt my eyes when I look at them?

@TonyinDallas, not if Col. Sanders sees it first. Then it is KFC.

People do reflect photons, that's why you can see them.

yeah I know. That was my end of the day attempt at humor. :)

Stephen, as you may have sensed, the question I posed regarding images and photons is really just a rephrasing of the classic philosophical chestnut regarding a tree falling in a forest... If no one's there to hear it, does it make a sound? The essence of this conundrum hinges upon ones definition of "a sound". Are the compressions of air created by the impact of the tree as it hits the ground "a sound"? Most would agree that they are not. They are merely compression waves travelling through the air... until they are picked up by the tympanic menbrane of a listener's ear, passed through an amazing series of three tiny bones in the middle ear, converted into electrical signals by the microscopic hairs within the cochlea, which are transmitted to the brain via the auditory nerve, where they are then finally interpreted as... "a sound".

An analogous pathway and perceptual process can of course be described for the photons of light striking one's retina. If I was too subtle in my earlier post to make it clear that I was well aware of all of this, I apologize.

In any case, listener and sound or no, the tree still falls. Viewer and image or no, the star still explodes. The photons still fly, and time moves on.

So, a light is not a light if no one sees it?

However, if I leave the lights on all day and I'm not home, my electric bill is higher.

Nope

As Steve Martin once pondered... "Does the Pope $#!& in the woods?" and if so, does HE still stink?

Is a bear Catholic?

It may be sad to you, but good is all this knowledge? How will it get your next welfare check, thats what I want to know. If it does not belong to a union Obama will have nothing to do with it.

Get your FILTHY politics out of my science.

Thats right jbird, it was Obama passing gas. Or was it Biden, after all it was "Big f-ing deal".

Unfortunately, politics fund a lot of science.

Sentence should read, "the former star IS located...." It's still there, but it is no longer a main sequence star.

Other than that, what point are you looking at Code? I'm not following your drift.

We are now seieng where the star was 6,500 years ago. Not where it is now. Keep in mind that our own star Sol is moving through the galaxy at a pretty amazing pace.

Yep, but on this scale (both distance and time) it is still pretty much where we see it.

It's like continental drift. Holister California is moving relative to me, but at such a slow speed that even if I crawled to Cali the town will still be in pretty much the same place.

It's a pulsar (like the article said if you'd bother reading it) first recorded by the chinese in 1054 A.D.

It takes good ol' Sol 250 million yrs for a good lap around the block.

Maybe when it goes supernova a few wise men will follow it.

If it went nova right now it would take us 640 years to see it happen here.

But if it happened 639 years ago, we should see it in 2012.

good point Tony!

Scott - I'm with you until you got to Paul Allen. Paul promised a certain amount of funding, which was to be the BUILDING costs, and the other parties (University, State of Cali, etc) promised to cover OPERATING costs. Paul has done what he promised and more. He may chose to do even more, that is well beyond any obligations he may have agreed to.

Other than that quibble I'm with your post 100%. +1

Michael, After rereading my post I can see how it may have looked like I was blaming Paul but my post was not meant to denigrate anyone who helps fund special projects with thier own money, I meant only to make a point that the money was coming from several sources which are no longer available.

Thats what happens when you go on a rant.

with a few neutrons on the side. (au grautin of course)

everything is good au grautin. The crab nebula cake special, hold the GRB

Hiya John!

Good question.

The pulsar is spinning so fast, and has such a strong magnetic field, that it is working as a very large dynamo. As it spins the magnetic field lines get tangled, energy builds, and then the magnetic field can "snap" as they go back to the "at rest" polarity (rinse and repeat). When that happens lot of energy is released, which has an impact on the surrounding Crab Nebula (which is what are now observing).

Part of the attraction of pulsars is that they are high-energy physics labs, that play with energies that are far beyond what we can create here on Earth. They teach us much about the extremes of what is possible under the laws of physics; it is at the extremes that our understanding is most stretched, and we learn new things about how the Universe works.

Cheers! ~Michael (AFM★Radio / Astronomy.FM)