...extraordinary evidence to support it. I'm not an expert on this topic (will hear more about it from local experts for sure), but it doesn't sound a statistically significant claim to me.
For the life of me I can't recall a false study about something... I think it's about pulsars / neutron star. Astronomers found the first few pulsars and found them to be aligned in a similar orientation. This provoked a few new thoughs and fresh ideas among the community...but later only to realize that the first few detections happened to be a freak series of coincidence; further observations revealed that other pulsars orient in many different ways.
Choosing random samples is important here. I'm not sure how carefully that thought process has been applied here by this author (i.g., that is what Adam Rees alludes to, I think).
We have to be careful since some people tend to see what they want to believe in.
I guess one of these days I will have to go get one of these.
All manual cameras are really wonderful. Once you are out there, hiking a desert or marveling the cold of Antarctica, you ain't gonna be charging your batteries for a digital camera for sure...
What's the humidity inside your room? It's not completely dry, right? So, why don't you see a white patchy cloud in your room? Not even in summers?
Why?
Well, it has to do with the density. Even if there is a galaxy nearby, if the content of a galaxy is sparcely populated by ordinary stars (and they are, I RTFA), you ain't gonna see them. Just like you don't see "humidity" (water molecules) in your room.
So, if the diameter of the moon is about 0.5deg, this thing is about 70 x 0.5 = 35 deg in diameter (if circular, but mind you, the original article says it is not).
Quite frankly this is the kind of science that the Hubble cannot do. For one, the Hubble is designed for a finer spatial clarity, hence its field of view is so tiny that surveying the entire sky would literally takes decades (if not a century).
This work instead shows how invaluable ground observatories (esp the small ones) are. It's not a super-flashy job; it's a long, time-consuming, and slow-rewarding job. But once you've done it, you get your 15 minutes of fame (actually, in this case, you may make it into the history book).
The HST cannot do any X-ray observation; and my point is that the spatial resolution of an X-ray telescope must be a few order of magnitude better than that of Chandra.
It's hard to resolve the event horizon of a black hole spatially in X-rays, but NASA has one or two R&D dedicated to address such issues. Note that the angular resolution required to "see" such small angular size is far better than what the HST can achieve today (although such comparison may not be so prudent).
The statement by the parent poster is valid. One should not immediately discard the possibility that the small star on the side of a star is indeed merely a star in the line of sight.
Generally speaking, that is.
In the case of Polaris, we've known that the small companion exists somewhere near Polaris A. The fact is established a long ago based on spectroscopic observation of the wobbling of the star system (ie., Doppler effect of light). So they know roughly where it should be and they found it where it is expected to be found.
Then you may ask; if we know, why do we bother? The extent of our knowledge was that the companion star Polaris Ab exists, but not sure exactly what sort of star it must be. Now we have a measure for its brightness and its orbital position. These quantities will allow us to derive the masses of Polaris A and Ab (should be Aa and Ab now) to a fairly significant accuracy (unusual for astrophysics!).
One more lesson here. Why do we care about knowing the masses? Polaris, as it turns out, is changing quite fast. It used to twinkle somewhat (i.e., pulsation), but not really any more. Its physical condition inside/outside the stellar atmosphere is changing in a human timescale...yes, an astronomical object changing its appearance in front of your eyes! We have a good idea why this happens. But "the idea" needs to be tested rigorously with all the math and physics. Knowing the masses of these stars would definitely help us handle the physics with higher precision. That's why this simple research is quite robust and important to astrophysics.
B. Robots do the Skynet or War Games thing and try to exterminate or dominate us.
While reading that line, it occurred to me: how much influence have human-friendly robots in many Japanese animes had on the growning cyber-phile genre in Japan?
I am getting reports that they will attempt another landing on November 25th (JST), provided that the mishap is understood and the position of the satellite is corrected.
This is, what they'd call it, purely an engineering mission with scientific goals in mind.
In other words, they have never done any of these things (flying out autonomously, release a probe, land on an object, and return to the Earth) and this is their first test mission. It was thought to be too freaking bold to try all that at the first attempt; but they tried it anyway.
The mission is plagued with technical failures; the failure of torque wheels is probably the worst. That really made that autonomous part difficult.
Rotational frame dragging is (I think?) one of the last unverified ones.
I believe this phenomenon was observed much earlier by the Rossi X-ray Timing Explorer (RXTE). I think the author was Todd Strohmeyer (sp?), but I can be wrong in detail.
I don't have time to address all the points you asked. (and I was just going to moderate tonight but...)
But let me simply put that: (1) a dense gaseous material in space coagulate, sometimes by accident, sometimes by external force. (2) by chance, the gaseous goo must become dense enough such that it is stable against thermal gas expansion (as things collapse, it gains heat; as it heats up, it tends to expand; so the gravitational collapse must overcome that). (3) Or by external force, the original goo can be compressed into the denser goo. (4) once dense enough, it'd collapse under its own gravitational force and generally continue to accumulate extra materials from the neighboring prenatal environment. At this point the "proto" star shines as a thermal source (in infrared), or when some magnetic field is twisted around (they are usually there) on the surface of the star or its accreting (accumulation) surface, the field "reconnects" and release its magnetic energy into kinetic and radiative energies. Some X-ray or optical flares are seen from these proto stars. (5) Eventually it becomes critically massive enough that it begins its own self-sustained nuclear fusion reaction at its core. From there on, the proto star quickly progresses and becomes one of those main-sequence stars.
Now, I believe this news article by Antonella is about finding the (3) process. Basically she thinks that the pressure from radiation and stellar winds of these "bluish" stars are compressing the neighboring nebula and forming an arched prenatal environment (dark arched silhouette in the image). I'm guessing this is a speculation to sell so that she can ask for some infrared observing time with Spitzer IR telescope (and perhaps rightly so). The image alone doesn't really show you how exactly stars are born in the field (which sort of annoys me a bit...these EP/O folks are often too liberal in their interpretation of the finding sometimes...).
Everything -- that has mass and that moves -- generates a ripple in gravity. You do it, your mom does it, too. Heck, so does any movement of Earth (e.g., techtonic plate movement, oceanic changes due to El Nino, etc).
Even though these gravitational waves generated from these local sources are weak compared to a truly remarkable astrophysical sources (e.g., mergers of blackholes), these terrestrial sources are closer; hence damned stronger compare to any expected extraterrestrial sources.
And yet, we have not detected a coherent signal of gravitational wave from local sources. This science is that hard. And that's why this is so fascinating. I think physicists have spent the last decade identifying these local sources and how the local signal would manifest itself in their experiment. I'll tell you, having seen some of the modeling, etc., detecting a gravitational wave from an orbiting pulsar is like trying to catch a person who's yelling "Yankees Rule" in the Fenway stadium via TV broadcasting. Oh that may be actually easier (since the guy would be dead on the spot by the mob of the BoSox fans).
Actually, according to Einstein's Principle of Equivalence, every and each person can define him/herself as the center of the Universe.
Try to verify for yourself by doing the following:
(1) get a blank sheet of paper, (2) mark a dot (visibly large, but not terribly so) on the sheet, (3) and then mark more dots around them, (4) now take the sheet to a copier and copy it in the original size,
then copy it again but with some magnification at this time
(e.g., 125%)...be sure to print on transparency sheets. (5) now put the magnified transparency overlaid onto the original
(use the first marker at (2) as a reference first)...you see
all the dots are moving away from the first dot. (6) Now shift the reference point to another dot...choose whatever.
You'll notice that, whatever dot you choose, the other dots
appear to move away from it. Hence, everyone can be the center
of the Universe.
And thank god that the solar maximum has passed. Or else the influence of the active Sun would have energized our atmosphere, let it expand out farther than the usual, and increased the drag force at a higher altitude.
Coronal Mass Ejection can be leathal to satellites that way, too. Its impact affects the atmosphere and let the air extend out. This can quicken the effect of decay in orbits (and we have lost a number of satellites this way).
Alchemy? It seems like the process takes a simple chemical combustion, not atom-altering alchemy.
It's bad when the old chemistry trick is viewed like some kind of magic... [nontheless, this is a cool stuff, though. Beats drinking my own urine via filtering.]
Slashdot Mirror
...extraordinary evidence to support it. I'm not an expert on this
topic (will hear more about it from local experts for sure), but
it doesn't sound a statistically significant claim to me.
For the life of me I can't recall a false study about something...
I think it's about pulsars / neutron star. Astronomers found the
first few pulsars and found them to be aligned in a similar
orientation. This provoked a few new thoughs and fresh ideas
among the community...but later only to realize that the first few
detections happened to be a freak series of coincidence; further
observations revealed that other pulsars orient in many different ways.
Choosing random samples is important here. I'm not sure how carefully
that thought process has been applied here by this author (i.g., that
is what Adam Rees alludes to, I think).
We have to be careful since some people tend to see what they want
to believe in.
I get more phishing emails than spams these days.
Not that I actually *see* them, since spamassassin hasn't missed one to filter them into my spam box.
Films are lighter in general. And I like my pack to be ligher.
I guess one of these days I will have to go get one of these.
All manual cameras are really wonderful. Once you are out there, hiking a desert or marveling the cold of Antarctica, you ain't gonna be charging your batteries for a digital camera for sure...
What's the humidity inside your room? It's not completely dry, right? So, why don't you see a white patchy cloud in your room? Not even in summers?
Why?
Well, it has to do with the density. Even if there is a galaxy nearby, if the content of a galaxy is sparcely populated by ordinary stars (and they are, I RTFA), you ain't gonna see them. Just like you don't see "humidity" (water molecules) in your room.
Roughly sqrt(5000) ~ sqrt(4900) = sqrt(7*7*10*10)= 70.
So, if the diameter of the moon is about 0.5deg, this thing is about 70 x 0.5 = 35 deg in diameter (if circular, but mind you, the original article says it is not).
That's huge.
By definition, "dwarf" really refers to its mass / luminosity content, I think.
I don't really pay attention to these guys and type of work, so I could be wrong.
Quite frankly this is the kind of science that the Hubble cannot do. For one, the Hubble is designed for a finer spatial clarity, hence its field of view is so tiny that surveying the entire sky would literally takes decades (if not a century).
This work instead shows how invaluable ground observatories (esp the small ones) are. It's not a super-flashy job; it's a long, time-consuming, and slow-rewarding job. But once you've done it, you get your 15 minutes of fame (actually, in this case, you may make it into the history book).
The HST cannot do any X-ray observation; and my point is that the spatial resolution of an X-ray telescope must be a few order of magnitude better than that of Chandra.
It's hard to resolve the event horizon of a black hole spatially in X-rays, but NASA has one or two R&D dedicated to address such issues. Note that the angular resolution required to "see" such small angular size is far better than what the HST can achieve today (although such comparison may not be so prudent).
The statement by the parent poster is valid. One should not immediately discard the possibility that the small star on the side of a star is indeed merely a star in the line of sight.
Generally speaking, that is.
In the case of Polaris, we've known that the small companion exists somewhere near Polaris A. The fact is established a long ago based on spectroscopic observation of the wobbling of the star system (ie., Doppler effect of light). So they know roughly where it should be and they found it where it is expected to be found.
Then you may ask; if we know, why do we bother? The extent of our knowledge was that the companion star Polaris Ab exists, but not sure exactly what sort of star it must be. Now we have a measure for its brightness and its orbital position. These quantities will allow us to derive the masses of Polaris A and Ab (should be Aa and Ab now) to a fairly significant accuracy (unusual for astrophysics!).
One more lesson here. Why do we care about knowing the masses? Polaris, as it turns out, is changing quite fast. It used to twinkle somewhat (i.e., pulsation), but not really any more. Its physical condition inside/outside the stellar atmosphere is changing in a human timescale...yes, an astronomical object changing its appearance in front of your eyes! We have a good idea why this happens. But "the idea" needs to be tested rigorously with all the math and physics. Knowing the masses of these stars would definitely help us handle the physics with higher precision. That's why this simple research is quite robust and important to astrophysics.
B. Robots do the Skynet or War Games thing and try to exterminate or dominate us.
While reading that line, it occurred to me: how much influence have human-friendly robots in many Japanese animes had on the growning cyber-phile genre in Japan?
I am getting reports that they will attempt another landing on November 25th (JST), provided that the mishap is understood and the position of the satellite is corrected.
This is, what they'd call it, purely an engineering mission with scientific goals in mind.
In other words, they have never done any of these things (flying out autonomously, release a probe, land on an object, and return to the Earth) and this is their first test mission. It was thought to be too freaking bold to try all that at the first attempt; but they tried it anyway.
The mission is plagued with technical failures; the failure of torque wheels is probably the worst. That really made that autonomous part difficult.
Rotational frame dragging is (I think?) one of the last unverified ones.
I believe this phenomenon was observed much earlier by the Rossi X-ray Timing Explorer (RXTE). I think the author was Todd Strohmeyer (sp?), but I can be wrong in detail.
Mod Parent Up Higher!
I don't have time to address all the points you asked. (and I was just going to moderate tonight but...)
But let me simply put that: (1) a dense gaseous material in space coagulate, sometimes by accident, sometimes by external force. (2) by chance, the gaseous goo must become dense enough such that it is stable against thermal gas expansion (as things collapse, it gains heat; as it heats up, it tends to expand; so the gravitational collapse must overcome that). (3) Or by external force, the original goo can be compressed into the denser goo. (4) once dense enough, it'd collapse under its own gravitational force and generally continue to accumulate extra materials from the neighboring prenatal environment. At this point the "proto" star shines as a thermal source (in infrared), or when some magnetic field is twisted around (they are usually there) on the surface of the star or its accreting (accumulation) surface, the field "reconnects" and release its magnetic energy into kinetic and radiative energies. Some X-ray or optical flares are seen from these proto stars. (5) Eventually it becomes critically massive enough that it begins its own self-sustained nuclear fusion reaction at its core. From there on, the proto star quickly progresses and becomes one of those main-sequence stars.
Now, I believe this news article by Antonella is about finding the (3) process. Basically she thinks that the pressure from radiation and stellar winds of these "bluish" stars are compressing the neighboring nebula and forming an arched prenatal environment (dark arched silhouette in the image). I'm guessing this is a speculation to sell so that she can ask for some infrared observing time with Spitzer IR telescope (and perhaps rightly so). The image alone doesn't really show you how exactly stars are born in the field (which sort of annoys me a bit...these EP/O folks are often too liberal in their interpretation of the finding sometimes...).
I'm moderated up and this guy isn't. Where is the justice?
Everything -- that has mass and that moves -- generates a ripple in gravity. You do it, your mom does it, too. Heck, so does any movement of Earth (e.g., techtonic plate movement, oceanic changes due to El Nino, etc).
Even though these gravitational waves generated from these local sources are weak compared to a truly remarkable astrophysical sources (e.g., mergers of blackholes), these terrestrial sources are closer; hence damned stronger compare to any expected extraterrestrial sources.
And yet, we have not detected a coherent signal of gravitational wave from local sources. This science is that hard. And that's why this is so fascinating. I think physicists have spent the last decade identifying these local sources and how the local signal would manifest itself in their experiment. I'll tell you, having seen some of the modeling, etc., detecting a gravitational wave from an orbiting pulsar is like trying to catch a person who's yelling "Yankees Rule" in the Fenway stadium via TV broadcasting. Oh that may be actually easier (since the guy would be dead on the spot by the mob of the BoSox fans).
...enough said.
Guys, you need to get laid. You guys take this example way too seriously.
It's obviously a very, very simplified way to demonstrate the concept of curved spacetime and you'd have to tell your audience that.
Actually, according to Einstein's Principle of Equivalence, every and each person can define him/herself as the center of the Universe.
Try to verify for yourself by doing the following:
(1) get a blank sheet of paper,
(2) mark a dot (visibly large, but not terribly so) on the sheet,
(3) and then mark more dots around them,
(4) now take the sheet to a copier and copy it in the original size,
then copy it again but with some magnification at this time
(e.g., 125%)...be sure to print on transparency sheets.
(5) now put the magnified transparency overlaid onto the original
(use the first marker at (2) as a reference first)...you see
all the dots are moving away from the first dot.
(6) Now shift the reference point to another dot...choose whatever.
You'll notice that, whatever dot you choose, the other dots
appear to move away from it. Hence, everyone can be the center
of the Universe.
Just send me and a handful of cute women into space. I promise, I'll be a good boy.
And thank god that the solar maximum has passed. Or else the influence of the active Sun would have energized our atmosphere, let it expand out farther than the usual, and increased the drag force at a higher altitude.
Coronal Mass Ejection can be leathal to satellites that way, too. Its impact affects the atmosphere and let the air extend out. This can quicken the effect of decay in orbits (and we have lost a number of satellites this way).
Alchemy? It seems like the process takes a simple chemical combustion, not atom-altering alchemy.
It's bad when the old chemistry trick is viewed like some kind of magic...
[nontheless, this is a cool stuff, though. Beats drinking my own urine via filtering.]