Hubble views the star that changed the universe

May 23, 2011
NASA's Hubble Space Telescope has been trained on a single variable star that in 1923 altered the course of modern astronomy. V1 is a special class of pulsating star called a Cepheid variable that can be used to make reliable measurements of large cosmic distances. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)

(PhysOrg.com) -- Though the universe is filled with billions upon billions of stars, the discovery of a single variable star in 1923 altered the course of modern astronomy. And, at least one famous astronomer of the time lamented that the discovery had shattered his world view.

The star goes by the inauspicious name of Hubble variable number one, or V1, and resides in the outer regions of the neighboring , or M31. But in the early 1900s, most astronomers considered the Milky Way a single "island universe" of stars, with nothing observable beyond its boundaries. Andromeda was cataloged as just one of many faint, fuzzy patches of light astronomers called "spiral nebulae."

Were these spiral nebulae part of the Milky Way or were they independent island universes lying outside our galaxy? Astronomers didn't know for sure, until found a star in Andromeda that brightened and faded in a predictable pattern, like a lighthouse beacon, and identified it as V1, a Cepheid variable. This special type of star had already been proven to be a reliable distance marker within our galaxy.

The star helped Hubble show that Andromeda was beyond our galaxy and settled the debate over the status of the spiral nebulae. The universe became a much bigger place after Hubble's discovery, much to the dismay of astronomer Harlow Shapley, who believed the fuzzy nebulae were part of our Milky Way.

Nearly 90 years later, V1 is in the spotlight again. Astronomers pointed Edwin Hubble's namesake, NASA's , at the star once again, in a symbolic tribute to the legendary astronomer's milestone observation.

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Video Credit: NASA, ESA, and Z. Levay, G. Bacon, and M. Estacion (STScI)

Astronomers with the Space Telescope Science Institute's Hubble Heritage Project partnered with the American Association of Variable Star Observers (AAVSO) to study the star. AAVSO observers followed V1 for six months, producing a plot, or light curve, of the rhythmic rise and fall of the star's light. Based on this light curve, the Hubble Heritage team scheduled telescope time to capture images of the star.

"V1 is the most important star in the history of cosmology," says astronomer Dave Soderblom of the Space Telescope Science Institute (STScI) in Baltimore, Md., who proposed the V1 observations.

"It's a landmark discovery that proved the universe is bigger and chock full of galaxies. I thought it would be nice for the Hubble telescope to look at this special star discovered by Hubble, the man."

But Hubble Heritage team member Max Mutchler of the STScI says that this observation is more than just a ceremonial nod to a famous astronomer.

"This observation is a reminder that Cepheids are still relevant today," he explains. "Astronomers are using them to measure distances to galaxies much farther away than Andromeda. They are the first rung on the cosmic distance ladder."

The Hubble and AAVSO observations of V1 will be presented at a press conference May 23 at the American Astronomical Society meeting in Boston, Mass.

Ten amateur astronomers from around the world, along with AAVSO Director Arne Henden, made 214 observations of V1 between July 2010 and December 2010. They obtained four pulsation cycles, each of which lasts more than 31 days. The AAVSO study allowed the Hubble Heritage team to target Hubble observations that would capture the star at its brightest and dimmest phases.

The observations were still tricky, though. "The star's brightness has a gradual decline followed by a sharp spike upward, so if you're off by a day or two, you could miss it," Mutchler explains.

Using the Wide Field Camera 3, the team made four observations in December 2010 and January 2011.

"The Hubble telescope sees many more and much fainter stars in the field than Edwin Hubble saw, and many of them are some type of variable star," Mutchler says. "Their blinking makes the galaxy seem alive. The stars look like grains of sand, and many of them have never been seen before."

For Soderblom, the Hubble observations culminated more than 25 years of promoting the star. Shortly after Soderblom arrived at the Institute in 1984, he thought it would be fitting to place a memento of Edwin Hubble's aboard the space shuttle Discovery, which would carry the Hubble Space Telescope into space.

"At first, I thought the obvious artifact would be his pipe, but [cosmologist] Allan Sandage [Edwin Hubble's protege] suggested another idea: the photographic glass plate of V1 that Hubble made in 1923," Soderblom recalls.

He made 15 film copies of the original 4-inch-by-5-inch glass plate. Ten of them flew onboard space shuttle Discovery in 1990 on the Hubble deployment mission. Fittingly, two of the remaining five film copies were part of space shuttle Atlantis's cargo in 2009 for NASA's fifth servicing mission to Hubble. One of those copies was carried aboard by astronaut and astronomer John Grunsfeld, now the STScI's deputy director.

Telltale Star Expands the Known Universe

Prior to the discovery of V1 many astronomers thought spiral nebulae, such as Andromeda, were part of our Milky Way galaxy. Others weren't so sure. In fact, astronomers Shapley and Heber Curtis held a public debate in 1920 over the nature of these nebulae. During the debate, Shapley championed his measurement of 300,000 light-years for the size of the Milky Way. Though Shapley overestimated its size, he was correct in asserting that the Milky Way was much larger than the commonly accepted dimensions. He also argued that spiral nebulae were much smaller than the giant Milky Way and therefore must be part of our galaxy. But Curtis disagreed. He thought the Milky Way was smaller than Shapley claimed, leaving room for other island universes beyond our galaxy.

To settle the debate, astronomers had to establish reliable distances to the spiral nebulae. So they searched for stars in the nebulae whose intrinsic brightness they thought they understood. Knowing a star's true brightness allowed astronomers to calculate how far away it was from Earth. But some of the stars they selected were not dependable milepost markers.

For example, Andromeda, the largest of the spiral nebulae, presented ambiguous clues to its distance. Astronomers had observed different types of exploding stars in the nebula. But they didn't fully understand the underlying stellar processes, so they had difficulty using those stars to calculate how far they were from Earth. Distance estimates to Andromeda, therefore, varied from nearby to far away. Which distance was correct? Edwin Hubble was determined to find out.

The astronomer spent several months in 1923 scanning Andromeda with the 100-inch Hooker telescope, the most powerful telescope of that era, at Mount Wilson Observatory in California. Even with the sharp-eyed telescope, Andromeda was a monstrous target, about 5 feet long at the telescope's focal plane. He therefore took many exposures covering dozens of photographic glass plates to capture the whole nebula.

He concentrated on three regions. One of them was deep inside a spiral arm. On the night of Oct. 5, 1923, Hubble began an observing run that lasted until the early hours of Oct. 6. Under poor viewing conditions, the astronomer made a 45-minute exposure that yielded three suspected novae, a class of exploding star. He wrote the letter "N," for nova, next to each of the three objects.

Later, however, Hubble made a startling discovery when he compared the Oct. 5-6 plate with previous exposures of the novae. One of the so-called novae dimmed and brightened over a much shorter time period than seen in a typical nova.

Hubble obtained enough observations of V1 to plot its light curve, determining a period of 31.4 days, indicating the object was a Cepheid variable. The period yielded the star's intrinsic brightness, which Hubble then used to calculate its distance. The star turned out to be 1 million light-years from Earth, more than three times Shapley's calculated diameter of the Milky Way.

Taking out his marking pen, Hubble crossed out the "N" next to the newfound Cepheid variable and wrote "VAR," for variable, followed by an exclamation point.

For several months the astronomer continued gazing at Andromeda, finding another Cepheid variable and several more novae. Then Hubble sent a letter along with a light curve of V1 to Shapley telling him of his discovery. After reading the letter, Shapley was convinced the evidence was genuine. He reportedly told a colleague, "Here is the letter that destroyed my universe."

By the end of 1924 Hubble had found 36 variable stars in Andromeda, 12 of which were Cepheids. Using all the Cepheids, he obtained a distance of 900,000 light-years. Improved measurements now place Andromeda at 2 million light-years away.

"Hubble eliminated any doubt that Andromeda was extragalactic," says Owen Gingerich, professor emeritus of Astronomy and of the History of Science at Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. "Basically, astronomers didn't know the distance to novae, so they had to make a rough estimate as to where they were and therefore what their absolute luminosity was. But that is on very treacherous ground. When you get a Cepheid that's been reasonably calculated, the period will tell you where it sits on the luminosity curve, and from that you can calculate a distance."

Shapley and astronomer Henry Norris Russell urged Hubble to write a paper for a joint meeting of the American Astronomical Society and American Association for the Advancement of Science at the end of December 1924. Hubble's paper, entitled "Extragalactic Nature of Spiral Nebulae," was delivered in absentia and shared the prize for the best paper. A short article about the award appeared in the Feb. 10, 1925, issue of The New York Times. Gingerich says Hubble's discovery was not big news at the meeting because the astronomer had informed the leading astronomers of his result months earlier.

Edwin Hubble's observations of V1 became the critical first step in uncovering a larger, grander universe. He went on to find many galaxies beyond the Milky Way. Those galaxies, in turn, allowed him to determine that the universe is expanding.

Could Hubble ever have imagined that nearly 100 years later, technological advances would allow amateur astronomers to perform similar observations of V1 with small telescopes in their backyards? Or, could Hubble ever have dreamed that a space-based telescope that bears his name would continue his quest to precisely measure the universe's expansion rate?

Explore further: Hubble shows farthest lensing galaxy yields clues to early universe

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tkjtkj
4.2 / 5 (5) May 23, 2011
This article simply thrills me.
The_P
5 / 5 (2) May 23, 2011
agreed
spectator
1.3 / 5 (16) May 23, 2011
I'm wondering how they allegedly detect this small amount of radiation.

The power of the Sun is 1.333E26 watts.

I calculated this using the solar flux of 1360 watts/m^2, and then make a sphere of 1a.u. and calculate area in meters square, then multiply by solar flux.

Now by the fact that light propagates in spherical shells, the luminosity of any non-laser light source degrades by the inverse square, the same as gravity, as per Newton.

This means that if you divide the distance in meters to Andromeda by the distance from Earth to the Sun, then square the result and divide that into the solar flux at the Earth, then you'd get the solar flux of a sun-clone star, as seen from the same distance as Andromeda.

This would come to 8.904E-20 watts/m^2, for an alleged distance of 2 million light years.

And to put that in perspective, if eery star in Andromeda were a sun clone, and there were 600billion stars, that would only be: 5.34E-8 watts/m^2.
spectator
1.7 / 5 (17) May 23, 2011
Wh ich I know I'm going to get flamed over this, because nobody else is going to bother to do the math for themselves, but that comes to just 1/20th of a MICROwatt of luminous flux per meter squared for the entire galaxy, or a BILLIONTH of a TRILLIONTH of one watt luminious flux for a single star, which is one tenth of one electron volt per meter squared.

Now who here knows of any device that is actually capable of detecting and measuring that, nevermind cyclical fluctuations in that value?

The anwer is of course, we do not even have such a precise and accurate instrument even today. If we did, we'd have atomically precise nanomachines already.

The electron volt is not a directly measured value, nor is the energy of individual photons. It's a calculated value from Avagadros number and chemistry, because you can't actually directly measure energy levels that low.

They only just invented stuff able to directly detect nano-scale events.
spectator
1.5 / 5 (15) May 23, 2011
So the calculations MUST be wrong, because the accuracy and precision of this alleged measurement is not possible with any existing technology today, nevermind 80 or 90 years ago. If it was, we would have had photonic computers back then.

Our own weather satellites looking at the earth do not even have that high of precision or resolution. If they did, the meteorologists would surely be using it in computer models, but they don't because it simply isn't possible to do that. Currently, the computer models are capable of higher precision and resolution than the measuring instruments can provide in input data, so the input data is actually limiting improvements in forecasting, for example, because you CANNOT measure that precisely, even across terrestrial distances...

Further, detecting the flux of something supposedly 10 billion light years distance would be, by the inverse square law, 25 MILLION times more faint than at Andromeda's alleged distance.
Na_Reth
4 / 5 (2) May 23, 2011
I think they do capture gamma rays...
eachus
4.3 / 5 (10) May 23, 2011
There are two flaws in spectator's assumptions. The first flaw is that radiation, including light, is quantized. So no matter how dim, if a star gives off a single quantum of light that is caught by a "light bucket" (large telescope) it can be detected. In practice, using CCD collectors, each pixel recorded is a separate packet of charges, and you have to go to pretty extreme care to detect "only" a few quanta. But CCD cameras on telescopes larger than about 30 inches are normally cooled to liquid nitrogen temperatures so that counts of a few photons are real, not thermal noise.

Second, the sun, as I am sure you have been told is an average star. When you see an image of the Andromeda galaxy, any recognizable stars are thousands (or hundreds of thousands) of times as bright as the sun. The Cephid V1 mentioned in the article has an absolute magnitude of -5.63. That makes it about 100 times as bright as Sirius--and a bit more than 10,000 times as bright as the sun.
spectator
1 / 5 (20) May 24, 2011
That makes it about 100 times as bright as Sirius--and a bit more than 10,000 times as bright as the sun.


Do you realize how absurdly STUPID that claim is?

Excluding supernovas, it isn't even possible for a star to be that bright.

We know that because of the Schwartzchild radius and the speed of light.

In order to be that bright, it would need 1000s of solar masses, which would have collapsed instantly to a black hole and you wouldn't even see the damn thing at all.

For God's sake why don't you bother looking up even their own information on the masses of stars and black holes.

It's a totally inconsistent false science.
tkjtkj
1.5 / 5 (2) May 24, 2011

The power of the Sun is 1.333E26 watts.

I calculated this using the solar flux of 1360 watts/m^2, and then make a sphere of 1a.u. and calculate area in meters square, then multiply by solar flux.

Now by the fact that light propagates in spherical shells, the luminosity of any non-laser light source degrades by the inverse square, the same as gravity, as per Newton.

This means that if you divide the distance in meters to Andromeda by the distance from Earth to the Sun, then square the result and divide that into the solar flux at the Earth, then you'd get the solar flux of a sun-clone star, as seen from the same distance as Andromeda.

This would come to 8.904E-20 watts/m^2, for an alleged distance of 2 million light years.
/q]

I think that is totally wrong: you seem to assume the earth is a plane. It is not.
Pyle
4.5 / 5 (15) May 24, 2011
@spectator: Go away. You are wrong. Your math is wrong. It isn't worth anybody here's time to show why you are wrong. Those are pictures up at the top of the article. If you want a math lesson go over to physicsforums and one of the very nice Phd's over there will show you how to do the math properly. I wonder were QC went... You two would make quite a... JUST A MOMENT!!!

Great article.
RealScience
4.7 / 5 (13) May 24, 2011
spectator - A 31-day Cephid is 10,000 times as bright as a sun. It does not needs 10,000 times the sun's mass because it burns fuel so much faster that it has a much shorter life.

10,000 suns at 2M light years is 9E-16 Watts/m2, or 5E-15 Watts for the 100-inch telescope used in 1923. At an average photon energy of 1.5 EV = 2.4E-19J, that is 2E4 photons per second on essentially a point. A photographic exposed for 500 seconds would capture 10,000,000 photons, and many exposures were longer than that.

So your basic math isn't wrong, but your understanding of a telescope plus a photographic plate is very wrong (as is your understanding of the relationship between a star's mass and its brightness).

Two pupils at night dilate to ~1 cm2, 5.3E-8W/m2 is 5.3E-12W or ~2E7 photons per second. An unaided human eye can easily see 20,000,000 photons/sec over a small area, and Andromeda is indeed visible to the naked eye.

Photons are plentiful and were easily detectable even in 1923.
Pyle
5 / 5 (3) May 24, 2011
RS: I stand corrected. There are people here willing to take the time to show QC why he is wrong.

Good on ya!
dompee
5 / 5 (2) May 24, 2011
RC to the rescue it's nice to know not everyone is a complete idiot who pretends to know wtf their talking about and kudos for the lesson I wouldn't have wasted my time trying to educate these fools for free, ha! Your better a scientist then me my friend, I prefer to absorb the knowledge and keep the tech part of it to myself but perhaps someone actually learned something from the correct math...prob not but good lookin
spectator
1 / 5 (11) May 24, 2011
I think that is totally wrong: you seem to assume the earth is a plane. It is not.


The earth is a sphere, but as anyone who knew anything about the topic would know, every planet presents a DISK equal to the area of a circle of it's own radius to a light source.

If you think I'm a crank on this, sorry, you're wrong, google/wiki solar constant, and then find the area of a circle of radius equal to the earth's radius.

To save you time, solar constant is:

~1360 watts/m^2 -> ~1.74E17 watts per earth. (174 petawatts).

wikipedia.org/wiki/Solar_constant

Which you can then calculate the AREA of the earth's cross-sectional disk, and find its correct.

Even though a hemisphere (2pir^2) faces the sun, the cross sectional area (pir^2) is actually what matters for incident radiation.

Additionally, I should point out that the Earth actually reflects around 30% of solar radiation away BECAUSE it is a sphere and behaves like an average ~30% convex mirror.
spectator
1 / 5 (12) May 24, 2011
So your basic math isn't wrong, but your understanding of a telescope plus a photographic plate is very wrong (as is your understanding of the relationship between a star's mass and its brightness).


I can prove to you by local examples that it is not possible for a star to actually be 10,000 times brighter than the sun. Unfortunately, it will take several posts to be thorough.

First of all, you can notice that the SUN is a stable star, but just barely stable: It regularly blows it's own atmosphere away in solar winds and coronal mass ejections, which we observe all the time.

What this tells you is that the Sun is at the upper limit of a luminosity to mass ratio for a "Stable" star. If it were any brighter, it would blow itself apart due to radiation pressure alone (which it's actually already doing as solar wind, just "barely",) because light and gravity obey the exact same inverse squared relationships with respect to distance.
spectator
1 / 5 (10) May 24, 2011
Now let's say you have a hypothetical 100M star.

The internal pressure (related to the square of mass, since mass times gravity gives weight, and gravity is itself determined by mass,) in this star "should" be 10,000 times greater than the sun, which would THEORETICALLY allow it to burn nuclear fuel around 10,000 times faster.

HOWEVER, the problem with that is it doesn't work, because the star would be unstable and blow it's own self apart almost instantly. It's brightness would be increased by a factor of 10,000, but it's surface gravity would have only increased by a factor slightly more than 12 times the solar surface gravity. (You have to figure the volume formula and back out the radius, then plug into gravitational formula).

So you see a problem with this yet?

Allegedly 10,000 times the radiation pressure, but only 12 times the surface gravity, give or take a few tenths?!

It would blow itself apart within a few seconds through CONTINUAL CME and solar wind.
spectator
1.1 / 5 (11) May 24, 2011
Now imagine, the Sun "barely" produces CME's in local outbursts as energy becomes concentrated by magnetic anomalies.

But imagine how often that would happen in a star which supposely has a luminosity to gravity ratio 833 times higher?

The thing would be non-stop Coronal Mass Ejections in every direction until it blows it's entire mass away, and by "non-stop" I'm not using "hyperbole". I mean it would literally be a continual flow of CMEs in every direction.

And you wonder why I don't believe the standard model of the universe.

It's because I ask common sense questions, and plug numbers into known formula for myself and find that they absolutely do not work.

Oh yes, 10,000 times the Sun's internal pressure theoretically allows 10,000 times the rate of fusion, but it also EASILY blows the star apart under it's own radiation pressure from that fusion reaction.
spectator
1 / 5 (10) May 24, 2011
The Sun only has CME's when it's energy in a local spot exceeds the threshold of local gravity and magnetism.

A star with the insanely high alleged 10,000 solar luminosities would have non-stop CME in every direction, because the radiation pressure and other forms of energy transfer would ALWAYS be far, far above the gravitational and magnetic threshold for CME to occur.

It would just go on and on until the Star's entire mass was ejected, or at least until it reached and equilibrium mass, which actually would not happen until it either exploded totally, or collapsed to a black hole.

Just because the INTERNAL pressure appears to be in a balanced ratio (10,000 solar pressurevs vs 10,000 suns luminosity,) that doesn't mean the surface pressure and surface gravity are balanced with the radiation, because anyone who can do math for themselves can see it's woefully insufficient. The surface pressure and surface gravity would only be 12 times the sun vs 10,000 times the brightness...
spectator
1 / 5 (10) May 24, 2011
Or to put it more directly:

The Radiation pressure for a star allegedly 10,000 times as bright as the Sun would be...10,000 times greater.

But the Escape velocity would only be around 8.5 times greater than the Sun.

Let's see what that ratio is:

10,000 solar luminosities / 8.5 solar escape velocities = 1176 ratio

Does ANYONE comprehend what that means?

It clearly means that since our own Sun gradually blows itself apart, a star with a ratio that much higher would be in a literally continual nova explosion which asolutely would not stop until all of it's mass was ejected OR the core collapsed to a black hole, which ever came first (which may depend on what the Star was originally made of, since that would alter it's density and brightness too.)

But I hope you see that it's not as simply as saying, "Oh, a star can be 10,000 times as bright if it burns 10,000 times the fuel with 10,000 times the internal pressure".

The star would self-destruct immediately.
spectator
1 / 5 (10) May 24, 2011
I should make one minor correction above, since the star's average density would be more dense than the average density of the Sun, it's surface gravity would be "slightly" stronger, around 40% stronger on top of the factor above, but it's escape velocity is close enough anyway, since the change in density is not very large and only makes about an 8 to 10% difference in escape velocity.

Anyway, this is not significant, because it's such a pathetically small number compared to what the radiation pressure would be.

I only added this last post because I know "some" smartass is going to mention it and accuse me of not knowing this.
spectator
1 / 5 (10) May 24, 2011
Right, geniuses.

Give me negative feedback because I use my brain for myself, and actually tested the mathematical consequences of the alleged distances and brightnesses that would be needed, instead of believing everything someone wrote in an article.

Like my first comment since this morning, you morons gave that low feedback. Why?

It is absolutely correct based on available encyclopedic or textbook knowledge, which I corrected a know-nothing comment by tkjtkj...

Good call guys. you really know good comments when you see it.
spectator
1 / 5 (9) May 24, 2011
Two pupils at night dilate to ~1 cm2, 5.3E-8W/m2 is 5.3E-12W or ~2E7 photons per second. An unaided human eye can easily see 20,000,000 photons/sec over a small area, and Andromeda is indeed visible to the naked eye.


Andromeda is visibe to the naked eye for SOME people.

Personally, I cannot see it, even with a ~10cm telescope with autoslew, or binoculars manually looking.

I can see Sirius, Rigel, and Betelgeuse pretty easily because of their brightness and their easy to find position in the constellations.

Photons are plentiful and were easily detectable even in 1923.


Only under controlled experiments in a lab, and even then "individual" photons were not directly detected at all. All they did was slit experiments with photographic plates and the photoelectric effect.

The way they did slit experiments, because they could NOT actually directly detect photons, was to let the experiment run for several hours or even days and look at interference on a plate.
spectator
1 / 5 (9) May 24, 2011
We are just now getting to where we have quantum dots and other detection devices that are still approximately the molecular scale or slightly larger, up to about a micron, and even those do not actually directly detect individual photons.

So someone 80 years ago would never have directly detected individual photons, and would never have made the claim either.

They measured an accumulated interference line on a photographic plate under laboratory conditions. Additionally, they had the advantage in a slit experiment of knowing ahead of time the input power of the light source, and thus it's maximum luminosity, which allowed them to know maximums and minimum ranges of the photon energy levels based on efficiency of the light source.

In the case of astronomy you cannot "know" how bright something is unless you know it's absolute luminous flux at your own location, AND know the exact distance to that object to begin with.
spectator
1 / 5 (9) May 24, 2011
You cannot extrapolate an unknown distance to an object of unknown mass, since you cannot know either of those things without knowing the other.

If it's outside the range of triangulation, or parallax, then you can't even get a ballpark figure that is anything other than a pure GUESS.

If you don't know how bright an object is absolutely, then you cannot tell how far away it is, even with understanding the propagation of light, because you still have two unknowns.

You know:

Luminous flux at your own location. (for the sake of argument...)

You don't know:

Absolute luminosity of the Star (or power).

Distance to the star.

It is not possible to solve for the absolute luminosity without knowing distance absolutely.

And it is not possible to solve for the absolute distance if you can neither triangulate nor solve for absolute luminosity.

It's a completely fictional guesstimate with no factual basis whatsoever.
antialias
5 / 5 (10) May 24, 2011
If you think I'm a crank on this, sorry, you're wrong,

Why don#t you just go outside and look at the sky. andromeda is right there for you to see. Your own eyes will tell you that you're wrong.

We are just now getting to where we have quantum dots and other detection devices that are still approximately the molecular scale or slightly larger, up to about a micron, and even those do not actually directly detect individual photons.

Head over to wikipedia for 'single photon multipliers'. Those have been around since the 1930's. current photomultipliers go as high as 99% detection efficiency.

It is absolutely correct based on available encyclopedic or textbook knowledge

No, because you assumed a non-quantized nature of light. That was a false assumption. For some applications that is fine, but when considering extreme circumstances you need to be aware of the fine details.
spectator
1 / 5 (10) May 24, 2011
antialias:

How do you solve an equation in two unknowns for a specific, individual solution, when you have no related system of equations?

That is not mathematically possible.

You might guess and get it right, by chance, a percent or two of the time, but that's about it.

Further, in the case of astronomy, you can't even use "guess and check," because there is no way to actually check.

To check the guess, you'd need to be at an absolutely known distance and make an absolute measure of the brightness from that absolutely known distance.

At best, you could assigne a probability to certain ranges of brightness, which would allow a probability to certain ranges of distance, but that isn't what their claim is.

They claim to have calculated the absolute distance from the absolute brightness of the star, which they fabricated out of nowhere, because they have no way of knowing that value.
spectator
1 / 5 (10) May 24, 2011
Now I said I'd use other "local", and so I turn to the astronomer's own data on nearby stars to show how absurd it is to use brightness to try to find the distance to something.

Betelgeuse is close enough to earth such that triangulation is still able to get a "ball park" estimate of distance.

Yet even combining triangulation and common sense measurements of the angular diameter, and making common sense estimates of upper and lower mass, COMBINED with estimates of brightness, etc...they STILL have a margin of error of +/- 22% in the most up-to-date calculations of it's distance (and therefore it's brightness as well).

This means that even today there is still an error of up to 59% from one end of the range to the other, for a Star which is basicly in our own back yard, and close enough to apply both triangulation, doppler shift techniques, and al other techniques to correlate with one another and reduce margin of error.
spectator
1 / 5 (10) May 24, 2011
Now if they can't get Betelgeuse's range down any more accurately than that even using multiple techniques which are possible for objects of this approximate range, why would I believe their values for something allegedly thousands of times farther away?

Secondly, Betelegeuse is SUPPOSEDLY 140,000 solar luminosities, one way to explain this is thermal runaway, in which the radiation pressure itself is sufficient to further fuse atoms faster than gravitational pressure alone can explain...

...BUT predictably it is exploding under it's own radiation pressure, and losing mass very rapidly.

In fact, Betelgeuse is actually losing mass so rapidly that it cannot logically be more than a few thousand years old.

If it were significantly older than that, then it would have had to start out orders of magnitude more massive than it is now, and you would detect hundreds or even thousands of solar masses worth of ejected material in an expanding shell around it.
spectator
1 / 5 (9) May 24, 2011
So the applied consequence of what even the ASTRONOMERS know about Betelgeuse is that any alleged 10,000 solar luminosities star in some distant galaxy should have and would have totally burned up in a relative pin-prick of cosmic time compared to the allegedly billions of years galaxies have allegedly existed.

So it's a complete contradiction in measurements and conclusions, given KNOWN properties and ranges of properties for far more accurately and precisely measured objects which are definitely closer...
El_Nose
4.8 / 5 (5) May 24, 2011
@specter

man you are doing a lot of imagining with out a lot of observations to back up your claims

Lets take your theory to the next level -- you are claiming that cephids are wrong - just plain bogus science- you are claiming that once again all observable luminous matter is within our galaxy because by your understanding -- what we claim is one of our closest neighbors amdromeda is within our galaxy by shear virtue that we can see it and you do not believe that we could see ANY star from that far away.

Not only do you not like cephids but you don;t like gamma ray bursts and the conclusions that come from equations solving for the red shifting of that energy --

are you supposing that once again the Earth is the center of the universe

you came off as intelligent in other posts on different topics - but now you are wearing us a little thin
RealScience
5 / 5 (9) May 24, 2011
Spectator:
Cephid variables are not stable - that's what makes them so variable.
The nearest Cephid variables are in this galaxy, and close enough that the parallax from the earth's movement around the sun can be measured, providing an absolute measure of distance and thus allowing the absolute brightness to be determined.
So that eliminates one of the two unknowns for nearby Cephids.

The variability period and the absolute brightness are nearly perfectly correlated, eliminating an unknown even when we cannot measure parallax. That plus Cephids being very bright is exactly what makes Cephids such great standard candles for determining distances beyond what we can measure directly.

All of this is discussed in a college level astronomy course. You might want to take at least on such course before assuming that you know more about astronomy than thousands of professional astronomers who spend their lives working these things out.
RealScience
5 / 5 (6) May 24, 2011
As for the sun being near the upper mass limit, we can actually directly measure the distance to many stars in our galaxy using parallax (for example, Sirius, where is a near neighbor and MUCH brighter than the sun). Do you doubt that the earth goes around the sun, or that the diameter of its orbit is known?

As for super-bright stars having burned out long ago, your argument is like saying that because mosquitoes live less than a year, the universe can't be more than a year old. Yes, the ones that were around long ago did burn out. We see their death throes as supernovae in distant galaxies. But new ones form all the time.

And each photon hitting photographic film triggers the precipitation of a cluster of dozens of silver atoms, which is then enlarged through development. So yes, even in 1923 groups of million of photons were easy to detect. (The double-slit experiment has nothing to do with this).
spectator
1 / 5 (9) May 24, 2011
El_Nose:

Kindly QUIT attributing statements to me that I absolutely did not say.

I never said galaxies weren't visible. YOU falsely accused me of saying that.

Oh yeah, the Earth IS THE CENTER OF THE OBSERVABLE UNIVERSE, and PROVABLY so, because the universe is exactly symetrical in every direction.
spectator
1 / 5 (10) May 24, 2011
And each photon hitting photographic film triggers the precipitation of a cluster of dozens of silver atoms, which is then enlarged through development. So yes, even in 1923 groups of million of photons were easy to detect. (The double-slit experiment has nothing to do with this).


And you just argued against something completely different than what I said, because you're either too dishonest to admit the difference, or too stupid to know the difference.
Donutz
5 / 5 (8) May 24, 2011
Wh ich I know I'm going to get flamed over this, because nobody else is going to bother to do the math for themselves, but that comes to just 1/20th of a MICROwatt of luminous flux per meter squared for the entire galaxy,


This is typical of someone who knows just enough math & science to be dangerous, and is arrogant enough to believe they haven't missed anything. Notice who spectator comes up with an apparent contradiction, and IMMEDIATELY and WITHOUT ANY DOUBT leaps to the conclusion that there is a vast global conspiracy to present false information. No chance, I guess, that you just might not have all the facts? No, of course not.

Well, here's a couple of facts. 1) The 200-inch palomar telescope, which used to be the biggest telescope on earth, can collect over 500000 times as much light as the human eye, assuming equal efficiency (which is giving the eye a huge benefit of the doubt).

cont'd
RealScience
5 / 5 (7) May 24, 2011
Spectator - to quote you directly:

Now who here knows of any device that is actually capable of detecting and measuring that, nevermind cyclical fluctuations in that value?

The anwer is of course, we do not even have such a precise and accurate instrument even today. If we did, we'd have atomically precise nanomachines already.


I pointer out earlier that the 100-inch Hooker telescope and 1923-era photographic plates made light from a single 10,000-suns brighness star in Andromeda easily detectable in 1923. In this post I added an explanation of how photographic plates recorded a single quantum event and made it detectable.

Are you smart enough to understand this, and honest enough to admit that you were wrong on this point?
Donutz
5 / 5 (3) May 24, 2011
Aw crud. RealScience is already making the point, and better than I could. Moving on...
Pyle
5 / 5 (6) May 24, 2011
This is typical of someone who knows just enough math & science to be dangerous, and is arrogant enough to believe they haven't missed anything.


Hey y'all!!!! QC is nuts.

spec-potater: You are a very bright person. If you would get the (insert whatever condition you have here) under control you actually have a lot to contribute here. Try posing your posts as questions rather than attacking the world and insulting everybody (Yes, I am the pot).

A better forum, if you actually want to learn, is physicsforums where "know-it-alls" like to flex their mind muscles for public display and you can make half of them look silly half the time because they are more ill-informed and ill-educated than you. Besides, based on your history here you are actually, as I said, a bright person. Just a little nuts. Why did you change nicks?
Gawad
5 / 5 (8) May 24, 2011
Aw crud. RealScience is already making the point, and better than I could....
This is an excellent article. It provides a succinct retrospective of the understanding of the cosmos at the turn of the last century and how the technology coming on line at the time changed all that. This was equipment as revolutionary for the time as the Hubble space telescope has been for us. Think about it, how the universe "got bigger" with the realization that those spiral nebulae were galaxies of their own, and how those same variable stars were pivotal in the determination that the universe's expansion is accelerating instead of decelerating: making bigger still than we thought hardly a dozen years ago. And in the meantime, this forum section descends into another argument stream because of a crazy bible thumping Jesus freak who trots out his little math kit to prove the world of science is trying to undermine his religious based world view. Guys, Q_C is batshit crazy. Let it be, let it be.
RealScience
4.8 / 5 (6) May 24, 2011
I gave spectator credit for doing the math (which is more than many people do), and thus gave him/her a detailed answer.

Spectator got the flux right, but didn't realize that a 100-inch telescope concentrates ~5 square meters of that flux onto a tiny point less than a millimeter in diameter, increasing the power density more than a billion fold, and that a photographic plate integrates that flux over long periods, making it easily detectable and measurable.

Donutz says it well - instead of checking spectator his own logic or politely asking where he went wrong, he assumes that most of astronomy is an obvious lie and that he is the first to discover this.

But spectator at least attempts the math, so there is hope that after a few such mistakes being pointed out he will learn.
DirtyBurger
not rated yet May 24, 2011
Holy anxiety attack! Theses things intrigue and frighten me at the same time...well space/unknown does. Awesome, regardless.
Pyle
5 / 5 (3) May 24, 2011
But spectator at least attempts the math, so there is hope that after a few such mistakes being pointed out he will learn.
QC has been trolling here for a long time. Ever since I started paying attention to the comment boards about a year ago. Now that he has changed nicks you think he is going to change? He consistently gets the math wrong, is corrected, and rails against the next article with more bad math. Again, bright guy, serious mental health issues.

RS, while I agree with you for the most part, I just want you to realize he is "batshit crazy" and a bible thumper to boot. It is admirable that he cracks open the math book. But unfortunate he doesn't listen when correted and is entrenched in his self-contradicting belief system.
RealScience
5 / 5 (5) May 24, 2011
Pyle - If spectator is indeed QC, which seems likely given the similarity in style, then he actually isn't too bad except for anything that conflicts with his certainty that the earth is young.

When QC/spectator says something that makes sense, I give him a decent rating. When he goes off the deep end, I give him a bad rating. If he at least tries to think, I give him an explanation and guidance.

Although I have never seen QC acknowledge it when I have pointed out the errors in his math, he has often stopped repeating his arguments so I know that the message has gotten through.
(And his frustration with that may be one reason that he is even more strident on his next denunciation of science going against how he interprets the bible.)
RealScience
5 / 5 (6) May 24, 2011
to continue -
I also generally only answer QC/spectator if I think that my answer may be of interest to others reading the board.

For example, in this case many people assumed that spectator's math was wrong, while he actually had the power density from a 1-sun star in Andromeda right. What he/she failed to realize was that Cephids are very bright, that a telescope concentrates that power onto a spot, and that even in 1923 single quantum events were detectable.

Under the right conditions the unaided human eye can detect a single photon, so that ability has actually been around a lot longer than since 1923. That's really cool, and lots of people, even those reading physorg, may not know about it.
tkjtkj
5 / 5 (3) May 26, 2011
That makes it about 100 times as bright as Sirius--and a bit more than 10,000 times as bright as the sun.


Do you realize how absurdly STUPID that claim is?

Excluding supernovas, it isn't even possible for a star to be that bright.

We know that because of the Schwartzchild radius and the speed of light.


To be wrong is one thing, but to be wrong (as you are) *and* to be arrogant and denigrating (which you were) rather than instructive are far greater sins. Cephids do not behave as you describe ..
But would i call you 'stupid' ?? .. well.... actually ..... mmmm ...errrrrrr...ah....mmmmm....
specpotater
3 / 5 (4) May 26, 2011
But would i call you 'stupid' ?? .. well.... actually ..... mmmm ...errrrrrr...ah....mmmmm....

Not only is it you the one who is STUPID, but your nick is stupider than you are, tkjtkj!

Hey guys, I admitted on another thread I am wrong sometimes. That I failed to admit it here and act contrite, SO WHAT? Are you going to hold it against me just because I called scientists who were actually right complete idiots and morons because I failed to understand the physics of photon emission and absorption?
You can't judge me. I am just a spectator. WATCHING. Not ACTIVELY involved. Think Charles Schultz. Peanut gallery. IRRELEVANT but annoying like all adults in the Peanuts. I am not nearly as cool as Snoopy, or even Charlie Brown for that matter. I love that zigzag shirt...
Objectivist
5 / 5 (1) May 28, 2011
And you just argued against something completely different than what I said, because you're either too dishonest to admit the difference, or too stupid to know the difference.

Spectator, I'm not going to judge you at all. But please, just watch this and tell me if you identify yourself with any of the things she says. Ignore the title and give the clip a chance. It's very interesting either way. Keep the quote above in mind as you're watching it.

http://www.ted.co...ong.html
specpotater
5 / 5 (1) May 28, 2011
I watched it. I don't think your Kathryn Schulz is any relation to Charles Schultz. YOU TRICKED ME! And you down rated me!

You are such a Lucy.

Everyone else. Watch a TED video a day. TED rocks.
Shelgeyr
1 / 5 (1) May 28, 2011
Elvis?
Dummy
1 / 5 (2) May 29, 2011
"you're stoopid" "no, you're stoopid" " No, YOU'RE stoopid....

Jesus listen to yourselves...
vulture
not rated yet Jun 24, 2011
You know, I am not a math whiz or even a scientist. I enjoy reading these articles simply because I like to know what's going on. Objectivist, I have to say you were dead on with that TED video. As I re-read the posts above I noticed spectator going through all the phases described in the video. A little creepy, really. And now I have another place to go and learn interesting things. Thanks for the post.