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The Extraterrestrial Hypothesis and the null hypothesis

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posted on Apr, 30 2014 @ 11:21 AM
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originally posted by: WilliamMook
a reply to: tanka418

α CMa B - Sirius B - This is invisible to the naked eye
Mass 0.978 M☉ (as massive as the sun)
Radius 0.0084 R☉ (5,842 km radius - smaller than the Earth!)
Luminosity 0.026 L☉ far less luminous than the Sun.
Surface gravity 371.53 million gees!!!! (vastly larger than the Earth)
Temperature 25,200 K (this is as hot as an X-ray machine filament!) - peak output 115 nm (Xray)


The system is 300 million years old. It was originally composed of two bright bluish stars. The more massive of these, Sirius B, consumed its resources and became a red giant before shedding its outer layers and collapsing into its current state as a white dwarf around 120 million years ago.



Thank you...actually learned something new...


Your reference to the "filament of an X-Ray" tube though...a bit off as the filament of any vacuum tube never gets that hot...they are after all only coated Tungsten wire...X-Rays are produced by a electron stream impacting a metallic target...

On the age of Sirius A. I know that the "published" age is on the order of hundreds of millions of years, however, I have talk to Astronomers who seemed to indicate that Sirius could be much older, perhaps nearly as old as Sol. While this is never confirmed, it does seem probable.

Firstly, as I understand it there are two "ages" for any given star, though they nearly always agree more or less. These would be the "movement" or kinematic age, and the "color" age. If I understand correctly the 300 million year age is the "color" age for Sirius A. That being the case; what is it's kinematic age?

Is there a way to find out what the "habitable zone" for Sirius A might be?

How difficult would it be for the kind of orbital resonance you speak of to occur naturally? Could it be engineered?

thanks





posted on Apr, 30 2014 @ 04:20 PM
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a reply to: tanka418

tanka418 wrote;

:Your reference to the "filament of an X-Ray" tube though...a bit off as the filament of any vacuum tube never :gets that hot...they are after all only coated Tungsten wire...X-Rays are produced by a electron stream impacting :a metallic target...

You are quite right! Thermionic emissions haven't been a source of x-rays since Roentgen's discovery, however in recent times metal jet anode x-rays are used for vastly increased power levels by increasing anode temperatures to that of liquid tungsten.

I should have said the surface of Sirius is so hot that it produces more X-rays per unit area than the anode of an x-ray tube! In terms of X-rays the surface of Sirius is 'hotter' (in a black body thermodynamic sense) than these tiny bits of tungsten rhenium alloy flooded with electrons.


Thermionic Cathode
www.genesis.net.au...

Rotating Anode
upload.wikimedia.org...

Metal Jet Anode
xray.chem.wisc.edu...

edit on 30/4/2014 by WilliamMook because: (no reason given)



posted on Apr, 30 2014 @ 06:49 PM
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a reply to: tanka418

Tanka418 writes:

:On the age of Sirius A. I know that the "published" age is on the order of hundreds of millions of years, :however, I have talk to Astronomers who seemed to indicate that Sirius could be much older, perhaps nearly :as old as Sol. While this is never confirmed, it does seem probable.

Well this is a complicated issue, but a well understood one. Google 'stellar evolution' and 'Hertzsprung Russell Diagram' for more detail.

Generally speaking Sirius A and Sirius B started out life about 300 million years ago, collapsing from a molecular cloud in about 10 million years time. Sirius A is 2.02x as massive as the Sun and Sirius B started out life 5x as massive as the Sun.

Now Luminosity, the rate at which a Star burns up its fuel, is determined by its mass. This is known to be;

Lstar = Lsun * ( Mstar / Msun ) ^ 3.5

So, a star as large as Sirius A 25.4x as luminous as the Sun today. A star 5x as massive as the Sun is 279.5x as luminous as the Sun today.

So before Sirius B blew off its shell, Sirius would have been very bright in the night skies of Earth. It would have been incredibly bright to any planet orbiting around the pair! You'd have to be 2.5 billion km away (the distance of Uranus from the Sun in solar system terms) to maintain liquid water oceans on a planet. Of course, the star would radiate in the extreme UV or soft X-ray region mostly, as discussed previously.

Now lifetime is proportional to Mass divided by Luminosity, since Mass tells us how much nuclear fuel we have, and Luminosity tells us how much nuclear fuel we're using per unit time. We've studied the Sun very closely, and it is has a lifetime of about 10 billion years fusing hydrogen. So, astronomers estimate that Sirius B, being 2.02x as massive as the Sun will have a life cycle lasting 1,724.3 million years whilst Sirius B, starting out with 5.00x more mass than the Sun will have a life cycle lasting 178.9 million years. That is, starting 300 million years ago, Sirius B has already gone through its life cycle, and is now a White Dwarf cooling off. Sirius A has another 1,420 million years to go. In contrast the Sun is 4.5 billion years old and has another 5.5 billion years to go before it becomes a White Dwarf like Sirius B after blowing off 45% of its mass into a planetary nebula.

tanka418 writes:

:Firstly, as I understand it there are two "ages" for any given star, though they nearly always agree more or :less. These would be the "movement" or kinematic age, and the "color" age. If I understand correctly the 300 :million year age is the "color" age for Sirius A. That being the case; what is it's kinematic age?

There are two ways to talk about the age of a star. The first is how far along its life cycle it is. The second is to talk about how old it is in years. Stars that live fast and die young - like Sirius B and Sirius A - may be only 300 million years old, but be far in advance of the Sun through their life cycle, even though the Sun is 4.5 billion years old.

Check out Hertzsprung Russell Diagram. This organizes our understanding of stellar evolution very well. The diagram plots a star according to its luminosity on the Y-axis and according to its temperature on the X-axis.

Do this for all stars you see and you get a 'main sequence' of stars with 'branches' where they like to hang out.

www.mtholyoke.edu...

Clouds of interstellar gas and dust that fall together to form stars, follow a specific path based on their initial mass. Here's the path of the Sun. This path is determined by the physics of black bodies and the physics of nuclear fusion;

skyserver.sdss.org...

Tanka418 writes:

: Is there a way to find out what the "habitable zone" for Sirius A might be?

Yes, the circumstellar habitable zone is

CHZ = SQRT( Luminosity )

in Astronomical Units. So, Sirius A is 25.4x as bright as the Sun, so its CHZ(Sirius A) = 5.03 AU. Sirius B is 0.026 as luminous as the Sun so CHZ(Sirius B) = 0.16 AU. At these distances liquid water could form on a planet's surface. Other factors may not be conducive to life as we know it, however, life may evolve anyway, that thrives in these conditions as I pointed out. And, even other factors may apply, for example, a planet that is inside the Roche Limit for a star would tend to have tidal effects so large as to pull the planet apart into a ring. This is the basis of Larry Niven's 1984 sci-fi novel 'Integral Trees' which I recommend to anyone who wants to think creatively about the possibility of life around a White Dwarf star.

Tanka418 writes:

:How difficult would it be for the kind of orbital resonance you speak of to occur naturally?

Not difficult at all. We see resonances of every type in the solar system.

: Could it be engineered?

Yes.

Yet, if you are promoting the concept of life evolving in the Sirius star system I would say there isn't enough time - not for the sort of planet bound evolution we see here on Earth - with the life forms we have.

Caveat

Yet, we should always keep in mind, the comment of JBS Haldane, in his 1927 paper on the future, that the universe is not only stranger than we imagine. The universe is stranger than we CAN imagine. Which is merely a re-statement of an even older statement of Shakespeare in his play Hamlet in 1599 - where Hamlet talks to his school chum Horatio saying, "There are more things in Heaven and Earth, Horatio, than dreamed of in your philosophy."

Life in the Molecular Cloud predating Sirius A and Sirius B

So, with an open mind, we can ask, how old is the Molecular cloud from which Sirius and the 200 other stars nearby were formed? The answer is, older than the Sun. Now we have known since 2003 that these clouds possess amino acids and since 1998 that they have water

physicsworld.com...
www.cfa.harvard.edu...

So, its not too difficult to imagine that they hold life. How old could this life be? Older than life on Earth!

In that context, it may be that life forms living in the cloud arrange the collapse of supermassive stars from the cloud, the same way we seed clouds to produce rain. Why? To produce heavier elements needed for life and industry, along with energy.

Rapid Evolutionary Development around Hot Stars

Since the rate of evolution is proportional to the energy levels involved, and since UV and X-ray light is vastly more energetic, it may very well be that once life gets started on worlds orbiting UV and X-ray emitters, that evolution proceeds far faster than it does on Earth. We may be slow-pokes compared to the life forms that life around these stars. So, notwithstanding the shortened life span, it may very well be that life is vastly more advanced in these systems than here on Earth.

Stupendously Rapid Evolutionary Development in Hot Stars

My friend Robert Forward wrote an excellent book in 1980 called Dragon's Egg. In the novel he described a star ship he designed and proposed to NASA and Congress to be built actually. However, he also described a life form that evolved on the surface of a neutron star! Very similar to Sirius B. Again, because the energy levels are so high, life evolved very rapidly indeed leaving us in the dust!



posted on Apr, 30 2014 @ 07:20 PM
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a reply to: WilliamMook

A final remark about the possibility of life on the surface of a neutron star! With a gravity some 315 million times the gravity on Earth, the ability of things to rise and fall will be damn near impossible! Even for life powered by nuclear resonances or nuclear reactions! A 100 kg being, could be as complex and capable as any human. However, being made of material the same density as a nucleus they would be the size of mustard seeds and live 1 million times faster! They would also be a living incarnation of Edwin Abbott's "Flatland: A Romance of Many Dimensions" written in 1884.

en.wikipedia.org...
www.geom.uiuc.edu...

Here, 2D creatures encounter 3D creatures. If we take the size of creatures to be 2 mm - and equate that to a flatland dimension of 2 meters equivalent to a human - total area of Sirius B is 4.22e14 sq km. An area 830,000x the area of the Earth for these tiny beings. Each year that passes on the surface of the star is equal to a million years evolution on Earth.

The energy for life processes arise from 'below' in the bright core of the star that is cooling. The sky would be invisible to them, being too dim and washed out by the intensity of the light. The idea of up and down might be comparable to our idea of past and future. It exists, but its not anything more than the way things are, here, since the orientation is constant and beyond our ability to affect in any way.

According to the story the star ship from Earth arrives in the star system of the neutron star. It turns on its anti-matter powered photon rocket and produces gamma rays during the 6 month boost to slow the starship down to arrive at the star system. The intense gamma ray beams strike the surface of the neutron star, and its the first thing visible to the creatures within the star's ecosphere. Furthermore, it remains a constant brightness across one hemisphere of the star's surface for 6 months - the equivalent of 500,000 years of evolutionary time for the tiny creatures. This source of pure gamma energy is like manna from heaven for the creatures on the surface. The star which rotates at 31.6x per second, in terms of the creatures takes one year to rotate. Half the year the gamma ray source rises in the sky, and sets. The other half, is night - the old ways dominate.

In the 6 months Earth time, the ship boosts to a halt in the star system, creatures on the star think more deeply about 'up' and 'down' and this wonderous star so constant and stable. They begin to think about astronomy. They develop technology and science. They reach a rather high level of development by the time the boosting stops - destroying the basis of the technology that depended on the gamma rays arriving half the time to the star's ecosphere. This spawns a new development - the development of space travel - for the tiny beings - who after generations of study, figure out what's up with the star - and leave their 'homeworld' for other stars beyond theirs.

I find this very satisfying story highly educational. It shows that things can occur at different time scales, at different energy levels, and even different geometric conceptions - for life evolved say on the surface of a neutron star versus live evolved on the surface of a planet orbiting a G type star.



posted on May, 14 2014 @ 01:20 PM
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a reply to: WilliamMook

I suppose you could direct us to a source instead of a 'great wall of text'.
edit on 14-5-2014 by radkrish because: (no reason given)



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