What’s white chicken stock? Its simply stock that doesn’t involve roasting.

One important rule to remember, never add salt or pepper to your stock when you are making it. Season only when you’re gonna use.

Ingredients

2 x chicken carcass

Mirepoix

Cold water

2 x Bay leafs

Preparation

Please all the ingredients into a pot and make sure its fully covered with cold water. Bring to boil. Once its boiling, reduce to simmer and let it simmer for about 3 to 4 hours, stirring occasionally.

Once the stock its reduced, use a tong to remove the carcass (if you have a pet dogs, you can save the carcass for them). Next remove all the vegetables and strain it. You can strain out quite abit of juices. Return those juices back into the pot. Using a stainer again, pour the stock into the strainer and into a container to remove residues.

Leave to stand for awhile to let it cool. Once cooled, place into the refrigerator. Oil will congeal at the top which can be easily removed. You can save that oil for other recipes, for example, chicken chilli sauce. Or if you’re really health conscious, you can just dispose it.

Stock must be consumed within a week if its in the refrigerator. For longer shelf live, you can simple put in it the freezer, making sure you put right amounts into a plastic bag. In the freezer, it can last for 3 months.

Soup

Short pork ribs in white chicken stock with scallions and mirepoix garnished with spring onions.

Meat

Lean pork meat, liver, fat pork meat marinated in dark soya source, sesame oil. Cooked in claypot.

Vegetables

Pan fried garlic leaves with fat pork, garlic and seasoned with fish oil

Staple

Thai white rice

Port Arthur, originally uploaded by daecon.

SMC and LMC amongst the trees. Taken from Stewart’s Bay at Port Arthur. 18mm unguided 30 sec exposure at f/3.5. I was glad to see these two majestic galaxies, our companion to the Milky Way.

Techniques of detecting a black hole

Accretion Disk and Shooting Gas Jets

We cannot have visual observations of black holes since not even light can escape it. To detect its presence we have to study it indirect by observing the behavior stars, gases and matters within its vicinity. Therefore, a good candidate of finding a black hole is to look at close binary star systems (Refer to Table-1 for a list of stellar-mass black hole candidates in binary star systems within the Milky Way). If one of the companions in a close binary system is a black hole and is orbiting close enough, tidal forces can draw material from its companion star. If the black hole is rotating, the materials falling into the black hole will form an accretion disk. Materials in the accretion disk also plays another role in the black hole’s spin, the formation of two narrow but powerful jets of gas that appears shooting out of some black holes.

Although accretion disk does not definitively represents a presence of a black hole, it does point scientist to its possibility of having one. Accretion disk can be explained by the presence of a white dwarf or a neutron star. Therefore we have to eliminate that possibility by studying the gravitational influence of the black hole candidate. As the duo orbit around their centre of mass, the visible star would wobble. By observing the Doppler shift of the companion star spectral lines, we can conclude the mass of the candidate. If for example it is calculated to be 7 solar masses or more, is too large for to be a white dwarf or a neutron star, we can assume that it is a good black hole candidate.

As the in-falling materials spirals into the hole it is heated up by friction. These extremely heated gases emit x-rays that fluctuates rapidly ^{2, 3}. We shall discuss further upon X-rays later in this essay.

Figure 1 - Illustration of a black hole in a binary star system.

Gravitational Lensing

Apart from observing binary star systems to look for black holes, we can also infer a black holes presence from gravitational lensing. Since the gravitational pull of a black hole is so strong, a black hole passing in front of a light source will cause the light wave from the light source to bend around it 4. (Refer to Table-2 for a list of stellar-mass black hole candidates found by gravitational lensing within the Milky Way).

Figure 2 – Illustration of a black hole causing gravitational lensing.

Gravitational Waves

Predicted by Einstein’s General Theory of Relativity, gravitational waves are formed by the fluctuation of the curvature of spacetime by the presence and oscillations of massive objects. The greater the object is, the greater the curvature. If the object oscillates in the right way, ripples in spacetime will spread like ripples in a body of water. This is called gravitational waves or gravitational radiation. Detecting such signals is extremely difficult because gravitational radiation is a lot weaker then electromagnetic radiation. Indirect evidence has come from the observation of a binary system of 2 neutron stars, the Hulse-Taylor binary (PSR B1913+16). ⁵

To directly observe this, scientists around the world have built sensitive detectors to detect gravitational waves. There are two types of such detectors, through laser interferometer and resonant detectors. Here is a listing of these facilities: ⁶

• Interferometric Detectors

• LIGO (USA) – 2 Detectors
• LISA (USA/EU) – 2 Detectors
• GEO 600 (Germany)
• TAMA (Japan)
• VIRGO (France)
• AIGO (Australia)

• Resonant Detectors

• ALLEGRO (USA)
• AURIGA (Italy)
• EXPLORER (Italy)
• NIOBE (Australia)
• miniGRAIL (Netherlands)
• GRAVITON (Brazil)

Gamma Ray Burst

Gamma ray burst (GBR) are one time occurrences that are the most luminous events in the universe. The common consensus amongst the scientific community is that GBRs occur with the gravitational collapse of a massive star. It can be the collision of between two orbiting neutron stars, which can possibly form a black hole. Or it can even be the a neutron star colliding into a black hole. Gamma ray detecting satellites such as the now defunct Compton Gamma-Ray Observatory detects on average one GBR per day. However, all of the detect GBR are located beyond our Milky Way ⁷.

Stellar-Mass Black Hole Candidates within the Milky Way

Stellar-Mass black holes in binary star systems [Table -1]

Detectable due to interactions with the companion star (black hole mass, 3-20 solar masses) ⁸

Isolated stellar-mass black holes [Table – 2]

Detectable due to gravitational lensing of background light (black hole mass, 3-20 solar masses) ⁸

Cygnus X-1

Located in the constellation of Cygnus, the swan, it was discovered in 1970s by the Uhuru X-ray satellite. Since it was the first X-ray source to be discovered in the constellation of Cygnus, it was given the designation of Cygnus X-1. A binary star system, its visible orbiting companion is a B0 supergiant known as HDE 226868 with a surface temperature of 3.1 x 104K. Its spectral line indicates that HDE 226868 has an orbital period of 5.6 days. The unseen companion however, is too dim to yield it’s own set of spectral lines. From what we understand of supergiant stars, HDE 226868 is estimated to have a mass of 30 solar masses. We can therefore infer that the mass of its unseen companion to be about 7 solar masses. Because 7 solar masses it dim far too for it to be a white dwarf or a neutron and also from the fact that it does not emit any visible light, it is likely that the unseen companion could be a black hole. We are not totally sure if it could be a black hole because the mass of HDE 226868 is only estimated to be at 30 solar masses. For its spectral class, it could have a lower mass, which would mean that its unseen companion might be a neutron star ⁹.

V404 Cygni

This is probably the best candidate as a stellar-mass black hole. The binary star system yields a visible orbiting companion is estimated to be a main-sequence F0-K2 star. Doppler shift measurements indicated an orbit of 6.47 days, which puts its unseen companion an estimated mass of 6.26 solar masses. Much bigger then a white dwarf or a neutron star, we can conclude with a high degree of certainty that the unseen companion is a black hole ⁹.

A0620-00

At a distance of a mere 2,700 light years, this binary star system black hole candidate is our closest known black hole. Flaring twice in the last century, 1917 and in 1975, its second flare was detected by the orbiting British Ariel 5 satellite hence it’s A reference. Visual observations of its visible companion shows that it is an orange K5 main-sequence star with an orbit of 7.75 days. Since its visible star is relatively faint, scientist were able to observe the spectral lines of visible companion and its X-ray source. Thus, it is estimated that the mass of the X-ray source is between 3.2 solar mass and 9 solar mass ⁹.

X-ray sources from a black hole

As surrounding materials and gases from a companion star goes into the accretion disk around a black hole, friction from collisions between the particles and gases heats up as angular momentum causes it spirals into the black hole to a temperature reaching 2 x 106K. This produces X-rays that flicker or vary in intensity within a second after which they disappear beyond the event horizon. Satellites such as the Chandra X-Ray Observatory detect these X-rays. The rate of X-ray emitted is highly variable and irregular up to one-hundredth of a second. Since nothing can travel faster then the speed of light, the X-rays that are emitted around the object cannot be larger then 3000km across ¹⁰.

In Conclusion

In this essay, I have discussed on the various methods used at present to aid in the detection of black holes through indirect observations. This includes observing a black hole candidates effects on its surroundings in the form of accretion disks and gas jets. We have also discussed on observations of gravitational lensing and the use of sensitive detectors like laser interferometer and resonant detectors to detect gravitational waves. I briefly discussed on stellar-mass black holes within our Milky Way that scientist have identified so far, either from observations of binary star systems or by gravitational lensing. And how the interaction of particles and gases in accretion disks emits X-rays, which we can detect.

References

1. Thorne, Black Holes and Time Warps, pp 349 ~ 350
2. Freedman & Kaufman, Universe 7th Edition, pp 531, 546
3. Don Nardo, Black Holes, pp 46 ~ 47
4. Freedman & Kaufman, Universe 7th Edition, pp 600 ~ 601
5. Freedman & Kaufman, Universe 7th Edition, pp 538 ~ 539
6. The Gravitational Wave Community
7. Gamma-Ray Bursts: Introduction to a Mystery
8. List of black hole candidates
9. Freedman & Kaufman, Universe 7th Edition, pp 540, 541
10. Freedman & Kaufman, Universe 7th Edition,, pp 540

Illustrations in this essay are works of the author. HET 603 Essay.

I hooped over to the site and was asked for the serial number of the battery, apparently only certain batches are entitled for a free replacement. As luck would have it, mine was entitled to the exchange! So duly filled up the form and waited. From my last experience in getting delivery from Apple, it wasn’t the 3~5 days as stated. But to my surprised, got it today. Just 3 days after I submitted.

A week has past now and I finally received my package from Apple. Much to my delight the pakaging was simple as I would have preferred it to be. On the online Apple Store, I made the purchase with an engraving on the iPod in her name, it also comes with a nifty card which I duly filled out.

G loves to take long walks alone to have some solace and some reflection. I hope with this little box of sounds, that it’ll accompany on her sojourns, to inspire and add harmony to her journeys.

p/s : Sorry for the poor image quality. My Nokia camera just doesn’t cut it.

Though we chatted, I never fully gotten to know Bernard well. But suffice to say, as would all who knew him, he was a good and decent man. It doesn’t take long to know that he has a heart of gold and a willing penchant to help. With spoken words, it was all to easy to know that he has sincerity in his words. The last I spoke to him was on the 5 July 2007. I missed my ride to range and chanced upon him and we exchanged the usually pleasantries.

Though I knew him only at the surface, hardly knowing his full worth. I was deeply saddened to hear of his demise. Somehow, I just feel really down because he was truly a good man. My hear goes out for his widow for she has certainly lost a precious one.

So here’s to you Bernard, may we meet again up there and have a long and good chat.

I didn’t get to go to range on the third day though, much to my disappointment. I had to skip training and head down to HDB to handle some stuff. Though I advocate peace I love shooting. This year during the IMT range on the first day, I decided to adopt some tips I watched on discovery channel. Much to my surprised it worked! Off course this may not apply to everyone but I guess it worked for me. I didn’t missed a target and all my rounds found its mark. My MPI was 4.4cm at 100m! So here’s some things I do consider important for rifling and shooting.

• Find your own comfort position when shooting. If it differs from what your commanders tell you, so be it. You are your own shooter.
• When adjusting, shift your hips, not your arms. This slight difference is pretty obvious through your sights.
• Breath deep. Breath half out and hold when firing
• Leave both eyes open until you’re ready to fire. Do this for every shoot, this reduces eye fatigue and is especially good during night shoots
• Have enough butt pressure to your shoulders, never more. Find the sweet spot

Well, that served me well enough I guess. Only 2 more years of reservist to go before I’m let off from this national duty. On reflection I guess I would miss it. Sure, most if not all of us would find it a waste of time. But that’s cause its a need to defend, not a want to serve. Its kinda fun to let your hair down away from work and to switch to the ‘national dialect’ hokkien once in a while.

While we did our trainings, I observe with some measure of admirations of my fellow platoon mates and extending to the rest of the battalion for that matter. We’ve all move along so much in life. So many are fathers now. We had a survey in which one of the questions was, “Would you die in the defense of your country.” (Or something to that extend). I’m not too sure what the survey to that question would yield. I suspect most of us would say “SIAO!” I reckon if they change the question to “Would you die defending your family and love ones” it would certainly yield a different answer. Cause I would equate defending my country to defending my family in times of a crisis. But that’s just me.

I look and wonder will we ever be put to the test. I pray we never will but should we be called, it would break my heart to ever see any of my mates fall. Therefore, should we be called, we’d better kick ass.

Thank you for making the effort in creating a barrier free environment here in Singapore. It would be great if BCA engage The Society of the Physically Disabled and the Singapore Association of the Visually Handicap as consultants to this project. Rather then just get their feedback, work with them, perhaps even paying them for consultation services and let them try the access methods that are current and future models. These Hands On feedback will be invaluable to BCA in formulating plans and policies. I had on one occasion, tried using a wheelchair to wheel myself up on a ramp constructed in a HDB estate and I have to say it was incredibly difficult even for a able bodied person like myself. Even my fiancee’s aging father had to get off his wheelchair to walk himself up. The inclines are just to great regardless of expert opinion. So please, try very hard to engage these disabled people, along with your executives and go to the ground and try it out.

Also, although it might not be in BCA’s purview, perhaps you might like to recommend and influence for a more stringent policy on people who park or block at designated disabled lots which is unfortunately pretty indiscriminate now.

I’ve often find ‘expert opinions’ for construction of buildings and areas very wanting. It would be great if they followed Professor Tommy Koh’s ‘friendly advice’ and sit in a wheelchair for a day to feel what its like. If ramps are constructed, it seems to me that its done just for the sake of it, like making a statement that its handicap friendly. Often, they are too steep and/or the areas leading to them aren’t too accessible.

It would be great if some business model can be made from consulting The Society of the Physically Disabled and the Singapore Association of the Visually Handicap. That way, real practical advice and feedback can be solicited and they can earn some well needed cash.