Why We Want to Redefine Kg???

What we call a kg might soon change in future.? Yes you heard right, a substantial change to the International System of Units (SI) is currently under discusstion and might be a reality by 2019. The General Conference on Weights and Measures (CGPM) is scheduled to have its 26th meeting in 2018 and will likely vote on a proposal put forward by the International Committee for Weights and Measures (CIPM) to revise the SI. According to this proposal, the structure of the SI will change fundamentally. The present SI is built upon seven base units: the metre, the second, the kilogram, the ampere, the kelvin, the mole, and the candela. The goal of the new SI is to define all of these units completely in terms of fundamental constants with exact values. Some constants, such as the speed of light, are currently defined in this way, as exact quantities.

At present, the kilogram is the SI unit of mass and is equal to the mass of the international prototype of the kilogram which is an artefact, not a constant of nature. The kilogram is the only SI unit still based on a physical object. The kilogram will be defined in terms of a quantum-mechanical quantity known as the Planck constant (h) which will be assigned an exact fixed value based on the best measurements obtained worldwide.

The International Prototype Kilogram(IPK) or “Le Grand K” or “Big K” is the palm-sized platinum and iridium cylinder that for 126 years has defined the kilogram from a high-security vault outside Paris where it was protected from dust, moisture, fingerprints, and other corruptions of the outside world and was hailed as the “perfect” kilogram”. Since hydrocarbons on fingertips or moisture in the air could contaminate its pristine surface, it goes untouched for decades, under triple lock and key at the International Bureau of Weights and Measures. Every 40 years, the weight is ushered from its chamber, washed with alcohol, polished, and weighed against 80 official replicas hand-delivered from laboratories around the world.

It is seen that world’s most perfect weight isn’t so perfect anymore. In its most recent weigh-in in 1988, it was found to be 0.05 milligrams,about the weight of a grain of sand, lighter than its underling replicas. But Le Grand K’s guardians are not sure if it is Le Grand K that has slimmed, or whether its comparators have gained weight. Whatever is right ,its not good for a standard to change. You may think why should we care whether a kilogram in a vault is “perfect” or not? We must, as a small discrepancy can become a gargantuan one if you’re dealing with a large quantity, for eg. a full tanker of Rice. Also the kilogram is used as a building block in other measurements. As in the case of the joule( the amount of energy required to move a one-kilogram weight one meter) and candela, a measure of the brightness of light, is measured in joules per second. Therefore if the kilogram is flawed, so are the joule and candela, which could eventually cause problems in an array of industries, particularly in technology.

The slighter instability of big K is unacceptable in precise fields like medicine or engineering, where tiny differences can cause immense problems. Therfore a more reliable standard has to be defined for measuring kg. For instance, the meter, which was originally represented by a metal bar, was redefined in 1983 as the distance light travels in a vacuum during 1/299,792,458 of a second. However standardizing the kilogram is little trickier as the standard could not be changed physically due to environmental changes, accidental damage, or even sabotage. To overcome such risks and also to improve our system of units, we need a definition that depends on nothing other than the value of a fundamental constant, e.g. the Planck constant h, a fixed quantity linked to E=MC2 and quantum theory that specifies the amount of energy carried by a single particle of light, or photon.

To be continued....

Babies & Vaccination

As a parent, everyone wants best for their children. Protecting your child's health is one of your main concerns. So most of us choose to vaccinate children to prevent previously devastating, widespread disease by significantly reducing childhood infection rates. Vaccines not only help keep your child healthy, they help all children by stamping out serious childhood diseases.

We may often wonder why vaccines are given at such an early stage?? Its because the diseases they prevent often strike at an early age. Since their immune systems are not yet fully mature and also their stomachs produce less acid, making it easier for ingested bacteria and viruses to multiply. These factors leave them more susceptible than older kids and adults to the devastating effects of these serious diseases. Infants need 2-5 doses of each recommended vaccine. Each dose increases your baby’s protection against a specific disease. For the earliest and best protection, your baby needs to complete each vaccine series on time.

Next Question is whether your infant's immune system can handle all the vaccines. The truth is that infants can respond to multiple vaccines, which play a vital role in helping their immune system avoid diseases. Babies may get some temporary immunity (protection) from mother during the last few weeks of pregnancy, but only for the diseases to which mom is immune. Breastfeeding may also protect your baby temporarily from minor infections, like colds. These antibodies do not last long, leaving your baby vulnerable to disease. Natural immunity occurs when your child is exposed to a disease and becomes infected. It is true that natural immunity usually results in better immunity than vaccination, but the risks are much greater. A natural chickenpox infection may result in pneumonia, whereas the vaccine might only cause a sore arm for a couple of days.

Vaccines are made from the same germs (or parts of them) that cause disease; for example, polio vaccine is made from polio virus. But the germs in vaccines are either killed or weakened so they won’t make you sick. Vaccines containing these weakened or killed germs are introduced into your body, usually by injection. Your immune system reacts to the vaccine in a similar way that it would if it were being invaded by the disease i.e. by making antibodies. The antibodies destroy the vaccine germs just as they would the disease germs like a training exercise. Then they stay in your body, giving you immunity. If you are ever exposed to the real disease, the antibodies are there to protect you.

Vaccines, like any medication, may cause some side effects. Most of these side effects are very minor, like soreness where the shot was given, fussiness, or a low-grade fever. The se side effects typically only last a couple of days and are treatable. For example, you can apply a cool, wet washcloth on the sore area to ease discomfort. Serious side effects following vaccination, such as severe allergic reaction, are very rare and doctors and clinic staff are trained to deal with them. The disease-prevention benefits of getting vaccines are much greater than the possible side effects for almost all children.
Some people have suggested that thimerosal (a compound that contains mercury) in vaccines given to infants and young children might be a cause of autism, and others have suggested that the MMR (measles- mumps-rubella) vaccine may be linked to autism. However, numerous scientists and researchers have studied and continue to study the MMR vaccine and thimerosal, and reach the same conclusion: that there is no link between them and autism. 

Getting every recommended dose of each vaccine provides your child with the best protection possible. Depending on the vaccine, more than one dose is needed to build high enough immunity to prevent disease, boost immunity that fades over time, make sure people who did not get immunity from a first dose are protected, or protect against germs that change over time, like flu. Every dose of a vaccine is important because they all protect against infectious diseases that are threats today and can be especially serious for infants and very young children.

The recommended schedule is designed to protect infants and children by providing immunity early in life, before they are exposed to life-threatening diseases. I prefer and advise every parent to vaccinate as the consequences of these diseases can be very serious, and even life-threatening, for infants and young children. For more information about vaccination in India, click here.