100 old grams are 0.1 new kilograms

 

We visited a new 100 Gramm Bar with Russian tapas and cocktails with vodka based infusions. As 100 gram is a standard unit of measurements for drinks in Russia in following discussion we explain the history of standardization of the units of measurements and how these units were tied to the constants of nature in the modern times.

What?

Bar 100 Gramm

Location

Weinbergsweg 25

Prices

9-10 €/cocktail

 

 

Introduction

100 Gramm is a new bar in Russian or US-American style close to Rosenthaler Platz. Why Russia or US? Because in this bar you can order food. This is common in these two huge countries, however there are not many bars in Berlin, where it is possible. It has some advantages as you can have a dinner and continue with drinks after or you can satisfy your cravings after a second cocktail immediately while having a third one. The food is Russian signature food reinvented as tapas. It is delicious and can be served together with infusions (e.g. garlic-infused vodka).

The cocktail card consists of 4 parts – you can choose between cocktails and longdrinks as well as between classic or signature drinks. The signature drinks are mostly made with infusions based on vodka, however also some of the classic cocktails are served with twist.

The price of the cocktails is moderate and however some of the cocktails remind a visitor on the “little black dress” – beautiful to contemplate, but short on the substance. In the end you might end up ordering more than usual cocktails during the evening and end up in the same condition. Even though the service is nice and corteous it is not exactly fast, which, combined with the size of some drinks, can leave you dry for some time.

The owner invested in interior design in contrast to many bar in Berlin. The marmor plate at the bar, the lights and the tables make an impression, the bar is however not flamboyant or glamorous. We will recommend it to anyone, who has some time and wants to enjoy quality drinks and food in a pleasant atmosphere.

Discussion

Do you know that feeling? You are about to cook something – maybe your remember a great dish your grandma used to cook or maybe your New Year’s Eve resolution was to change your eating habbits and now you looked up a new great and healthy recipe. But of course the recipe provides the measuremets in cups, as it was uploaded by a funky Instagram guru from California (for our readers from US – just imagine it vice versa). In this situation you will have to convert the volume of an ingredient to its mass in gram, so your can weight it. Of course you will have to take in account a difference in density of each type of food and, even if you have a measuring cup at home, it can be US american (240 ml) or Common Wealth cup (250 ml). Cup also is a part of the Imperial measurements system, where lot of units (inch, foot, mile, gallon etc.) derived from common dimensions are included. The units of length for example originated from the body dimensions, which was already the case in Ancient Egypt or Ancient Greece.

It is for sure fun to have a diverse system of measurements, which varies depending on which foot or cup you have available, but it hits it’s limits, if you want to do international trade or sientific measurements. Especially for the last purpose a system with simple and logical conversion to increasing and decreasing values is of high significance. However it was international trade, which started the unification of the measurement system. The birth of the metric system is assigned to the 7th of April 1795 as the 6 basic units – metre, are, stere, litre, gramme, franc – were assigned to the decimal system based on suggestions of the Academie des sciences. This six units replaced over 800 units, which were used for trade by the Ancien Regime. Additionally the decimal parts of the basic units were defined as milli-, centi-, deci-, deka-, hecto-, kilo- and myria-.

Only two units of the French decimal system went on to be a part of the modern metric system – the meter and the kilogram. However already on the 7th of April 1795 these two units were defined based on nature phenomenons. Metre was defined as one ten millionth of the distance between North Pole and Equator through Paris and the gramme, upon which the kilogramme was based, as “the absolute weight of a volume of pure water equal to a cube of one hundredth of a metre, and at the temperature of the melting ice” [BIPM2019].

On 19th May of 2019 the world was redefined. To be exact the definition of the reference unit for the weight: the kilogram, was tied to the Planck constant. The prototype of the kilogram, sometimes known as “the grand k”, was stored in a safe in Paris and all the states – members of SI community received a copy. The copies were exact, however with time the copies got heavier than the reference. In 2019 this difference was as high as 50 micrograms, which is already quite significant e.g. for medicine. As a solution to this problem it was decided to redefine the kilogram based on a value, which is measurable with high precision and doesn’t change with time and space [PTB2019].

Planck constant is such a value. It establishes the relationship between the energy and the frequency of a photon in quantum mechanics by equation E = h · f and could be measured with precision up to 10th numerical position (h = 6.626070040(81) · 10-34 Js). The uncertainty is given due to the uncertainties of the measurements and basic units, such as the kilogram. However, starting with 20th of May 2019, the chain of measurement was reversed. The kilogram was redefined based on Planck constant with value exactly h = 6.62607015 · 10-34 Js.

The kilogram was therefore redefined as 1 kg = h · s2 / m2, where second and meter are defined based on the distance traveled by light in a second and the frequency of 133Cs atom. This definition is more complex as the previous one, but as it is based on nature constants only, it is much more precise [IJMQE2016].

There are two ways to measure kilogram experimentally – 1) with Kibble balance [Metrologia2016] or 2) with Silicium sphere [PTB2018].

  1. The Kibble balance equalizes the weight with electrical force. Here the mass is placed on top of the plate, which is placed on a conductor, formed into a coil, in a static magnetic field. If an electric current with high enough strenght is send through this conductor, it induces an magnetic field, which can balance out the weight of the mass. The current is then connected to the Planck constant and quantum mechanics through the unit Ampere.
  2. To measure the kilogram with help of a silicium sphere a perfect sphere made out of pure single crystal silicium has to be manufactured. In fact silicium was chosen, as it can be formed to a perfect single crystal sphere. This spheres consist to 99.999% of 25 · 1024 28Si Isotop atoms and are 93.7 mm in diameter. The exact number of the atoms and the lattice parameters are connected with the Planck constant, which can be extracted from the exact number of the atomsin the sphere.

You can find further information of the SI-units and how measure them in praxis at the homepage of Bureau International des Poits et Mesures.

Summary

100 Gramm Bar is an Russian style upscale bar close to Rosenthaler Platz. The name and the quantities of the food and drinks inspired us to look closely as the topic of precise measurements, which are nowadays based on SI-units tied to the constants of nature.

References

  1. The International System of Units (SI), Bureau International des Poids et Mesures (2019)
  2. Luca Mari, Peter Blattner, Franco Pavese. Improving the understandability of the next edition of the International System of Units (SI) by focusing on its conceptual structure (2017)
  3. F. Pavese, A. Charki. Some important features of the proposed new definition of theInternational System of Units (SI): realization and hierarchicalproblems that the users should know about. International Journal of Metrology and Quality Engineering (IJMQE) 7:403 (2016)
  4. I. A. Robinson, S. Schlamminger. The watt or Kibble balance: a technique for implementing the new SI definition of the unit of mass. Metrologia 53:56-74 (2016)
  5. www.ptb.de. Physikalisch-Technische Bundesanstalt (2018)
  6. www.ptb.de. Physikalisch-Technische Bundesanstalt (2019)

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