Scientific Principles: Space, Energy, and Human Biology

Posted on Mar 9, 2026 in Biology

Pakistan’s Space and Nuclear Program

Functions of Rockets

In the third stage, the payload takes the place of instruments or humans. The payload may be a man-made satellite designed to orbit the Earth, a probe carrying instruments to explore space, or a spacecraft with astronauts heading to conduct research on other planets.

Satellites and Their Functions

Artificial satellites are man-made objects sent from Earth to orbit the planet via rockets. These objects must maintain a speed of almost 8 km/s.

Functions of Satellites:

  • Data Collection: Information is sent back via radio transmitters. Optical and other sensing instruments collect data such as magnetic fields and radiation from the sun and space.
  • Meteorology: Satellites transmit weather information; video cameras capture cloud images to send back to Earth.

Space Shuttles

A space shuttle is a spacecraft designed for transferring humans and cargo between Earth and orbit. The first space shuttle was developed in the 1970s to serve as a reusable rocket and spacecraft.

Functions and Uses:

  • Deploying satellites into orbit.
  • Carrying scientific experiments.
  • Conducting military missions.
  • Repair and maintenance of orbiting satellites.
  • Returning previously deployed spacecraft to Earth.

The cargo bay is adaptable to hundreds of tasks, carrying spacecraft and scientific laboratories for the modular space lab system. It serves as a workstation for astronauts to perform repairs.

Remote Sensing and Environmental Science

  1. Remote Sensing and Application (RSA) Division: Engaged in the dissemination of satellite remote sensing (SRS) data, research, and demonstration studies using GIS technology for mapping and environmental monitoring.
  2. Environmental and Space Science: Involved in research and application programs relating to space and atmospheric science and satellite meteorology.
  3. Ionospheric Research (IR) Division: Engaged in research studies concerning the ionosphere.

Pakistan’s Nuclear Program

Pakistan started its nuclear program for the benefit of humanity. The commission’s program is formulated on three main objectives, primarily focusing on nuclear power for economic development.

Physics and Electrical Engineering

Basic Electrical Concepts

  • Electric Current: The rate of flow of electric charge through a conductor. Its SI unit is the ampere (A).
  • Electric Resistance: The opposition offered by a conductor to the flow of electric current. Its SI unit is the ohm (Ω).
  • Ohm’s Law: At a constant temperature, the current flowing through a conductor is directly proportional to the potential difference across its ends (V=IR).
  • Ohm Definition: One ohm is the resistance of a conductor when a potential difference of 1 volt produces a current of 1 ampere through it.

Capacitors and Transformers

  • Capacitor: An electrical device used to store electric charge and energy, consisting of two metal plates separated by a dielectric. In D.C. circuits, it blocks current after charging; in A.C. circuits, it allows current to pass.
  • Transformer: A device used to increase or decrease A.C. voltage based on the principle of mutual induction.

Electrical Safety

  • Common Dangers: Electric shock, short circuits, fire, appliance damage, and burns.
  • Safety Suggestions: Avoid touching switches with wet hands, use proper insulation, avoid overloading sockets, and use fuses.
  • Fuses: Used to protect appliances by melting and breaking the circuit during excessive current flow.

Galvanometers

  • Working: A sensitive instrument used to detect small currents. The coil deflects when placed in a magnetic field.
  • Conversion: A galvanometer becomes an ammeter with a parallel low-resistance shunt, or a voltmeter with a series high-resistance.

Environmental Science

Atmosphere and Pollution

  • Atmosphere: The layer of gases surrounding Earth. Composition: Nitrogen (78%), Oxygen (21%), Carbon dioxide (0.03–0.04%), and trace gases.
  • Layers: Troposphere, Stratosphere (ozone layer), Mesosphere, Thermosphere, and Exosphere.
  • Global Warming: Caused by greenhouse gases from fossil fuels, deforestation, and industrial pollution.
  • Air Pollution: Contamination by CO, CO₂, SO₂, and smoke.
  • Water Pollution: Caused by industrial waste, agricultural runoff, and sewage.

Agriculture and Ecosystems

  • Coal Formation: Formed from buried plant remains under heat and pressure. Types: Peat, Lignite, Bituminous, and Anthracite.
  • Crop Production: Main crops include wheat, rice, cotton, and sugarcane. Production is boosted by better seeds, irrigation, and fertilizers.
  • Ecosystem: A system formed by the interaction of living organisms and non-living components in a specific area.
  • Deforestation Effects: Soil erosion, floods, loss of wildlife, and climate change.

Human Biology and Nutrition

Food Components

  • Carbohydrates: Energy (Rice, wheat).
  • Proteins: Growth and repair (Meat, beans).
  • Fats: Stored energy (Butter, oil).
  • Vitamins & Minerals: Disease protection and body functions.
  • Water: Digestion and temperature regulation.

Vitamins and Glands

  • Water-Soluble Vitamins: Vitamin B (energy/nerves) and Vitamin C (immunity/healing).
  • Endocrine Glands: Pituitary (growth), Thyroid (metabolism), Adrenal (stress), Pancreas (blood sugar), and Gonads (reproduction).

Digestion and Blood

  • Fat Digestion: Occurs mainly in the small intestine via bile emulsification and pancreatic lipase.
  • Blood Composition: Plasma (55%) and blood cells (45%).
  • Blood Cells: RBCs (oxygen), WBCs (immunity), and Platelets (clotting).