Curiosity Tea ☕️

​​What is déjà vu?

The term déjà vu is French and means, literally, "already seen." Those who have experienced the feeling describe it as an overwhelming sense of familiarity with something that shouldn't be familiar at all. Say, for example, you are traveling to England for the first time. You are touring a cathedral, and suddenly it seems as if you have been in that very spot before. Or maybe you are having dinner with a group of friends, discussing some current political topic, and you have the feeling that you've already experienced this very thing, same friends, same dinner, same topic.

As much as 70 percent of the population reports having experienced some form of déjà vu. A higher number of incidents occurs in people 15 to 25 years old than in any other age group.

Déjà vu has been firmly associated with temporal-lobe epilepsy. Reportedly, déjà vu can occur just prior to a temporal-lobe seizure. People suffering a seizure of this kind can experience déjà vu during the actual seizure activity or in the moments between convulsions.

​​​​What is TDS in water? How TDS meter works?

Total dissolved solids (TDS) are the amount of organic and inorganic materials, such as metals, minerals, and ions, dissolved in a particular volume of water. When a solvent, such as water, encounters soluble material, particles of the material are absorbed into the water. TDS in water can come from just about anywhere, including minerals in springs from a water source, chemicals used to treat the water supply from sewage systems, runoff from road salts and yard chemicals or fertilizers, even the plumbing in your home.
Testing your water using a TDS meter is the easiest way to measure for total dissolved solids. Some filtration systems are equipped with a TDS meter to monitor the levels periodically.
A TDS meter is a small hand-held device used to indicate the Total Dissolved Solids in a solution, usually water. Since dissolved ionized solids, such as salts and minerals, increase the conductivity of a solution, a TDS meter measures the conductivity of the solution and estimates the TDS from that reading.
Total dissolved solids (TDS) is measured as a volume of water with the unit milligrams per liter (mg/L), otherwise known as parts per million (ppm). According to the EPA secondary drinking water regulations, 500 ppm is the recommended maximum amount of TDS for your drinking water. Anything measurement higher than 1000 ppm is an unsafe level of TDS. If your TDS reading exceeds 2000 ppm, then a filtration system may be unable to handle it.

​​What is Carbon dating?

Carbon dating is a method used to determine the age of organic materials that are up to around 50,000 years old.

It is based on the fact that all living organisms contain a small amount of radioactive carbon-14 (14C), which is formed in the atmosphere when nitrogen-14 is bombarded with cosmic radiation.

When an organism dies, it stops taking in new carbon-14, and the existing 14C begins to decay at a steady rate, with a half-life of approximately 5,730 years.

By measuring the amount of 14C remaining in an organic sample, scientists can calculate how long ago the organism died.

Carbon dating is widely used in archaeology, anthropology, and geology to date ancient artifacts, human remains, and geological events.

However, it has limitations, such as the need for organic material and the assumption that the sample has not been contaminated with modern carbon.

​​What is OCR (Opitcal Character Recognition)?

OCR (Optical Character Recognition) is a technology that converts different types of written or printed text, such as scanned documents, images, or PDFs, into machine-readable text. It allows computers to recognize and process characters (letters, numbers, and symbols) from images or physical documents.

How OCR Works:

Image Preprocessing: First, the input (like a scanned document) is cleaned to improve accuracy. This involves noise reduction, deskewing (aligning the text), and binarization (converting the image to black and white).
Text Detection: OCR identifies the regions containing text, separating them from other parts like images or diagrams. It then breaks down the text region into smaller units like lines, words, and finally, individual characters.
Character Recognition:
Pattern Matching: The OCR engine compares characters in the image with pre-stored character patterns. For example, it identifies shapes and matches them with a database of fonts and letters.
Feature Extraction: This method breaks each character into features (e.g., curves, lines) and recognizes it based on the structure, even if the font or style differs.
Post-Processing: OCR uses language models to improve accuracy by checking word predictions based on context, grammar, and common usage.

Applications:
Digitizing printed books to make them searchable.
Converting business documents like invoices into digital formats.
Reading text from images for accessibility tools, such as screen readers.

​​Why does the Earth have a magnetic field?

The Earth's magnetic field is generated by the movement of molten iron and other metals in the Earth's outer core.

This movement creates electric currents, which in turn produce the magnetic field. The process is known as a geodynamo.

The Earth's core is divided into two layers: a solid inner core and a liquid outer core. The outer core is about 2,250 kilometers (1,400 miles) thick and is composed of molten iron and nickel. The movement of this molten metal is caused by heat from the Earth's interior and the decay of radioactive elements.

As the molten metal moves, it creates electric currents through a process called electromagnetic induction.

These currents generate a magnetic field, which is strong enough to extend from the Earth's core to the surface and even into space.

​​What are Insectivorous Plants?

Insectivorous plants, also known as carnivorous plants, are a group of plants that derive some or most of their nutrients by trapping and consuming insects or other small animals. These plants typically grow in nutrient-poor environments, such as bogs and wetlands, where the soil lacks sufficient nitrogen or phosphorus. To supplement their nutrient intake, they have evolved specialized structures to trap prey.
Insectivorous plants digest insects through specialized enzymes or bacterial activity that break down the prey into absorbable nutrients.

Here’s how the process generally works:
Trapping: The plant first traps the insect using various mechanisms like snap traps (Venus flytrap), pitfall traps (pitcher plants), sticky traps (sundews), or suction traps (bladderworts).
Secretion of Digestive Enzymes: Once the prey is captured, the plant secretes digestive enzymes, such as proteases and phosphatases, or hosts symbiotic bacteria that aid in digestion. These enzymes break down the insect’s soft tissues into simpler compounds like amino acids, nitrates, and phosphates.
Absorption of Nutrients: After the insect is broken down, the plant absorbs the released nutrients through its specialized leaf tissues. The nutrients, especially nitrogen, phosphorus, and other minerals, are then used to support the plant’s growth and development.
Excretion: The indigestible parts of the prey, such as exoskeletons or other hard remains, are either washed away by rain (in the case of pitcher plants) or remain in the trap until it reopens and the remnants fall or blow away (as with Venus flytraps and sundews). In bladderworts, the empty remains are expelled when the bladder resets itself for the next capture.
Examples include Venus Flytrap, Pitcher Plants, Sundrews.

​​Why Lightning and Thunder Occur in Clouds?

Lightning and thunder are complex atmospheric phenomena involving electrical processes. Thunderstorms typically form in cumulonimbus clouds, which develop when warm moist air rises, forming tall vertical structures. Inside these clouds, updrafts and downdrafts cause collisions between water droplets and ice crystals, leading to triboelectrification—a process that separates charges.

The upper part of the cloud (above 10 km altitude) becomes positively charged as smaller ice crystals are lifted, while the lower part (below 5 km) becomes negatively charged due to heavier water droplets. This charge separation creates a strong electric field between the cloud and the ground, most intense near the cloud’s base.

As the electric field strengthens, a leader stroke, a narrow channel of ionized air, forms from the cloud toward the ground. The leader stroke, about 1-2 cm in diameter, is negatively charged and follows the path of least resistance. Once the leader stroke connects with the ground, a return stroke of positive charge surges back through the channel. This is the bright flash we see as lightning, which can reach temperatures of up to 30,000°C, hotter than the sun’s surface.

The return stroke’s immense speed, about 270,000 km/h, heats the surrounding air, creating a shockwave. This rapid air expansion causes the sound of thunder. Since sound travels slower than light, the thunder is heard after the lightning flash. By timing the interval between the two, we can estimate the lightning’s distance.

Several factors influence lightning formation including humidity which increases storm intensity, wind which can disperse charges, topography as mountains force air upward, and weather fronts which create instability leading to storms. These conditions together drive the dramatic displays of lightning and thunder.

​​What is LiDAR technology? What are its applications?

LiDAR (Light Detection and Ranging) is a remote sensing technology that uses laser light to measure distances and create detailed, high-resolution 3D maps of environments. It works by emitting laser pulses, which bounce off objects and return to the sensor. The time it takes for the light to return is used to calculate the distance between the sensor and the object. LiDAR can operate in different wavelengths, such as near-infrared or ultraviolet, depending on the application.

How LiDAR Works:

Laser Pulse Emission: The system sends out laser pulses.
Reflection: The pulses hit objects (buildings, terrain, vehicles, etc.) and reflect back.
Detection and Calculation: The sensor measures the time taken for the light to return and calculates the distance to the object.
Data Processing: The system compiles data to create a 3D point cloud representing the shape and distance of objects in the environment.

Applications of LiDAR:

Autonomous Vehicles: LiDAR is used in self-driving cars to map the surrounding environment, detect obstacles, and navigate safely. It provides real-time 3D mapping to assist in decision-making for autonomous systems.
Surveying and Mapping: LiDAR is widely used in topographic mapping, creating detailed 3D models of terrain, buildings, and other infrastructure. It helps in applications like urban planning, construction, and archaeology.
Forestry and Agriculture: In forestry, LiDAR helps in assessing canopy heights, biomass, and tree density. In agriculture, it aids in precision farming by monitoring crop growth and analyzing terrain for water drainage.
Geology and Seismology: LiDAR is used to map faults, landslides, and terrain changes, providing valuable data for earthquake risk assessment and other geological studies.
Aerial and Drone Mapping: LiDAR-equipped drones are used for surveying large areas quickly, which is useful in applications like disaster response, mining exploration, and infrastructure inspection.
Urban Planning and Smart Cities: LiDAR is used to create 3D models of cities, helping in traffic management, infrastructure planning, and designing smart city solutions.

​​What are Security Mirrors?

Security mirrors are convex mirrors designed to improve visibility in areas where surveillance and safety are important. They are often used in places like retail stores, warehouses, parking lots, and intersections to reduce blind spots, monitor activity, and prevent accidents or theft.

Convex Shape: Security mirrors are typically convex, meaning they have a curved, outward-bulging surface. This shape allows them to provide a wide-angle view, enabling someone to see around corners, monitor large areas, or observe places that are difficult to see directly.

Wider Field of View: The convex design reflects light in a way that covers a broader area than a flat mirror would. This lets you see more of the surroundings, making them ideal for monitoring blind spots or areas that would otherwise be obscured.

Security mirrors are used at blind corners or intersections in buildings, driveways, or parking lots to help prevent accidents by allowing drivers or pedestrians to see oncoming traffic.
In retail stores or warehouses, security mirrors help staff monitor areas that are out of their direct line of sight, making it easier to deter shoplifting or ensure safety in large spaces.

​​How 3D movies are produced?

A 3D movie is a motion picture that enhances the illusion of depth perception by employing stereoscopic film techniques. This is achieved by recording images from two slightly different perspectives, mimicking the way human eyes perceive depth and form a three-dimensional view of the world. When these images are simultaneously projected onto a screen and viewed through special glasses, the brain integrates them into a single three-dimensional image. 
Different cameras system used to record 3D movies.

Dual Camera Rig:
Two cameras mounted side by side or vertically to capture stereoscopic 3D images.
Mirror Rig:
Uses mirrors to redirect light to two cameras, creating a compact 3D camera system.
Integrated 3D Cameras:
Single cameras with dual lenses, like the Arri Alexa 3D or RED Epic 3D.

Technologies Used:

Stereoscopic 3D:
Captures two separate images, one for each eye.
Autostereoscopic 3D:
Captures multiple views, allowing for glasses-free 3D.
Light Field Technology:
Captures light intensity and direction for advanced 3D.

​​​​What is Cultured Meat?

Cultured meat is meat produced by in vitro cultivation of animal cells, instead of from slaughtered animals. It is a form of cellular agriculture.
Cultured meat is produced using many of the same tissue engineering techniques traditionally used in regenerative medicine.The concept of cultured meat was popularized by Jason Matheny in the early 2000s after co-authoring a seminal paper on cultured meat production and creating New Harvest, the world's first non-profit organization dedicated to supporting in vitro meat research.
The objective of this process is to recreate the complex structure of livestock muscles with a few cells. A biopsy is taken from a live animal. This piece of muscle will be cut to liberate the stem cells, which have the ability to proliferate but can also transform themselves into different types of cells, such as muscle cells and fat cells.
The cells will start to divide after they are cultured in an appropriate culture medium, which will provide nutrients, hormones and growth factors. The best medium is known to contain fetal bovine serum (FBS), a serum made from the blood of a dead calf, which is going to be rate-limiting, and not acceptable for vegetarians nor vegans. More than one trillion cells can be grown, and these cells naturally merge to form myotubes which are no longer than 0.3 mm; the myotubes are then placed in a ring growing into a small piece of muscle tissue as described in different reviews. This piece of muscle can multiply up to more than a trillion strands. These fibers are attached to a sponge-like scaffold that floods the fibers with nutrients and mechanically stretches them, “exercising” the muscle cells to increase their size and protein content.
Based on this process, fewer animals will be necessary to produce huge amounts of meat due to cell proliferation, thereby avoiding killing as too many animals but potentially lots of calves if FBS is still used.

​​Why Surgical Lamps don’t cast shadows?

Surgery lamps, also known as surgical lights or operating lights, are designed to provide high-intensity, focused lighting for surgeons during medical procedures.

One of the key features of these lamps is that they are designed to minimize shadows.There are several reasons why surgery lamps are able to reduce or eliminate shadows,

Multiple light sources: Surgery lamps often have multiple light sources, typically in the form of LEDs or halogen bulbs, that are arranged in a specific pattern. This allows the light to come from multiple angles, reducing the likelihood of shadows.

Diffusion: Some surgery lamps use a diffuser, which is a translucent or semi-transparent material that scatters the light in different directions. This helps to soften the light and reduce shadows.

Polarization: Some surgery lamps use polarized light, which can help to reduce glare and shadows. Polarized light is filtered to only allow light waves of a certain orientation to pass through, which can help to reduce reflections and shadows.

Beam shaping: Surgery lamps often have a beam-shaping system that allows the light to be focused and directed precisely where it is needed. This can help to reduce shadows by ensuring that the light is only illuminating the area of interest.

Shadow-reducing optics: Some surgery lamps use specialized optics, such as aspheric lenses or Fresnel lenses, that are designed to reduce shadows.

These optics can help to bend and shape the light in ways that minimize shadows.
Overall, the combination of multiple light sources, diffusion, polarization, beam shaping, and shadow-reducing optics all work together to help minimize shadows in surgery lamps.

​​Why are Printed Circuit Boards usually green in colour?

A ‘green’ printed circuit board is not actually green all the way through. The only green part is the outer covering of resin called the solder mask or solder resist/oil. This is a hardened resin with colored pigments that is applied to the boards in a silkscreen fashion. The purpose of solder mask is to protect the electronic traces underneath from moisture and dust and to control the flow of molten solder. The actual core of a typical FR-4 circuit board is a plain, dull, yellow color, but the solder mask can come in many colors such as blue, red, yellow, black and white. Even more exotic colors can be found for the extravagant such as orange, pink, purple, matte versions and even mixed color boards. So, the question remains, why green?
Green can relieve visual fatigue and aid in inspections.

Other colors may not provide sufficient contrast for component visibility.
Some colors can interfere with automated optical inspection (AOI) systems.
- High-frequency or high-power PCBs might use different colors (e.g., red or blue) for better thermal dissipation.
- Specialty PCBs, like those for medical or aerospace applications, may use unique colors.

The green color has become an industry standard, but advancements in materials and designs may lead to more varied color options.

What is the difference between cold-blooded and warm-blooded?

​​The main difference between warm-blooded (endothermic) and cold-blooded (ectothermic) animals lies in their ability to regulate body temperature:

Warm-blooded (Endothermic) Animals:

-Maintain constant body temperature: Regardless of environmental temperature.
-Generate heat internally: Through metabolic processes, like cellular respiration.
-Sweat to cool down: To regulate temperature when it gets too high.

Examples: Mammals (humans, dogs, bears), birds, and some fish (like sharks).

Cold-blooded (Ectothermic) Animals:

-Body temperature varies with environment: They absorb heat from their surroundings.
-Rely on external heat sources: Like sunlight, water, or air temperature.
-Bask to warm up: Expose themselves to heat sources to increase body temperature.

Examples: Reptiles (snakes, lizards, turtles), amphibians (frogs, toads), fish (most species), and insects.

Key differences:

- Thermoregulation: Warm-blooded animals control their temperature internally, while cold-blooded animals rely on external sources.
- Metabolism: Warm-blooded animals have a faster metabolism to generate heat, while cold-blooded animals have a slower metabolism.
- Activity levels: Warm-blooded animals can maintain activity levels regardless of temperature, while cold-blooded animals are often more active in warmer temperatures.

​​​​What is Cabin Pressure and Why do we need to maintain it in Aeroplane?

Earth's atmospheric pressure varies with altitude. At the Earth's surface(sea level) , It is measured at 14.7 pounds per square inch(P.S.I) - which human beings are accustomed to because it provides the optimum amount of Oxygen.
As Aeroplane ascends to higher altitudes, the atmospheric pressure decreases. There isn't oxygen to breathe and humans cannot survive more than a minute at such altitudes.In order to prevent this from happening , Cabin Pressure is maintained at appropriate levels.
To maintain the pressure in the cabin equal to that at low altitude, even while the airplane is at 30,000 feet, the incoming air is held within the cabin by opening and closing an outflow valve, which releases the incoming air at a rate regulated by pressure sensors. Think of a pressurized cabin as a balloon that has a leak but is being inflated continuously.

​​What is Narco Test?

A person is able to lie by using his imagination. In the Narco Analysis Test, the subject's imagination is neutralised by making him semi-conscious. In this state, it becomes difficult for him to lie and his answers would be restricted to facts he is already aware of.
Experts inject the subject with Sodium Pentothal or Sodium Amytal. The dose is dependent on the person's sex, age, health and physical condition. A wrong dose can result in a person going into a coma, or even death.
The subject is not in a position to speak up on his own but can answer specific but simple questions. The answers are believed to be spontaneous as a semi-conscious person is unable to manipulate the answers.
Sodium pentothal, or sodium thiopental, is a fast-acting, short-duration anaesthetic used in larger doses to sedate patients during surgery.
It belongs to the barbiturate class of drugs that act on the central nervous system as depressants.
Because the drug is believed to weaken the subject’s resolve to lie, it is sometimes referred to as a “truth serum” and is said to have been used by intelligence operatives during
World War II.

​​What’s the Difference Between Copyright and Copyleft?

Intellectual property is a valuable asset for your business and it’s important that you take the necessary steps to secure its protection. One type of intellectual property that a business can own is copyright. This gives the owner an exclusive right of the copyright material to reproduce, reuse and republish it. However, there is a school of thought that seeks to override copyright and allow anyone to modify specific pieces of work. This form of licensing is known as copyleft and is commonly used in relation to software development. 
Copyright- Copyright attaches automatically to original artistic works. Therefore, you don’t need to register the right. When an author or creator expresses the idea in material form, the work gains copyright protection. Accordingly, you don’t have to publish material work for it to be afforded protection under copyright law.
Copyleft- Copyleft, as the name suggests, heads in the opposite direction to copyright. Playing on the word ‘copyright’, copyleft overrides copyright and promotes the concept that materials should be:
freely used, copied and modified by others.
Copyleft also requires that all versions of the material that users modify are freely accessible so that others can use and modify it. 
The principles of copyleft are commonly used within the software industry, where source code is often free for anyone to modify.

​​Why so some lifters pass out from Heavy Deadlifts?

Weightlifting is an anaerobic exercise.
The reason lifters pass out is due to a phenomenon called orthostatic intolerance: the body's inability to quickly vasoconstrict when blood pressure drops suddenly.

When lifters pick up heavy weights, their blood pressure soars and their blood vessels dilate.
Lifters experience a drop in blood pressure when they drop the weight, because their blood vessels remain dilated despite the weight being removed.

The blood pressure can drop so much that the brain is starved for a split second, triggering a syncopal response.
The body's response to this sudden drop in blood pressure is syncope, causing lifters to faint and fall horizontally, which enables blood to reach the brain once again.

​​What’s the difference between Meteor, Meteorite, Meteoroid, Asteroid, Comets & Shooting Star?

Meteor:
A small particle from space that enters Earth's atmosphere, producing a bright streak of light. Burns up completely, leaving no physical evidence. Also known as a shooting star. Typically seen at night.

Meteorite:
A piece of a meteor that survives its passage through the atmosphere and lands on Earth's surface. Can be composed of rock, metal, or a combination of both. Provides valuable insights into the formation of our solar system.

Meteoroid:
A small particle from space that orbits the Sun, potentially becoming a meteor if it enters Earth's atmosphere. Can range from tiny dust grains to large boulders. Found in various orbits around the Sun.

Asteroid:
A large rocky object that orbits the Sun, often found in the asteroid belt between Mars and Jupiter. Can be thought of as a "minor planet." Ranges in size from a few meters to hundreds of kilometers.

Comet:
An icy body that releases gas and dust as it approaches the Sun, creating a bright tail. Originates from the outer solar system. Can be seen from Earth when close to the Sun.

Shooting Star:
A colloquial term for a meteor. A bright streak of light seen in the night sky as a small particle burns up in the atmosphere.