Science, Art, Litt, Science based Art & Science Communication
Q: Why do we have two nostrils instead of a one big one?
Krishna: Oh, for double nose piercing! Jokes apart, we also have two eyes, two ears and two nostrils but only one trachea connecting them to two lungs.
We need our doubles for 1. stereoscopic vision - because the few inches of space between the eyes allow us to sense depth and perceive the world in three dimensions; 2. stereo sound, we have two ears because the difference in time between a sound reaching one ear over the other allows us to localize the source of the noise; and 3. super smelling - our nostrils are separated by a septum, in effect giving us two noses. Most of the time, one nostril allows less air to pass through than the other, with the nasal flow switching every few hours. This is called 'nasal cycle'. The slower airflow is caused by the tissue inside swelling with increased blood flow. While we don't consciously notice it, we breathe predominantly through one nostril at a time, and the other side becomes a bit congested and rests. You can test this yourself: try breathing through one nostril and then the other, and you'll probably find that one becomes stuffier than the other. This automatically changes over about four to six hours, so then the other side relaxes.
We smell using sensory cells high up in the nose, and some odour chemicals need more time than others to bind to these receptors. So a low-airflow nostril gives slow-acting odours more time to be detected, giving us a greater range of smell. So two nostrils provide a better ability to detect scents than one.
Also according to some experts (1), human development is responsible for this. This happens because early on, when the human body develops, it forms almost from a flat plate that folds itself in two.
Q: Why is our government not taking a fast decision on booster doses for covid-19 ?
Krishna: This decision has to be taken after a thorough thought. We have to weigh several things. It cannot be taken just because some people demand it.
If you can’t and if this just is your perception, it is not correct.
Scientific research is all about finding the facts. With evidence.
This universe runs on scientific principles. Science tries its best to unravel these mysteries so that they can be used for the benefit of the world.
If you think something else that you imagined is truth, and while you are unable to show evidence, science tries to demolish these baseless beliefs. Is that fear? Come on.
First you think your imagination is true and then make false allegations against science.
Now tell me, who is afraid of what? What is afraid of what? Who is afraid of who?
Q: Do some parts of the Earth have less gravity?
Krishna: Gravity is a natural phenomenon by which all things with mass or energy—including planets, stars and galaxies, and even light are attracted to (or gravitate toward) one another.
Gravity is most accurately described by the general theory of relativity which describes gravity not as a force, but as a consequence of masses moving along geodesic lines in a curved spacetime caused by the uneven distribution of mass.
Gravity is the weakest of the four fundamental forces identified.
Gravity isn't uniform all over the Earth's surface. It's a result of mass, which means the varying density of the Earth at different locations can affect how much you weigh there. Gravity is weaker at the equator due to centrifugal forces produced by the planet's rotation. It's also weaker at higher altitudes, further from Earth's centre, such as at the summit of Mount Everest.
For more than 40 years, scientists have tried to figure out what's causing large parts of Canada, particularly the Hudson Bay region, to be "missing" gravity. In other words, gravity in the Hudson Bay area and surrounding regions is lower than it is in other parts of the world.
Two theories have been proposed to account for this anomaly. But before we go over them, it's important to first consider what creates gravity. At a basic level, gravity is proportional to mass. So when the mass of an area is somehow made smaller, gravity is made smaller. Gravity can vary on different parts of the Earth. Although we usually think of it as a ball, the Earth actually bulges at the Equator and gets flatter at the poles due to its rotation. The Earth's mass is not spread out proportionally, and it can shift position over time. So scientists proposed two theories to explain how the mass of the Hudson Bay area had decreased and contributed to the area's lower gravity.
One theory centers on a process known as convection occurring in the Earth's mantle. The mantle is a layer of molten rock called magma and exists between 60 and 124 miles (100 to 200 km) below the surface of the Earth . Magma is extremely hot and constantly whirling and shifting, rising and falling, to create convection currents. Convection drags the Earth's continental plates down, which decreases the mass in that area and decreases the gravity.
A new theory to account for the Hudson Bay area's missing gravity concerns the Laurentide Ice Sheet, which covered much of present-day Canada and the northern United States. This ice sheet was almost 2 miles (3.2 km) thick in most sections, and in two areas of Hudson Bay, it was 2.3 miles (3.7 km) thick. It was also very heavy and weighed down the Earth. Over a period of 10,000 years, the Laurentide Ice Sheet melted, finally disappearing 10,000 years ago. It left a deep indentation in the Earth.
To get a better idea of what happened, think about what happens when you lightly press your finger into the surface of a cake or a piece of really springy bread. Some of it moves to the sides and there's an indentation. But when you remove your finger, it bounces back to normal. A similar thing happened with the Laurentide Ice Sheet, the theory proposes -- except the Earth isn't so much "bouncing" back as it is rebounding very slowly (less than half an inch per year). In the meantime, the area around Hudson Bay has less mass because some of the Earth has been pushed to the sides by the ice sheet. Less mass means less gravity.
So which theory is correct? It turns out that both of them are. Convection and the ice sheet's rebound effect are both causing some of the decrease in gravity around Hudson Bay. First, we'll consider the ice sheet theory.
To calculate the impact of the Laurentide Ice Sheet, scientists at the Harvard-Smithsonian Center for Astrophysics used data gathered by the Gravity Recovery and Climate Experiment (GRACE) satellites between April 2002 and April 2006. The GRACE satellites are highly sophisticated machines, orbiting about 310 miles (500 km) above the Earth and 137 miles (220 km) apart. The satellites can measure distances down to a micron, so they can detect minor gravitational variations. When the lead satellite flies over the Hudson Bay area, the decrease in gravity causes the satellite to move slightly away from the Earth and from its sister satellite. This shift in distance is detected by the satellites and used to calculate the change in gravity. Any shifts detected can also be used to create maps of gravitational fields.
The GRACE data allowed scientists to create topographical maps approximating what Hudson Bay looked like during the last ice age, when it was covered by the Laurentide Ice Sheet. These maps revealed some interesting features about the area, including two bulging areas on the western and eastern sides of Hudson Bay where the ice was much thicker than the rest of the sheet. Gravity is now lower there than in other parts of the gravity-depleted bay.
Another important finding came from the GRACE data: It turns out that the ice sheet theory only accounts for 25 percent to 45 percent of the gravitational variation around Hudson Bay and the surrounding area. Subtracting the "rebound effect" from the area's gravitational signal, scientists have determined that the remaining 55 percent to 75 percent of gravitational variation is likely due to convection.
The Hudson Bay area is going to have less gravity for a long time. It's estimated that the Earth has to rebound more than 650 feet to get back to its original position, which should take about 5,000 years. But the rebound effect is still visible. Although sea levels are rising around the world, the sea level along Hudson Bay's coast is dropping as the land continues to recover from the weight of the Laurentide Ice Sheet.
Q: Why don't modern scientists acknowledge ancient India's scientific advancements?
Ancient knowledge has to subject itself to the right validation using the scientific method. If it refuses to do so nobody would recognise it as genuine science.