Kennirich SPACE

THE ACTUAL SHAPE OF A STAR IS NOT THIS (⭐).

In reality, a Star is a huge ball of very hot gas(mainly hydrogen and helium).

When we look at stars from Earth, especially with our naked eyes, they appear to twinkle and have pointed rays....but that’s only an optical illusion caused by this:

✦ Atmospheric Distortion (Twinkling)

Light from a star passes through layers of Earth’s atmosphere(Exosphere, Thermosphere, Mesosphere, Stratosphere and Troposphere).

These layers have different temperatures and densities, which bend (refract) light in random directions.

This makes the star’s light wiggle and shimmer, causing it to look like it’s sparkling with little spikes.

The actual shape of a star is in the image(Spherical, just like the Sun).

DO YOU KNOW THAT THE SUN IS A STAR?

The Sun ☀️ is classified as a dwarf star ⭐ because there are stars 100+ times bigger than the Sun 🌞
These are called MASSIVE STARS.

However, there are some stars that are not as big as the Sun.

THE SUN ☀️ AND ITS FATE 😢

Our Sun was born from a giant cloud of gas and dust called a NEBULA

Gravity pulled this gas together until it became hot and dense enough to start nuclear fusion....and that’s how the Sun was formed.

The Sun’s “fuel” is hydrogen gas.

Inside the Sun, hydrogen atoms fuse together to form helium(Nuclear fusion), releasing energy....that’s what makes the Sun shine.

In about 5 billion years, the Sun will run out of hydrogen fuel, swells into a red giant.
It loses its outer layers into space and form a planetary nebula.

The core that remains becomes a white dwarf....a small, very dense, hot star.

It’s more like a "retired star"😄

It no longer burns fuel because there's no more nuclear fusion, but, it still glows brightly because it’s extremely hot (over 100,000°C).

Over billions of years, it slowly cools and fades.

Before then, the SOLAR system including the earth would have been destroyed.

SATURN AND ITS RING 🪐

SATURN 🪐 is extremely cold ❄️.
It's a giant gas(of hydrogen and Helium).....it has no solid surface(like land)
If you find urself inside Saturn today, you will see no solid surface to land on....you will just keep sinking deeper inside this gas...and don't forget the extremely cold temperature🌡️that u cannot survive

But can you even get inside Saturn 🪐???

Let's see.

The circular Ring u see around Saturn is called the ring of Saturn.
It comprises what???

It comprises icy particles...these particles, some are as small as dust particles, and some are as big as building 🏢 -- Mind-blowing 😳???

Not just that, these particles are moving at a speed of up to 20,000 meter in one second.
If u are hit by these particles, Otilor.

Mercury moves round the Sun ☀️ in 88 days
That means one year in Mercury is 88 days

Venus moves round the Sun 🌞 in 225 days
One year in Venus is 225 days

One year on Earth is 365 days

One year on Mars is 687 days

Jupiter is 4,333 days (≈ 12 Earth years)

Saturn is 10,759 days (≈ 29 Earth years)

Uranus is 30,687 days (≈ 84 Earth years)

Neptune is 60,190 days (≈ 165 Earth years)

THE DIFFERENCE BETWEEN CIRCULAR MOTION AND ROTATIONAL MOTION

In CIRCULAR MOTION, both the position of the object in motion and its direction are changing.
For example, you draw a wide circle ⭕ on the ground and you are moving along the circle.
You will observe that ur body left ur initial position to another position.
And also, u are changing direction.
Using a circle and a compass 🧭, 0° is East, 90° is North, 180° is West, 270° is South and 360°(complete circle) is East again.
While moving round this circle, u start from East and move curly to North, from North to West and from West back to East.
You can see that u are changing direction.
And u also changed ur position -- that's CIRCULAR MOTION.
Another example of this is the movement of a car round a roundabout.

In ROTATIONAL MOTION, only ur direction is changing.
U sit on a chair that can swing 360°....U are turning and changing direction, from East to North to West and to South without leaving that same position.
Another example of this is the movement of a ceiling fan.

THE EARTH 🌎, MOON 🌕 AND THE SUN ☀️.

The earth 🌎 moves in a direction just like a kicked ball 🏀.
When you kick a ball, the ball rotates on its axis and also moves in the forward direction.

The earth rotates on its axis and also moves round the Sun ☀️.

The Moon 🌕 in turn, moves circularly round the Earth 🌎 and also follow the earth as the earth is moving round the Sun ☀️.

As the Earth 🌍 is rotating on its axis, if it completes one rotation(moves from 0° to 360°), that's a DAY

The complete rotation of the earth on its axis is known as SOLAR DAY(The passage of the day and night).
SOLAR DAY is 24hrs.

The Moon 🌕 moves round the Earth 🌎 (one complete cycle) in 28 days...that's one MONTH.

The Earth 🌍 moves round the Sun ☀️ in 365 days.
And that's a YEAR

Mercury moves round the Sun in 88 days -- that means, 1 year in Mercury is 88 days
One year on Earth is 365 days

In the electromagnetic spectrum, ROYGBIV are the visible light to we human beings.

R is Red ♥️ colour
O is Orange 🧡
Y is Yellow 💛
G is Green 💚
B is Blue 💙
I is Indigo
V is Violet

Red has the longest wavelength
Violet has the shortest wavelength

According to Wein's displacement law, the lower the wavelength, the higher the temperature and vise versa.

What that means in essence is that, Red colour that has the longest wavelength has the lowest temperature and Violet colour that has the shortest wavelength has the highest temperature.

Let's talk about fire 🔥

Wein's displacement law is applicable to fire as well

Red ♥️ coloured fire has the lowest temperature.
Orange 🧡 coloured fire has a temperature higher than Red coloured fire.
Yellow 🟡 coloured fire has a temperature higher than Orange coloured fire 🔥
Green 💚 coloured fire has a temperature higher than Yellow coloured fire 🔥
Blue 🔵 coloured fire has a temperature higher than Green coloured fire 🔥

That means, the hottest fire among these 5 fires is the blue 💙 coloured fire

The most expensive substance on earth is ANTI MATTER

SCALAR QUANTITIES ARE PHYSICAL QUANTITIES THAT HAVE ONLY MAGNITUDE WITHOUT DIRECTION.

VECTOR QUANTITIES ARE PHYSICAL QUANTITIES THAT HAVE BOTH MAGNITUDE AND DIRECTION.

Magnitude is the value of the quantity.
If we say, "he moves 50 metre northward".
The magnitude is 50m
The direction is Northward.

Distance is the space between two points.

The space may be 20 metre or 5 metre or any value....you can see that Distance didn't talk about Direction. It only talks about the magnitude of space between two points.
That makes Distance a scalar quantity.

Displacement is the DISTANCE moved in a specific DIRECTION.
Let say, your workplace is at the northern direction and your home is at the eastern side.....If you move from your workplace to your home, let say the distance between your workplace and home is 20m, that means, you moved 20m Northeast.

You can see that displacement talks about Magnitude and direction...and that makes it a Vector quantity.

In the case of temperature, we cannot say, "the temperature of her body is 30°C east"....it doesn't make sense

We can only say, "The temperature of her body is 30°C"

When we discussed the temperature of her body, we only say "30°C"
That means, we only talk about Magnitude.

A physical quantity that has only magnitude is a scalar quantity..... therefore, temperature is a scalar quantity.

We cannot say, "the mass of his body is 50kg South" and we cannot also say, "the time is 3pm East".
MASS and Time only have magnitude that makes them Scalar quantities.