Neutron stars: fast spinning spheres

Can you think of something that is perhaps the size of your city but weighs more than our sun, that's what you call a neutron star!

Neutron stars are the remains of the cores of dying stars. They are formed when a star which has the mass of 6 to 20 suns explodes into a supernova. They are small in size but extremely dense. About a tablespoon of material of neutron stars would weight about one billion ton, more than the Mount Everest. 

They are also the objects with the strongest known magnetic fields, billions of times that of the Earth's.

They spin, much like a lot of objects in the space. But their pace in very fast. These rapid spins, combined with the strong magnetic fields, causes these to emit light. These are called pulsars. The pulsar, PLS J 1748-2446A spins about 43000 times every single minute. 

And for a little bit of a fun fact the signals from the neutron stars first made the astronomers believe that they were messages from aliens .

Well, that is it for this post. See you next Sunday!!!

gravitational waves

Gravitational waves are like 'ripples' in space. They are invisible and travel at the speed of light. 

But before going into their properties, let us discuss how they're formed. 

Just as I mentioned above, imagine you move your finger though a calm water body. Ripples would be formed, right? That is somewhat similar to how gravitational waves are formed.

Picture it like this. Your finger is a body in space that accelerates, and the calm water is the fabric of space time.  That is how these waves are formed. 

They are formed due to the acceleration of anything, even you and me. But the light weighed objects produce very weak waves, which cause no direct effect and cannot be detected using present technologies.

We can only detect waves that are very strong. And the strength of a gravitational wave is directly proportional to the mass of the cause. So, the greater the mass of the objects accelerating, the stronger the wave.

These strong gravitational waves include the ones formed when two black holes merge, or when there is an asymmetrical supernova formation, or neuron star collisions!

Now, let's understand the physics behind this.

When these massive objects accelerate they disrupt the fabric of space time that waves form

Now speaking of their properties, gravitational waves stretch and squeeze the fabric of space time itself as they pass, resulting the stretching and squeezing of the matter that come in the way. 

However, they do impact the matter that comes in way but they do not interact with matter, meaning they don't get blocked by it. This comes as an advantage for research because light and electromagnetic radiations get absorbed or scattered the matter coming in their way. But gravitational waves do not, meaning we can study their sources in detail.

If there is anything in particular about space that fascinates you, please share you enthusiasm in the comments down below!

The observable universe: The part we can see

Observable universe, on hearing, might sound like the amount of universe we have observed so far. But that is not what it is. So the observable universe (with a diameter of 93 billion light-years) is the region from which light has had the time to reach our Earth so far.

Let me explain. So, as we all know, our universe is about 13.8 billion years old. This means that the light from the distant object has to travel about 13.8 billion years. 

And as no object can travel faster than the speed of light. However, the universe or space is expanding faster than the speed of light. So light has to travel this obscure amount of space, and it is getting redshifted (I have discussed redshift in detail in one of my previous posts.)

Some amount of this redshifted light is significant so we can see it. But the light of the bodies far away from us is getting redshifted to the radio spectrum, which cannot be seen by us.

But don't worry as the observable is, in fact, constantly growing.

I hope you found this post helpful. 

See you next Sunday! 

Why were constellations so important so the ancients

 It is truly fascinating how all of the ancient civilisations gave significance to constellations. Then a question arises, why were constellations so important to them? They weren't scientifically developed enough to think an alien life might exist on a planet near any of these. 

So again, why? 

The First reason could be their search for a reason. Ever since its early stages, humanity has tried to find a reason for everything. Whether it be the rain, eclipses, mountains, snow, or our own existence. Constellations also come in this list. That is why they tried to find a reason as to why certain stars always exist in groups and form a certain shape. They used it in storytelling, connected it to mythology and folklore, comparing them to gods and goddesses and connecting them to legends. 

People needed something to guide them philosophically. And hence astrology came into existence. 

But this guidance was not just emotional. They also needed it to guide them through journeys as they did not have maps, and physical features like wind and weather were not reliable. 

But constellations were. They were stationary. 

Constellations appeared at different times of the year. And hence helped in determining the season, helping in determining cropping patterns.