During the 20th century, scientists would just look at the night sky and imagine How do we know how far a star is and what is its brightness? Because a star which would be very bright wold seem to be very dim if it was very distant from you. Stars pulse too i.e., they blink from bright to dim, they may do that really fast or slow.Henriatta Leavitt clicked photos of a clusters of stars in the sky for a veryyy long period of time, and she discovered a pattern, a pattern which opened all doors of space science. It was:The brighter a star is, the slower it pulses.read it thrice, think about it.

Henriatta Leavitt

Hubble measured the distance to a star which was so far, that the science community declared it to be of somewhere out of the Milky Way Galaxy; the andromeda galaxy.Henriatta indirectly hepled discovering a new galxy, and the expansion of the universe. Hubble noticed that the galaxies are moving apart and apart. This idea completely changed everyone's perception. Before this discovery, it was believed that the cosmos is constant. It has always been there and it never contracts or expands.Assume a balloon with dots on it, you inflate the balloon and the dots move apart. This is an analogy.

The doors she opened

The dots on the balloon move apart, when you blow air in it. What causes the universe to do so or to expand?.It turns out to be dark energy. Scientists know 1 thing about dark energy that they don't know it. Dark energy is 1 of the biggest mysteries, no one can say anything about it. But we know it is causing the universe to expand.So, if the universe is expanding, it would have started with 0, right? I mean imagine the expansion in reverse. This imagination is what gave rise to The big bang theory (about that in another stash)

Beginning and dark energy

Let us understand this- Suppose stars are light bulbs ok? 100 watt bulb=bright star.Now, you see a 100 watt bulb in the sky, but you notice that it pulsing very fast i.e., it is going from bight to dim to bright to dim very fast. But according to Henriatta, a 100 watt bulb would pulse slow (a bright star pulses slow). which means that this is a 30 watt bulb close to the earth, and you see it bright because it is close to you . BINGO!Ex 2- you see a dim star pulsing slowly, which is false cuz Dim pulses fast. Hence, this star is actually very bright but it is far away from you.(Got it?)

Understanding her discovery

Imagine you throw a ball up in the sky, but instead of coming down, it slows for 1 sec and then shoots off in space like a rocket. What will be your reaction?Scientists had the same reaction when they discovered that the expansion of the universe is speeding up very fast.Because it was thought to be slowing down but it has always been speeding up.Physics is so astonishing.

Speed of the expansion

If universe has a beginning, it must have an end, right? I mean look at you, you born and you will die. There are 2 ways:<ol><li>The heat death- It states that everything will go sooooooooooooooooooo distant that the entropy would be zero and nothing will interact. And all will die. (More likely)</li><li>The Big Rip- This states that everything will start to rip from the centre. The stars to planets to earth to humans to atoms to quarks. AMD dark energy will cause this. And that's how it will end. (Hoho, hollywood)</li></ol>But relax you won't experience it anyways. 100 billion years to go bro.

The end of the universe

Listen to this episode from Unexplainable on Spotify. In the early 1900s, Henrietta Leavitt made one of the most important discoveries in the history of astronomy: a yardstick to measure distances to faraway stars. Using this tool, scientists eventually transformed our understanding of the universe. They realized space was expanding, that this expansion was accelerating, and that ultimately, everything will end.  For more, go to http://vox.com/unexplainable It’s a great place to sign up for our newsletter, view show transcripts, and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

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Henrietta Leavitt and the end of the universe

”Across the sea of space, the stars are other suns.”

“We are finite, in that we are a product and source of the infinite.”

“Without space, there is no time.”

”That's one small step for a man, one giant leap for mankind.”

”What we call 'time' isn't chronological but spatial; what we call 'death' is merely a transition between different kinds of matter.”

I will always want to know what is beyond our planet. Hopefully, at some point, humanity will be able to travel and see other worlds.

Love space exploration quotes and quotes about space? Look no further, we have curated the perfect list for you to get into space explorer.

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Quotes For All Budding Astronauts 

The Great Filter might be a solution to the Fermi Paradox.A civilization might be situated in one of two positions. Before or after this Great Filter.Being before the filter means that the civilization hasn’t yet overcame the final challenge, which could be anything. For humanity, it might be interstellar travel for instance.Being after the filter means that the civilization is prone to prosperity and continous advancement.So where are we, regarding this Great Filter? Before or after?

Before or after The Great Filter

Can we be after the filter?What if the biggest challenge for a civilization is developing a consciousness?What if that final point is just evolving from a bacteria into a more complex life form?What if not discovering fire or electricity means extinction?What if no other civilization passed any of this? Could we be the first one? Could this be the reason why we can’t see any aliens? Are we alone in this universe?Well, isn’t this a scary thought?

What if we passed The Great FWhat if we passed The Great Filter?

In 1950, the physicist and Nobel laureate Enrico Fermi famously asked his colleagues: “Where are they?”Given the vastness of the space and how our civilization had evolved, theoretically, there should be some other civlization in the universe that we could somehow see. We have pretty powerful tools and if other intelligent life forms would exist, they would have probably evolved in a similar way we did. Thus, they would also have tools to give or intercept signals. Yet, where are all these aliens? Why haven’t they contacted us? Are we the most intelligent life form in the entire universe?

What is Fermi Paradox?

Well, the answer of the above question might be yes!The Great Filter is a terrifying concept. It states that civilizations must overcome certain challenges in order for them to survive. These challenges might vary based on where the life took form, however, every civilization gets to a point, a final challenge, which is the most difficult to pass.Passing it means continous prosperity and evolution for that civilzation, failing it results in complete extinction.

The Great Filter

Do you ever wonder if we are alone in the Universe? Do you ask yourself why we don’t see extraterrestrial beings? This might answer these questions.

Henrietta Leavitt and the end of the universe

Quotes For All Budding Astronauts

The Great Filter, a possible solution for Fermi Paradox

It's time to
Read like a Pro.

Henrietta Leavitt and the end of the universe

Quotes For All Budding Astronauts

The Great Filter, a possible solution for Fermi Paradox

It's time to Read like a Pro.

It's time to
Read like a Pro.