Tag Archives: Carl Sagan

The Star Nearest Us

31 Jul

Sun

If you go outside at night, and it’s dark enough, you will see a seemingly endless number of twinkles in the sky. It’s easy for us to think that those twinkles have no relation to the sun. After all, the sun is a large, ever-present and hugely impactful part of our lives. We owe liquid water and most likely life on our planet itself, purely to its existence.

The truth is, the sun is just another twinkle when you look from any other position in the universe (the speed of light not withstanding). Furthermore, the sun isn’t even that interesting of a star. While it may be 110x the diameter of the Earth, it is more than 1,000x smaller than the largest stars we know of. It’s even too small to explode or form a black hole.

So, what does make our Sun special? It harbors us, and we, as Carl Sagan so eloquently put it, “are a way the universe can know itself”.

I encourage everyone to consider that our sun is one among approximately 1,000,000,000,000,000,000,000,000 stars in the universe. We should all seek to have an appreciation of it as a link to the cosmic scale. Aside from the Earth we live on, it is by far the most imposing and obvious component of the universe from our perspective.

It’s difficult not to marvel at the sheer scope of reality. Even acknowledging that the universe is incomprehensibly large, and that a quark is incomprehensibly small.. is incredibly humbling. Here’s a jumpstart for you:

The Earth Wasn’t Made for Us

23 Jul
Earth

How many planets are there like earth?

It’s not at all uncommon for a theist to make the argument that god must exist, because he provided the perfect environment for us to live in. In an abrupt 180 degree turn, they will use science as a theological weapon:

  • The Earth has the water needed for life.
  • It’s the right temperature.
  • It has an atmosphere of oxygen that we need to breathe.

Alongside these (generally accurate) claims, inaccurate ones are introduced:

“If the Earth’s orbit was slightly off, we’d all die!”

“There’s no way all this could happen by chance!”

How to respond to this?

Our Situation Isn’t That Precarious

The “habitable zone” in astronomy is the area surrounding a star within which a planet could have liquid water. So, what does our solar system’s habital zone look like?

Our Solar System's Habitable Zone

Impressively large, isn’t it?

Basically, it’s huge. Truly, most people have concept of the scale of the universe, but let’s put some context on this:

The habitable zone of our star is up to 3 astronomical units, or 3 times the distance from the sun that we are! So, the margin of error here is considerable.

It’s Easy to Win the Lottery With 1,000,000,000,000,000,000,000,000 Tickets

There are an estimated 10^23 power stars in the universe, and recent scientific studies have found that it is likely that most of those stars have planets (research can be found here).

Given the size of the habitable zone of a star like ours, and the odds that most stars will have planets, it’s probably not unreasonable to assume there are as many potential habitable bodies in the universe as their are stars.

Needless to say, my analogy spells it out pretty clearly: the odds of winning the lottery may be low, but they pale in comparison to the astronomical scales we are talking about.

Planets Harbor Life Because They Can

The entire concept of the theistic argument that the Earth was made for us, is that it’s “unrealistic” to think that the Earth could possibly exist, and life have evolved on it, without some divine intervention. The more we come to know about the universe around us, the more we realize that Earth-like, life-sustaining planets are far more likely to exist than not to exist.

We evolved on this planet because the necessary conditions were there to begin with, and life has likely evolved on numerous other planets for the same reason.

It’s an Arrogant Perspective

Many religions pride themselves on a sense of humbleness (that the constituents rarely exude). What could possibly be more arrogant than saying that the entire universe – all 10^23 stars and likely more planets – were created just for us? I’ve linked this before, but I feel it warrants repeat-viewing:

“Our posturings, our imagined self-importance, the delusion that we have some privileged position in the universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark.” – Carl Sagan

A truly humble perspective comes with an understanding of how truly insignificant we are.

So remember, the Earth wasn’t created for us, nor we for it – we are simply the end result of a set of conditions that were set into motion at the beginning of time. But, if that isn’t awe-inspiring, I don’t know what is.

The Thinking Atheist’s “Pale Blue Dot”

12 Jul

Carl Sagan had an amazing talent for adding a sense of wonder and awe to science. In this video, The Thinking Atheist has taken an excerpt of Carl talking about “The Pale Blue Dot” – a photo Voyager 1 took of earth from 3.7 billion miles away.

I watch this video at least once a week, just to remind myself of the amazing scale of the universe and of how petty we can be.