Looking Into the Past

When I started this blog I sought to share with everyone what might be considered "weird science". Not weird because it's not true, or it was discovered in some strange fashion but because the conclusions it gives us are not easy to accept into our daily lives.

The fact that the measured speed of light tells us that we are often looking into the past is one of those.

Let's start with some easy examples:

The Moon

The Moon is approximately 400,000 km (the amount of kms most cars end up going in their lifetime!) and speed of light is about 3 m/s, so the time it takes light to travel between Earth and the Moon is: 1.26 seconds.

So..if the Moon blew up, we wouldn't see the explosion for 1.26 seconds


The Sun

The Sun is about 150,000,000 km (no car can put that much on it's engine, not even a Honda) away from Earth. 

So ..if the Sun blew up, we would still see the Sun up in the sky for about 8.3 minutes

Everything Else

Just recently I talked about a famous image from the Hubble space telescope containing thousands of galaxies. Now, if we apply the concept above to these images we get an astounding conclusion:

The stars and galaxies we are seeing in all of these images are actually in the past, not a few seconds or minutes..but years and years into the past:

As you can see from the image above the further out a telescope captures an object the further back it is in time as far as we can see (i.e almost a billion years).

Basically the light waves from that object took a billion years to reach us, so we have no idea what it's current state is and we wont know for another billion years.

Just another example of #Scale.

Always in the Past

My final thought that I want to leave you with is this. If light travels at a certain speed and is not instantaneous, does this mean we're always seeing things in the past? The simple answer is yes.

But, it's so fast that for all intents and purposes it's instant (nanoseconds). Still something to think about when you see your friend waving at you from a distance...

The Ruthless Red Giant

It may sound like a typical villain in an upcoming children's film this summer, but it's far from that. This is the ultimate fate of our Sun; the next stage in it's natural life cycle.

As the Sun ages it will use it will use up more and more of it's hydrogen core which will in turn increase it's size, luminosity and energy generated i.e the Sun will get hotter and larger. In fact in about 4.8 billion years the Sun will compare to its current size like this:

Yah that's a huge upgrade. And a huge problem for Earth. So big in fact that as I alluded to earlier...no life will survive.

But that's the ending of the story, how about the things that will happen along the way?

• [50,000 Years from Now] Niagara Falls will continue erode into Lake Erie will no longer bexist
• [50 Million Years From Now] Africa will be divided into two continents as Red Sea floods into the East African Rift
• [250 Million Years From Now] All the continents may fuse back together into a supercontinent
• [500-600 million Years From Now] Supercontinent breaks up 
• [1 Billion Years From Now] Surface Temperature reaches 47 degrees celcius. Most water has evaporated. Most multicellular life has died out (yes that's us)

The Earth is 4.5 billion years old. 1 Billion years from now it will no longer sustain life. Therefore...the Earth has already been around more than 80% of it's expected life.

The earth post-destruction by the Sun

Takeaways

It's truly amazing that something that gave us life (The Sun) will also likely take it away from us. The Human Species has a very likely end date. Depending on what scale you look at things, things won't really stay the same...

Or..things will stay the same. 

Consider this, Humans (Homo Sapien) on Earth have only been around for about 400,000 - 250,000 years ago. That's not even a million years. The Earth has been around for 4.5 billion years. 

We've only been around for 0.003 % of Earth's existence. Therefore to us things really do stay the same.

Like I've said all along...it's all about Scale.

Scale

Back in the 1990s, movies could be pretty hit and miss. Some (including myself) would even say that genres like sci-fi, fantasy and superhero have "grown up" in the current era. But that doesn't mean that they didn't have their moments of pure genius. Men In Black was a both a box office hit and a critical success. But for me the most memorable moment was this:

Wow. How novel an idea is that? Our entire universe...could actually be just a marble in the hands of some random alien. What this scene really did for me was help me realize how important and exciting the concept of scale was. 

The difference in size between a very tiny object (atom) and a very large one (the sun) is mind boggling. But what was even more interesting was something I like to call "Infinite Scale". This is the idea that as science advances we will find smaller and smaller objects (neutrino) and on the other end of the spectrum, larger and larger ones (Sloan Great Wall). 

But hey, why listen to me drone on about it when instead you could play around with an awesome flash animation made by a couple of apparently genius teenagers:

Wicked-Awesome? Thought so. But there's an even better example of scale much closer to home:

It would take 1.3 million earths to fill 1 sun (source)

Now that..admittedly...is a little terrifying, and really puts a perspective on how far we are from the sun to be able to see it as a friendly, yellow floating smiley face (instead of that very ominous monster above).

To top off my discussion about scale I will leave you with this. Scientists now tell us that the largest scale possible is the "End of Greatness" , where the universe looks the same in all directions, and there is no longer any sense of being able to tell one part from another. You've basically zoomed out so far that it all looks like one big homogeneous structure....

Kinda looks like a marble wouldn't you say?