Radio and television broadcasting may be only a brief passing phase in our technological development. When we imagine alien civilizations broadcasting signals with radio telescopes, are we any different from earlier generations who imagined riding cannon shells to the moon? Civilizations even slightly more advanced than ours may have already moved on to some other mode of communication, one that we have yet to discover or even imagine. Their messages could be swirling all around us at this very moment, but we lack the means to perceive them just as all of our ancestors, up to a little more than a century ago, would have been oblivious to the most urgent radio signal from another world. 

But there’s another more troubling possibility: Civilizations, like other living things, may only live so long before perishing due to natural causes, or violence, or self-inflicted wounds. Whether or not we ever make contact with intelligent alien life may depend on a critical question: What is the life expectancy of a civilization?

- Episode 11: The Immortals, Cosmos: A SpaceTime Odyssey




via crookedindifference:

The Hubble Ultra Deep Field in 3D

In 1996, scientists took a huge risk when they pointed the Hubble telescope to an inky field that they believed to be void of stars and planets. As images from Hubble are in constant demand, the worry was that devoting so much time to a black space would prove futile. Once the photons finally registered, though, that leap of faith proved fruitful: light from over three thousand galaxies illuminated the image. A few years and missions later, Hubble’s glimpse into what is known as the deep field has revealed that we are just one tiny part of a vast system comprising 100 billion galaxies.

There are moments and experiences that you remember forever. They are signposts that paint a new road ahead of us, and tweak our rear-view mirror so that we may never see the past the same way again. Our lives are full of them: First loves, births, deaths, that one best meal.

Experiencing the Hubble Ultra Deep Field is one of those moments. Take a sec and truly internalize what you’re seeing. When you stare into an empty piece of the universe and find it overflowing with galaxies just like our own, and not like our own at all, stretching to the beginning of time itself … if you are alive in the least bit, you are forever changed. 

We are time travelers all.

There are several Astronomical images that moved me in some way, but this and the Pale Blue Dot are the two photos that profoundly affected me.