Olbers’ Paradox

In the beginning, the Universe expanded very, very fast.
In the beginning, the Universe expanded very, very fast.

At 13.8 billion years ago, our entire observable universe was the size of a peach and had a temperature of over a trillion degrees.

That’s a pretty simple, but very bold statement to make, and it’s not a statement that’s made lightly or easily. Indeed, even a hundred years ago, it would’ve sounded downright preposterous, but here we are, saying it like it’s no big deal. But as with anything in science, simple statements like this are built from mountains of multiple independent lines of evidence that all point toward the same conclusion — in this case, the Big Bang, our model of the history of our universe. [The Universe: Big Bang to Now in 10 Easy Steps]

But, as they say, don’t take my word for it. Here are five pieces of evidence for the Big Bang:

#1: The night sky is dark

Imagine for a moment that we lived in a perfectly infinite universe, both in time and space. The glittering collections of stars go on forever in every direction, and the universe simply always has been and always will be. That would mean wherever you looked in the sky — just pick a random direction and stare — you’d be bound to find a star out there, somewhere, at some distance. That’s the inevitable result of an infinite universe.

And if that same universe has been around forever, then there’s been plenty of time for light from that star, crawling through the cosmos at a relatively sluggish speed of c, to reach your eyeballs. Even the presence of any intervening dust wouldn’t diminish the accumulated light from an infinity of stars spread out over an infinitely large cosmos.

Ergo, the sky should be ablaze with the combined light of a multitude of stars. Instead, it’s mostly darkness. Emptiness. Void. Blackness. You know, space.

The German physicist Heinrich Olbers may not have been the first person to note this apparent paradox, but his name stuck to the idea: It’s known as Olbers’ paradox. The simple resolution? Either the universe is not infinite in size or it’s not infinite in time. Or maybe it’s neither.


See Also:

(1) Star ‘DNA’ Survey Could Reunite the Sun with Its Long-Lost Siblings

(2) SpaceX Falcon 9 rocket blasts off from Cape Canaveral carrying NASA’s $337 MILLION planet-hunting TESS satellite

(3) Scientists say they’re ‘confident’ polygon features seen on Mars were formed by MUD

(4) Dive into the Lagoon Nebula

(5) Nasa will have a space station that will orbit the moon in 2025

(6) Unveiling the secrets of the Milky Way galaxy

(7) Is dark matter made of primordial black holes?

(8) The current ability to test theories of gravity with black hole shadows

(9) Muons spin tales of undiscovered particles

(10) Simulations suggest Saturn may have helped create Jupiter’s big moons

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