The Universe Shrunk, And Is Still Expanding At The Same Time — But How?

Recently, scientists figured out that the universe shrunk, even though it appears to be expanding at the same time. To understand this, you need to understand the history of the calculations scientists made almost 100 years ago.

Scientists finally figured out that the observable universe is expanding that almost century ago, and about 20 years ago, scientists realized that the observable universe is expanding at a faster rate each day. But the way that they did their calculations seems almost backward because their conclusions resulted in the hypothesis that the entire universe itself (which includes the observable and unobservable universe) appears to be shrinking.

observable universe limits
Image by Unmismoobjetivo via Wikipedia, CC BY-SA 3.0.

In fact, Forbes says that it’s disappearing altogether, and there’s not a damn thing humans can do to fix it. One day, there will be no hope of ever reaching another galaxy because it’s traveled so far away from us in spite of the shrinkage.

Seem strange? That’s because it is indeed mind-bending, just as the physics and calculations behind the theory are, and everything we know about science tells us it’s true. Here’s why.

A set of calculations made some 13 years ago aren’t accurate today. Indeed, scientists used the best information and technology to create those calculations, all of which were at the cutting edge of science at the time. Our current access to technology and information is much more advanced. And using that more advanced information to update the scientists’ calculations resulted in a change in facts, which is something that happens in the scientific world quite often.

The fact that changed, and proven independently? The universe shrunk and is actually quite a bit smaller than we thought it was. A whole 320 million years smaller to be exact, in all directions.

In spite of this change, it’s still expanding rapidly, and still also appears to be shrinking; naturally, and not because of the calculations. Instead, it is because of the way we perceive the light traveling towards us from everything that exists in the universe.

Boiling it down to layman’s terms, the way we do this is by calculating what’s called the “redshift” of visible light. A redshift is a light we detect from objects taking so long to travel to us that it’s literally turned redder than it was when it left home. Essentially, redshifted light reacts depending on how long it’s been traveling through the universe. The redder the light is from an object, the farther away that object is from us.

Here’s an explanation of how redshifting works:

To date, we’ve been able to “see” as far away as 13.8 billion years, which means we see 13.8 billion years back into the past. Before the new method that scientists used to calculate space and time became the norm, 13.8 billion years might have seemed like the best way to determine how big the universe was, or most logical anyway.

Image by NASA/IJC-CALTEC via Forbes.

According to Business Insider:

“You’d reason that since the Big Bang happened some 13.8 billion years ago, there’s a 13.8 billion-light-year radius marking the edge of what mere mortals could see.”

However, this is not the case. Scientists proved time and again that even before those 13.8 billion years, a history of the universe existed. In fact, about 378,000 years after when we know the Big Bang happened, a cloud of blinding light existed.

Scientists call that point of time “recombination.” This is the point in the universe’s history at which the gasses emitted from the Big Bang cooled enough to make actual matter and energy. Those first 378,000 years are called the “afterglow” of the Big Bang.

big bang afterglow
Image: Screenshot via PSC.

However, the data that Paul Halpern and Nick Tomasello used to make the initial calculations, physicists from the University of the Sciences, was from the Wilkinson Microwave Anisotropy Probe (WMAP) satellite. At one time, it was the gold standard of universe mapping, but because technology advances at such a fast pace, now, 15 years later, that data is out of date. The new calculations are much more accurate and what resulted in their seeing that the universe shrunk.

That data comes from the Planck satellite at the European Space Agency, and the two physicists were able to calculate that the observable universe’s edge is 0.7 percent smaller than we thought it was. This translates to a radius of 45.34 light years. This is how they came up with the “320,000 million years smaller” calculation, of which Tomasello said:

“A difference of 320 million light-years might be peanuts on the cosmic scale, but it does make our knowable [observable] universe a little bit cozier.”

Cozier indeed. We already can’t reach about 97 percent of the galaxies within the universe. How many more will slip our potential grasp as the universe continues to accelerate the rate at which it expands while the observable universe continues shrinking? That’s a question humanity will need to answer soon if we ever hope to travel to the stars outside our solar system.

Check out this example of the way the universe expands and light redshifts (The square-looking portion is an actual photo that the Hubble took some years ago. It contains millions of redshifted galaxies. This is the farthest back Hubble has been able to see — 13.8 billion light years.):


Featured Image: CC-0 by NASA/JPL-CALTECH via Forbes

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