just how big did the hubble telescope say the universe was?

Es­ti­mated reading time is 3 min­utes.

JUST HOW BIG IS THIS UNIVERSE in which we find our­selves? I am not an as­tronomer, but the ques­tion has popped into my head on oc­ca­sion. I sup­pose the most in­ter­esting phe­nom­enon of the 20th cen­tury was dis­cov­ering that no matter how big we dis­cover it to be using state-of-the-art tech­nology, it proves to be stag­ger­ingly bigger with new tech­nology. 1

“Using the Hubble tele­scope and other ob­ser­va­to­ries, as­tronomers have com­pleted the most ac­cu­rate census of galaxies in the ob­serv­able uni­verse to date. The part of the uni­verse that’s vis­ible to us on Earth con­tains ten to twenty times as many galaxies than pre­vious estimates!

That raises the total to some­where be­tween 1 and 2 tril­lion galaxies, which is up from the pre­vious es­ti­mate of 100 bil­lion. This means we have to up­date the number of stars in the ob­serv­able uni­verse, which now number around 700 sex­til­lion. 2

Pre­vious es­ti­mate of galaxies: 100,000,000,000

New es­ti­mate of galaxies: 2,000,000,000,000

Cur­rent es­ti­mate of stars: 700,000,000,000,000,000,000,000 3

How many galaxies?

Be­cause the cosmos emerged some 13.8 bil­lion years ago, we’re only able to ob­serve ob­jects up to a cer­tain dis­tance from Earth. Any­thing out­side this Hubble Bubble is in­vis­ible to us be­cause the light from these dis­tant ob­jects simply haven’t had enough time to reach us.

It’s difficult—if not impossible—to know how many galaxies re­side out­side this cos­mo­log­ical blind spot.

To come up with the new figure, an in­ter­na­tional team of as­tronomers from the Uni­ver­sity of Not­tingham used deep space im­ages from Hubble and com­bined them with data col­lected by other astronomers.

The re­searchers say there must be a fur­ther 90% of galaxies in the ob­serv­able uni­verse that are too dim and far away for us to see using cur­rent telescopes.”

AbelS1063 900 full

FEATURED IMAGE: The photo at the top of this page is of Abell S1063, a cluster of galaxies whose huge mass acts as a cosmic mag­ni­fying glass and en­larges even more dis­tant galaxies, so they be­come bright enough for Hubble to see. I cropped the orig­inal photo (im­me­di­ately above) and added color to make it a wee bit more eye-catching and to pro­vide a some­what darker back­ground for the title of this article.

“This view of the cluster, which can be seen in the centre of the image, shows it as it was 4 bil­lion years ago. But Abell S1063 al­lows us to ex­plore a time even ear­lier than this, where no tele­scope has re­ally looked be­fore. The huge mass of the cluster dis­torts and mag­ni­fies the light from galaxies that lie be­hind it due to an ef­fect called grav­i­ta­tional lensing. This al­lows Hubble to see galaxies that would oth­er­wise be too faint to ob­serve and makes it pos­sible to search for, and study, the very first gen­er­a­tion of galaxies in the Uni­verse.” (Hubble)

Fi­nally, most of the para­graphs in quo­ta­tion marks above were adapted from an ar­ticle ti­tled “We Were Very Wrong About the Number of Galaxies in the Uni­verse” by George Dvorsky for As­tronomy (Oc­tober 13, 2016). The orig­inal ar­ticle con­sists of 432 words; my adap­ta­tion is 220 words, so there’s more to read of Mr Dvorsky’s piece.



1   Al­most like it’s growing its size to meet our growing expectations.

2   I be­lieve that 700 sex­til­lion is a bit more than the gazil­lions that Scrooge Mc­Duck bragged of having.

3   That’s a cur­rent es­ti­mate for stars. With these new galaxies, that number then be­comes min­i­mally 700,000,000,000,000,000,000,000 x 10, or max­i­mally x 20. And that’s just the 10% of the uni­verse we can see.

Using fig­ures with twenty-three zeros, we are reaching num­bers so large that we might as well be dis­cussing in­finity. In which case, even if in­tel­li­gent life is the merest of ac­ci­dents, it’s a mere ac­ci­dent that has prob­ably oc­curred bil­lions of time. Al­ready. Right now, as I type this, there could be an­other me out there writing an ar­ticle about the number of galaxies in the uni­verse. There could be an­other you reading that ar­ticle. And you know what that means? Some­where, many Elvises live with lots and lots of fans . . .


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