as far as we can see across the cosmos we don't see anything that may look like the
edge of the universe the only limit we know of our universe is how much of it we can observe
for example scientists believe that the universe is not infinitely old it's theorized to have begun
with the big bang 13.8 billion years ago which is why we can't see the entire universe as light
has only had 13.8 billion years to travel thus making up the entirety of the observable universe
but what is there outside this visible bubble countless galaxies as far as there can be
or does the universe have an actual end welcome the Factnomenal
and today let's find out if the universe is infinite
about a hundred years ago two genius scientists Harlow Shapley and Herbert Curtis met in the great
auditorium of the Smithsonian institution's natural history museum in Washington DC
to debate over a simple question how big is the universe mind you this discussion
happened a little earlier than Edwin Hubble discovered the nature of galaxies
Curtis argued that the cosmos may consist of many separate island universes
claiming that the spiral nebulae were distant systems of stars outside our milky way
shapely believed that the so-called spiral nebulae were merely gas clouds within the milky way
Shapley also positioned our sun in the corner of the milky way which in his theory was the entire
universe oddly Curtis Counter argued that the sun was rather near to the center of our galaxy
both of these gentlemen were right and wrong Curtis got the size of the universe somewhat
right but he failed to accurately calculate the sun's position in our galaxy shapely was obviously
wrong about the size of the universe however he was quite accurate in positioning the sun
we have come a long way since then we understand the observable universe better and in 1996 the
debate was resurrected once more and this time it was galaxy researchers Sydney Vandenberg
and Gustav Tommen who argued over this question Gustav Tommen firmly claimed that the Hubble
constant has a low value of about 55 kilometers per second per parsec but Vandenberg offered
evidence supporting a higher value of the Hubble constant 80 kilometers per second per parsec
signifying that the universe may be younger and smaller than we had thought before Hubble constant
for the uninitiated is the unit of measurement used to describe the expansion of the universe
the cosmos has been getting bigger since the big bang kick-started the universe and it in
fact is getting faster in its acceleration as it gets bigger however Tamman did have some
strong arguments both of them had data supporting their side and neither succeeded in convincing
astronomers from the other cap even today 25 years after that debate astronomers are limited by both
assumptions and a lack of adequate data to agree on the cosmic distance scale yet based on the
available data astronomers can set some limits on what must be true about the size of the universe
thanks to the powerful telescopes available in present times astronomers can observe galaxies
located over 13 billion light years from earth our current cosmic horizon of visibility is somewhere
around 26 billion light years in diameter but it is inarguably true that the universe should be
much larger than what we are able to see for now if the hypothesis proposed by Alan Guff in 1980
is true then the universe must have expanded so rapidly in its earliest moments that it ballooned
from the size of a subatomic particle to the size of a softball almost instantly
if inflation did indeed occur then the universe is much larger than we might
expect based on current observations and that's where it gets wonky for lack of a better term
in our video about was the big bang a white hole link in the description below we explained how
the big bang didn't occur at one single point but everywhere so keeping that in mind if inflation
happened in the earliest moments of time and space then it should have occurred in many
places and perhaps many here means in an infinite number of places it's a pretty valid school of
thought that many of those places where inflation helped expand the universe may lie beyond our
cosmic horizon and the limits of the space-time continuum we are so familiar with so in that case
either our universe is indeed infinite or maybe there is another universe beyond our limitation
andromeda the nearest galaxy to the milky way is somewhere around two and a half million light
years away from us when we try to see what's going on in there we are actually looking at
what it must have looked like about 2.5 million years ago we have no idea what andromeda galaxy
looks like today because the light cannot get any sooner from that galaxy than our own
light needs two and a half million years to reach our eyes from the moment it was emitted
as we look to greater distances we also wind up looking back in time more distant galaxies
appear as they were tens of millions hundreds of millions or even billions of years ago
as we look even farther away in space the light we see from the universe comes from its progressively
younger days and when we kept on seeking answers to whatever light has offered us to see
we've found the light emitted all the way back in the beginning the cosmic microwave background
CMB or cosmic microwave background is the leftover glow that was emitted by the big bang we also
discovered that except for a few regions being more or less dense the universe was perfectly
uniform these non-uniform regions constituted only one in 30 thousandths of the universe
but for a universe as vast as it is this much area was enough to give birth to stars
galaxies galaxy clusters and cosmic voids we see today and astonishingly the space
curvature is perfectly flat if that wasn't the case distant lights would converge or diverge
but light always moves in its original direction with the fluctuations we have and thus indicating
perfect flatness the conclusion we get from this combined information is that if the universe was
finite it has to be at least 250 times bigger than what we call the observable universe
the calculation reasoning behind that is that as we live in a three-dimensional universe
250 times the radius means 250 to the third power times the volume or more than 15 million
times as much space that would be about 11 trillion light years in all directions
but big as that is it still isn't infinite
now let's consider if the universe does have an edge what's beyond that
there's a reason to believe that the universe may not have an edge at all for now we are certain
that the big bang indeed began the observable universe as we know it but what if time and space
existed long before that we are aware that long before the big bang the universe was filled with
only energy inherent to space itself it was also expanding at a constant exponential rate what we
call cosmic inflation this also created new space so quickly that the smallest physical length scale
the planck length would be stretched to the size of the presently observable universe every 10 to
the negative 32 seconds it's true that inflation came to an end in our region of space but we still
need an answer to three questions number one how big was the region of the universe post-inflation
that created our hot big bank number two is the idea of eternal inflation correct
number three and finally how long did inflation go on prior to its end and the resultant hot big bang
these questions are so broad that explaining the answers to these questions would require a whole
video of its own from our best observations we know that the universe is an awful lot bigger than
the part we can observe beyond what we can see we strongly suspect that there's plenty more universe
out there just like ours with the same laws of physics the same types of physical cosmic
structures and the same chances at complex life however a single universe or multiple universes
or if you'd like to call it a multiverse whatever we might find at the end shouldn't be infinite
unless inflation went on for a truly infinite amount of time
or the universe was born infinitely large the universe ought to be finite in extent
but to get the correct answer we may have to find a way to extend our reach beyond the observable
universe for the answer might be encoded somewhere else in the universe itself until then the
possibilities are infinity and beyond so what are your thoughts tell us in the comments also would
you like to explore the universe before the big bang and as always thanks for watching Factnomenal