How small can small be?Compared to the size of Universe how small are we?
923222
The smallest anything can be is called Plank length and it is approximately 1.6 × 10 (to the -35th power) meters.  \nAssuming "we" is the earth, we are very small compared to the size of the universe.  The "volume" of the observable universe is about  1.9 × 10 (to the 33rd power) light years, and the earth has a volume of approximately 8.2 x 10 (to the 12th power) miles, or 4 x 10 (to the -26 power) of a light year.  The universe, then, is about 4.7 x 10 (to the 58th power) times bigger than the earth.
1049415
the universe is one big fractal and that is most likely true, but don't think to much about it or your head might explode. Our solar system is a tiny tiny aberration on the pinhead of space. There are parralels everywhere... in nature and in fractals. Think of it as so much bigger than your senses could ever understand and you'll be fine... just don't go killing busloads of people.
333265
There's The Universe, then there's the observable universe. No one knows the size of the first one; it's probably infinite. The second one is the universe with a boundary; that boundary is how far we can see into The Universe, about 13.7-billion light years.
619195
taking into consideration the size of the universe, i believe earth is just a tiny speck on the universe. to think that we are alone would be an ignorant statement, i dont believe in aliens in flying saucers, but other life forms and organisms living their lives as we are, maybe not the same lifestyle but still living
618201
How do you know its small? You must have compared it to another.
570269
at the present time we define the universe by four dimensions, length, width, height, and time.\n\nhttp://en.wikipedia.org/wiki/Spacetime
800785
Ah yes, people like to give mumbo jumbo bullshiet answers to this question to confuse you further.\n\nThe thing is, we really have no idea. This is half the reason the answer is so confusing.\n\nScientists, like myself, have defined the universe as everything and like to say it isn't expanding into anything because, quite frankly, they don't know what's going on and it's easier to just define the universe as that for the time being. I don't know, neither does anyone else.\n\nFrom recent science, we know that the universe is absolutely finite, therefore it's size is increasing; it is getting larger. This can also be seen by looking at microwave radiation maps of the universe.\n\nSo then, what is it expanding into? Well, if ANYONE could answer this question, they would probably go down in history as greater than even people like Einstein, Newton, Galileo...but the reality is, we don't know. All answers to this question are purely spectical and usually formed to fit a belief system that has been adapted from that person.\n\n\nPersonally, it's probably expanding into more space, which probably contains an indefinite number of universes and extends infinitely.\n\nBut that is only my personal view. Just like all other views.
337568
There is no limit to how small they can get, but there is a limit to what we can observe and that's as small as Plank's Constant.
659476
"...What are the dimensions (length, width, and height or thickness) of the physical universe (in light years)?..."\nThe universe can't be measured in terms of length, width, and height. Such parameters require some reference point from which measurements can be made, along with some distant boundary where the measurement would end. You simply can't do that with the universe because the universe is isotropic, meaning it's the same in all directions from any observing point. From Earth we can look outward in any direction and 'see' about 13.7-billion light years. From Earth that represents a boundary. Here comes the tricky part: if some alien in a galaxy 13.7-billion light years away from Earth looked outward in all directions (including back towards Earth) they'd 'see' a universe that appeared to be 13.7-billion light years in scope. In other words, the universe has no boundary. To have one it would have to be inside some "thing" else, and there's absolutely no evidence that such is the case.\n\nTo confuse the issue even more, if we had the ultimate telescope with limitless viewing power we still will never be able to see into the universe beyond a certain range. That's because at almost the same instant of the Big Bang the universe briefly expanded faster than light (this doesn't violate relativity because it was the space of the universe that did the expanding). In our 'normal' universe the speed of light is the speed limit which prevents us from ever seeing any of that inflation because it's moving away faster than the speed of light.\n-----------------------------------------------------------\n"...I've read that the universe is thought to be "saddle shaped..."\nMore recent observations point more towards the universe being geometrically "flat." This simply means that the universe appears to be infinite, that its space will expand forever while cooling more and more over the eons.\n------------------------------------------------------------\n"...What does it mean for example, to say that the universe is expanding at a rate of 70 kilometers per second per (x number of light years)?..."\nYou've described the so-called Hubble Constant. (70 km/sec/Mpc) It means if galaxy 'A' is 1 Mpc (1-million ly) away from us it's recessional velocity will be 70 km/sec. If galaxy 'B' is 2 Mpc away then it's velocity will be 140 km/sec It's important to keep in mind though that it's space that's expanding like that, not the galaxies moving THROUGH space; they just get carried along.\n------------------------------------------------------------\n"...I was not able to find a rate of acceleration of expansion..."\nI've been looking for a figure too. So far the only thing I've come up with is -3.15^36 /sec/sec  Darned if I know what the units of measurement are though. Maybe someone else on Yahoo can help us out with that.
164688
There are ways of calculating the average mass and the size of the universe, but so far nobody there have been several flawless answers that don't agree with one another.\n\nThe answer is going to depend on what shape space is. Gravity is going to work differently in flat space, positively curved space, or negatively curved space. At the tiny, tiny, tiny level (say, a planet or moon), gravity is just going to pull you to the closest physical body. Even on the slightly larger level (a star and its planets), gravity is pretty constant. But when you start looking at the effect of galaxies on one another, and those wacky and inexplicable quasars way the hell out there, suddenly the principles of gravity that seem to simple are breaking apart!\n\nSo is it infinite? Go find an answer you like, and there's probably good evidence to support it. Does the universe stop? That's most likely true, but if you go to the edge of the universe, then the edge of the universe won't be at that point anymore. So again, find an answer you like and be happy with it, because nobody can prove you wrong!
784741
The universe may be infinite in size, or it may be of only finite size. Doesn't the universe have to be infinite? It doesn't make any sense that it would be finite, then there would be some end or edge, and what would be beyond that?\n\nStrange as it may seem, the universe could be finite, a finite universe would not have to have any edges or an end, it could 'wraparound'. The universe could be curved. Huh? How could you curve the universe?\n\nAn analogy should help, consider the surface of the Earth. It looks flat and many children and ancient people might assume that it is flat and that it is either infinite or must have an end or edge somewhere.\n\nBut the Earth's surface is curved, it wraps around and closes in on itself. There is only a finite amount of area yet there is no ends or edges. The two-dimensional flat surface of the Earth is wrapped around into a sphere when viewed in three dimensions. If you set out flying westward in a plane, you will wraparound and eventually return to where you started, approaching from the east.\n\nThe universe may be a curved three-dimensional space that wraps around and closes on itself. If you set out in a spacecraft heading one direction, you could eventually return to the same spot from the opposite direction.\n\n \n\nA nice demonstration of the scale of the universe is to start with a view showing our galaxy and then zoom by a factor of ten once per second. Such a demonstration is done at http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10/ \n\nClick on this link and view the demo. Use your browser's Back button to return to this page after watching the demo.\n\n\nThe entire universe, or just the visible portion of the universe if its infinite, is roughly 27 billion light-years across. That's 159,000,000,000,000,000,000,000 miles. Our solar system, from the Sun to Pluto, is .00063 light-years across or 3,720,000,000 miles. That makes our solar system 42,700,000,000,000 times smaller than the whole universe.\n\nCan we put that into a more meaningful perspective? If the entire Earth's surface represents the whole universe, the solar system on that scale would be one-millionth of a meter wide, about 1/25,000 of an inch, the size of a single, small bacteria.
1055858
If you've ever wondered how big the universe is, you're not alone. Astronomers have long pondered this, too, and they've had a hard time figuring it out. Now an estimate has been made, and its a whopper.\n\nThe universe is at least 156 billion light-years wide. \n\nIn the new study, researchers examined primordial radiation imprinted on the cosmos. Among their conclusions is that it is less likely that there is some crazy cosmic "hall of mirrors" that would cause one object to be visible in two locations. And they've ruled out the idea that we could peer deep into space and time and see our own planet in its youth.\n\nFirst, let's see why the size is a number you've never heard of before.\n\nStretching reality\n\nThe universe is about 13.7 billion years old. Light reaching us from the earliest known galaxies has been travelling, therefore, for more than 13 billion years. So one might assume that the radius of the universe is 13.7 billion light-years and that the whole shebang is double that, or 27.4 billion light-years wide.\n\nBut the universe has been expanding ever since the beginning of time, when theorists believe it all sprang forth from an infinitely dense point in a Big Bang.\n\n"All the distance covered by the light in the early universe gets increased by the expansion of the universe," explains Neil Cornish, an astrophysicist at Montana State University. "Think of it like compound interest."\n\nNeed a visual? Imagine the universe just a million years after it was born, Cornish suggests. A batch of light travels for a year, covering one light-year. "At that time, the universe was about 1,000 times smaller than it is today," he said. "Thus, that one light-year has now stretched to become 1,000 light-years."\n\nAll the pieces add up to 78 billion-light-years. The light has not traveled that far, but "the starting point of a photon reaching us today after travelling for 13.7 billion years is now 78 billion light-years away," Cornish said. That would be the radius of the universe, and twice that -- 156 billion light-years -- is the diameter. That's based on a view going 90 percent of the way back in time, so it might be slightly larger.\n\n"It can be thought of as a spherical diameter is the usual sense," Cornish added comfortingly.\n\n(You might have heard the universe is almost surely flat, not spherical. The flatness refers to its geometry being "normal," like what is taught in school; two parallel lines can never cross.)
1183745
Mars is much smaller than Earth.  About 1/2 the diameter (0.53), and 1/10 of the mass (0.107) of the Earth.\n\nHere's a great set of illustrations showing the relative sizes of all the planets, and the sun.\n\nhttp://www.comagz.com/webmagazine/story/proportions_how_small_we_are
1158544
This "nothing" is what we perceive without the laws of physics. Our universe is limited by the knowledge we have about it. Recent theories (the "M" theory) suggest that endless universes exist, and sometimes they even collide one into other. Probably, out there, beyond the boundaries of 12 billions light years, others dimensions, other plan of existence exist.
1020906
Quarks are smaller.  Also the string theory says that quarks can be further divided into strings.  Strings are so small that if an atom is the size of our solar system, then strings are only about as big as a tree.
1048593
Thank you! Very informative (and correct) information!\nWell, according to Physics, the same vast quantities, dimensions etc., we have to the large scale, we also have to the small scale, going from our size into smaller (cells, moles, atoms, electrons, nuclei, ....)\nFurther, according to my theory, the Universe we described above is the connection between other universes! As a matter of fact, each one of us is a Universe greater that the one we usually talk about! After all, people discover the dimensions, Greeks named 4 of them and we, somehow think we understand them! People understand only what has been named! That is why we can not comprehend the other dimensions, since we have not discover how the Greeks named them!
203555
"...the number of atoms in the observable universe can be estimated to be between 4×1078 and 6×1079. However, because of the possibly infinite nature of the universe, the total number of atoms in the entire universe may be much larger or even infinite."\n\nThis website for confirmation and more info --> http://www.biocrawler.com/encyclopedia/Atom