If the Milky Way has a mass near to the average that means the observable universe has … If the average distance between galaxies is 2 Mpc, and the average mass of a galaxy is 10^11 solar masses estimate the average density of the universe in kilograms per cubic meter only.
What is the density of the universe? This suggests that the universe began – very small and very dense – about 13.8 billion years ago, and it has expanded and (on average) become less dense ever since. WMAP determined that the universe is flat, from which it follows that the mean energy density in the universe is equal to the critical density (within a 0.5% margin of error). On average, each star can weigh about 10 35 ... the overall matter density of the universe remains the same over time.
The shape of the universe depends on its density.
There are an estimated 1.25×10^11 (125 billion) galaxies in the observable universe. The present density of the observable universe is estimated to be very low – roughly 9.9 × 10-30 grams per cubic centimeter. Spazzy- McGee . The present day average density of the universe is only a few percent of the critical density, much less than the amount needed to close the universe. Observations indicate that the universe is flat, but even when dark matter is taken into account, the observed density of matter accounts for only about 25-30% of the critical density. To date, the critical density is estimated to be approximately five atoms (of monatomic hydrogen) per cubic metre, whereas the average density of ordinary matter in the Universe is believed to be 0.2–0.25 atoms per cubic metre. The density of the universe means the amount of matter there is per unit volume, averaged for the entire universe. To put this in perspective, the Solar System is thought to be 4.5 billion years old and humans have existed as a genus for only a few million years.
Confirmation of the Big Bang mostly depends on knowing the rate of expansion, average density of matter, and the physical properties of the mass–energy in the universe. Thats 1.2×10^42 kg. Favorite Answer. If the density is more than the critical density, the universe is closed and curves like a sphere; if less, it will curve like a saddle. 4 Answers.
This critical mass density is currently equal to 6e-27 kg/m^3.
But in you, normal matter outmasses dark matter by 2 x 10 24! Another way to try to find the density would be to study the way the universe is working. That’s two septillion times.
The average density of the universe can be used to determine if the universe is open or closed.
Until recently, astronomers estimated that the Big Bang occurred between 12 and 14 billion years ago. The Friedmann equations start with the simplifying assumption that the universe is spatially ... the critical density is estimated to be approximately five atoms (of monatomic hydrogen) per cubic metre, whereas the average density of ordinary matter in the Universe is believed to be 0.2–0.25 atoms per cubic metre.
If the Universe is at the critical density, then the total mass of the Universe is closer to 1e53 kg, and the number of atoms (assuming that most of the mass is in the form of hydrogen atoms) about 6e79. Eg. First, find the average distances of the 6 nearest major galaxies to the Milky Way, and assume the Galaxy occupies a sphere of diameter half this average distance. One way to find the average density would be to add up all the matter in the universe and then divide by the number of cubic meters in the universe. The mass of our galaxy is 5.8×10^10 M☉ or solar masses. This is equivalent to a mass density of 9.9 x 10 -30 g/cm 3 , which is equivalent to only 5.9 protons per cubic meter.
However, this process is difficult to accomplish. Answer Save. A system with a wooden block with iron nails in it has an average density somewhere between wood and iron. The total weight of a system divided by its total volume. Lv 6.
Assume a galaxy is 'major' if its mass is greater than 50% of the Milky Way, otherwise minor.