Tadokoro, 1968) is calculated to be 7 x 10^-29 grams per cubic centimeter, which translates to about 40 hydrogen atoms per cubic meter. The best vacuum ever constructed on Earth was done at CERN at reported to achieve a density of about 1000 atoms per cubic centimeter.
The best man-made vacuum so far, Extreme Ultra-high Vacuum, ≈ 10Torr, corresponds roughly to a density of ≈ 3×10particles per cubic meter. The average density of the entire Universe (as calculated by WMAP/NASA), is said to be ≈ 9.9×10kg/m, equivalent to ≈ 5.9 particles (protons) per cubic meter.
Answer. Practically, it is impossible to make a perfect vacuum. A perfect vacuum is defined as a region in space without any particles.
The best vacuum in a laboratory setting has a pressure around 13 picoPascals (13 x 10-12 Pa). A cryogenic vacuum system achieves a near-perfect vacuum with a pressure around 6.7 femtoPascals (6.7 x 10-15 Pa).
Ultimately, a perfect vacuum isn't possible because quantum theory dictates that energy fluctuations known as 'virtual particles' are constantly popping in and out of existence, even in 'empty' space. Read more: How can something explode in the vacuum of space?
Any negative pressure significantly below standard atmospheric pressure (760 Torr/mmHg, 29.9 inHg or 14.7 PSI) is considered a vacuum.
Another option is that the universe is, in some sense, in a temporary state and what we think of as reality is what is called a false vacuum. A false vacuum occurs when a field has two “ground” states, one higher than the other. You can think of the false vacuum as being like a valley.
The ultimate vacuum, defined as the lowest pressure that can be produced and measured reproducibly in a vacuum system at room temperature, has decreased by a factor of about 10 since the first measurement of sub-atmospheric pressure by Robert Boyle in about 1660.
Because the maximum theoretical vacuum at sea level is 29.92 in. -Hg, actual pump capabilities are based on and compared to this theoretical value. Depending on pump design, the vacuum limit ranges from 28 to 29.5 in.
Absolute Pressure
Vacuum can refer to any pressure between 0 PSIA and 14.7 PSIA and consequently must be further defined. For applications concerned with measuring vacuum pressures over this full range, two different approaches are often taken.
—Why does outer space look black? "No human can survive this — death is likely in less than two minutes," Lehnhardt said. According to NASA's bioastronautics data book, the vacuum of space would also pull air out of your lungs, causing you to suffocate within minutes.
Complex, multi-cellular life wouldn't be able to survive in a vacuum, but microbes might. Microbiologists have discovered extremophiles – microbes that can survive in extreme conditions – such as Deinococcus radiodurans, which can survive high levels of radiation, as well as a vacuum, a lack of water and cold.
Without air in your lungs, blood will stop sending oxygen to your brain. You'll pass out after about 15 seconds. 90 seconds after exposure, you'll die from asphyxiation. It's also very cold in space.
The maximum strength of vacuum at see level is about -15 psi. A related phenomenon that could help you better understand the limit of vacuum is: what is the loudest sinusoidal wave possible at see level? The answer turns out to be about 194 db.
A perfect vacuum, if measured in absolute terms is zero (0 inches Hg) but is 29.92 in-Hg V (-29.92 in-Hg G) if the measured units are deemed relative (vacuum or gauge).
But Einstein showed that the universe does, in fact, have a speed limit: the speed of light in a vacuum (that is, empty space). Nothing can travel faster than 300,000 kilometers per second (186,000 miles per second). Only massless particles, including photons, which make up light, can travel at that speed.
It is therefore called a black hole, and its surface is called the "event horizon." But contrary to popular myth, a black hole is not a cosmic vacuum cleaner. If our Sun was suddenly replaced with a black hole of the same mass, Earth's orbit around the Sun would be unchanged.
Thus, according to the theory, even the vacuum has a vastly complex structure and all calculations of quantum field theory must be made in relation to this model of the vacuum. Summing over all possible oscillators at all points in space gives an infinite quantity.
The vacuum you can make by sucking is limited by the amount your lungs can expand. For an average man the residual volume (least amount of air you can have in your lungs) is about 1 litre while the total lung capacity is about 6 litres.
Ultrahigh vacuum (UHV) is defined as the pressure range between 10-6 Pa (in Europe) or 10-7 Pa (in the USA) and 10-10 Pa; extreme high vacuum (XHV) is defined as the range of pressure below 10-10 Pa (7.5 × 10-13 Torr or 10-12 mbar).
Perfect vacuum is an ideal state of no particles at all. It cannot be achieved in a laboratory, although there may be small volumes which, for a brief moment, happen to have no particles of matter in them.
By definition, a vacuum is devoid of matter. Space is almost an absolute vacuum, not because of suction but because it's nearly empty. Related: What would happen if you shot a gun in space? That emptiness results in an extremely low pressure.
At nearly 330 million light-years in diameter (approximately 0.27% of the diameter of the observable universe), or nearly 236,000 Mpc3 in volume, the Boötes Void is one of the largest known voids in the Universe, and is referred to as a supervoid.
Our Galaxy Is Also Surrounded By A Void. Not only is the inside of the Milky Way home to a big void, but chances are we're also surrounded by one. This is known as a Local Void, and likely surrounds the outside of the Milky Way galaxy. However, our galaxy tends to move towards areas with more density.
Authors' example. In their paper, the authors consider a hypothetical example with w = −1.5, H0 = 70 km/s/Mpc, and Ωm = 0.3, in which case the Big Rip would happen approximately 22 billion years from the present.