"We are able to measure the local dark matter density using direct acceleration measurements for the first time." ...

"We are able to measure the local dark matter density using direct acceleration measurements for the first time. And on average we find that there's less than 1 kilogram of dark matter in a volume ...

At first, the photons settle into a state with zero momentum, but as this state 'fills up', pairs of photons begin to spill ...

Astrophysics Professor Neta Bahcall discusses her research on dark matter and its effects on the expansion of the universe.

Density also depends on the material. A piece of iron with the same dimensions as a piece of aluminium will be heavier because the atoms are more closely packed and each iron atom has much more ...

If something seems very heavy for its size (like a heavy metal object), we say it is more dense. If something seems light for its size (like a bag of cotton or pumice rock), then we say it has low ...

The same mass of liquid will have slightly greater volume than the solid. As density equals \(\frac{\text{mass}}{\text{volume}}\), the liquid will have slightly lower density. The density of solid ...

Density in particular is an important property ... Physical properties vary with the amount of heat and the amount of dissolved matter contained in the water, as well as the ambient pressure.