Hippos can’t swim. Hippos do have big bones, so big and dense that they’re barely buoyant at all. They don’t swim and instead perform a slow-motion gallop on the riverbed or the sea floor. Hippos can even sleep underwater, thanks to a built-in reflex that allows them to bob up, take a breath, and sink back down without waking.
100 Mind-Blowing Dense Facts
It rains methane on Saturn’s largest moon. Titan is the only moon in our Solar System with a dense atmosphere and the only body except Earth with liquid rivers, lakes and seas fed by rainfall. This rainfall isn’t water, though; it’s liquid methane.
Birds have hollow bones which help them fly. Birds are unique creatures with many interesting facts to feature. However, one of their more creepy features is their hollow bones. Deep inside, birds are pretty much paper mache. While humans have dense bones filled with marrow, most birds of flight have only air and struts in their bones.
Farmers plant tall, dense trees on the edges of farms. The trees provide a barrier to harsh weather and prevent soil erosion.
The lungs are the only organs that can float on water. The shortest explanation is that air is less dense than water. With air in our lungs, we float. Each lung cavity has about 300 million balloon-like structures called alveoli. Proper breathing is crucial to swimming because you’d sink (not to mention, drown) without air in your lungs.
Cans of diet soda will float in water, regular soda cans will sink. It sounds ironic, but this funny fact is proven. Cans of regular soda tend to be more dense than water, so they sink. Cans of diet soda are usually less dense than water, so they float.
Hippopotamuses can’t swim. We always see them in the water, but hippos can’t swim. Their bones are large and dense, making it hard for them to float. Instead, they do a sort of “slow-motion gallop on the riverbed or on the sea floor.”
1 tsp of neutron star weighs the same as the human population. A neutron star’s density is mind-boggling. These stars are composed almost entirely of neutrons packed together in a tiny radius. Just a teaspoonful of this material would weigh over a trillion kilograms — more than the weight of the entire human population (which reaches a few hundred billion kilograms). To make something as dense as a neutron star, the whole of humanity would need to be crammed into a space the size of a sugar cube.
Jupiter’s magnetic field is bigger than the Moon. The region of space in which a mass’s magnetic field dominates is known as its magnetosphere. These regions surround planets, pulsars and even our Galaxy. The planets in our Solar System have magnetospheres that interact with and are shaped by the charged particles in the wind streaming from our Sun. The largest magnetosphere in our Solar System surrounds Jupiter. Jupiter rotates very fast and has a very strong magnetic field, and its magnetosphere is filled with plasma from its volcanically active moon, Io. These features, coupled with the fact that the solar wind is slower and less dense at Jupiter than at Earth, lead to a very sizeable Jovian magnetosphere. It is easily big enough to contain a body the size of our Sun and, if visible, would be larger than the Moon in our night sky; quite an achievement considering that it is over 1,500 times farther away.
Black holes give off light. Venture beyond the event horizon and you’ll not be able to escape the powerful gravity of a black hole. Black holes are objects so dense that not even light can escape their gravitational pull. Yet despite this, black holes can shine brightly, and this may be one of the most contradictory-sounding facts about space on our list. Supermassive black holes can illuminate the centre of galaxies and are known as active galactic nuclei. How can this be? As cosmic material falls into a black hole, it forms an accretion disc that swirls around it. This material gets very hot and glows: it can even power jets of material that shoot out of the black hole into space. This all occurs just outside the event horizon and is one of the ways astronomers can detect black holes even though they can observe them directly.