What is the Coldest Place In the Universe? And Other Cool Facts

For each thousand-foot rise in elevation, the average temperature is 5½°F cooler, an effect called the adiabatic lapse rate, if you want to impress people. That 5½°F is using the Fahrenheit scale, which we’ll continue citing since it’s so familiar to Americans. 

We’re aware the rest of the world uses Celsius instead of Fahrenheit, so first, let’s take a moment to ponder that confusion. Daniel Fahrenheit, who did his work in the 18^th century, started by creating the coldest liquid temperature he could easily obtain in his lab by mixing ice, water, and salt, and called that “zero.” He then created his scale and the size of each of its degrees so that water’s boiling and freezing points would be 180 degrees apart, 212° and 32°. 

Cold Fact #1

And here’s where we get to the first cool thing you probably never knew. Fahrenheit’s freezing and boiling points exist because he specifically wanted a 180-degree spread between water’s “opposites,” which he deemed to be freezing and boiling. And 180 degrees was (and still is) used everywhere to designate opposites: That many degrees denotes antipodal points on every circle, like when we still speak of a military “about face” as the soldier “doing a 180.”

Unlike ice and steam, which occur in vast temperature ranges—nearly a half thousand degrees for ice and several thousand for steam—water narrowly exists at only 180 degrees on the Fahrenheit scale. 

Cold Fact #2

And, second cool thing: water’s existence range gets narrower if you’re not at sea level. Water boils one degree lower for every 550 feet of altitude. Atop Mt. Washington in New Hampshire, the hottest coffee is 12 degrees cooler than it is in Boston. You can easily feel that difference since water is 800 times denser than air, and any small liquid temperature change is very noticeable, as hot tub owners will tell you.

As you continue to climb, the boiling point keeps plummeting until, at 63,000 feet, water boils at body temperature. This is called the Armstrong Limit. It’s where exposed body fluids like tears or nose drippiness boil immediately. So you don’t want to go there. And no, it’s not named after astronaut Neil Armstrong.

 So happens, liquid water can only exist under pressure. The oceans on Jupiter’s moon Europa are liquid only because the thick ice covering that world supplies the needed pressure. Here on Earth, our atmosphere provides the pressure that lets us have lakes and seas. But just try to bring a pail of water to Mars, whose air pressure is just one percent of ours. It would boil immediately while simultaneously freezing solid, producing a grotesquely distorted ice sculpture. Same with the Moon. No bird baths possible there.

It thus might seem that space, way beyond the Armstrong Limit, would be absolutely cold. But it isn’t …

Cold Fact #3

Space, being a vacuum, has no temperature at all. That’s because temperature (fun fact number three) is merely a way to express the motion of atoms. Whether a solid, liquid, or gas, any object’s temperature is simply how fast its atoms move or jiggle. Room temperature air molecules jiggle at 1,036 miles an hour. But space, being basically nothingness, has no temperature at all.  

If you place any object like yourself in space, heat will be lost from your body. But it will happen slowly, and you will not feel cold very quickly because, like a thermos bottle with a low-pressure seal inside, your skin’s jiggling atoms would have nothing to jiggle against to slow them down. So, space is actually rather protective of a person’s body heat! But eventually, you’d reach equilibrium with your surroundings. 

We used to think that was “absolute zero,” something we’ll get to in a minute. But we’ve known since the ‘60s that the leftover energy from the Big Bang permeates all of space and is equivalent to 3.726 degrees above absolute zero Celsius or Kelvin or -455 degrees Fahrenheit. So that’s the coldest anything in space can get.

Or so we thought.

The Coldest Place in the Universe?

In 1995, astronomers studying the Boomerang Nebula in the constellation Centaurus discovered it was expanding. When anything expands, it cools, like a whipped cream can when you push its nozzle. So that’s the coldest known place in the universe.

A planetary nebula is a region of cosmic gas and dust formed from the cast-off outer layers of a dying star. Boomerang is expanding more rapidly because its dying star is losing its mass about 100 times faster than other similar dying stars and 100 billion times faster than Earth’s Sun. 

Dr. Raghvendra Sahai of NASA’s Jet Propulsion Laboratory, Pasadena, CA, who co-discovered the cold region, says that it “has a temperature of about 1 Kelvin, or minus 458 degrees Fahrenheit. It represents the outer regions of a cold wind being blown by a dying star.

 Even the -455° background glow from the Big Bang is warmer than this nebula. It is the only object found so far with a temperature lower than the background radiation.

The Actual Coldest Place in the Universe

The coldest natural place, that is. Lord Kelvin, a 19th-century experimenter, realized that things can be much colder than the zero point on either the Fahrenheit or the Celsius scale. (Anders Celsius had simply set his zero point at water’s freezing point.) 

Countless experimentation came to the conclusion that all atomic motion stops when anything reaches -459.67 F. And since atoms can’t go any slower than “stopped,” that’s the coldest anything can get. Kelvin called it “absolute zero.” Science honored that insight by calling that temperature “zero degrees K” or zero Kelvin. Each of Kelvin’s degrees is the same size as Celsius’—roughly twice as big as Fahrenheit’s – but, as we’ve seen, the scales begin at very different places.

Modern science labs have cleverly achieved coldness just a few billionths of a degree above absolute zero. This is cool (no pun intended) because some bizarre things happen when substances approach that temperature. 

1. First, they lose their viscosity or resistance to motion. When helium is cooled to that temperature, which makes it a liquid, it scampers up and out of its container as if gravity doesn’t exist.

2. Second, even way before that degree of coldness, conductors lose all resistance to electrical flow. But the strangest phenomenon was predicted by Albert Einstein in 1924 when he basically wrote up an idea proposed by the Indian physicist Satyendra Nath Bose. You see, quantum mechanics says that you can never simultaneously know both the motion and the position of tiny things. But consider that at absolute zero, we know particles have no motion, so that fact is already at hand. And when we study such an object, we can see its position—it’s right there. So, doesn’t this violate the strange quantum realm?

Not so, said those brilliant guys. A change must happen to preserve the truth of quantum mechanics. And so it does. As anything nears absolute zero, its atoms duly reach a standstill, as expected. But something else also unfolds, something bizarre. Instead of us seeing innumerable separate particles, which would have given us forbidden knowledge of their locations, they all turn blurry and merge into a single new fuzzy entity, a kind of super atom, in which their individualities essentially merge and thus vanish.

This constitutes a brand new state of matter, neither a gas, liquid, solid, or plasma. And it exhibits a range of never-before-seen properties, just as gases are very different from solids. Well, on June 5, 1995, the coldest-ever temperature was finally achieved, and a team of scientists created the first Bose Einstein condensate—the fifth state of matter.

Space by itself, thanks to the little warmth of the cosmic microwave background that fills the entire universe, doesn’t provide the needed chill for the Condensate to be able to be a feature on alien worlds. So the strange new Condensate, along with the coldest temperatures anywhere in the known universe, are items found only here on Earth!