Absolutely Significant

The Significant Figures site has got almost totally waylaid with computing tips and tricks for bloggers hoping to get the best out of their software or fix stuff when it goes wrong. It’s almost like we’ve abandoned our diehard MoanWare and sigfig fans, so here’s a quickie numerical post inspired by a query over on The Straight Dope. It is not exactly chat up line material, but you never know.

Think absolute zero, and some of us picture a chilly summer’s day in northern England, but seriously absolute zero is as cold as you can go. Atoms are almost at a standstill, there’s virtually no vibration, and only the minute fluctuations of Heisenberg’s Uncertainty Principle come into play at the theoretical limit of the Big Zero, zero Kelvin, that is. While absolute zero (minus 273.15 Celsius, you will have to use our online conversion tool to get a Fahrenheit value yourself) is a theoretical limit nothing ever gets that cold, even outer space resides at a balmy fraction of a degree above 0.00000000 K. The coldest scientists have ever taken a material is within a few billionths of a degree above the absolute. In 1994, a NIST team cooled a material to 700 nanoKelvin, and in 2003, MIT scientists reached 450 picoKelvin (0.45 nK).

But, what about the other end of the scale is there a super hot temperature beyond which nothing can be heated further? Well, according to the Straight Dope there is indeed and it is an incredibly big number - a ten followed by 32 zeros Kelvin (10^32 K). That’s greatly hotter than the center of the Sun, which merely sizzles at 15 million degrees K (15×10^6 K). The opposite of absolute zero is known as the Planck temperature, after the “constant” scientist and is the theoretical upper limit on just how much energy a material could have.

So, what limits temperature, why can a material not be heated and heated to an infinite temperature. Well, the simple answer is that there is just not enough energy in the universe to go above the Planck temperature, but even if there were, the vibrating particles in a substance would have to move so fast that they would outpace the speed of light, something that, in the vacuum of the spaces in between atoms, is not possible. But, even if they could be shaken faster than that mass increases (viz E=mc²) as vibration speed rises and ultimately each shaken (but not stirred) particle would become its own black hole as its mass approached infinity, at which point the laws of physics break down and the whole conundrum would collapse in the biggest fry up you could ever imagine.

Meanwhile, back the Big Bang, theorists have worked out that a minute fraction of time (Planck time, 0.0….1 seconds, where …. represents 41 more zeroes) after that universal event, the temperature of the universe was the Planck Temperature. Things have been getting more and more chilled out ever since. Never mind global warming, we are talking universal cooling on a grand scale.