# How to make a "super-cooled" vacuum? **URL:** \ **Category:** Factual Questions\ **Created:** [January 4, 2011, 8:10pm UTC](https://boards.straightdope.com/t/how-to-make-a-super-cooled-vacuum/566409 "2011-01-04T20:10:35Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [January 4, 2011, 8:10pm UTC](https://boards.straightdope.com/t/how-to-make-a-super-cooled-vacuum/566409/1 "2011-01-04T20:10:35Z")
I’m always reading about this new particle or process designed with the aid of, or only existing, in some vacuum “1 bazillionth above absolute zero.” How do they make such devices? How do they even _measure_ such temperatures? ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [January 4, 2011, 8:32pm UTC](https://boards.straightdope.com/t/how-to-make-a-super-cooled-vacuum/566409/2 "2011-01-04T20:32:03Z")
Vacuum has no temperature. Temperature is a measure of energy content of a substance. No substance, no temperature. As for how you achieve really low temperatures, that’s a fascinating topic on its own. There are many stratagems and dodges, depending on what your temperature already is. The lower you go, the harder it becomes and thecleverer you have to be. here’s a start: > **[Refrigeration](https://en.wikipedia.org/wiki/Refrigeration)** > > Refrigeration is any of various types of cooling of a space, substance, or system to lower and/or maintain its temperature below the ambient one (while the removed heat is ejected to a place of higher temperature). Refrigeration is an artificial, or human-made, cooling method. > Refrigeration refers to the process by which energy, in the form of heat, is removed from a low-temperature medium and transferred to a high-temperature medium. This work of energy transfer is traditionally driven by mech... > **[EDN - Voice of the Engineer](https://www.edn.com/)** > > Electronic Design News (EDN) is an electronics community for engineers, by engineers. Find the latest articles, magazines, tools, and blogs in the industry. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [January 4, 2011, 8:33pm UTC](https://boards.straightdope.com/t/how-to-make-a-super-cooled-vacuum/566409/3 "2011-01-04T20:33:49Z")
> **[Cryocooler](https://en.wikipedia.org/wiki/Cryocoolers)** > > A refrigerator designed to reach cryogenic temperatures (below 120 K, −153 °C) is often called a cryocooler. The term is most often used for smaller systems, typically table-top size, with input powers less than about 20 kW. Some can have input powers as low as 2–3 W. Large systems, such as those used for cooling the superconducting magnets in particle accelerators are more often called cryogenic refrigerators. Their input powers can be as high as 1 MW. In most cases cryocoolers use a cryogenic f... > **[Laser cooling](https://en.wikipedia.org/wiki/Laser_cooling)** > > Laser cooling includes a number of techniques in which atoms, molecules, and small mechanical systems are cooled, often approaching temperatures near absolute zero. Laser cooling techniques rely on the fact that when an object (usually an atom) absorbs and re-emits a photon (a particle of light) its momentum changes. For an ensemble of particles, their thermodynamic temperature is proportional to the variance in their velocity. That is, more homogeneous velocities among particles corresponds to ... ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [January 4, 2011, 9:29pm UTC](https://boards.straightdope.com/t/how-to-make-a-super-cooled-vacuum/566409/4 "2011-01-04T21:29:05Z")
Thank you. The measurement link was more my speed…But I’m interested enough to kind of slog though, with minimum understanding–Welcome to my World–the other stuff. Leo ---
**Author:** ![Kevbo](https://avatars.discourse-cdn.com/v4/letter/k/e47774/32.png) [@Kevbo](https://boards.straightdope.com/u/Kevbo)\ **Post date:** [January 4, 2011, 11:42pm UTC](https://boards.straightdope.com/t/how-to-make-a-super-cooled-vacuum/566409/5 "2011-01-04T23:42:08Z")
> **[NOVA | Absolute Zero | PBS](https://www.pbs.org/wgbh/nova/zero/)** > > In this companion Web site to the NOVA program Absolute Zero, learn about the theoretical upper limit of temperature, find an article by author Tom Shachtman on the cultural impact of artificial refrigeration, read an interview with physicist Luis... A bit thin on details, but a good story. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [January 5, 2011, 12:32am UTC](https://boards.straightdope.com/t/how-to-make-a-super-cooled-vacuum/566409/6 "2011-01-05T00:32:15Z")
> [@Kevbo](#): > > [NOVA | Absolute Zero | PBS](http://www.pbs.org/wgbh/nova/zero/) > > A bit thin on details, but a good story. Thank you very much. ---
**Author:** ![GameHat](https://avatars.discourse-cdn.com/v4/letter/g/ed655f/32.png) [@GameHat](https://boards.straightdope.com/u/GameHat)\ **Post date:** [January 5, 2011, 3:13am UTC](https://boards.straightdope.com/t/how-to-make-a-super-cooled-vacuum/566409/7 "2011-01-05T03:13:19Z")
> [@Kevbo](#): > > [NOVA | Absolute Zero | PBS](http://www.pbs.org/wgbh/nova/zero/) > > A bit thin on details, but a good story. Sorry, this is incorrect. It’s a **fascinating** story.