Low temperature physics dangerous?

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Discussion Overview

The discussion revolves around the potential dangers associated with extremely low temperatures, particularly those approaching a fraction of a kelvin. Participants explore various aspects of low temperature physics, including human safety, material behavior, and theoretical implications such as vacuum decay.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • Some participants express concern about the dangers of temperatures at a fraction of a kelvin, questioning if such conditions could lead to vacuum decay in confined spaces.
  • Others argue that temperatures below 20°C can be dangerous for the human body, but suggest that materials at temperatures below 1K primarily pose a risk of frostbite rather than significant danger.
  • A participant notes that air at low temperatures could become liquid, which may present a fire hazard due to concentrated oxygen.
  • Some participants assert that it is unlikely for anyone to come into contact with materials at temperatures below 1K, as they would not survive long enough for contact to occur.
  • There are repeated inquiries about the concept of vacuum decay, with one participant requesting references to the physics behind it, suggesting skepticism about its relevance to the discussion.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the dangers of low temperature experiments. While some express concerns about potential risks, others downplay these dangers and question the feasibility of encountering such low temperatures.

Contextual Notes

Some claims depend on specific definitions of danger and the context of low temperature experiments. The discussion includes unresolved questions about vacuum decay and its implications.

stuart1
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Could temperatures at a fraction of a kelvin be dangerous? We have only naturally observed temperatures of 1k

But in a lab they did 100pk
 
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Temperatures of less then 20°C of the whole body and temperatures of less then about 0°C below the skin are dangerous for the human body. Just prevent these things from happening. If you have a block of copper somewhere at less then 1K it will just collect frost on top and not much will happen. If you touch it you will get frostbite. That's it. No worries. The reason why temperatures lower than say 10K are not much more dangerous than temperatures around 10K is that most substances have already lost all their heat capacity at 10K. (Boiling helium is an exception, in that is has a significant enthalpy of vaporization at 4.2K)
 
I wonder if low temperature experiments at a tiny fraction of a Kelvin could be dangerous.
Could a vacuum decay occur if you lower the temperature of a confined space sufficiently?
 
Air at low temperatures could turn liquid which would be a possible fire hazard with the highly concentrated Oxygen present.
 
stuart1 said:
I wonder if low temperature experiments at a tiny fraction of a Kelvin could be dangerous.
Could a vacuum decay occur if you lower the temperature of a confined space sufficiently?

We've gotten things REALLY REALLY cold already. The record is 100 picokelvins, 0.0000000001 k.
http://en.wikipedia.org/wiki/Absolute_zero#Very_low_temperatures
 
I wouldn't worry.
There's no way you can possibly come into contact with something less than a kelvin.

It wouldn't survive long enough for you to touch it.
 
stuart1 said:
I wonder if low temperature experiments at a tiny fraction of a Kelvin could be dangerous.
Could a vacuum decay occur if you lower the temperature of a confined space sufficiently?

I am waiting for the OP to come back and produce the references to the physics of "vacuum decay". If not this is a "When did you stop beating your wife?" question, and this thread will be closed.

Zz.
 
ZapperZ said:
I am waiting for the OP to come back and produce the references to the physics of "vacuum decay". If not this is a "When did you stop beating your wife?" question, and this thread will be closed.

Zz.

Oh!
I didn't realize...
The guy is worried about them crazy scientists messing with the universe?
 

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