Never trust a high altitude astronomer.

There is a lot of willful incompetence in high altitude astronomy that is in the process of coming to light.

My memories of my time in high altitude astronomy indicate that there were no oxygen concentration monitors or alarms in the areas that liquid nitrogen was in use at the high altitude astronomical facilities where I had worked.

The toxicity of medical and industrial gas to the human depends on where it is used. A gas that is regarded as safe in a well ventilated environment at sea level may be a toxic gas in an indoor environment at high altitude.

When I worked in astronomy, I routinely observed young college and university students working with liquid nitrogen and breathing nitrogen gas as they discharged it into the indoor environment at high altitude.

In high altitude astronomical facilities we routinely discharged large amounts of nitrogen gas into closed spaces. We were never informed by the astronomy management team about the abnormally low oxygen environments that the use of liquid nitrogen creates, how long term exposure to it manifests itself in human health and the resulting abnormal mental behaviors.