your soda drink. Normally it will pretty much stay put in which ever container you may keep it. It will not creep out by itself, because of its own weight, or differently stated: Because gravity keeps your drink where it belongs. But in an orbit with zero gravity, how to keep our liquid HeII nice and well-behaved? - If questions like this one have to be dealt with, of course you will not say "at zero gravity" all daFor a couple of years, I was working with superfluid helium in a low-temperature physics lab. Helium is the second lightest element, right after hydrogen, the lightest. Like all gases, helium changes from the gaseous state to the liquid state when cooled down sufficiently. (Some gases additionally need higher than atmospheric pressure to get liquid.) But at normal pressure, it will never solidify. And amongst its other amazing properties, when cooled down nearly to the absolute Zero of temperature, liquid helium acquires the ability to move without friction, a property which is called "Superfluidity".

In that strange state, it is the ideal cooling medium if you have to cool something down to temperatures that low. "Superfluid helium" is somewhat long if you have to say and write it hundred times a day. So physicists call it helium two, written HeII.

We have been a bunch of excited people working long hours in the lab doing superfluidity research. Everybody we had contact with was somehow related to our work. Everybody understood what we meant when talking about HeII.

Our work was not just basic research. We worked for an application of our findings. In those days, there have been outer space telescope projects like the IRAS satellite where sensors had to be liquid helium cooled to work properly. Our team was to provide a means to control a superfluid helium tank which had to be taken into orbit alongside with the other appliances.

In orbit, there is no gravity. You may have seen TV pictures of people and stuff aboard a space shuttle moving around in all directions, and water drops exactly round floating in mid-air. Well, think of your soda drink. Normally it will pretty much stay put in which ever container you may keep it. It will not creep out by itself, because of its own weight, or differently stated: Because gravity keeps your drink where it belongs. But in an orbit with zero gravity, how to keep our liquid HeII nice and well-behaved? - If questions like this one have to be dealt with, of course you will not say "at zero gravity" all day

er amazing properties, when cooled down nearly to the absolute Zero of temperature, liquid helium acquires the ability to move without friction, a property which is called "Superfluidity".

In that strange state, it is the ideal cooling medium if you have to cool something down to temperatures that low. "Superfluid helium" is somewhat long if you have to say and write it hundred times a day. So physicists call it helium two, written HeII.

We have been a bunch of excited people working long hours in the lab doing superfluidity research. Everybody we had contact with was somehow related to our work. Everybody understood what we meant when talking about HeII.

Our work was not just basic research. We worked for an application of our findings. In those days, there have been outer space telescope projects like the IRAS satellite where sensors had to be liquid helium cooled to work properly. Our team was to provide a means to control a superfluid helium tank which had to be taken into orbit alongside with the other appliances.

In orbit, there is no gravity. You may have seen TV pictures of people and stuff aboard a space shuttle moving around in all directions, and water drops exactly round floating in mid-air. Well, think of your soda drink. Normally it will pretty much stay put in which ever container you may keep it. It will not creep out by itself, because of its own weight, or differently stated: Because gravity keeps your drink where it belongs. But in an orbit with zero gravity, how to keep our liquid HeII nice and well-behaved? - If questions like this one have to be dealt with, of course you will not say "at zero gravity" all da

t helium two, written HeII.

We have been a bunch of excited people working long hours in the lab doing superfluidity research. Everybody we had contact with was somehow related to our work. Everybody understood what we meant when talking about HeII.

Our work was not just basic research. We worked for an application of our findings. In those days, there have been outer space telescope projects like the IRAS satellite where sensors had to be liquid helium cooled to work properly. Our team was to provide a means to control a superfluid helium tank which had to be taken into orbit alongside with the other appliances.

In orbit, there is no gravity. You may have seen TV pictures of people and stuff aboard a space shuttle moving around in all directions, and water drops exactly round floating in mid-air. Well, think of your soda drink. Normally it will pretty much stay put in which ever container you may keep it. It will not creep out by itself, because of its own weight, or differently stated: Because gravity keeps your drink where it belongs. But in an orbit with zero gravity, how to keep our liquid HeII nice and well-behaved? - If questions like this one have to be dealt with, of course you will not say "at zero gravity" all da

satellite where sensors had to be liquid helium cooled to work properly. Our team was to provide a means to control a superfluid helium tank which had to be taken into orbit alongside with the other appliances.

In orbit, there is no gravity. You may have seen TV pictures of people and stuff aboard a space shuttle moving around in all directions, and water drops exactly round floating in mid-air. Well, think of your soda drink. Normally it will pretty much stay put in which ever container you may keep it. It will not creep out by itself, because of its own weight, or differently stated: Because gravity keeps your drink where it belongs. But in an orbit with zero gravity, how to keep our liquid HeII nice and well-behaved? - If questions like this one have to be dealt with, of course you will not say "at zero gravity" all da

your soda drink. Normally it will pretty much stay put in which ever container you may keep it. It will not creep out by itself, because of its own weight, or differently stated: Because gravity keeps your drink where it belongs. But in an orbit with zero gravity, how to keep our liquid HeII nice and well-behaved? - If questions like this one have to be dealt with, of course you will not say "at zero gravity" all day long. The usual symbol for "gravity" is "g". So physicists would say: "at g equal zero" or "at zero g" and write "g=0".

The colleague with whom I worked closest in those days was a nice young blond lady. I told you already that we have been excited about our work, so don't suppose ANYTHING now. When funds were low again and her contract was about to finish, rather than looking for another better paid job, she was seeking unemployment benefits to be able to continue work "free of charge" for our project and bridge the gap to our next project funding date. So she had to go out to the real world outside the lab.

She came back somewhat bewildered from her visit to the employment office. "The lady there asked me what I am presently doing and how I am paid. So I told her I am working with HeII at zero g. She then got a very strange disquieted expression on her face, no idea why. I figured I'd better go!" - Well, it took me a while, but finally it dawned on me... we had just lost touch with the world outside our niche. Must have been some alien experience for that employment office employee. My colleague was lucky to have such an inoffensive look; else she might have ended up in a strait jacket.

Guess why scientists are always depicted as maniacs in cartoons.

If you are interested in a look at the extreme world of physics which doesn't require you to be first introduced to extremely outlandish lingo, and specifically if you are interested in helium, have a look here:

Regards,