Speaking of tricky physics questions (space-related).
I'm tagging along on the Apollo 11 mission.
When Neil is done with his pompous statements about small and giant leaps for mankind in general, I finally get to climb out of the spacecraft and start my work.
So now I'm thinking of starting with measuring the temperature on the moon.
Yes, and how do you do that?
And what kind of results can you expect?
I'm tagging along on the Apollo 11 mission.
When Neil is done with his pompous statements about small and giant leaps for mankind in general, I finally get to climb out of the spacecraft and start my work.
So now I'm thinking of starting with measuring the temperature on the moon.
Yes, and how do you do that?
And what kind of results can you expect?
Sticking a thermometer into the dust? 
Edit: Otherwise, it works well to measure with an IR camera from Earth. You just have to account for/calibrate away the atmosphere's attenuation and self-radiation.
Edit: Otherwise, it works well to measure with an IR camera from Earth. You just have to account for/calibrate away the atmosphere's attenuation and self-radiation.
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Well, it's only matter that can have a temperature, and on the moon, there's no atmosphere, i.e., no gaseous matter that can have a temperature in the same way as here on Earth. So it's reasonable to assume that the question refers to the temperature of the moon's surface, which varies from about -200 C to about +100 C, as I recall.
Yes, it's a bit of a trick question since "outside temperature" doesn't quite work as we envision it here on Earth. In the absence of a medium to measure in/on, it becomes tricky. If the moon were surrounded by an atmosphere or liquid, we could measure in that medium, in the same way as on Earth.
So it requires first defining what we want to know, in order to then determine how and where we should measure.
We can check the speed of particles in the moon's "atmosphere" because even though it's virtually a vacuum, there are still some particles. This gives a (high) temperature as an answer. But it's a rather pointless task nonetheless.
We can try to measure incoming radiation (mainly from the sun), but then we get an indication of energy, not temperature. And an enormous difference between night and day.
We can attempt to determine the temperature of the moon's surface itself. A little bit below the surface should provide some kind of average of the heating from day and night radiation. Nighttime radiation would presumably be directed from the moon out into space.
The error lies mainly in the question itself.
So it requires first defining what we want to know, in order to then determine how and where we should measure.
We can check the speed of particles in the moon's "atmosphere" because even though it's virtually a vacuum, there are still some particles. This gives a (high) temperature as an answer. But it's a rather pointless task nonetheless.
We can try to measure incoming radiation (mainly from the sun), but then we get an indication of energy, not temperature. And an enormous difference between night and day.
We can attempt to determine the temperature of the moon's surface itself. A little bit below the surface should provide some kind of average of the heating from day and night radiation. Nighttime radiation would presumably be directed from the moon out into space.
The error lies mainly in the question itself.
Administrator
· Skåne
· 8 351 posts
Perhaps we should try creating a subforum "Building Physics" under Building Materials & Construction Techniques, just as a test? If it doesn't feel right, you can just move the topics out and discontinue the subforum.
I think it would be fun to have more theoretical discussions gathered in one place. It's not as practically oriented and useful when building, as discussions normally are with us. The advantage of placing them in their own "category" is that they become easy to find and overview for those who are interested. It would be fun to see what you plan to write there, Mikael.
I think it would be fun to have more theoretical discussions gathered in one place. It's not as practically oriented and useful when building, as discussions normally are with us. The advantage of placing them in their own "category" is that they become easy to find and overview for those who are interested. It would be fun to see what you plan to write there, Mikael.
As I wrote in the first post, I actually think there are too few topics in such a category for it to be worthwhile, although I do miss the forum section, admittedly.
One simple solution is to have a sticky thread with links to building physics-oriented threads.
I'm planning a little bit on a sound, soundproofing, and acoustics thread. And a thread about moisture, and all sorts of things related to it.
But that's buried somewhere in the five-year plan.
One simple solution is to have a sticky thread with links to building physics-oriented threads.
I'm planning a little bit on a sound, soundproofing, and acoustics thread. And a thread about moisture, and all sorts of things related to it.
But that's buried somewhere in the five-year plan.
Administrator
· Skåne
· 8 351 posts
It was like that when we started the subforum for furniture making; we were uncertain if there was any interest at all. Only one or two people had asked for it. It started as a subforum, but the interest far exceeded expectations and quickly changed to a regular forum. Let me know if you're interested, I'm happy to give it a try.
We have now created a forum called Building Physics. The link is http://www.byggahus.se/forum/byggnadsfysik/.
