Hello, I am an eighth grade student working on science fair. I have the idea to make a sort of "soil x-ray". The concept is a sort of tool to be able to see the water/moisture levels in soil. The idea being to measure it qualitatively instead of with a hygrometer. I have researched the concept of x-ray machines. They use electromagnetic radiation, which is supposedly similar to visible light except with higher energy. This higher energy allows the picture to see through certain, less dense, objects. I was thinking if I could somehow make the water be (or seem) more dense than the soil it is in, I could use the same technology (just tweaked quite a bit) as an x-ray to create the image, being able to see the water in the earth. Maybe if this didn't work, I could find the atomic energy in water and it hopefully being cooler or hotter than soil, use night vision mechanics to see the difference in water in soil. I would like a soil scientist to help me move forward to see if this idea of mine would work. Please and thank you!
Thank you,
Charlotte
Moderator note: I'm cross-posting this to the Physical Sciences forum, in case one of those experts has some ideas. I've also add the words "measuring soil moisture" to your title to give your post more visibility.
Measuring Soil Moisture: I need help moving forward please!!
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Re: Measuring Soil Moisture: I need help moving forward please!!
Hello, and welcome to Scibuddies.
Your idea of using X-rays to ‘see’ soil water shows thinking by analogy, which is great—but as you said, X-rays are too energetic. They would pass right through water as if it weren’t there. So, you need some other way to register soil water. You did not say exactly what you mean by looking for water in the earth. Are you thinking about the degree of moisture that would affect crops if there is too little or too much? If so, then there already is an electronic device that will read the amount of moisture in the soil:
https://www.epicgardening.com/best-soil-moisture-meter/
You put a probe in the soil at the correct depth for you plants and it sends out a small pulse of electricity and reads the conductivity in the dirt. The moister it is, the higher the conduction of the electric current.
If you are thinking about water in the earth in terms of drinking water flowing in an aquifer underground then you would need to use some tool that geologists use to find differences in density that indicate the presence of large bodies of water underground. Seismic detonations and ground-penetrating radar are two of the possible methods for seeing deep water:
https://en.wikipedia.org/wiki/Ground-penetrating_radar
It is possible that some type of electromagnetic pulse—much longer than X-rays or infrared—maybe radio waves of a certain wavelength could be used. Microwaves are absorbed by water and cause it to heat up—that’s how a microwave oven cooks food or heats up your coffee. Maybe if you shot a beam of microwaves into the ground you could measure a change in temperature that would correspond to how much water was present. If there’s no water, than the change should be zero. The more water, the higher the temperature. I just don’t know if microwaves would penetrate soil far enough to be useful. You could research, but I don’t know how you would test it because microwaves can harm you. That’s why a microwave oven has a shield built into it that limits your exposure.
I hope this helped. Please post again if you have more questions.
Sybee
Your idea of using X-rays to ‘see’ soil water shows thinking by analogy, which is great—but as you said, X-rays are too energetic. They would pass right through water as if it weren’t there. So, you need some other way to register soil water. You did not say exactly what you mean by looking for water in the earth. Are you thinking about the degree of moisture that would affect crops if there is too little or too much? If so, then there already is an electronic device that will read the amount of moisture in the soil:
https://www.epicgardening.com/best-soil-moisture-meter/
You put a probe in the soil at the correct depth for you plants and it sends out a small pulse of electricity and reads the conductivity in the dirt. The moister it is, the higher the conduction of the electric current.
If you are thinking about water in the earth in terms of drinking water flowing in an aquifer underground then you would need to use some tool that geologists use to find differences in density that indicate the presence of large bodies of water underground. Seismic detonations and ground-penetrating radar are two of the possible methods for seeing deep water:
https://en.wikipedia.org/wiki/Ground-penetrating_radar
It is possible that some type of electromagnetic pulse—much longer than X-rays or infrared—maybe radio waves of a certain wavelength could be used. Microwaves are absorbed by water and cause it to heat up—that’s how a microwave oven cooks food or heats up your coffee. Maybe if you shot a beam of microwaves into the ground you could measure a change in temperature that would correspond to how much water was present. If there’s no water, than the change should be zero. The more water, the higher the temperature. I just don’t know if microwaves would penetrate soil far enough to be useful. You could research, but I don’t know how you would test it because microwaves can harm you. That’s why a microwave oven has a shield built into it that limits your exposure.
I hope this helped. Please post again if you have more questions.
Sybee