How To Measure The Tiniest Forces In The Universe

TL;DR

Scientists explain how precision measurement is achieved through the use of kilogram standards and advanced measurement techniques, allowing the measurement of forces as small as nanonewtons.

Transcript

This is 10 micrograms. You think that I might be able to see? I think you might be able to. Oh boy. It's an arrow right there. Yeah, yeah, yeah. This flashlight will help. I feel like I need to get video of this. [Dr. Shaw] I don't know how. (Dr. Shaw laughing) It kinda looks like a hair, like a tiny,- Yeah. like a smaller than an eyelash. If you w... Read More

Key Insights

• 🥺 The traditional definition of the kilogram based on a physical object led to variations in its mass over time.
• 👻 Redefining the kilogram using Planck's constant allows for more accurate and stable measurements.
• ⚖️ Advanced measurement techniques like the Kibble balance and electrostatic force balance enable precise measurements of forces ranging from milligrams to femtonewtons.
• ✊ Precision measurement has practical applications in various industries, including automotive manufacturing, laser power measurements, and pharmaceutical dosing.

Questions & Answers

Q: How is the kilogram traditionally defined?

The kilogram was historically defined by a platinum-iridium cylinder stored in Paris, with replicas sent to different countries to serve as mass standards.

Q: Why is it necessary to redefine the kilogram?

The mass of the traditional kilogram standards was found to vary over time, leading to the adoption of a definition based on Planck's constant for greater accuracy and stability.

Q: How are forces smaller than a kilogram measured?

Advanced measurement techniques such as the Kibble balance and electrostatic force balance allow for the precise measurement of forces ranging from milligrams to nanonewtons.

Q: What are some practical applications of precision measurement?

Precision measurement has important applications in industries such as automotive manufacturing, where the mass of particulates in exhausts needs to be measured, as well as in laser power measurements and pharmaceutical dosing.

Summary & Key Takeaways

• The kilogram has been traditionally defined by a platinum-iridium cylinder in Paris, but its dependence on a physical object led to discrepancies in its mass over time.

• Scientists now define the kilogram based on Planck's constant, allowing for more accurate and reliable measurements.

• Advanced measurement techniques like the Kibble balance and electrostatic force balance allow for the precise measurement of forces ranging from milligrams to femtonewtons.

• Precision measurement has applications in various industries, including automotive manufacturing, laser power measurements, and pharmaceuticals.