Main Menu

See All Software See All Instruments See All Transducers See All Vibration Testing Equipment See All Electroacoustics See All Acoustic End-of-Line Test Systems See All Academy See All Resource Center See All Applications See All Industries See All Services See All Support See All Our Business See All Our History See All Global Presence

Main Menu

See All nCode - Durability and Fatigue Analysis See All ReliaSoft - Reliability Analysis and Management See All Test Data Management See All DAQ Software See All Drivers & API See All Utility See All Vibration Control See All High Precision and Calibration Systems See All DAQ Systems See All S&V Hand-held Devices See All Industrial Electronics See All Power Analyzer See All S&V Signal Conditioner See All Acoustic See All Current and Voltage Sensors See All Displacement See All Force sensors See All Load Cells See All Pressure See All Strain Gauges See All Temperature Sensors See All Torque Sensors See All Vibration See All Accessories for Vibration Testing Equipment See All Vibration Controllers See All Measurement Exciters See All Modal Exciters See All Power Amplifiers See All LDS Shaker Systems See All Test Solutions See All Actuators See All Combustion Engines See All Durability See All eDrive See All Production Testing Sensors See All Transmission & Gearboxes See All Turbo Charger See All Training Courses See All Acoustics See All Asset & Process Monitoring See All Custom Sensors See All Data Acquisition & Analysis See All Durability & Fatigue See All Electric Power Testing See All NVH See All Reliability See All Smart Sensors See All Vibration See All Weighing See All Automotive & Ground Transportation See All Calibration See All Installation, Maintenance & Repair See All Support Brüel & Kjær See All Release Notes See All Compliance See All BKSV Worldwide Contacts

Main Menu

See All API See All Microphone Cartridges See All Microphone Sets See All Microphone Pre-amplifiers See All Sound Sources See All Acoustic Calibrators See All Special Microphones See All Accessories for acoustic transducers See All Experimental testing See All Transducer Manufacturing (OEM) See All Piezoelectric Charge Accelerometers See All Piezoelectric CCLD (IEPE) accelerometers See All Electroacoustics See All Noise Source Identification See All Environmental Noise See All Sound Power and Sound Pressure See All Noise Certification See All Industrial Process Control See All Structural Health Monitoring See All Electrical Devices Testing See All Electrical Systems Testing See All Grid Testing See All High-Voltage Testing See All Vibration Testing with Electrodynamic Shakers See All Structural Dynamics See All Machine Analysis and Diagnostics See All Dynamic Weighing See All Vehicle Electrification See All Calibration Services for Transducers See All Calibration Services for Handheld Instruments See All Calibration Services for Instruments & DAQ See All On-Site Calibration See All Resources See All Software License Management
October 2, 2020
No fruit has achieved such fame in the world of physics as the humble apple. After all, it was an apple falling from a tree that inspired Isaac Newton’s law of gravity. Time to pay tribute to the physics of the apple!


However, we don’t really know what happened when the apple supposedly fell on Newton. Many artists have depicted the inspirational moment with the apple falling directly onto the head of the famous and eccentric scientist. In reality, it was probably less spectacular, but it was undoubtedly Newton’s ‘eureka‘.


So what do we know? The apple variety that inspired Isaac Newton was the Flower of Kent, a variety that is not cultivated commercially today, being more of a cooking apple, mealy with a subacid flavour. In short – it would not appeal to the palate of today. We have no idea what Newton’s opinion of it was. Incidentally, apples have been available in many varieties for a very long time. Even the Romans cultivated different apple varieties, and today it is estimated that there are more than 30,000 varieties of apple  worldwide. You can, however, still find a few Flower of Kent apple trees in some private gardens – including some universities that choose to remember Isaac Newton in this way.


The apple is, in many ways, a fascinating plant. We have collected some exciting data from HBK’s product physics domains.


Let’s start with the weight. On average, an apple weighs between 110 and 150 grams. But there’s more to it than that. In Japan, according to the Guinness Book of Records, the world’s largest apple was bred ten years ago – weighing in at an impressive 1.8 kg.


Moving on to acoustics. The loudest apple crunch in the world (when you bite into it) is the New Zealand variety Sweetango, reaching 79.1 dB. Sweetango ranks in a noise league alongside a doorbell or a kitchen mixer.


Think back to your schooldays, when we experimented with generating electricity from an apple? It is relatively easy to do this with apples or indeed other fruits. An apple generates a voltage of around 0.9 V.


So as you can see, the world of physics can be represented in an apple. And yet, some very important questions remain unanswered. For example, the one about the gravitational constant that occurs when falling. Read how Scientists are pursuing this gravitational constant with increasingly precise methods.


With all this in mind – maybe we should also sit under an apple tree once in a while and see what happens?

Related blog articles

About HBK

Accelerate your product innovation with HBK solutions in virtual, physical and in-process testing.  From the electrification of mobility to the advancement of smart manufacturing, we support you throughout the entire product lifecycle, sharing your mission for a cleaner, healthier, and more productive world.