Sound cannot propagate through vacuum
Sound cannot propagate through vacuum. Here is an experiment to prove this.
- Take an airtight glass bell jar and an electric bell.
- Connect a vacuum pump to the bell jar.
- Suspend the bell inside the jar as shown
- Now ring the bell. The bell sound will be heard very clearly.
- Gradually start pumping out the air from the jar. Simultaneously, also ring the bell. The bell sound becomes feebler and feebler as the air is pumped out.
- When the air is completely pumped out, the sound will not be heard at all.
- This proves that sound does not travel through vacuum.