# If you have a light turned on, but the bulb is burnt out, does it use any electricity **URL:** \ **Category:** Factual Questions\ **Created:** [June 5, 2003, 4:24am UTC](https://boards.straightdope.com/t/if-you-have-a-light-turned-on-but-the-bulb-is-burnt-out-does-it-use-any-electricity/179768 "2003-06-05T04:24:35Z")\ **Posts on this page:** 9\ **Page:** 3
**Author:** ![bbeaty](https://avatars.discourse-cdn.com/v4/letter/b/c0e974/32.png) [@bbeaty](https://boards.straightdope.com/u/bbeaty)\ **Post date:** [June 5, 2003, 11:44pm UTC](https://boards.straightdope.com/t/if-you-have-a-light-turned-on-but-the-bulb-is-burnt-out-does-it-use-any-electricity/179768/41 "2003-06-05T23:44:13Z")
But a light bulb doesn’t use any electricity when lit. HAH! If we follow this definition of the word “electricity”… CHAPTER II Elementary Mathematical Theory of Statical Electricity Definition of Electricity as a Mathematical Quantity (J.C. Maxwell) 63.] "We have seen that the properties of charged bodies are such that the charge of one body may be equal to that of another, or to the sum of the charges of two bodies, and that when two bodies are equally and oppositely charged they have no electrical effect on external bodies when placed together within a closed insulated conducting vessel. We may express all these results in a concise and consistent manner by describing an electrified body as “charged” with a certain “quantity of electrcity” which we may denote by “e.” …then “electricity” does not mean energy. Instead it means coulombs, it means charge. An electric current is a flow of “electricity,” i.e. it is a flow of charge. And in an AC circuit, the charge wiggles back and forth. It sits inside the wires and vibrates. None of it is used up. So a light bulb does convert plenty of electromagnetic energy into light, but it uses up no electricity at all. Every single electron that momentarily flows clockwise through the circuit will flow counterclockwise in the next half-cycle, returning to its point of origin (well, it does if we ignore thermal diffusion, QM, etc.) ---
**Author:** ![Early\_Out](https://avatars.discourse-cdn.com/v4/letter/e/6f9a4e/32.png) [@Early\_Out](https://boards.straightdope.com/u/Early_Out)\ **Post date:** [June 6, 2003, 2:22am UTC](https://boards.straightdope.com/t/if-you-have-a-light-turned-on-but-the-bulb-is-burnt-out-does-it-use-any-electricity/179768/42 "2003-06-06T02:22:24Z")
> [@](#): > > \*Originally posted by alice\_in\_wonderland \* > \*\*So, ignoring all this fascinating information for just a moment - does anyone have suggestions for making my lava-lamp bulb last longer? > > Just checking. \*\* Simple. Never plug it in. It’ll last for years. 😉 ---
**Author:** ![justwannano](https://avatars.discourse-cdn.com/v4/letter/j/7ab992/32.png) [@justwannano](https://boards.straightdope.com/u/justwannano)\ **Post date:** [June 6, 2003, 4:44am UTC](https://boards.straightdope.com/t/if-you-have-a-light-turned-on-but-the-bulb-is-burnt-out-does-it-use-any-electricity/179768/43 "2003-06-06T04:44:28Z")
Quote QED I’ve read cites that indicate that you can increase bulb life by 4 times, by running it at 75% rated power using a dimmer. Worth looking into, perhaps. I seem to recall seeing plug-in dimmers for table and floor lamps and the like. Perhaps you should look into the operation theory of a lava lamp. The temperature of the light bulb melts the wax and it flows. Use a hotter bulb,75 rather than 60 watts, and it does not hold its shape. Use a lower wattage bulb and it doesn’t melt. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [June 6, 2003, 4:53am UTC](https://boards.straightdope.com/t/if-you-have-a-light-turned-on-but-the-bulb-is-burnt-out-does-it-use-any-electricity/179768/44 "2003-06-06T04:53:09Z")
> [@](#): > > \*Originally posted by justwannano \* > \*\*The temperature of the light bulb melts the wax and it flows. > Use a hotter bulb,75 rather than 60 watts, and it does not hold its shape. > Use a lower wattage bulb and it doesn’t melt. \*\* What’s your point? If you use a 100 Watt bulb and run it at 75% power, there’s your 75 Watts. ---
**Author:** ![justwannano](https://avatars.discourse-cdn.com/v4/letter/j/7ab992/32.png) [@justwannano](https://boards.straightdope.com/u/justwannano)\ **Post date:** [June 6, 2003, 6:10am UTC](https://boards.straightdope.com/t/if-you-have-a-light-turned-on-but-the-bulb-is-burnt-out-does-it-use-any-electricity/179768/45 "2003-06-06T06:10:43Z")
Never even owned a lava lamp have you QED. While playing with the temperature you’ll destroy the wax. Alice. The lifetime of a GE lightbulb is supposed to be 2500 hours. Somthing slightly over 3 months. The unusual heat trapped by the lava lamp will lower the expected life… When we owned a lava lamp many years ago I changed the bulb to an appliance bulb and the bulb lasted a lot longer. If you are already using a bulb designed for use in ovens make sure it is a name brand. ---
**Author:** ![justwannano](https://avatars.discourse-cdn.com/v4/letter/j/7ab992/32.png) [@justwannano](https://boards.straightdope.com/u/justwannano)\ **Post date:** [June 6, 2003, 6:13am UTC](https://boards.straightdope.com/t/if-you-have-a-light-turned-on-but-the-bulb-is-burnt-out-does-it-use-any-electricity/179768/46 "2003-06-06T06:13:29Z")
Quote Me The lifetime of a GE lightbulb is supposed to be 2500 hours. Somthing slightly over 3 months. But not just 3 weeks. ---
**Author:** ![justwannano](https://avatars.discourse-cdn.com/v4/letter/j/7ab992/32.png) [@justwannano](https://boards.straightdope.com/u/justwannano)\ **Post date:** [June 6, 2003, 6:15am UTC](https://boards.straightdope.com/t/if-you-have-a-light-turned-on-but-the-bulb-is-burnt-out-does-it-use-any-electricity/179768/47 "2003-06-06T06:15:26Z")
Well I sure screwed that edit up. The unusual heat…lower life …but not to as little as 3 weeks. ---
**Author:** ![elfje](https://avatars.discourse-cdn.com/v4/letter/e/e19b73/32.png) [@elfje](https://boards.straightdope.com/u/elfje)\ **Post date:** [June 6, 2003, 10:29am UTC](https://boards.straightdope.com/t/if-you-have-a-light-turned-on-but-the-bulb-is-burnt-out-does-it-use-any-electricity/179768/48 "2003-06-06T10:29:48Z")
> [@](#): > > \*Originally posted by Q.E.D. \* > \*\*I should also point out that TV standby power is only on the order of a few watts, and not worth worrying over, unless electricity is _extremely_ expensive where you are. Go on and make him happy by leaving it on standby. \*\* will do. thanks 🙂 you just made his day 😃 ---
**Author:** ![Uncommon\_Sense](https://avatars.discourse-cdn.com/v4/letter/u/f9ae1b/32.png) [@Uncommon\_Sense](https://boards.straightdope.com/u/Uncommon_Sense)\ **Post date:** [June 6, 2003, 11:48am UTC](https://boards.straightdope.com/t/if-you-have-a-light-turned-on-but-the-bulb-is-burnt-out-does-it-use-any-electricity/179768/49 "2003-06-06T11:48:18Z")
**Alice** , seriously, you can buy long life **130 volt** (as opposed to 120 volt) bulbs that are supposed to have a stronger filament. Look for them at your nearest lighting supplier. Or online. [Previous page](https://boards.straightdope.com/t/if-you-have-a-light-turned-on-but-the-bulb-is-burnt-out-does-it-use-any-electricity/179768.md?page=2)