How do scientists slow light down?
Recent experiments involve slowing down the speed of light to very much below its value in vacuum (c). How is this possible?
Here's a link to a news article on one such experiment.
Although the speed of light in a vacuum is constant, light slows down when travelling through a medium. This doesn't make much difference when it is travelling through air, but it does make a difference in many other media. For example, light going through glass slows down to two-thirds its speed in a vacuum. Just like it's harder for a person to move through water than through air (so people swim slower than they run), photons (massless particles that make up light) move slower when going through a medium that is difficult for them. Certain states of matter slow light down a huge amount (imagine a person trying to run through a tank of molasses or silly putty), and by using these states of matter, scientists can slow light down to a "human" speed. I'm not an expert on the physics involved, so here's a link that will provide you with more information.
Get More 'Curious?' with Our New PODCAST:
- Podcast? Subscribe? Tell me about the Ask an Astronomer Podcast
- Subscribe to our Podcast | Listen to our current Episode
- Cool! But I can't now. Send me a quick reminder now for later.
- Why doesn't gravity change the speed of light?
- How can the Universe expand faster than the speed of light during inflation?
- Who first measured the speed of light?
- Does Cerenkov radiation travel faster than light?
- Is the speed of light constant?
How to ask a question:
If you have a follow-up question concerning the above subject, submit it here. If you have a question about another area of astronomy, find the topic you're interested in from the archive on our site menu, or go here for help.Table 'curious.Referrers' doesn't existTable 'curious.Referrers' doesn't exist
This page has been accessed 26815 times since July 16, 2003.
Last modified: February 13, 2004 10:40:16 PM
Ask an Astronomer is hosted by the Astronomy Department at Cornell University and is produced with PHP and MySQL.
Warning: Your browser is misbehaving! This page might look ugly. (Details)