7 digits of <a href="http://en.wikipedia.org/wiki/Pi" 
			         onclick="centeredPopup(this.href,'myWindow','500','300','yes');return false">&#960(pi)</a><br>
<strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3.141592</strong><br><hr>
  <a href="http://en.wikipedia.org/wiki/Speed_of_light" 
			         onclick="centeredPopup(this.href,'myWindow','500','300','yes');return false">Speed of light </a>in miles per second<br>
<strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;186,000</strong><br><hr>
 <a href="http://en.wikipedia.org/wiki/Speed_of_light" 
			         onclick="centeredPopup(this.href,'myWindow','500','300','yes');return false">Speed of light </a>in metres per second<br>
<strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;299,792,458</strong><br><hr>
How many minutes does it take light to travel from the <a href="http://en.wikipedia.org/wiki/Speed_of_light" 
			         onclick="centeredPopup(this.href,'myWindow','500','300','yes');return false">Sun to Earth (1 AU)</a>?<br>
<strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.3</strong><br><hr>
How many light-years is <a href="http://en.wikipedia.org/wiki/Parsec" 
			         onclick="centeredPopup(this.href,'myWindow','500','300','yes');return false">one parsec (1 AU)</a>?<br>
<strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3.26</strong><br><hr>
<a href="http://en.wikipedia.org/wiki/Speed_of_sound" 
			         onclick="centeredPopup(this.href,'myWindow','500','300','yes');return false">Speed of sound </a>in metres per second <br>
<strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;343</strong><br><hr>
<a href="http://en.wikipedia.org/wiki/Speed_of_sound" 
			         onclick="centeredPopup(this.href,'myWindow','500','300','yes');return false">Speed of sound </a>in feet per second<br>
<strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1,125</strong><br><hr>
<a href="http://en.wikipedia.org/wiki/Speed_of_sound" 
			         onclick="centeredPopup(this.href,'myWindow','500','300','yes');return false">Speed of sound </a>in miles per hour (mph)<br>
<strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;767</strong><br>