The Drake Equation Calculator
Created | Updated Oct 20, 2010
<SCRIPT>function Calc(obj) {obj.N.value = obj.N_star.options[obj.N_star.options.selectedIndex].value * obj.fp.options[obj.fp.options.selectedIndex].value * obj.ne.options[obj.ne.options.selectedIndex].value * obj.fl.options[obj.fl.options.selectedIndex].value * obj.fi.options[obj.fi.options.selectedIndex].value * obj.fc.options[obj.fc.options.selectedIndex].value * obj.fLife.options[obj.fLife.options.selectedIndex].value}</SCRIPT>
<P>Try out your own estimates and see how many Intelligent civillizations are out in our galaxy!</P><BR/>
<FORM>
<P><B>N*</B> = the number of stars in the Milky Way galaxy: <SELECT id="N_star">
<OPTION value="1000000000">1 billion
<OPTION value="10000000000">10 billion
<OPTION selected value="100000000000">100 billion
<OPTION value="200000000000">200 billion
<OPTION value="300000000000">300 billion
<OPTION value="400000000000">400 billion
<OPTION value="500000000000">500 billion
<OPTION value="600000000000">600 billion</SELECT>
<P><B>fp</B> = fraction of stars with planets around them:
<SELECT id="fp">
<OPTION value=".00001">.0001%
(1 of 1,000,000) <OPTION value=".0001">.001% (1 of 100,000) <OPTION value=".001">.01%
(1 of 10,000) <OPTION value=".005">.05% (1 of 2,000) <OPTION value=".01">.1%
(1 of 1,000) <OPTION value=".05">.5% <OPTION value=".1">1% <OPTION value=".1">2% <OPTION value=".1">5% <OPTION value=".1">10% <OPTION value=".2">20% <OPTION value=".3">30% <OPTION value=".4">40% <OPTION selected value=".5">50% <OPTION value=".6">60% <OPTION value=".7">70% <OPTION value=".8">80% <OPTION value=".9">90% <OPTION value="1">100% </SELECT>
<P><B>ne</B> = number of planets per star ecologically able
to sustain life: <SELECT id="ne"><OPTION value=".33">.33 <OPTION value=".5">.5 <OPTION value=".67">.67 <OPTION selected value="1">1 <OPTION value="1.5">1.5 <OPTION value="2">2 <OPTION value="3">3 <OPTION value="4">4 </SELECT>
<P><B>fl</B> = fraction of those planets where life actually
evolves: <SELECT id="fl"><OPTION value=".00001">.0001% (1 of 1,000,000) <OPTION value=".0001">.001%
(1 of 100,000) <OPTION value=".001">.01% (1 of 10,000) <OPTION value=".005">.05%
(1 of 2,000) <OPTION value=".01">.1% (1 of 1,000) <OPTION value=".05">.5% <OPTION value=".1">1% <OPTION value=".1">2% <OPTION value=".1">5% <OPTION value=".1">10% <OPTION value=".2">20% <OPTION value=".3">30% <OPTION value=".4">40% <OPTION selected value=".5">50% <OPTION value=".6">60% <OPTION value=".7">70% <OPTION value=".8">80% <OPTION value=".9">90% <OPTION value="1">100% </SELECT>
<P><B>fi</B> = the fraction of <B>fl</B> that evolves intelligent
life: <SELECT id="fi"><OPTION value=".00001">.0001% (1 of 1,000,000) <OPTION value=".0001">.001%
(1 of 100,000) <OPTION value=".001">.01% (1 of 10,000) <OPTION value=".005">.05%
(1 of 2,000) <OPTION value=".01">.1% (1 of 1,000) <OPTION value=".05">.5% <OPTION value=".1">1% <OPTION value=".1">2% <OPTION value=".1">5% <OPTION value=".1">10% <OPTION selected value=".2">20% <OPTION value=".3">30% <OPTION value=".4">40% <OPTION value=".5">50% <OPTION value=".6">60% <OPTION value=".7">70% <OPTION value=".8">80% <OPTION value=".9">90% <OPTION value="1">100% </SELECT>
<P><B>fc</B> = the fraction of <B>fi</B> that communicates: <SELECT id="fc"><OPTION value=".00001">.0001%
(1 of 1,000,000) <OPTION value=".0001">.001% (1 of 100,000) <OPTION value=".001">.01%
(1 of 10,000) <OPTION value=".005">.05% (1 of 2,000) <OPTION value=".01">.1%
(1 of 1,000) <OPTION value=".05">.5% <OPTION value=".1">1% <OPTION value=".1">2% <OPTION value=".1">5% <OPTION value=".1">10% <OPTION selected value=".2">20% <OPTION value=".3">30% <OPTION value=".4">40% <OPTION value=".5">50% <OPTION value=".6">60% <OPTION value=".7">70% <OPTION value=".8">80% <OPTION value=".9">90% <OPTION value="1">100% </SELECT>
<P><B>fL</B> = the fraction of the planet's life during which
the communicating civilizations survives: <SELECT id="fLife"><OPTION value=".000000001">1
/ 1,000,000,000th (10 years) <OPTION value=".00000001">1 / 100,000,000th
(100 years) <OPTION value=".0000001">1 / 10,000,000th (1,000 years) <OPTION selected value=".000001">1
/ 1,000,000th (10,000 years) <OPTION value=".00001">1 / 100,000th
(100,000 years) <OPTION value=".0001">1 / 10,000th (1,000,000 years) <OPTION value=".001">1
/ 1,000th (10,000,000 years) <OPTION value=".01">1% (100 million years) <OPTION value=".1">10%
(1 billion years) <OPTION value=".2">20% (2 billion years) <OPTION value=".3">30%
(3 billion years) <OPTION value=".4">40% (4 billion years) <OPTION value=".5">50%
(5 billion years) <OPTION value="1">100% </SELECT>
<CENTER>
<P><INPUT TYPE="button" NAME="Calculate" VALUE="Calculate" onClick="Calc(this.form)">
<BR/><B>N</B> = the number of communicating civilizations in the galaxy <INPUT type="text", id="N"></FORM>
</CENTER>
<BR/><BR/>
<B>More Information</B><BR/><BR/>
<P>If you want to know more about the equation go to the <A HREF="http://www.h2g2.com/A193240">Drake Equation</A> page.<BR/><BR/>
More information is available at the <A HREF="http://www.h2g2.com/A193466">SETI history</A> page or the <A HREF="http://www.h2g2.com/A193231">SETI@Home Project</A> page!
<BR/><BR/>
You can also try <A HREF="http://www.h2g2.com/A200223">Hudson's Equation</A> thanks to <A HREF="http://www.h2g2.com/U25578">Si</A>
</P>
<BR/>
<P>Try out your own estimates and see how many Intelligent civillizations are out in our galaxy!</P><BR/>
<FORM>
<P><B>N*</B> = the number of stars in the Milky Way galaxy: <SELECT id="N_star">
<OPTION value="1000000000">1 billion
<OPTION value="10000000000">10 billion
<OPTION selected value="100000000000">100 billion
<OPTION value="200000000000">200 billion
<OPTION value="300000000000">300 billion
<OPTION value="400000000000">400 billion
<OPTION value="500000000000">500 billion
<OPTION value="600000000000">600 billion</SELECT>
<P><B>fp</B> = fraction of stars with planets around them:
<SELECT id="fp">
<OPTION value=".00001">.0001%
(1 of 1,000,000) <OPTION value=".0001">.001% (1 of 100,000) <OPTION value=".001">.01%
(1 of 10,000) <OPTION value=".005">.05% (1 of 2,000) <OPTION value=".01">.1%
(1 of 1,000) <OPTION value=".05">.5% <OPTION value=".1">1% <OPTION value=".1">2% <OPTION value=".1">5% <OPTION value=".1">10% <OPTION value=".2">20% <OPTION value=".3">30% <OPTION value=".4">40% <OPTION selected value=".5">50% <OPTION value=".6">60% <OPTION value=".7">70% <OPTION value=".8">80% <OPTION value=".9">90% <OPTION value="1">100% </SELECT>
<P><B>ne</B> = number of planets per star ecologically able
to sustain life: <SELECT id="ne"><OPTION value=".33">.33 <OPTION value=".5">.5 <OPTION value=".67">.67 <OPTION selected value="1">1 <OPTION value="1.5">1.5 <OPTION value="2">2 <OPTION value="3">3 <OPTION value="4">4 </SELECT>
<P><B>fl</B> = fraction of those planets where life actually
evolves: <SELECT id="fl"><OPTION value=".00001">.0001% (1 of 1,000,000) <OPTION value=".0001">.001%
(1 of 100,000) <OPTION value=".001">.01% (1 of 10,000) <OPTION value=".005">.05%
(1 of 2,000) <OPTION value=".01">.1% (1 of 1,000) <OPTION value=".05">.5% <OPTION value=".1">1% <OPTION value=".1">2% <OPTION value=".1">5% <OPTION value=".1">10% <OPTION value=".2">20% <OPTION value=".3">30% <OPTION value=".4">40% <OPTION selected value=".5">50% <OPTION value=".6">60% <OPTION value=".7">70% <OPTION value=".8">80% <OPTION value=".9">90% <OPTION value="1">100% </SELECT>
<P><B>fi</B> = the fraction of <B>fl</B> that evolves intelligent
life: <SELECT id="fi"><OPTION value=".00001">.0001% (1 of 1,000,000) <OPTION value=".0001">.001%
(1 of 100,000) <OPTION value=".001">.01% (1 of 10,000) <OPTION value=".005">.05%
(1 of 2,000) <OPTION value=".01">.1% (1 of 1,000) <OPTION value=".05">.5% <OPTION value=".1">1% <OPTION value=".1">2% <OPTION value=".1">5% <OPTION value=".1">10% <OPTION selected value=".2">20% <OPTION value=".3">30% <OPTION value=".4">40% <OPTION value=".5">50% <OPTION value=".6">60% <OPTION value=".7">70% <OPTION value=".8">80% <OPTION value=".9">90% <OPTION value="1">100% </SELECT>
<P><B>fc</B> = the fraction of <B>fi</B> that communicates: <SELECT id="fc"><OPTION value=".00001">.0001%
(1 of 1,000,000) <OPTION value=".0001">.001% (1 of 100,000) <OPTION value=".001">.01%
(1 of 10,000) <OPTION value=".005">.05% (1 of 2,000) <OPTION value=".01">.1%
(1 of 1,000) <OPTION value=".05">.5% <OPTION value=".1">1% <OPTION value=".1">2% <OPTION value=".1">5% <OPTION value=".1">10% <OPTION selected value=".2">20% <OPTION value=".3">30% <OPTION value=".4">40% <OPTION value=".5">50% <OPTION value=".6">60% <OPTION value=".7">70% <OPTION value=".8">80% <OPTION value=".9">90% <OPTION value="1">100% </SELECT>
<P><B>fL</B> = the fraction of the planet's life during which
the communicating civilizations survives: <SELECT id="fLife"><OPTION value=".000000001">1
/ 1,000,000,000th (10 years) <OPTION value=".00000001">1 / 100,000,000th
(100 years) <OPTION value=".0000001">1 / 10,000,000th (1,000 years) <OPTION selected value=".000001">1
/ 1,000,000th (10,000 years) <OPTION value=".00001">1 / 100,000th
(100,000 years) <OPTION value=".0001">1 / 10,000th (1,000,000 years) <OPTION value=".001">1
/ 1,000th (10,000,000 years) <OPTION value=".01">1% (100 million years) <OPTION value=".1">10%
(1 billion years) <OPTION value=".2">20% (2 billion years) <OPTION value=".3">30%
(3 billion years) <OPTION value=".4">40% (4 billion years) <OPTION value=".5">50%
(5 billion years) <OPTION value="1">100% </SELECT>
<CENTER>
<P><INPUT TYPE="button" NAME="Calculate" VALUE="Calculate" onClick="Calc(this.form)">
<BR/><B>N</B> = the number of communicating civilizations in the galaxy <INPUT type="text", id="N"></FORM>
</CENTER>
<BR/><BR/>
<B>More Information</B><BR/><BR/>
<P>If you want to know more about the equation go to the <A HREF="http://www.h2g2.com/A193240">Drake Equation</A> page.<BR/><BR/>
More information is available at the <A HREF="http://www.h2g2.com/A193466">SETI history</A> page or the <A HREF="http://www.h2g2.com/A193231">SETI@Home Project</A> page!
<BR/><BR/>
You can also try <A HREF="http://www.h2g2.com/A200223">Hudson's Equation</A> thanks to <A HREF="http://www.h2g2.com/U25578">Si</A>
</P>
<BR/>
