I've not made a specific video for Valentine's Day this year - but here are some previous efforts.

This is a slightly tweaked version of our Valentine's video from a year ago, with a few new pictures (you'll know when you see it!!!) and now in high definition. More from us at http://www.periodicvideos.com/

Heart-shaped astronomical objects to mark Valentine's Day. We also look at Carl Sagan's pale blue dot. More at http://www.sixtysymbols.com/ Take a closer look at some of these images at http://www.flickr.com/photos/sixtysymbols

The periodicvideos team raids the chemical stores to make their "perfect perfume" - though we doubt it would be fit for human consumption. (Just a bit of fun for Valentine's Day!) More chemistry at http://www.periodicvideos.com/

We discuss the four fundamental forces - gravity, electromagnetic, weak and strong. Extra footage from this video http://www.youtube.com/watch?v=Fq9FCfZOJLk More physics at http://www.sixtysymbols.com/

We joke about this one being filmed on February 14 because we both had no other plans!

Chatting with Numberphile regular, Dr James Grime. Some links below from the discussion... Singingbanana: http://www.youtube.com/user/singingbanana Kylie's Caravan: http://www.youtube.com/user/kyliecaravan Amicable Numbers: http://www.youtube.com/watch?v=fUSZBVYZdKY James talks Enigma: http://www.youtube.com/watch?v=G2_Q9FoD-oQ Maths Gear: http://www.mathsgear.co.uk/ Base 12 video: http://www.youtube.com/watch?v=U6xJfP7-HCc Phil Moriarty on Tau: http://www.youtube.com/watch?v=83ofi_L6eAo Brady's other channels: http://periodicvideos.blogspot.co.uk/2012/06/here-are-my-channels.html

And because Simon Singh seemed to think this was a Valentine's video.

Professor Ron Graham discusses the famed Happy Ending Problem and Ramsey Theory.