The Particle Model Public Group Active 7 months ago Those interested in The Particle Model (TPM) as described by Bob de Hilster and David de Hilster. Public Group Organizer: Organized by Public Group Group Description Those interested in The Particle Model (TPM) as described by Bob de Hilster and David de Hilster. Leave Group Are you sure you want to leave ? Members 21 Feed Albums Discussions Photos 1 Reply To: A question about magnets