Alert icon
We're changing our privacy policy. This stuff matters.  Learn more  Dismiss

MRI MAGIC

Loading...

Sign in or sign up now!
298,893
Loading...
Alert icon
Sign in or sign up now!
Alert icon

Uploaded by on Sep 10, 2006

Watch these Biomed Techs (what I am training for now) put a solid hunk of metal in the field of an MRI machine, and it will fall in slow motion because of the powerful magnetic field. A field strong enough to pull a metal screw out of your body like a bullet shot.

  • likes, 9 dislikes

Link to this comment:

Share to:

Top Comments

  • The aluminum is NOT magnetic. When the aluminum is placed into a magnetic field its creates a flow of electrons that make an electromagnet that REPELS the magnetic field entering it, so it falls very slowly. The flow flow of electrons creates friction as they flow, and thats why it heats up and DOESNT FLOAT. However, there are superconductors that dont produce any friction(or very low friction at least) and they do float, so check out some videos about that.

    Hopefully that can help someone out

  • Not all metals are attracted to magnets, only alloys of Iron, Nickel and Cobalt. This means most steels and the metals in most batteries (plus a host of other things). Aluminum, Titanium, Brass, Copper, Zinc, and many others aren't magnetically attracted.

    However, all electrically conductive materials (like metals) are subject to the Lenz effect, which is what you're seeing here. Essentially, a conductive material in a magnetic field becomes resistant to motion by counter fields.

see all

All Comments (114)

Sign In or Sign Up now to post a comment!
  • However, it is 20,000 times stronger than the earths magnetic field. Powerful eyes. Please, do not have one if you have metal in your eyes O_O

  • MRI is a magnet composed of 3 gradients (smaller magnets). A screw will not shoot out of your body unless made of solid metal and in soft tissue without healing. Come on....

  • It's like magic! how does it work?

  • @PostTheMissing Just as a point of clarification, a material that repels magnetic field lines is classified as diamagnetic. Aluminum is paramagnetic, so it demonstrates a very weak magnetic attraction.

  • heý_ì_fËËl_sô_lòNËlý_tÓÐåy

  • @roidroid Though you might want to be less deadly and use something like Woods' metal for the experiment, I think it would work. ^ ^

  • @metamaterial it could look interesting if you poured the mercury down something - it might pour in slow motion.

  • That is just eddy currents (might be spelled incorrect) look it up on YouTube if interested further. There is a power running trough the conductor (aluminium) what causes the currents in the conductor "fighting" its own movements. (back emf.) Non magnetic materials can give back their inducted loads like on this example. The coper tube and magnet trough it is a nice test for home.

  • To quote xkcd..."Stand back! I'm going to try science!"

  • @trustthewater

    I think it has more to do with spinning inertia then with magnetic fields. They had this great experiment on the ISS with CD readers and a flashlight to show how you could use a spinning load to stabilize a system. In the case of the hard drive, the mass of the plates rotating gives makes the whole thing a gyroscope, hence why it resists being tilted when you push it over.

View all Comments »
Loading...
0 / 00Unsaved Playlist Return to active list
    1. Your queue is empty. Add videos to your queue using this button:
      or sign in to load a different list.
    Loading...Loading...Saving...
    • Clear all videos from this list
    • Learn more