# The Naked Scientists Forum

### Author Topic: If mass increases as you approach the speed of light, why are photons massless?  (Read 1365 times)

#### thedoc

• Sr. Member
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##### If mass increases as you approach the speed of light, why are photons massless?
« on: 19/10/2012 03:30:02 »
David Michaels  asked the Naked Scientists:

Hi Naked Scientists,

I have listened to pretty much all your podcasts, and have built up a lot of dumb questions, and knowing the only dumb question is the one not asked, I have loaded up.  (I apologize if any of these have been covered, or if I should have figured them out .)

First of all we all wonder how a show that is supposed to be accurate does not have really naked scientists, (but being radio, we can't  be sure)...

If mass increases as you approach the speed of light why are most objects that travel at that speed almost massless?

What if you by definition, call the speed of light 0 m/sec., wouldn't it make more sense, as objects slow down, they should get heavier?  If c were defined as zero, would you be able to say we are really moving through the aether?

Great show, I wouldn't change a thing (except for having really naked scientists).

Regards,
Dave

What do you think?
« Last Edit: 19/10/2012 03:30:02 by _system »

#### simplified

• Sr. Member
• Posts: 428
##### Re: If mass increases as you approach the speed of light, why are photons massless?
« Reply #1 on: 19/10/2012 20:18:34 »
So called gravitational mass does not increase at speed.Photon has "repellent" mass.

#### The Naked Scientists Forum

##### Re: If mass increases as you approach the speed of light, why are photons massless?
« Reply #1 on: 19/10/2012 20:18:34 »