# Can you touch something which is massless?

Can one touch mass-less things? If not then why the light get scattered by the tiny particles present in air? If light is massless how can it hit particles or dust to get scattered?

$$**OR**$$

The light do not need any medium to travel then why it changes its path by changing medium.

• Can you expand a bit on what you think touching a mass-less thing means? Your wording suggests to me that you may have some confusion, and its easier to help resolve such confusion if we have more of a sense of what you think is going on when light is refracted. – Cort Ammon Jan 5 '17 at 3:17
• Light gets scattered, not refracted, when it hits particles or dust or whatever you want to call them. And secondly, light is a wavefront. Different parts of the wavefront hit the refracting medium at different time, and hence the different parts change velocity (and hence change the path) at different times. – Prasad Mani Jan 5 '17 at 5:35
• Related: physics.stackexchange.com/q/23797/2451 and links therein. – Qmechanic Jan 5 '17 at 9:44
• Also related: air has mass. – probably_someone Jan 5 '17 at 11:21
• @PrasadMani, If light is massless how can it hit particles or dust to get scattered. – Harsh Kumar Mar 1 '17 at 4:05

The underlying level of nature is quantum mechanical, and the theory that describes the behavior of matter is the standard model of particle physics. All classical behaviors emerge from this underlying quantum mechanical level.

The photon is a massless particle and classical electromagnetic waves , for example light, emerges from a huge number of confluent photons.

can one touch mass-less things?

The particles interact, and the interaction can be felt as a "touch", for example light falling on your hand and felt as heat is the interaction of innumerable photons with your skin. The interaction with the retina of the eye and the transfer of the interaction to the brain builds an image of the world in our brains

If not then why the light get refracted by the tiny particles present in air

The massless photons scatter off the tiny particles and the light built up by them changes direction/refracts because of the interaction.

"The light do not need any medium to travel then why it changes its path by changing medium?"

**man because of ** Dual nature of light You should have some exposure to it . You know the tonnes of experiments done by scientists shows peculiar behavior of light , sometimes it behave like particle and other like wave . And more accurately when it interact with matter it behaves just like that it is made up of particles . So here is where this apply . And why it is happen you can go check out to the link given below They have explain this phenomenon the best way that any could have did.

And I really dont know whether we can touch massless thing in other aspects.