Neutrinos and photos are both created by fusion and both leave the Sun. The neutrinos reach the Sun's surface after about 3 seconds and the photons can take 100,000 years to reach the surface, which is why I said studying the neutrinos from the Sun tells us about fusion happening right now. Why do the particles take different times to cross the same distances?

Explanation:

Neutrinos are particles that do not interact with matter they just pass through. Photons however, interact with matter in the form of collisions. This means that photons are constantly coming into contact with matter and this slows the photons. There is a lot of matter in the distance between the Earth and the Sun.

This is why the photons take so much more time than neutrinos.

b.a device that inputs heat into a cool object