2 ms·
No, we explicitly placed the photons to be traveling in different directions so that they could meet. If they meet, and they meet with sufficient energy, they c
by btilly 3y ago
No, we explicitly placed the photons to be traveling in different directions so that they could meet. If they meet, and they meet with sufficient energy, they can create particle anti-particle pairs.
You can read more about this at https://en.wikipedia.org/wiki/Two-photon_physics https://en.wikipedia.org/wiki/Two-photon_physics.
- ars 3y agoThe angle they are traveling is one that's impossible to reverse - in annihilation it's impossible for the two photons to be emitted at such a close angle. I read about the two photon physics - and the two photons can scatter off of each other, but they can't produce particles except in very high electromagnetic fields, which isn't the case here.
- codethief 3y agoI'm really not following you. If two photons meet at an angle – any angle –, there will be a rest frame in which they're meeting from exactly opposite (180°) directions. They can absolutely produce electron positron pairs if their energy is high enough. The process γ γ′ → e+ e− is a classic calculation in QED, and although it's never been observed directly for two single/isolated photons[0], there is no good reason to believe QED should be wrong in this particular case and, indeed, all evidence we have is pointing towards this process being perfectly possible[1]. [0]: https://en.m.wikipedia.org/wiki/Breit%E2%80%93Wheeler_process https://en.m.wikipedia.org/wiki/Breit%E2%80%93Wheeler_proces... [1]: https://www.energy.gov/science/np/articles/making-matter-collisions-light https://www.energy.gov/science/np/articles/making-matter-col...