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Electromagnetic radiation from one star does not repel electromagnetic radiation from other stars. If it did, we wouldn’t be able to see stars at night from the

Electromagnetic radiation from one star does not repel electromagnetic radiation from other stars. If it did, we wouldn’t be able to see stars at night from the Earth.

xelxebar 7y ago
> If it did, we wouldn’t be able to see stars at night from the Earth. Ha! I love straighforward sanity checks like this. My initial reaction was to ask myself about photon-photon collisions which are im fact possible, but your comment gives a nice Fermi bound on how rare such events actually are. Cool!
- Robotbeat 7y ago
  Photon-photon collisions are still technically possible... I remember a professor mentioning this as one question he got in grad school... draw out the Feynman diagram and you see a vanishingly small probability of photon-photon interaction. But yeah. Ionized particles like Galactic Cosmic Rays can be repelled by the local stellar magnetic field, but mostly the lower energy rays are deflected. Higher energy -to-charge-ratio GCRs can punch right through the weak stellar magnetic field, just like do for our Sun’s interplanetary magnetic field.
  - soulofmischief 7y ago
    Thank you for understanding my question before reaching for dismissal :) I knew low-energy waves are partially deflected, I just wasn't sure about high-energy waves. Makes sense!
soulofmischief 7y ago
I should have been more clear in my question. Solar wind is a form of solar radiation, and I was curious about the effect of solar wind + the magnetic field that carries it would have on some frequencies of electromagnetic waves. I would expect mid-frequency radiation such as visible light to remain largely unaffected, I was thinking more about its effect on high-frequency extra-solar radiation. And it's likely not correct to visualize this as individual photons colliding but rather wave interference. Here is an article explaining the effect [0]. An excerpt: "The interplanetary magnetic field, which is embedded in the solar wind, deflects low-energy cosmic rays from us at the outer reaches of our solar system, decreasing the flux of these cosmic rays that reach us at Earth." [0] https://aasnova.org/2017/12/01/a-shifting-shield-provides-protection-against-cosmic-rays/ https://aasnova.org/2017/12/01/a-shifting-shield-provides-pr...

Electromagnetic radiation from one star does not repel electromagnetic radiation from other stars. If it did, we wouldn’t be able to see stars at night from the Earth.

xelxebar 7y ago

> If it did, we wouldn’t be able to see stars at night from the Earth. Ha! I love straighforward sanity checks like this. My initial reaction was to ask myself about photon-photon collisions which are im fact possible, but your comment gives a nice Fermi bound on how rare such events actually are. Cool!

Robotbeat 7y ago
Photon-photon collisions are still technically possible... I remember a professor mentioning this as one question he got in grad school... draw out the Feynman diagram and you see a vanishingly small probability of photon-photon interaction. But yeah. Ionized particles like Galactic Cosmic Rays can be repelled by the local stellar magnetic field, but mostly the lower energy rays are deflected. Higher energy -to-charge-ratio GCRs can punch right through the weak stellar magnetic field, just like do for our Sun’s interplanetary magnetic field.
- soulofmischief 7y ago
  Thank you for understanding my question before reaching for dismissal :) I knew low-energy waves are partially deflected, I just wasn't sure about high-energy waves. Makes sense!

soulofmischief 7y ago

I should have been more clear in my question. Solar wind is a form of solar radiation, and I was curious about the effect of solar wind + the magnetic field that carries it would have on some frequencies of electromagnetic waves. I would expect mid-frequency radiation such as visible light to remain largely unaffected, I was thinking more about its effect on high-frequency extra-solar radiation. And it's likely not correct to visualize this as individual photons colliding but rather wave interference. Here is an article explaining the effect [0]. An excerpt: "The interplanetary magnetic field, which is embedded in the solar wind, deflects low-energy cosmic rays from us at the outer reaches of our solar system, decreasing the flux of these cosmic rays that reach us at Earth." [0] https://aasnova.org/2017/12/01/a-shifting-shield-provides-protection-against-cosmic-rays/ https://aasnova.org/2017/12/01/a-shifting-shield-provides-pr...