Things We Thought Were True, But Are Not
When I was learning this stuff, I was told that:
- Astronomers would never see planets circling other stars
- We can see almost to the end of the universe and almost count everything that’s there
- The universe will stop expanding one day, and may even start to contract
- You’ve been as constant as the Northern Star, the brightest star that shines
Oh wait – that last one is from a song by Gerry Rafferty. It’s as wrong as all the other things in the list, though (Polaris, the “Northern Star”, is neither the brightest star, nor is it constant in brightness).
The latest bit of knowledge circa 1960 that’s gone “poof!” is the idea that the Earth’s atmosphere is pretty solidly connect to the planet, and is shielded from solar storms by the Earth’s magnetic field. These storms and the solar wind would otherwise drive the atmosphere off the planet. But unlike Mars, the air is not leaking away.
This may mean our planet’s magnetic shield may not be as solid a protective screen as once believed when it comes to guarding the atmosphere from an assault from the sun.
Researchers were stunned to discover recently that Earth is losing more of its atmosphere than Venus and Mars, which have negligible magnetic fields.
Once again, it’s the end of the world as we know it, and I still feel fine.