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Old 16-08-2016, 07:56 AM
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bojan
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Location: Mt Waverley, VIC
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Quote:
Originally Posted by alpal View Post
That's always confused me.
They say that even more energetic particles than are made at CERN
enter our atmosphere all the time.
Since these high energy particles have lifespans measured in nano
or femtoseconds - where are they being created?
It couldn't be very far away yet I also hear they made in quasars & such like beasts which
are half way across the universe - a very long way away.

Can anyone explain it?
If their energy is sufficiently high (speed is close enough to c) they may have time to reach us from further away (because of time dilatation).
However, most short lived particles that reach the ground-based detectors are created in the upper layers of atmosphere by colisions of gamma rays with atoms/molecules.
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