Dale's latest activity
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Yes sorry, only later I realized the point was about isotropy of light intensity and not light propagation process (speed). -
Dale replied to the thread I The Einstein Clock aka Light Clock.Consider a dipole antenna that emits a brief pulse. The emitted radiation is not isotropic in any frame. But the shape of the wavefront...
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On reflection (sorry) I'm not sure this is correct, and need to do a bit of maths. It is definitely true that if the source emits a...
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You don't. But you can have a moving source, one which is not always at the same point. The mirror will reflect the same fraction of...
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Dale replied to the thread I The Einstein Clock aka Light Clock.Aberration always applies. Aberration is a disagreement between two different reference frames about the direction of light. If you have...
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Dale reacted to russ_watters's post in the thread B Why would an atmosphere without greenhouse gasses be colder than with them? with
Like.
With the "warmed surface" radiating more heat directly into space it will be cooler and thus will heat the atmosphere less via... -
Dale replied to the thread B Why would an atmosphere without greenhouse gasses be colder than with them?.This was your question. But it is changing the amount of heat that transfers through that mechanism. To change the temperature (your...
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Dale replied to the thread B Why would an atmosphere without greenhouse gasses be colder than with them?.No. Substantially more than it does now. That is the point.
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Dale replied to the thread B Why would an atmosphere without greenhouse gasses be colder than with them?.IR will radiate directly from the ground into space.
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Any point is stationary relative to the observer - this is effectively the definition of a point in this context. No they aren't. They...
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I only have time for a quick reply now, just focusing on some issues with your first bullet: .. in the ship's inertial frame (assuming...
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Dale replied to the thread I The Einstein Clock aka Light Clock.This is not correct and it is not an implication of the light cone (sphere). The light cone says that if there are rays in every...
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Dale replied to the thread B Is space stretching or is new space being created?.I don't think that the plain language description is important. What is important for physics is an experimental description. Plain...
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Dale reacted to russ_watters's post in the thread B Why would an atmosphere without greenhouse gasses be colder than with them? with Like.
The surface radiates and not all of that energy is absorbed by the atmosphere...
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Dale replied to the thread B Why would an atmosphere without greenhouse gasses be colder than with them?.With GHG in the atmosphere the surface of the earth is in radiative “contact” with a reservoir that is at the temperature of the...