The latest episode of The Sky at Night brought to my attention a comparison of the JWST test image with the Spitzer Space Telescope (SST) image of the same location - see first attachment.
The SST was launched in 2003 and retired in 2020.
Just look at the difference in resolution!
The difference is seen to be even more remarkable if we access this GIF image:
The SST was launched in 2003 and retired in 2020.
Just look at the difference in resolution!
The difference is seen to be even more remarkable if we access this GIF image:
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Cosmic inflation does not break the speed of light, if that is what you are getting at.
Two photons created close to each other during the inflationary period still have to obey the laws of special relativity, so can only move relative to one another at a speed equal to the speed of light.
However, the space between the two photons is free to expand at whatever rate the Universe dictates.
I thought inflation was faster than c. It took place when the universe was absolutely minute, but it was still faster than c.
Technically, the expansion during the period of inflation proceeded faster than the speed of light.
Light's speed limit only applies to 'things' within the expanding universe.
However, the expansion rate of spacetime isn't a speed as such. It's a speed per unit distance and there are no physical bounds on its upper limit.
Light's speed limit only applies to 'things' within the expanding universe.
However, the expansion rate of spacetime isn't a speed as such. It's a speed per unit distance and there are no physical bounds on its upper limit.
When you say "things", do you mean those that are exclusively observable visually? So if you can't see it, it has no speed limit?
We might ask ourselves, "How can inflation (or even the more sedate expansion that followed it) exceed the speed of light?".
One answer I've found lies in general relativity, which describes the fabric of spacetime itself.
In this theory, there is no inertial frame.
Spacetime is not expanding with respect to anything outside of itself, so the speed of light as a limit on its expansion does not apply.
An alternative to the cosmic inflation hypothesis is that the speed of light was trillions of time faster than now.
Unfortunately, it's a hypothesis that contradicts Einstein’s theory of light, space and time.
I mean from the perspective of light itself. I think from an observational point of view it would have been the same...at the beginning.
If you read the accounts, the universe apparently expanded (this during the inflationary epoch) at a rate that was faster than c. the example I read was that, using an analogy for size, it went from the size of a golf ball to the size of the solar system in trillionths of a second - ie >> c and this remains one of the great quandaries of modern cosmology (iao of course).
here is a nice write up in wiki from where the above was taken:-
https://en.wikipedia.org/wiki/Big_Bang#Inflation_and_baryogenesis
A lot of these concepts are discussed in Stephen Weinberg’s ‘The First Three Minutes’ - updated version from the 1990’s. When he first wrote his book in the mid 1970’s, , cosmic inflation hadn’t been proposed - that only came a few yrs later with Alan Guth.
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Bonsai, your quoted source says that cosmic inflation was "unconstrained by the light speed invariance".
That's exactly what I have been saying - spacetime is free to expand at whatever rate it likes.
That's exactly what I have been saying - spacetime is free to expand at whatever rate it likes.
He's say's the collapse of the wave function is not dependent on observation.
David LePoint explains it perfectly.
Not the science . But y is well established psychologist is interviewing a physicist . Is there something mutual about this talk . Or is My science guy sick . Or jordan doing some social experiment. Thats the question actually
As Portsmouth's Premier Particle Physicist, imagine my Glee when I spotted these two Bargains today in the Main Drag!
Got both for £8. My friend Paul was willing to accept £7. But this a Charity Shop in which we try to help others less Fortunate.
I'll get back to you on any further gleanings about The Universe. Serious Reads.
Got both for £8. My friend Paul was willing to accept £7. But this a Charity Shop in which we try to help others less Fortunate.
I'll get back to you on any further gleanings about The Universe. Serious Reads.
Bargains indeed - enjoy.
And I'm willing to bet they are in perfect condition, as they likely went unread by their previous owner(s).
Coffee table books - that was probably their previous role!
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