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Just Chat! / Re: What is the silliest lie you've said to impress a female?

« Last post by Pseudoscience-is-malarkey on Today at 14:12:41 »

It makes no sense when dudes lie about their penis size to get a date. When the romance gets to the point where you see each other naked for the first time, she knows you lied and will probably end it there because she no longer can trust anything you say.

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New Theories / Re: What is the real readshift in the Cosmic Microwave Background (CMB)

« Last post by Origin on Today at 13:19:43 »

The real CMBR redshift only suggesting a motion of our galaxy of about 600km/sec?

Obviously not.  Since the the wavelength of the CMBR is the same in all directions, that would mean the galaxy is traveling in all directions at 600 km/sec, which hopefully you realize is not possible.

The CMBR exhibits a dipole, suggesting a motion of our star in our galaxy of about 600km/sec, relative to the CMBR. https://astronomy.swin.edu.au/cosmos/c/Cosmic+Microwave+Background+Dipole

I errored in my reply. 
The point is the CMBR is obviously not due to the our motion through space because the CMBR is very uniform in all directions, which would mean that for your idea to be correct we would have to be traveling in all directions, which is not possible.  By the way, a speed of 600 km/sec would give you only a very small wavelength shift and it would not be a uniform shift.

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New Theories / Re: What is the real readshift in the Cosmic Microwave Background (CMB)

« Last post by Halc on Today at 13:10:02 »

My simplistic understanding of what they said is:
- Roughly 15 (or 14) billion light years is the distance from "where the source was when the light was emitted" to "where we are now"

It's actually about 1/10000th of that. In cosmic coordinates (the only coordinate system I know that describes the universe), the oldest light we see (that of the CMB) was emitted at a proper distance of about 1.5 million LY away. The reason it took 13.8 billion years to get here is due to the very high expansion rate of the universe back at the time of the recombination event, perhaps 3M km/sec/mpc compared to 70 km/sec/mpc today.

Roughly 100 billion light years is the distance from "where the source is now" to "where we are now"

That would put it beyond the size of the visible universe which means we could not see it. So around 45 billion light years is the proper distance from "where the source is now" to "where we are now".

- There is an even smaller number which represents the distance from "where the source was when the light was emitted" to "where we were back then"

Well since we have not moved significantly in that time, that distance is also that 1.5 MLY figure. Cosmic coordinates has the Earth at the center, unmoving. You have to assign the origin somewhere.

As relativity illustrated, all times and distances are relative to which frame of reference you are talking about

Yes, which is why I carefully specified the cosmic frame and not say some inertial frame, which isn't valid at all at large distances since spacetime isn't Minkowskian.

And anything outside your light cone is irrelevant to you (eg if some object is now 100 billion light-years away, light from that object will probably never reach us, due to the expansion of the universe).

Correct. Any recombination light emitted from what is currently over about 58 BLY away will never reach us. Any light emitted today from over 16 BLY away will also never reach us. That latter figure is the current distance to the event horizon.

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Physics, Astronomy & Cosmology / Re: Will tidal power cause the moon to crash into us?

« Last post by vhfpmr on Today at 12:15:47 »

The rotational kinetic energy of the Earth is truly immense.....Human use of that energy would be minuscule by comparison.

Kinetic energy: 259000YJ
Global annual energy consumption: 634PJpa

259000YJ/634PJpa = 409 billion years

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New Theories / Re: What is the real readshift in the Cosmic Microwave Background (CMB)

« Last post by evan_au on Today at 07:53:26 »

the size of the Universe was about 92BLY....(or)  15 billion light years, than why they can't tell us how big it is.

There are some people on this forum who can explain this...

My simplistic understanding of what they said is:
- Roughly 15 (or 14) billion light years is the distance from "where the source was when the light was emitted" to "where we are now"
- Roughly 100 billion light years is the distance from "where the source is now" to "where we are now"
- There is an even smaller number which represents the distance from "where the source was when the light was emitted" to "where we were back then"

As relativity illustrated, all times and distances are relative to which frame of reference you are talking about
- And anything outside your light cone is irrelevant to you (eg if some object is now 100 billion light-years away, light from that object will probably never reach us, due to the expansion of the universe).

I apologise to those whose clear-sounding explanation I have mangled.... Please post an accurate description.

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New Theories / Re: What is the real readshift in the Cosmic Microwave Background (CMB)

« Last post by Dave Lev on Today at 04:22:23 »

The real CMBR redshift only suggesting a motion of our galaxy of about 600km/sec?

Obviously not.  Since the the wavelength of the CMBR is the same in all directions, that would mean the galaxy is traveling in all directions at 600 km/sec, which hopefully you realize is not possible.

The CMBR exhibits a dipole, suggesting a motion of our star in our galaxy of about 600km/sec, relative to the CMBR. https://astronomy.swin.edu.au/cosmos/c/Cosmic+Microwave+Background+Dipole

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New Theories / Re: What is the real readshift in the Cosmic Microwave Background (CMB)

« Last post by Dave Lev on Today at 04:11:16 »

At that time the science community claimed that our universe is quite compact.

Nope.
Here's what Wiki said 20 years ago.
"The size of the Observable Universe can be calculated as a sphere with a radius equal to the age of the Universe in light years. Thus the observable universe is a sphere with a radius of 15 billion light years. However due to initial inflation of the Universe soon after the Big Bang, the actual size of the Universe is much bigger than what is observable. ...
The Universe has no boundary but may be finite. This may be understood by a three-dimensional analogy: the Earth has no edge despite the fears of putative flat-earthers that they might fall off the edge if they travelled too far, but nonetheless the surface of the Earth has a finite area."

https://en.wikipedia.org/w/index.php?title=Universe&oldid=291910
Did you get confused about finite and bounded?

I do recall that in the past our scientists believed that the size of the Universe was about 92BLY.
However, this is not the issue.
As they claim today that the universe has no edge and it is bigger than a radius of 15 billion light years, than why they can't tell us how big it is.
You might claim that our scientists don't know. - I would claim that if they don't know the real size of the Universe, than how do they know that what they don't know is correct or incorrect?

the Earth has no edge despite the fears of putative flat-earthers that they might fall off the edge if they travelled too far, but nonetheless the surface of the Earth has a finite area."

If we discuss about the surface of the earth (two dimensions) than it has no edge, but in three dimensions it has a very clear edge.
However, there is no other real physical z dimension is our universe.
" The Universe, proper, is the single largest object with a name, and represents the culmination of full three-dimensional space interacting with time, forming a four-dimensional existence."
The space-time four-dimensional is excellent mathematical concept, but it doesn't add any real 4th physical dimension to our universe.
In the article it is also stated:
"There is some speculation that multiple universes exist in a higher-level multiverse. "

As our scientists are ready to consider so dramatic speculation of multiple universes exist in a higher-level multiverse, why they refuse to consider the possibility that the Universe could be just flat and infinite in its size?
Why our scientists are willing to consider all that possibilities/speculations for the universe just in order to bypass the key possibility that the universe could be infinite?
Could it be that they know that there is a possibility that the universe is infinite or at least - very very big.
Therefore, there is a possibility that any size that they might offer for the universe, would be too small for our real universe
However, if they would offer a too big size, (or even infinite) than the BBT would die.
So, could it be that in order to keep the BBT alive, our scientists bypass this key problem with the message of a "Universe with no edge"?

Therefore, the 3000K is a direct outcome from the BBT.

No.
It's a direct consequence of hydrogen.
If the material doing the emitting was helium, the corresponding temperature would have been roughly twice as high. (And the emission would have had more band structure to it).

I fully agree that the CMBR is a direct consequence of hydrogen as hydrogen is the most common atom in the nature.
However, why do you insist that the Atomic hydrogen welding (AHW) process (the 3000K) must be ALWAYS used in the CMBR redshift formula??

Let me ask you the following:
1. What is more dramatic speculation idea:
The idea of multiple universes exist in a higher-level multiverse, or the idea of a single flat & infinite Universe?
Do you agree that there is a possibility (at any chance) that the Universe is flat and is so big that technically it could be considered as infinite?
2. Do you agree that there is a possibility that the Universe age is much older than 13.8B years?
3. Do you agree that that there is a possibility that the CMB radiation is the reflection of that infinite Universe and not due to the Big bang that took place about 13.8By ago?
4. Even if the chance that the real CMBR reflects the radiation of the infinite universe is just one to one million of a trillion, why do you refuse to accept the understanding that in this very minor chance, the redshift in the CMBR can't be considered as 1100?

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Physics, Astronomy & Cosmology / Re: How important is it to recreate Earth's gravity on a manned spaceship?

« Last post by Peter11 on Today at 03:10:14 »

They pretty well know the limit the longest was around 450 days.They say without exercise they can loss up to 20% of muscle mass in two weeks not to mention bones start to weaken.A six month trip requires months of rehabilitation when they come back.It just hasn't happened yet and hopefully won't happen.

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Physics, Astronomy & Cosmology / Re: Will tidal power cause the moon to crash into us?

« Last post by Origin on Today at 01:44:15 »

Eventually, you'd expect Earth's rotation to slow down until a day was as long as a lunar orbit.

I think it is more likely that the earth would become tidally locked with the sun.

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Just Chat! / Re: Ridiculous Scientific Complaints

« Last post by alancalverd on Yesterday at 22:21:18 »

Fortunately science can come to the aid of our ovine correspondent.

Those of us of a crystallographic or medical imaging persuasion spend a lot of our working lives in k-space where the infinite becomes infinitesimal and teeny weeny ripples in the microcosmos are big enough to see.

Any tourist who is overwhelmed by the Grand Canyon is welcome to visit the road from my house to the research park, and study hundreds of natural canyons formed by the confluence of British council officials, British contractors, and British weather. The canyons are just big enough to destroy an alloy wheel or kill a cyclist. There is an annual ritual of "closing the road" just before the end of the financial year, and a few months later a whole new crop of canyons appear, so it's much more dynamic than its transatlantic counterpart, which hardly changes from one century to the next.

I believe work is already in progress to reform the minute, and the abolition of the leap second has already removed one of life's uncertainties. There are however opposing views on the next phase: when I say "just a minute" The Boss starts nagging after 30 seconds, but when she says it, it means as long as it takes to complete a telephone call, feed the dog and change handbags. I think the compromise might be to lengthen the second.

AFAIK there are no ethical objections to resurrection, and there is even a choice of procedures. Christians of my acquaintance are certain that their entire bodies will be restored to life at some time in the future, and adherents of other faiths are certain that minds and spirits are routinely reincarnated on a daily basis, though not necessarily in the same species. So the broad consensus is that Sir Isaac may indeed already be present as a crab louse or  tapeworm, or if not, he will turn up eventually at the same time as everyone else.