Everything posted by Genady
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Restaurant food (split from Heat Regulation - Obesity)
This is exactly my point. I love bread. But I never buy it in a supermarket. I get one or two kinds directly from a small local bakery.
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Best telescope
That was one of my first "jobs" in my astronomy club, when I was about 9. To manually follow a star with a telescope for a long exposure picture.
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Restaurant food (split from Heat Regulation - Obesity)
We aren't evolved to eat rice, corn, potatoes, squash, banana, olives, cereal, sheep, cheese, ... Maybe we don't need to be evolved to eat something?
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Homophobia, nature or nurture?
I think it's bad science. One can make a lot of other guesses on why they avoided the gap. For example, they knew that it is easier to stay on a flat surface.
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Curiosity about Infinite Sets
"If he had only stuck to math he would not have gotten into trouble with the Pope. There's a lesson in there somewhere." Also, if he had only stuck to strength of materials he would not have gotten into trouble with the Pope. Galileo's Beam Experiment (lindahall.org)
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Say something absurd
Sorry. Too lazy to cancel.
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Say something absurd
I give you -1 for putting this thread in a Science forum. I promise to cancel this -1 if you can justify that.
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Reintroduction of Quantum Field Theory into modern science
As for gravitational time dilation of proton, it is about 1-3*10-39. This is dilation of 10-22 second over the age of the Universe.
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Homophobia, nature or nurture?
How did they (the observers) know that they observed a fear of heights and not something else? Especially, it is strange because cats do not fear heights.
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Best telescope
Then consider / compare binoculars. See e.g. here: How to choose binoculars for astronomy and skywatching | Space
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What is the nature of our existence?
Yes, perhaps. But also, how we define 'relativity', 'relationship', and 'objective' in this context.
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Homophobia, nature or nurture?
I think that such a distinction is undefined. Can you clarify what you mean by "inborn or not"? Then why it's in the Ethics forum?
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Best telescope
Keep the expectations low. Stars will be just dots, anyway. You will see more of them, and they will be brighter. You will see some details of the Solar system objects, such as rings of Saturn and other planets' satellites. These will be exhausted soon. Nothing like crisp and spectacular images one finds online.
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What are alternative formulations of GR?
Thank you for the correction.
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Best telescope
What is the purpose?
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Space Expansion, wavelength and energy density
So, you can "measure the increase in volume from inside the volume."
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Space Expansion, wavelength and energy density
But the ruler is not a wavelength of a travelling photon. The ruler is defined locally. For example, like this: (Metre - Wikipedia) Such rulers do not expand. PS. I've picked that half a line because I saw it a pivot for the rest. It is relevant.
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Cosmological Redshift and metric expansion
IOW, define metric. Exactly.
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Space Expansion, wavelength and energy density
The ruler does not expand. The expansion is present on the distances of hundreds Mpc's. Expansion of space is a feature of homogenous isotropic space. But the physical space is not homogenous and isotropic. It has local areas of various densities of energy and momentum. They are sources of gravity, and they cause the spacetime to curve this way and that way, to shrink and to expand here and there with various rates. Only when all these local effects are averaged on the distances of hundreds Mpc's, the net effect of them becomes a uniform expansion of space.
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Cosmological Redshift and metric expansion
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Cosmological Redshift and metric expansion
You can say whatever you want about your pictures. But it is not how GR works. In GR, distances are determined via metric. Take two events in Minkowski spacetime, for example, events A and B: Which one is closer to 0?
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Overpopulation in 2023
Globally, regionally, locally ... Mentally, culturally, behaviorally ... Thank you for playing. As I don't intend to discuss this topic any deeper, I rather excuse myself.
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Overpopulation in 2023
I am not sure about it either, unless 'fewer humans' is 0. It changes all the time, IMO.
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Overpopulation in 2023
I don't see how it follows. (We are causing mass extinctions ⇒ we are too many)
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Cosmological Redshift and metric expansion
If the axes in the images above (see https://www.scienceforums.net/topic/131720-cosmological-redshift-and-metric-expansion/?do=findComment&comment=1248849) were labeled with metric units, e.g., 1 km, 2 km, etc., then they could represent a metric. In that case, it would be immediately obvious that they are just two different pictures of the same thing, i.e., a 2 km by 2 km area. But without units, they can mean anything, for example degrees of latitude and longitude. In this case, they show two shapes, both taking up 2 degrees of latitude and 2 degrees of longitude. Which is larger? This is impossible to tell as it depends where on Earth are they. Moreover, if they are on different planets, it also depends on the planets' radii.