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Physics, Astronomy & Cosmology / Re: Did the Sun change from orange to white 15 years ago?
« on: 11/04/2024 15:21:03 »
I can tell you this: The Sun has not changed color in the 65 yrs that I've been around.
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Krytptid's thoughts here mirror mine very closely and it seems I have a major gap in my understanding of SR(not surprising really). If one could travel at the speed of light surely one's rapidity would be infinite and hence time and space would have no existence- why does this not apply to light?. I have heard several physicists state that "light does not experience time or space" or something similar expressed more accurately: I cannot remember any names other than the mathematician Roger Penrose(who can be controversial at times). This question of mine is a bit muddled but I could not find a better wording."If one could travel at the speed of light ..." That's the issue. Anything that travels at c would be in the same boat as light.
Red light does indeed penetrate the epidermis to a greater extent than blue, but all the "red light therapy" installations I have seen (I get involved with a lot of "fringe" stuff!) also produce a fair bit of radiant heat, free coffee, and pleasant music. Plus handsome, enthusiastic, young therapists.No. It is because red light doesn't trigger the transition from night vision to day vision. Night vision uses the rods of our eyes, and they start activating due to the production of rhodopsin, which takes a good bit of time become fully effective. It reacts with and decays rapidly when exposed to high enough levels of light. Thus when your eyes have become dark adaptive, and you look at a bright light, this neutralizes the rhodopsin, shuts down the rods, and you lose your dark adaptation.
The dark-adapted human eye is more sensitive to red light, which is why it is used in cockpits and ships' bridges at night.
"Space-time" is said to be "curved". In Relativity, space and time are not the separate and distinct things they were considered in Newtonian physics. So, we have three spatial dimensions, Up-down, left-right, front-back. and a time dimension, past-future. and they are all "connected" in a way.
This part I don't get (science is not my strong suit). I thought that space is bent around the star, so how can this stick defy space that is bent, even if equipped with EM field?
I see talk of an expedition to find water at one of the lunar poles. I would have thought any frozen water would have sublimed in the high vacuum that exists on the moon.As long as the water is in a crater or other permanently shaded spot, it shouldn't be any more susceptible than ice in a comet far from the Sun. If mere exposure to a vacuum were enough, by now there would not be any icy bodies in the Solar system.
Andromeda is moving away from us as it is red shifted. And yet we are going to collide with it. So how can we collide with an object that is red shifted?Andromeda is blue shifted. It is part of our local group of galaxies which are gravitationally bound to each other. The Universe is composed as a hierarchy of structures. Star systems group together to form galaxies, individual galaxies form groups, groups form clusters... It isn't until you get beyond the cluster stage that you begin to see the effects of the expansion. So when it's said that the galaxies are receding from each other, it really means that structures that are formed from galaxies and are beyond a certain size are receding from each other.
It should be blue shifted if it is heading our way regardless of the universe expansion.
If the local gravity is overcoming the expansion and that is the explanation for our collision then how can it be red shifted when we observe it?
(local dynamics, such as the gravitational interaction between the Milky Way and Andromeda, cannot explain why Andromeda's light appears redshifted if it is indeed moving towards us).
AC electricity moves at the speed of E/M light and is massless just like photons. So 50/60 cycle per second domestic electricity could just be very low frequency E/M light.No, it doesn't. The drift velocity of the electrons is really quite low, and even the effective speed ( like the time it takes between flipping a switch and the light coming on) can be as slow as 2/3c, depending on the conductor.
Further problem is particles cannot accelerate to light speed without a huge amount of energy being pumped in.
So we need to rethink how we visualise electricity and the parameters surrounding photons inside a conductor.
Electro-magnetic energy is fundamental energy has the formula = V*A *Cosineϴ*Time.That formula refers to specific situation when you are dealing with an alternating current and a circuit with either capacitive or inductive reactance. In such an instance, the voltage and current can be out of phase with each other, the difference in phase angle is what you are taking the cosine of to get effective power usage of the circuit. If the circuit were purely resistive, than there is no phase difference and you can just multiply volts times amp to get watts and then that by time to get energy usage.
But if Cosineϴ is zero then even with volts and amps present we have no power energy only quantum power energy
Yes, E = hf. but what length or area dimension are you measuring in. Energy must occupy a volume it cannot be described physically without volume in cubic Metres x,y,z especially as it has no mass in Kg. Time in Seconds is relative.Energy is a property. It makes no more sense to say that energy must occupy a volume than it does to say weight must have a length.
MKS has a problem describing electricity and electro-magnetic light.
Exactly. MRNA vaccines are used to help train the body to do its natural job, fighting off viruses.The same way it has been working over the last 2 years.
Periods are not viral infections.
AFAIK baby mammals drink milk direct from the source. This covers every species from laboratory mice to blue whales, including all apes. If you find the "fresh taste of the countryside" a bit overpowering, you could wipe the teat with alcohol. Best get a friend to hold the head of the cow/sheep[/goat/horse if you are new to the game, and use a clean bucket.Based on a fair amount of personal experience, it is generally not the head you need to worry about.