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In rough terms it’s similar to a tsunami created by an earthquake - a sudden shift in a solid, and it pushes the fluid out of the way. The impulse creates a wave pulse. For something tearing, this is happening over and over, at a microscopic level.

Also, how much reaction mass do you need to carry? What is the payload? (At some point we get into the issue of how a craft survives hitting objects traveling near c)

Huxley was indeed prescient on the subject. Let's hope Nietsche was too.

Let's do it! Do what? All you've got ATM is, my bible is better than your scientific knowledge; I didn't think you liked that approach... Indeed. "God/alien's is the blanket we use to cover the unknowns and give it a shape." I think this was a quote from a roadie for the "Rolling Stones".

A bullet most definitely does make a noise as it flies through the air. Whether you hear it as a whizz or as a crack depends on whether it is sub- or supersonic as it passes. But in the case of paper and tape, you also have something else: a resonator. The surface of the paper or the tape will be made to move when the breaks take place and this will make a larger volume of air move.

I realize it's about fast motion, but then why doesn't a flying bullet squeal like crazy? That's fast motion too, what's the difference? The sudden movement of the tape, I read somewhere that the wave along the tape can move at supersonic speeds, but how does this all relate and cause this sound specifically?

If you think being 13.8 billion years old is "fresh and new", you have a curious conception of these terms.

Any sudden movement will disturb the adjacent air. In both the cases you mention there is a stretching action followed a break in quick succession. When the break occurs, the stored energy in the stretch is released suddenly, causing a very tiny but rapid movement of a portion of the paper or tape. This will create a sound wave. There does not have to be - and in this case there won't be - a vibration, just a single motion. This is shown in fact by the absence of any discernible pitch or tone to the sound. It's more or less white noise. If there were vibration, that would cause a sound at a particular pitch, or pitches.

Speculation: So one thing I observe is that everything is so "fresh and new". We are not hampered by anything from the past. This makes sense as according to modern theory everything came from an "infinite point" and evolved over billions of years. So in effect this is a new "time". The question is were there any previous "times". According to Roger Penrose (scientist), this universe is born from the collapse of a previous one. In effect there is an eternal cycle of expansion and contraction. The question is were there were any "earth worlds" previously in time? And if so were they more connected to that of previous times? For us we are not connected to previous time at all. We obviously inherit the previous history of this world through ancient monuments and written history and cave drawings. But we have no link per se to time previous to the formation of this world. And hence the search and theorizing about what did actually happen. Eg there were quarks and other subatomic particles per se. The theory is that this universe is a "rehash" of the "smashup" of previous times. Essentially like a "recycle garbage bin" in time. Yet we see ourselves as completely new. Wonderous, exciting etc. The theory is that previous times are reflected very well in this world. Through our stories, creativity, art etc. The theory is that there is no such thing as "creativity". Our minds are drawing upon a "mashup" of the past !!!

Hello, I had a hiccup in explaining how sound is produced when materials break down. For example, A) we are tearing paper, B) we're unwinding duct tape. There is a break in the adhesion bonds. The breakage results in a sudden release of energy, which is converted to kinetic energy in some way, creating sound. How does sound occur? What's vibrating in there to cause it? I'm interested in physical part of production of sound in these processes.

Hi About 5 years ago, i think it was a morning, I was walking on a small countryside road in north of France Then I looked on the side and I saw the moon being very huge compared to usually It scared me, i think it looked about twice the size as usual I don't remember well, I took no photo, I think the size decreased pretty quickly, i don't remember well Would someone have an explanation/assumption/idea about this? Could that have been some reflect/visual effect? I think it was during a cold season Regards

All of the data analysis stuff in Python begins with the numpy library. Use numpy.mean() and numpy.median() after casting your list to a numpy.array like so: Data = numpy.array([1,2,3]) Honestly the best advice though is use chatGPT for little coding questions like this.

OP sounds a bit like an AI, but it’s a cool speculative post. To Mordred, the challenges of defining consciousness seem insurmountable, but when you have this requirement that something be conscious of something else, it has a unique signature in terms of correlations, optic nerve signals being correlated with external lights, etc. No different with AIs. It’s just a base level: you can’t say this creates consciousness, but you can say without it there is none. Anyway these correlative relationships may turn out interesting for studying physical systems. The smart money is against anthrocentist notions, including the specialness of our minds.

Radio works at the speed of light. Lasers are also already used for some communication. No time travel involved. Edit: my comment above was posted before the message above was seen. What do you mean by "binary light frequency"? And, it's still not clear why you think/thought information would be received before it is sent.

Thanks for the great replies I actually just asked the same question on LBC radio and the presenter read it out and amazingly someone replied via the radio station having calculated how long it would take the laser to return to earth. I actually thought that if we sent binary light frequencies to a reflector deep in space via laser that the information could be received before the information was sent.

No

You’re not wrong. I, in fact, paused with a similar self-critique when typing it. I think where maybe I landed after chewing upon it momentarily was how assigning capitalism as a root cause for our mediocre milquetoast attempts at mitigating climate change thus far is both a) too simplistic, and b) too convenient a scapegoat to emotionally let ourselves as individuals off the hook. Perhaps a better root cause of our Fiddling_Nero-level lethargy on climate gets framed as a sort of selfish shortsightedness; a desire for relief in the present moment at the expense of some still unrealized potential future narrative. At the risk of being reductive: Capitalism isn’t the root cause of anything, really. Dopamine and how we each act to spike it is. That won’t change by switching the social order to a more socialistic or even communistic one, though would certainly be helpful if we could all just be a little less horrible to each other and think a bit more about what’s left when we’re gone.

What is it in your scenario is it that makes you believe information might be 'time traveling'? Is it because you use lasers? Or because of the speed of light? Because it is 'round trip' travel? Because there is something about Mars that is special?

That would be a causality violation c is the speed limit of information exchange as well.

If we reflected lasers back to earth from mars could we receive information before the information is sent? If the information travelled at the speed of light to mars and back to earth would it effectively be time travel for information?

found it I finally recalled it was a series of Black star research "Irreversible gravitational collapse: black stars or black holes?" https://arxiv.org/abs/1105.3394 I certainly wouldn't argue with this. LOL I know any personal modelling I do I set Planck units as a constraint on anything involving spacetime or other fields. Funny thing is that boundary works well with the FLRW metric for the 10^{-43} second boundary the average estimated temp of 10^19 GeV when you convert is in the same orders of magnitude as Planck temperature. With the temperature scale factor relation. Blackbody temp can be estimated by the inverse of the scale factor. This also corresponds to 1 Planck length. just an interesting tidbit on last.

One problem I have with the central singularity. What happens when you apply Heisenberg's Uncertainty Principle to the singular event ( whether spatial or temporal singularity )? An exact location would mean indeterminate, even infinite, momentum, while an exact time would mean indeterminate, even infinite, energy. How would a particle, localized in such a way, remain trapped within the Event Horizon ? Now make that argument for all particles ingested by the BH and you have a BH which cannot exist. IOW, the singularity renders the theory inconsistent; either a singularity cannot exist, or Black Holes cannot exist. Yet we have photographic evidence of Black Holes, so where does that leave us ? I would be interested in a link to this article also. I'm interested in the proposed method ( pressure or force ) used to resist gravitational collapse at this radius.

It was several peer reviewed article on Arxiv but it was a few years ago that I followed the research and some of the proposed tests. However I'll take a look and if I can find the papers. If I can I'll post it. Point of detail the singularity conditions regarding the EH involve infinite redshifts and subsequent time dilation relations involving the EH. These conditions are the ones directly involved with regards to Hawking radiation. This also involves Unruh radiation https://arxiv.org/abs/0710.5373

I like indulging nice guys, Moon, so I'll start us off. Consider a constant acceleration ship, say 1g, for the confort of the occupants. "From the planetary frame of reference, the ship's speed will appear to be limited by the speed of light — it can approach the speed of light, but never reach it. If a ship is using 1 g constant acceleration, it will appear to get near the speed of light in about a year, and have traveled about half a light year in distance. For the middle of the journey the ship's speed will be roughly the speed of light, and it will slow down again to zero over a year at the end of the journey. As a rule of thumb, for a constant acceleration at 1 g (Earth gravity), the journey time, as measured on Earth, will be the distance in light years to the destination, plus 1 year. This rule of thumb will give answers that are slightly shorter than the exact calculated answer, but reasonably accurate." From Space travel under constant acceleration - Wikipedia We can then make other quick estimates to travel time "From the frame of reference of those on the ship the acceleration will not change as the journey goes on. Instead the planetary reference frame will look more and more relativistic. This means that for voyagers on the ship the journey will appear to be much shorter than what planetary observers see. At a constant acceleration of 1 g, a rocket could travel the diameter of our galaxy in about 12 years ship time, and about 113,000 years planetary time. If the last half of the trip involves deceleration at 1 g, the trip would take about 24 years. If the trip is merely to the nearest star, with deceleration the last half of the way, it would take 3.6 years." Now you might say"That's not too bad.". Only 113 000years pass on their home world to send a ship 100 000 light years. And a relatively short time to send it to a nearby star. Even doubling that time for two-way journey seems reasonable. Now comes the hard part. ( and I'm not going to attempt to quickly find/perform the calculation; I'll leave it to better, more fastidious, minds than mine ) How much Hydrogen do you need to carry, or collect along the way, in order to sustain a fusion reaction capable of sustaining a constant 1g acceleration/deceleration ?

The collapsing star is a dynamic state, and quite different from a free-falling object. There's dense stuff, and then not even Pauli-exclusion can support it. OK, so there's even more squish, at least at first. A spatial dimension rotates and is replaced by time, and that time dimension is bounded. What was the time dimension rotates out to a spatial one, one with nearly infinite extension at that. Lots of new room to spread out, but the causal light cones don't allow arbitrary travel down this big space, so I cannot say the compression ends. An example of the space available inside a black hole, Sgr-A and the black hole at the center of Andromeda share a common singularity. They're the same black hole, a region of 4D spacetime bounded by a 3D event horizon hypersurface, and in that case, the same (connected) hypersurface. It's only in a slice of coordinate space at a given time that the one object has multiple cross sections, manifesting as a pair of black holes to us, for now. None of the above is particularly an answer to the question of if there is compressed matter in an established black hole. In coordinate time, yes, it's very dense, but that's more like length contraction than pressure. None of the matter actually reaches the event horizon in coordinate time, and yes, in that state, it (the original collapsing star matter) is very much under compression. The singularity condition exists, but isn't described, precisely because the physics there is singular, sort of like asking what the perspective of a photon is like. Got a link? That sounds like pop nonsense. Is it peer reviewed? That makes more sense. Still, to be matter, it has to persist, no? Agree to all. There's also a naked singularity. You can for instance just keep dropping electrons into a black hole until the charge is more than the gravity and no more (isolated) electrons can be added by any means. Similar issues if the infalling matter adds too much angular momentum. A given mass can only have so much of that. These are examples of frame independent singularities not obscured by the coordinate singularity of the EH. Ditto with the LLM answers, which is just massaged google results. Anyway, thanks for the post. Good informative stuff in there.