Ask any question you want about Physics

originally posted by: Arbitrageur
a reply to: Nochzwei
Yes but at 4:36 the purple band is even righter than at 4:52. There's not as much ambient light at 4:36, so more light from the light bulbs saturates the sensor. Then he backs up letting ambient light in, and the purple band gets fainter. I do see the sudden increase at 4:52 and I don't have an explanation but if I had to guess, it's so sudden it almost looks like maybe he flipped some kind of switch or changed some kind of setting on the camera.

Or it could be that at 4:52, the affects of time dilation start kicking in.

a reply to: ImaFungi

Well if you believe the universe is infinite then logic says so would it's energy. We know the creation of space causes quantum foam to appear. If the universe is finite then energy has no other choice to be finite as well. But I don't think we will ever have the answer to this question. The only way to answer it is leave our universe. And I don't think anyone will be making that trip.

How would you create a portal to a different dimension?

a reply to: itanosam

Acme Instant Hole™, of course.

Is it still ok to ask new questions about physics here?. My query is related to adapting part a technology I have seen used in a wave power plant to use just as a pump for small desalination "machines". These de-sal machines are designed and built for 3rd world/small communities and are not large commercial de-sal machines, they are solar powered and I have nothing to do with their production so I dont know how they work.

The design problem is that this pumping system has to basically be a DIY solution that can be cheaply and easily built and maintained by anyone, and with few if any commercial parts (the people supplying these de-sal machines are an NGO).

This is a news article about the wave power plant that gave me the idea to try and use similar sort of pumps:
econews.com.au...

We dont need to pump at a pressure high enough to spin a turbine, we just need to be able to pump to shore, and not at any major flow rare, 100L/h is overkill for this.

So far I am thinking of going with a plunger pump, and using 100mm PVC sewer pipe and the cylinder (because its easier to obtain and it takes higher pressure than storm-water pipe). With a 100mm bore, I figure I would need a stroke longer than 100mm or too much initial torque would be required to push it; 200mm stroke with a 100mm bore, by my calculations is a LOT more water than I need--but I dont trust my maths

I was going to machine the plunger head from layered perspex and am still trying to figure out a solution for the floating part.

44Gal drums were considered because they have enough weight to push down on a plunder and yet still have some buoyancy when filled with air. The issue however is shelf-life with metal in seawater.

I then considered plastic drums of about the same size, but I dont know how heavy they are (never worked with them) to be able to push the plunger.

Another consideration was your average foam fishing bouys, as these are readily available to the people using these de-sal machines, but again, weight for down force is the problem.

So my question is a bit awkward, but I want to know what sort of weigh to bore/stroke I will need to be able to be able to push the pump? I mean if I decided 100x200 bore stroke was no good and needed to make it out of Xmm with a Ymm stroke, is there some sort of way you can help me with some maths to be able to work that out?.

I mean I could be looking at this thing completely wrong, so any input is appreciated.

Thanks

originally posted by: itanosam
How would you create a portal to a different dimension?

Possible but highly dangerous

a reply to: ItVibrates

Didn't give enough details but here is how you figure it out I'll give you an example.
A 3" hydraulic cylinder with cylinder area 7.065 in2 moves a 30 inches stroke in 3 seconds. Required pump capacity can be calculated as

q = 0.26 (7.065 in2) (30 in) / (3 s)

= 18.4 gpm

a reply to: ItVibrates

You need to consider the forces involved a bit more. The buoy will experience a lot of sideways pull. Will your plunger pull out of the pump cylinder, or will the cylinder pull off the sea floor? If you have a strong enough buoyant force it will compensate off some of the lateral pull, but not all.

Even if we ignore the lateral forces, what will happen in high seas when the height of the wave is much more than your pump stroke? The buoy will pull up rather fierce, and again the plunger will be likely to pull off.

I think I would try to figure out some geometry where the sideways pull is securely anchored off and I can convey just the up-and-down bobbing to the pump mechanism. And in the pump mechanism I need to be able to accommodate a wide range of wave heights, and sea levels.

You have an interesting, important, and laudable problem. Unfortunately I do not see an immediate simple small-scale solution.

originally posted by: Nochzwei

originally posted by: itanosam
How would you create a portal to a different dimension?

Possible but highly dangerous

Yes but how?

a reply to: Pirvonen

First: What is a "different dimension"?

If I assume that you mean a different universe, we should take a look at wormholes with a white hole on the other end. I remember something about Einstein/Rosen who said that it might be possible that this opens to a whole new universe.

If I assume that you mean a fourth or fifth dimension, I would say that we already are surrounded by those, but we can't sense them. Stringtheory assumes that there are many (11 up to 26, thats up to the scientist you ask) dimensions, but they are "rolled up". This is a difficult thing for us three-dimensional apes to understand, but I read about a nice little idea how to visualize "small, rolled up extra-dimensions". Consider looking at a parking area. It is flat, 2-dimensional. Take a closer look. You see those small cracks and patches of tar? Those are extra-dimensions. Looking closer, you see many more which are expanding the 2-dimensional plane of the parking lot into an n-dimensional "thing".

originally posted by: ImaFungi
Is it possible an area of #1 absolute nothing, can exist in the universe? Even 1 by 1 by 1 picometer?

I don't know, but I tend to doubt it. You could build a faraday cage to block the cosmic microwave background that permeates space, but I don't know of anything that will block gravity and unless you can block gravity somehow any space will contain gravitational effects. The best you might do in that regard is find some point where there are gravitational effects but they sum to zero, and you'd also have to make your faraday cage spherical so the gravitational effects from that would sum to zero inside.

Even if you do that you've still got vacuum energy which might be around 6 × 10^-10 joules per cubic meter, which is about what we've measured for the amount of energy in space causing the expansion of the universe to accelerate, though it's a bit of a guess that the two are the same thing, probably a good guess though. That's pretty close to nothing in a cubic picometer and even in a cubic meter it's not much, but because space in the universe is so vast, when you add it all up it ends up being maybe 2/3 of the mass/energy content of the universe, so it's far from nothing. We are fairly ignorant about vacuum energy and don't know enough about it to say how you could get rid of it, maybe you can't, at least not in our universe; I don't know how, and I doubt anybody does.

But regardless, just because the universe might be infinite, or lets say the universe is infinite (first of all I dont even know what you mean by that, but you must admit, at any given time, there cannot exist 'beyond finite' quantity of stuff. It is impossible at any given time, for there to exist in total a non finite quantity...it is a meaningless proposition)

Increasingly accurate measurements of the geometry of the universe suggest it's very "flat", but measurements aren't accurate enough to say if it's perfectly flat. If it's perfectly flat, one implication is that it's infinite. For me there's a conceptual problem whether it's infinite or not. If it's infinite, how can it go on forever? It's beyond our comprehension. Even if it's finite, you still have a similar conceptual problem of asking what's beyond it and what's beyond that etc. So our brains are fried either way . The energy need not be infinite if something like this is true:

Total Energy In the Universe is Zero?

Lets say the universe is infinite, in whatever terms you explain what that means;

The reason this is important, the idea of 'area of absolute nothing'... is because';

Lets say the totality of something, matter energy, universe, exists in an absolute area of nothing;

That fact (which is the most logical potential for being the truth) may have very significant influence on the nature of how matter interacts with itself, and whether or not there are pockets of true absolute nothingness inside the universe.

The most likely truth about this topic of reality is that;

There exists a finite quantity of matter and energy (which cannot be created or destroyed, just moves and interacts and changes form) which is surrounded by (and which exists in/on/amidst) an infinite area; meaning infinite ft by infinite ft by infinite ft of #1 absolute nothingness.

That sounds like a bubble universe concept if I understand your explanation and I wouldn't rule it out, but it's speculative, and as dragonridr said speculations about what is "beyond our universe" are likely to remain speculative forever since regardless of how much technology advances it's hard to imagine anybody leaving our universe. If you've heard of Occam's razor, then maybe you've also heard of the other razor that says "if the question can't be resolved by experiment or observation, it's not worth debating".

There's no experiment to prove who is right in a prediction for what's "outside our universe", so it's not a scientific topic from that perspective, and probably not worth debating.

originally posted by: Nochzwei
Or it could be that at 4:52, the affects of time dilation start kicking in.

If you think there might be some kind of correlation with whatever is making that whirring noise, why does the whirring sound spin up gradually, but that light change is so sudden? Obviously there are other factors affecting that purple strip as I mentioned, such as the amount of ambient light other than the light from the light bulbs, which affects the camera's iris setting. If the iris contracts the purple strip will get dimmer and if it expands the purple strip will get brighter.

If you make a list of all possible variables affecting it why would time dilation seem more likely than any of the others? It seems far less likely to me based on the lack of correlation with the machine.

Now if the intensity of the artifact were to increase in correlation with the spin-up of the whirring sound, then I might infer a correlation with the machine, but even then I'd be more likely to suspect some kind of EM interference between the machine and the camera's circuitry, maybe like interference on the television when someone uses a hair dryer. There are lots of other possibilities besides time dilation, which seems very unlikely to have anything to do with it.

originally posted by: ItVibrates
So my question is a bit awkward, but I want to know what sort of weigh to bore/stroke I will need to be able to be able to push the pump?

That depends on a number of factors you didn't provide, such as:

1. You want to pump water to what height above the height of the pump?
2. You want to pump the water to what distance from the pump?

This gets a little complicated, but these tech briefs explains the variables:

Fundamentals of Hydraulics: Pressure
Fundamentals of Hydraulics: Flow

If your pump is anchored to the sea floor like the example you cited, an empty plastic barrel will displace an amount of water equal to its volume, though if part of the barrel is above the surface obviously there's no water being displaced by the part of the barrel above the surface. The mass of water that would occupy the displaced volume gives you an idea of how much force can be generated. This isn't a simple project even for an engineer and it seems you're not an engineer so it will be quite a challenge.

I'm glad to see you're thinking of maintenance issues like metal barrels rusting, but even plastic barrels degrade in the sunlight. Black plastic barrels usually use carbon black pigment which makes a good UV inhibitor which slows down degradation of the plastic from sunlight but it doesn't stop it. Other maintenance issues would be the seals and valves in the pump; did you have some thoughts on what you use for those or did you have a specific pump design in mind? If you're picking up any sand in the pumped water the sand will act like sandpaper and affect your seals.

If you had a sketch of your idea it might help us figure out exactly what you're trying to do.

originally posted by: Pirvonen

originally posted by: Nochzwei

originally posted by: itanosam
How would you create a portal to a different dimension?

Possible but highly dangerous

Yes but how?

Take a region on space bound by 3 coordinates. Now bring the time to stop in this volume of space and you have a portal.

Though not a question, i thought that i would still post this here since physics is the topic

www.nobelprize.org...

soundcloud.com...
soundcloud.com...

mainly because I have worked with one of these magnificent gentlemen for about 6 years, and have met the other at a couple of conferences. Both amazing guys

originally posted by: Nochzwei
Take a region on space bound by 3 coordinates. Now bring the time to stop in this volume of space and you have a portal.

Won't it be hard to move through the portal if time is stopped?

You might be able to bring time to a stop relative to Earth time inside a black hole, but otherwise I'm not sure how you could stop time. It's generally assumed that entering a black hole would probably be a lethal one way trip. If the radiation didn't kill you, the spaghettification would.

a reply to: Arbitrageur

Also goes for so called wormhole travel, which would require generating a huge gravitational potential, and prying it open if you will, which requires injecting negative mass.... something which we have zero evidence for existing

So not only being unable to move in the first instance, but basically being atomized is not going to help so much either

a reply to: ErosA433
That was the final nail in the coffin of electric universe pseudoscience which claimed mainstream physics had a problem with modeling solar neutrinos. That solved the problem with the mainstream model, but the EU folks can't seem to let go of that claim as I still see them trying to claim there's a solar neutrino problem. Time to let go of the past and admit science advanced.

Congratulations to the award recipients.

a reply to: Arbitrageur

That has always puzzled me, that the EU people pretty much ignore that result...[edit] or basically just say that "its wrong" without any real explanation as to why

a reply to: ErosA433

that means absolutely NOTHING !!!
Obama has a Nobel prize for piece if you remember

a reply to: KrzYma
The piece prize is usually a political farce, the science prizes tend to be well worth it.

This award has been something like 15 years in the waiting. Bit more than pretty much every arm chair scientist ever has done. Far more scrutiny than any EU 'scientist' has ever applied to anything at all

originally posted by: Arbitrageur
I don't know, but I tend to doubt it. You could build a faraday cage to block the cosmic microwave background that permeates space, but I don't know of anything that will block gravity and unless you can block gravity somehow any space will contain gravitational effects. The best you might do in that regard is find some point where there are gravitational effects but they sum to zero, and you'd also have to make your faraday cage spherical so the gravitational effects from that would sum to zero inside.

Even if you do that you've still got vacuum energy which might be around 6 × 10^-10 joules per cubic meter, which is about what we've measured for the amount of energy in space causing the expansion of the universe to accelerate, though it's a bit of a guess that the two are the same thing, probably a good guess though. That's pretty close to nothing in a cubic picometer and even in a cubic meter it's not much, but because space in the universe is so vast, when you add it all up it ends up being maybe 2/3 of the mass/energy content of the universe, so it's far from nothing. We are fairly ignorant about vacuum energy and don't know enough about it to say how you could get rid of it, maybe you can't, at least not in our universe; I don't know how, and I doubt anybody does.

Ok I should have asked; 1 by 1 by 1 planck length of nothing in the universe? Or even 1 planck length of nothing? Or less than a planck length?

If you do not think even 1 planck length of absolute pure nothing is in the universe, than you are presuming 'some factor' is keeping the universe infinitely compressed, especially if you believe it expands.

Imagine there is a 3d perimeter/area around the energy/matter of the universe (because there more likely is), Either with expansion you believe 2 opposing points on that perimeter are literally and actually increasing in distance from one another (like blowing up a balloon) or you believe your weird 'nothing moves, things maybe just tumble in place, raisins in bread yada yada'.

Consider truly nothing is beyond the perimeter, so you could take an apple at the edge, and toss it away from the entire universe, and that apple would be surrounded by no matter and energy, but drift off into pure nothingness; (there I suppose is where some quacking is made to declare that the universe could technically be a black hole, because it may be impossible to escape velocity away from the edge of the universe, because the gravitation of all the mass of the universe? maybe...)

The wondering part of this, is how there would and could not even be a planck length of that pure absolute nothing style area in the universe; the thought presumes that the universe is almost a perfectly dense object (as there are things that are air tight, the universe would be 'nothing space tight') and no matter how the material points within the universe move, and no matter the fact the totality of material of the universe exists unavoidably surrounded by absolute pure nothing space; no 2 particles of material, however small, can ever separate from one another at a distance to reveal between them, absolutely purely nothing.

If true, this is EXTREMELY SIGNIFICANT.

If it's perfectly flat, one implication is that it's infinite. For me there's a conceptual problem whether it's infinite or not. If it's infinite, how can it go on forever? It's beyond our comprehension. Even if it's finite, you still have a similar conceptual problem of asking what's beyond it and what's beyond that etc. So our brains are fried either way

. The energy need not be infinite if something like this is true:

If you mean that 'the universe is "infinite"' like the real numbers in quantity are infinite; you cannot be correct in saying so.

Hypothetically, if time were stopped (motion of all matter and energy), but you still had a metronome which clicked in seconds so I can say time was stopped for a million years;

To say that 'planets and stars really exist', is to say that they are hypothetically and theoretically countable.

If you were to stop time, to stop all the motion of matter and energy, hypothetically and theoretically all the stars and planets that are said to exist, would technically exist, and therefore be countable.

So there is no moment of time, in which you could say, the energy and material of the universe is quantitatively infinite.

It is only the fact that energy cannot be created or destroyed, which you must say, time is infinite, or the fact that energy will always exist, is temporally infinite; there can be over time, an infinite number of stars, but right now you cannot say the quantity of stars that exists, is an infinite quantity. That would be like saying the quantity 999,999,999,999,999,999,999,999,999,999,999^999,999,999,999,999,999,999 is an infinite quantity.

Technically, potentially, the universe may be 'spatially infinite' but also, because including the caveat of 'over time', because in any given moment, the quantity of energy and matter cannot 'take up an infinite quantity of area', because hypothetically and theoretically, that area can always be squared, cubed, or to the power of a quintillion.

So there always must be a limit at any given time, the quantity, and the area. Which compels an intelligence to presume, there always must be 'area of absolute pure nothing' (whatever that means) beyond the limit of area of matter/energy.

These are the perfect rails of logic I build my trains of thought on.

That sounds like a bubble universe concept if I understand your explanation and I wouldn't rule it out, but it's speculative, and as dragonridr said speculations about what is "beyond our universe" are likely to remain speculative forever since regardless of how much technology advances it's hard to imagine anybody leaving our universe. If you've heard of Occam's razor, then maybe you've also heard of the other razor that says "if the question can't be resolved by experiment or observation, it's not worth debating".

There's no experiment to prove who is right in a prediction for what's "outside our universe", so it's not a scientific topic from that perspective, and probably not worth debating.

I am not speaking about 'beyond our universe' in terms of your comprehension of the term universe. I am speaking about, beyond the totality of energy and matter. If your definition of universe is, the absolute totality of energy and matter that exists in all of possible reality, then, yes, I am speaking of beyond your comprehension of the term universe.

Beyond stuff, something, energy matter... must truly exist... real, absolute, pure nothing.