# TakenItSeriously

Senior Members

511

1. ## Properties of Expansion

I don't understand, so was the method I described involving Hubble's law and scale factors to solve for v₀ not the correct method? Well, when light speed creates an insignificant delay, it's effectively fine. However for large distances, it doesn't exist since it allows 0 time for information to travel.
2. ## Does mathematics has anything to do with physics?

I had brothers that taught me about QM, GR, and cosmology at the age of 7 and I understood it though I probably didn't know much beyond simple arithmetic at that age. I think my age actually made it easier to understand before life experiences had biased my intuition too much against accepting the unintuitive. I'm still not very good at math though. An open mind is the biggest hurdle for understanding science IMO, and math is mostly useful for proofs or sometimes problem solving. In college, there was a non-math physics class for all majors that weren't technical in nature and they even used the same text.
3. ## combination formula

If you divide each factor in the numerator by n you get (-1/n)(-2/n)(-3/n)... (-(1+r)/n) Therefore you can see the r! Term in the top forcing it to be true..
4. ## Collision during relatively fast interstellar travel

It's close but I think it's more correct to just subtract the failures from 1 Pc should be failure to repair so that collision and failure to repair = an unsuccessful state. Ps = (1-Ps PC) If you wanted to include maneuverability in that equation Ph = probability of intersecting trajectory Pc = probability of failure to avoid collision Pd = probability of failure to repair damage Ps = 1-Ph*Pc*Pd This avoids overlapping probabilities
5. ## Properties of Expansion

It's definitely possible, I'm still struggling to find an article that explains the math in a simplistic way without getting too involved with the details behind all the measurements that include multiple measurements for distance. I don't think that independent galaxies that show a trend for velocities increasing/decreasing with time or distance proves acceleration. I do think the trend is highly suggestive that it's true, especially considering the timeframes axis symmetry that is involved. How the solution for "proving", acceleration was found I'm only guessing at at this point as I haven't seen anything that verifies the method used yet. My guess is that the solution involves using the Hubble law with the Hubble constant and Lookback distance then use the scale factor with redshift to find projected velocities at proper time but I don't know this for a fact. It's just that all the variables are there to provide v₀. As you pointed out this only creates the boundary conditions that could show an average acceleration/deceleration. However as Mordred pointed out earlier, you could do this for any common density assuming a homogeneous isotropic state existed. The issue is you'd need the values for the Hubble variable which I'm still looking into. But for my purposes, finding even an average deceleration over time would suffice. For calculating acceleration over time, since it's such a symetricle statement, I thought it would be easy to simply rearrange the formulas and solving for dv/dt. Unfortunately, I forgot that an equivalent form of the Hubble constant (inverse of Hubble distance) is needed. I may have to solve both for the lookback timeframe instead which should also verify what I need. In fact it may be preferred since I don't actually believe claim that requires proper time for many reasons including: No timeframe would ever define proper time no matter what position or velocity the observer was in. It can be shown that such a state is nonsensical using the properties of simultaneous time. And even if we just assumed the universe was in proper time anyway, no object in the universe would be able to see any other object in the universe much less allow their gravity or energy to have any impact on expansion. Its ironic that such a state would be used to prove dark energy. Finally, I can't understand how a major property such as dark energy could be validated by projected data defining a hypothetical state that doesn't exist. As for why I'm doing this excercise if I don't believe in it: I don't believe in proper time, but I am trying to verify a potential Lorentz transform that GR may have overlooked some how. If such is the case, then I have an idea of what GR is missing. But if I'm wrong then I'd clearly need to reevaluate that hypothesis. Isn't dx/dt velocity and dv/dx (different dx) acceleration over a distance?[
6. ## Search for signs of Intelligent ET's in the Solar System

I think you need to rephrase this to change "disprove" to something like "what method creates the best odds for finding finding them" Even so, given your parameters of a fixed population of 5,000 and 2,000 years. It seems like they would need to have developed a closed echo system eliminating any waste detection methods. If they use technology similar to ours and aren't actively trying to avoid detection, I'd say scanning for radio signals are your best chance. But if you eliminate radio since SETI hasn't detected them, you might try scanning for EMI sources. Also they would need a completely renewable source of power so If the moon or other body has no thermal activity, then you could look for solar or wind power sources, though wind turbines could still be hidden. If they are actively hiding and sacrifice any technology they could be virtually undetectable. Seismic detection might work though that's a hell of a lot of area to cover. If they could find a way to survive in a gas giant... I'd say you had no chance. If you had the resources, you could try countless numbers of nano bots.
7. ## Properties of Expansion

I'm afraid I may not have been very clear in my OP. to clarify: Since we found expansion accelerating over distance (dv/dx) is increasing. If we looked at the problem differently and noted that. Galaxies we observe later in time have a lower regression speed. Since every distance measured can also be seen as a delta time from proper time as in a galaxy 10Billion ly away is also 10Billion years in the past. Then by Swapping distance with time and modifying the equations, we can then solve for expansion accelerating over time (dv/dt) It seems like we would get the opposite result due to a spacetime axis symmetry. I'll edit my OP to add the clarification. Edit to add again: Since I don't know where to find the data used, I can't check it myself. If anyone could direct me to where the data was published. assuming it's in the public domain, I'd really appreciate it if they could provide a link. Sorry for all the edits.
8. ## Properties of Expansion

If the Hubble Law is ultimately based on this fact: Galaxies that are farther away have a faster regression speed. And from that we conclude: The expansion of the universe accelerates as it grows. Then what about the statement: Galaxies that exist later in time have a slower regression speed. Symmetry should tell us that: The expansion of the universe decelerates as it ages. Both statements should be true but how does the expansion of the Universe do both? accelerate with distance decelerate with time Does anyone else see a second order Lorentz transform here? Just puttin it out there. Edit to clarify: Since we found expansion accelerating over distance (dv/dx) is increasing. If we looked at the problem differently and noted that. Galaxies we observe later in time have a lower regression speed. Since every distance measured can also be seen as a delta time from proper time as in a galaxy 10Billion ly away is also 10Billion years in the past. Then by Swapping distance with time and modifying the equations, we can then solve for expansion accelerating over time (dv/dt) It seems like we would get the opposite result due to a spacetime axis symmetry..

10. ## Search for signs of Intelligent ET's in the Solar System

This comes down to the misunderstanding of what was once a law (medieval times) in classical logic stating that you can't prove a negative which isn't true. What many believe this statement is supposed to mean and which is true: You can't prove non-existence. For example you can't prove the non-existence of unicorns, Santa Clause, God, or a aliens. I believe this was the point that ajb was making. For the kind of life we understand which is limited to life that evolved on Earth, the standard method is to prove absence of liquid water. Since liquid water can only exist at a certain region of a phase diagram, you only need to eliminate the possibility of temperature and pressure being able to reach this state, such as being too far from the sun. Of course there are still things that we may overlook such as when gravitational tides heat the inside of a moon in an elliptical orbit. Edit to add: After re-reading your OP, I should mention that this only precludes the existence of life that requires liquid water in order to evolve. It doesn't say anything about colonies of life that evolved elsewhere. Which was ajb's second point. In fact we are already thinking seriously about how to create inhabitable environments on off planet bodies within our solar system such as Mars, moons, or asteroids, and underground bases are the most likely scenario since it requires the least amount of materials to bring with you and just sealing off the entrances of underground caves and pumping it full of air may be more feasible.
11. ## Collision during relatively fast interstellar travel

Then you've clearly never driven through the desert on an empty highway where driving a 100MPH feels like your standing still. Things don't just materialize in front of you. A deer suddenly appearing in front of you after you've come around a blind bend is when you get into trouble. A deer that you see approaching the road off in the distance when there's no other objects around to hide it isn't going to be an issue. This kind of problem is important even for satellites today, although the scale is different. It's due to the speed at which objects move in space with no atmosphere to slow them down. Then even tiny lightweight objects such as a paint chip can be traveling at several times the speed of a bullet and would kill any astronaut unlucky enough to be on a spacewalk in its path. Fortunately objects in space are also easy to detect. The main issue is how much debris there is to avoid. All objects in Earth orbit down to the size of a baseball are tracked and satellites or the ISS must occasionally move in order to avoid collisions. Satellites that have lost the ability to maneuver become a threat since they may be hit creating many more pieces of debris. The ISS can has shielding material that can offer some protection but I think there's a gap in what it can handle and debris that's tracked. Because of this, I believe there are plans to move the space station into a higher orbit that's not as dense with space junk. Space junk has become a serious issue since there's so much of it. A large collision could suddenly create much more debris which could cause a chain reaction of collisions making satellites that depend on orbits in high traffic areas such as geosynchronous orbits no longer viable. It's a statistical problem which has already been worked out for determining a tipping point for the density of items which I believe we are very close to surpassing.
12. ## Collision during relatively fast interstellar travel

I'd disagree, the higher the speed: The greater the energy imparted from collisions, regardless of size. The smaller the object that becomes a threat. The more difficult it becomes to detect intercept trajectories at a distance. The less time you have to react to those trajectories. The more you need to armor your craft. The greater the mass of your craft. The less maneuverable you'll be for evading objects. The more you'll cut into your safe detection lead time. These are the potential issues I can think of off the top of my head.
13. ## Collision during relatively fast interstellar travel

At those speeds I'm not sure if gravity assists are going to be much help. Why not just avoid the orbital plane altogether? I get the impression that the ort cloud wouldnt be that big an issue to navigate.
14. ## Relative model of the universe

He referred to expansion which is the same model that accelerated expansion and therefore dark energy was extrapolated from later. This model defines its own hypothetical states of measuring time and distance which may be extrapolated from GRs field equations but do not follow the laws of GR. For example, using these definitions of time and distance, the speed of light is not a constant and you can have relative motion that exceed the speed of light due to expansion. In this model measuring distance is done following a line where time is held constant or its equivalent in a homogeneous isotropic universe where density is a constant. To clarify my point about time regression, this model uses measurements that take time regression out of the equation. Your right in that this may not be the point he was trying to make which is why I worded my post the way I did. Your also right in that I do have a problem with how expansion handles its model which I think I made clear. However, I can assure you it wasn't done as an attempt to hijack this thread.
15. ## Relative model of the universe

I think the OP is referring to what the conclusions about that rate of expansion of the universe is increasing and therefore requires dark energy is based upon which isn't GR, though it claims to follow GR. The way that the rate of expansion of the universe has been defined seems to rely on the notion that change can only be measured across states of fixed time which GR denies. Therefore the "states" of the universe were redefined to fit this notion. They use hypothetical states of the universe which are defined to follow a fixed timeframe in an attempt to get around GR. For example, GR requires states of existence that involve a time regression of 1year/light year of distance from the observer. I would agree that this doesn't follow GR and the notion that fixed time is a requirement for measuring change is a false axiom that was created based upon how we typically think of change occurring.
16. ## How could fast space travel be possible?

I recall one book that had presented gravity as a pushing force that all bodies in the universe exerted on all other bodies. Given that, then planets were shields that would block this pushing force. The larger the planetary mass, the greater the shielding strength and the more you would be pushed into the planets surface. They had discovered how to simulate the shielding force that all matter exhibited, only without needing the large volume such as a planet sized shield. Therefore, based on the above, all you needed was a shield to be placed on one end of your spaceship and just turning up your shield strength gave you all the gravity thrust you needed to reach relativistic speeds. I don't recall the name of the book but I really appreciated the creativity that went into creating a new theory for Gravity which could be correct for all we know about how gravity works, and allowed for the existence of Gravity drives.

18. ## about entanglement and time

While FTL communication could not be done between two parties, one possible use for this type of information transfer would be for sending encryption keys to two parties who could then securely send messages to each other via conventional means. The keys would be nondeterminately random to everyone else but the two parties who received them. Im not sure how cost effective it would be but it proves that secure two party communication without a trusted third party intermediary is theoretically possible which is a big deal in some circles. I Doub't that's what you had in mind when talking about changing time though.

Well, I still believe in the BB, I just have my own ideas about what comes before the BB. While I agree that we can only speculate about what occurs before the BB, to say that there is nothing before the BB is also speculation. Therefore if speculation doesn't create an unphysical condition and is a more reasonable solution than nothing (IMO) I may as well use it until a better option comes along.

If you believe that the universe is bounded by the Big Bang, as in nothing came before the Big Bang, then it seems to imply that you would believe in nothing as a state of nonexistance. I have trouble with such a concept myself. This would seem to mean that everything came from nothing and nothing would include no matter, no space, no time, no forces, no information, no energy, no god? In fact there would be nothing to induce the Big Bang either, so the Big Bang just happened for no reason. Since I don't believe in such a concept, I don't believe in nothing as an absolute state of nonexistance.
21. ## Why would we expect an Anti-Universe to be detectable?

Well, actually, by keeping the anti-universe within the domain of negative time (time before the Big Bang) then it avoids the problems of paradox because then positive time and negative time wouldn't have any points in time in common. You could actually think of it as two distinct timelines (or I guess you would have to call them time rays) that both start at the Big Bang. Regarding singularities, as best that I can understand it. Singularity seems to come about with a bounded system where the Big Bang must eventually compress to infinite density which denies Planc's constant where density should not increase to a point beyond which would include spaces smaller than a wavelength. With a symmetrical model that has an expanding universe on either side of it, then we can avoid singularities.
22. ## Why would we expect an Anti-Universe to be detectable?

True but it would be in a piece of the universe that occurred 15 billion years (or whatever the age of the universe is) before the Big Bang, though it would occupy the same space. So do we agree that CPT symmetry theory does hold up for antimatter exhibiting negative time properties. I actually think that CPT does take the time property literally, though I don't know if it has been validated beyond just showing all of the properties of negative time. This is actually my favorite way of looking at the differential universe model. The anti-universe would simply be the flip side of our universe. Or each universe would be opposite views of the same coin.
23. ## Why would we expect an Anti-Universe to be detectable?

Is there such a thing? Depends on who you ask. According to many well respected physicists, there should exist a universe before the Big Bang that would be symmetrical to our universe. What things would this resolve?And can you show (i.e. mathematically) that this would resolve many things? Well, it would explain where all the antimatter went for one. It would also help to explain how we got everything from nothing since a differential universe would yield a net of nothing. Without getting too involved into it, a differential universe could provide for a differential particle wave model that may make a little more sense than QM alone. For instance, entanglement would fall out naturally since every act of observation would occur simultaneously on both ends in a matter/antimatter universe that was closely linked together. While I'm still looking into singularities, I've seen many references which I will try to locate, that seem to imply that a differential universe could resolve the singularity. It doesn't.And looking for it isn't pointless as we have found it. I know that we have discovered antimatter that came from high energy events and have even created it with the LHC. I'm speaking of the original anti-universe that would account for the missing antimatter without needing to annihilate trillions times the mass over trillions of big bangs, just to create a single universe. To me, such a theory seems to suggest that God is not much more clever than a monkey painting a Rembrandt. I agree that they may not necessarily be equivalent but it doesn't deny it either. General relativity does rely on warped space time being the equivalent to the angular momentum of gravity. It's true that general relativity it has been validated by lensing but it's difficult to imagine a way to validate that antimatter would exhibit properties that could demonstrate reverse time properties. Perhaps creating an anti-atom that could show a reverse decay effect.
24. ## Why would we expect an Anti-Universe to be detectable?

Apparently, I chose a bad title as many are answering the question out of context of the OP or, as I tried to re-explain the question in post #9. My question was intended to be asking that if antimatter existed in negative time (traveled backwards in time from the point of it's creation at the Big Bang) then looking for it in our own spacetime would be pointless.
25. ## Why would we expect an Anti-Universe to be detectable?

The anti-universe would exist in Negative Spacetime. After the Big Bang, antimatter would appear and travel backwards in time while matter would appear and travel forwards in time. This means that matter and antimatter would never have coexisted in the same spacetime so they could not have been annihilated with each other. However, according to CPT symmetry theorem, where C is charge, P is linear and angular momentum, and T is time, if antimatter were to exhibit the opposite of all three properties than an anti-universe would appear as being the same as our matter universe. Now if the anti-universe was connected to our universe through entanglement, then you can have a differential universe that could resolve many things.
×