# Is the Expansion of the Universe Slowing Down?

Knowledge of basic physics might lead one to think the expansion of the universe is slowing down, but, as World Science Festival co-founder and Columbia University physicist Brian Greene explains, observations tell a different story.

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Chris Sanchez

I did read about that! Has not sunk in what a 4-D start would “look” like.

Dakota Sobon

it is speeding up not slowing down.. lol not surprised coming from huffington post

Jeff Epes

I've suspected that dark energy is in fact, the implosion of parallel worlds dying.

Chris Sanchez

Thanks! I came up with idea while reading two astrophysics articles. One had to do with the shape of the universe. The other had to do with the density of the universe. On the shape of the universe, there were several options. In common, they were all toroids, or 3-D surfaces, not 3-D solids. This would imply an unknown 4th dimension. The most entertaining one was the donut shape, it was even featured on a Simpsons Episode. The one I thought was most interesting was the Picard Horn. The Picard Horn is a 3-D surface wrapped around a 4th dimension of infinite length. At one in, the radius of the Picard Horn would be infinite. On the other end, the horn would fall to a singularity. At any point along the horn, the topology transverse to the length would a 3-D ring, or approximately a donut. On the density, the author noted that the total project mass of the universe and the total projected radius of the universe meet the criteria of the schwarzschild radius. This has lead many to believe our known universe is within the confines of a black hole, or within the limits of an unknown event horizon. Taking these two together, I came up with the analogy that we are falling into (or from) a singularity (possibly the Big Bang). The appearance of the ever expanding universe is the effect of the Picard Horn. The only thing in our physical world that resembles this that I can think of is water falling from a faucet. Enjoy!

A common sense approach is in need in science also. And by disassociating us non science majors who challenges your so call theories of nonsense, scare you.

Joey Jordan

What amazes me is that people who seem to have no knowledge of it real interest in science make multiple comments on science threads.

Joey Jordan

It is actually a very random universe that shows no signs of being brought into being by anything other than natural processes.

Jerry Sexton

Without a center of gravity, there is no reason for the expansion to slow down, but the acceleration? The gravitational pull from a parallel universe would be my guess.

Joey Jordan

Except of course that, like your other claims, is unsupported

Simon St-Onge

Science has spoken: 26 comments, only one "like". ;^)

Simon St-Onge

The expansion is slowing down? I really hope not... Because if it's true, the continuing expansion of our universe, that would have left us dispersed and separated, in isolated galaxies in the distant future, in the vast and infinite space, is not going to happen. Instead the second most known theory, "the Big Crunch" is likely to occur. If the gentle continuing expansion stops, the matter in the universe will slowing fall on itself, due to gravity, doing the same path in reverse. And in the same amount of time that it took to inflate, so to speak, our universe will extremely slowly shrink to about the size of your fist, and everything, literally, in it: Crunch! The good news is we know exactly when it's going to happen, in about 13.8 billion years... Plenty of time. :)

What amazes me is the clock work precision how our universe works. It can not be that accidentally all came to be, unless you believe in magic. And we do know that when it comes to magic, well, it is only a simple bag of tricks.

Joey Jordan

Well, not actually. This is based on actual measurements. We know that the expansion is accelerating.

Joey Jordan

OK. Now you are a conspiracy theorist. I know there is not reasoning with a conspiracy theorist. Good luck with that! Cheers.

Levi Lavender

Actually basic physics tells you that it's not slowing down. It tells you that objects in motion tend to stay in motion

Joey Jordan

You seem unaware of how science actually works. You see, there is a process for determining the veracity of any paper, it is called peer-review. Other scientists who are experts in the field try to disprove the thesis. Only after rigorous peer-review is an idea likely to gain acceptance.

Joey Jordan

If only AnDrea had deleted her comment an hour ago, it would have saved me the effort.

AnDrea Garner Lopez

You're not only an idiot,but also a liar. Typical liberal mentality. I have asked you kindly to leave me alone, but as liberals do, you must harass people that don't agree with you because they are more intelligent. Now you're blocked. Have fun spreading lies.

Joey Jordan

No. You are demonstrably wrong. I have demonstrated with good sources where you are mistaken. You have not made one single accurate assertion. This is a science thread after all, and the science is not on your side.

AnDrea Garner Lopez

What part of what I just said was wrong? Nothing...except liberals don't like the truth and that's what I just served you with. Get lost, please.

Joey Jordan

From the previous source, in case you didn't read it, "In science, a "fact" typically refers to an observation, measurement, or other form of evidence that can be expected to occur the same way under similar circumstances. However, scientists also use the term "fact" to refer to a scientific explanation that has been tested and confirmed so many times that there is no longer a compelling reason to keep testing it or looking for additional examples. In that respect, the past and continuing occurrence of evolution is a scientific fact. Because the evidence supporting it is so strong, scientists no longer question whether biological evolution has occurred and is continuing to occur. Instead, they investigate the mechanisms of evolution, how rapidly evolution can take place, and related questions."

Joey Jordan

Again, you are simply wrong. Your lack of an understanding of the science is not an argument against it. I gave you a good source. Would you like another to help you understand? It is based on observation. It makes testable predictions which have been borne out in every field of research for over 150 years. Without it, biology makes no sense whatsoever. http://evolution.berkeley.edu/evolibrary/home.php

AnDrea Garner Lopez

I'm done with you...You have officially been "schooled". Now don't go away mad, just go away.Goodbye

AnDrea Garner Lopez

No, it is not considered fact whatsoever. Two problems prevent anyone from legitimately calling evolution a theory. First, there’s no direct, observable experiment that can ever be performed. Scientists can measure bones, study mutations, decode DNA, and notice similarities in morphology (the form and structure of animals and plants), but they can never test evolutionary events in the past. Some point to natural selection as a form of “evolution in action,” but natural selection can only act upon the genetic potential that already exists. What we do observe from natural selection fits perfectly with a recent creation and does not point to common descent. Secondly, and related to the above, evolution misses the mark as a theory because all the supposed “tests” to confirm Darwinism do not necessarily and distinctively correspond to the idea. In other words, each has an alternate and equally viable explanation. A theory requires that the confirming experiments correspond to one specific hypothesis. Otherwise, the experiment cannot establish legitimacy. Evolution has no such legitimacy.

Joey Jordan

Well that is another topic. Let's finish one at at time shall we? I fear your nonsense is boundless and we need to stay focused.

AnDrea Garner Lopez

You're just mad at Dr. Carson because he says being gay is a choice. Homosexuals are not born homosexuals. That's science...and you deny that. Hypocrite. Haha

Joey Jordan

Again, if you are going to just delete this out of shame, the sooner the better .I can tell that is where this is heading. :)

AnDrea Garner Lopez

Evolution is a hypothesis...denying a hypothesis is not denying science, genius.

Joey Jordan

That's what I thought. You people are long on insults and short on facts.

Joey Jordan

If you plan to delete this comment out of shame, do it now and save me the trouble of responding further.

AnDrea Garner Lopez

I wasn't speaking about science, idiot...and Dr. Carson doesn't deny science. Again, you don't know what you're talking about...and why would you? You're not an American.

Joey Jordan

Could you be thinking of Ben Carson perhaps? He is the only science-denying current Presidential candidate I know of. Which is quite odd, given his education.

Joey Jordan

You obviously don't know anything about science.

Joey Jordan

Except of course he won't. But then who would? That is irrational.