Outrider

Thanks Mordred I probably have a few more questions later when I have more time.

You are a lot of help!

So both 1 and 2 are correct? The faster rate of expansion in that area and the lack of mass (gravity) to hold us back are both factors in our rate of velocity towards Shapley Supercluster?

There is no supernatural point.

Agreed

They are coincidences.

Agreed

You should expect them to exist, if you cast your net wide enough, just because statistics and probability is a thing.

Yeah but when they do happen such as in this case I still find it amazing and noteworthy.

Causial relationship for some too. Lincoln brand came from Lincoln Motors which was named after the first President the founder voted for.

+1 for obscure yet relevant fact.

Roughly 220 Mpc from us, https://en.m.wikipedia.org/wiki/Dipole_repeller

In regards to the push action this isn't due to gravity. It involves key relations between energy density and pressure. In essence the thermodynamic relations can overcome the localized gravity. Much the same way as to our universe expansion itself.

I wasn't thinking of push gravity but because I have seen a number of threads on the board in the past pushing that idea I can see why you made that clear.

I have read quite a few articles on the Repeller in the last couple of days and there seems to be two schools of thought here.

1. The dipole repeller actually does push because the space in that region (due to less gravity) is expanding faster than the space around it. I think this is Yehuda Hoffman's stance. He is the author of the paper that started all this.

 

 

2.The dipole repeller just seems to push because there is more mass ahead than there is behind. IOW Shapley Supercluster is pulling and the void, dipole repeller, is not so we go faster.

[latex]7.176*10^8[/latex] light years

Yay my wild guess (800mly) was off by less than 100. Lol

Hi Mordred and Luis thank you both for your comments and links. Am I correct in assuming that the distance calculated depends on which theoretical model is used?

Hey Phi for All.

The point (for me) was that it's kind of hard to read any supernatural point into the Lincoln/Kennedy alleged coincidences. Most of the time when we hear of some strange coincidence it's something like "I was getting on the plane when so and so called an I missed my flight and then the plane went down and so I was meant to live." My point is coincidences do happen but that's all they are and even tho JFK/Lincoln has been explained away I still think it's remarkable.

BTW Snopes is on your side.

http://www.snopes.com/history/american/lincoln-kennedy.asp

This is supposed to be "Lincoln was shot in Ford's Theater, and JFK was shot in a Lincoln."

That was my wee joke...Very wee apparently. The Lincoln was made by Ford motors.

 

Hi Swansont

I'm not touching that one.

Please mention more coincidences. They are welcome.

Abraham Lincoln was elected to Congress in 1846.

John F. Kennedy was elected to Congress in 1946.

 

Abraham Lincoln was elected President in 1860.

John F. Kennedy was elected President in 1960.

 

The names Lincoln and Kennedy each contain seven letters.

 

Both were particularly concerned with civil rights.

 

Both wives lost their children while living in the White House.

 

Both Presidents were shot on a Friday.

 

Both were shot in the head.

 

Both were assassinated by Southerners.

 

Both were succeeded by Southerners.

 

Both successors were named Johnson.

 

Andrew Johnson, who succeeded Lincoln, was born in 1808.

Lyndon Johnson, who succeeded Kennedy, was born in 1908.

 

Abraham Lincoln was shot in a Ford and so was JFK.

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Try as you might I don't think you will ever beat this string of coincidences.

I read the Forbes article on this and the writer said the scale showing it all was 1.5billion light years across, from looking at the diagrams how far away from the Dipole Repeller would we be?

Hi Ant Sinclair I read your link with much interest but I'm sorry I can't answer your question. I can only guess (if the diagram is more or less to scale) 800 million light years. Keep in mind that's just a wild guess.

The abstract for the article in Nature Astronomy gives the "supergalatic coordinates as [11,000, −6,000, 10,000] km s−1" which is pretty much greek to me.

http://www.nature.com/articles/s41550-016-0036

The abstract also gives the size of the diagram as "40,000 km s−1 " so that equals to 1.5 Bly?

My question though is why should we assume that intelligence is that common and not just some evolutionary rarity of the highest order?

Hi Cynic

A very good post by you and BTW me and Enrico Fermi agree so your in good company.

 

http://abyss.uoregon.edu/~js/cosmo/lectures/lec28.html

This article claims the Milky Way could be explored in less than 4 million years but I have seen estimates up to 50 million years. It doesn't really matter because the Milky Way is over 10 billion years old. Any long lived (as in millions of years of continuous existence) intelligent community with a curiosity like ours would have colonized or at least explored the galaxy by now. So either they don't exist,my opinion, or they are not very curious or technological civilizations tend to end their selves fairly quickly.

 

I hope that in my lifetime someone or something will land on Jupiter's moon Europa and probe the ocean that almost surely exists under the ice. I think that big moment will give us a good idea whether or not life (any kind) is prevelant or not.

 

* Successfully used the phrase "whether conditions" in a sentence, won a 5 euro bet with imatfaal.

 

Congrats...Where are we going for lunch?

Yes, it's confusing if you think about it. We know space to bend around matter so there would be absolutely no reason for it to push it. On the other hand, how could matter be getting further apart if space wasn't pushing it along with its expansion? The more I think about it, the more questions get raised.

 

 

Yep I'm confused too.

 

Yes but what does ''same direction mean''. Does it mean:

 

1) parallel to one another? That wouldn't make sense to me. The only way that they could be travelling parallel is if they were bound into one body by gravity but that would be the only way they could be moving anyway then

2) inwards from parallel, towards a focal point? Shapley supercluster being the focal point, for example. But that could be easily calculated and verified, no?

3) outward from parallel? But you wouln't be saying this if that were the case and the Shapley supercluster couldn't be the destination then anyway.

That's a little complicated and I don't think I can choose any of your 3 options.

What I do know is that in 1964 Robert Wilson and Arno Penzias discovered the cosmic microwave background and then the 70's scientists measured a slight temperature difference on one side of our galaxy the Milky Way. From this they calculated the direction of travel through the universe and the speed 600 km/second.

As I understand it it's sort of like a bunch of rubber ducks in a bathtub and you pull the plug they start out all over the tub but all head for the same place.

 

Just for fun here's another article maybe it will help.

https://www.google.com/amp/www.universetoday.com/113150/what-is-the-great-attractor/amp/

 

But where are we going? Just around in a great big circle? Or an ellipse? Which is going around in another circle… and it’s great big circles all the way up? Not exactly... Our galaxy and other nearby galaxies are being pulled toward a specific region of space.

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While the Norma Cluster is massive, and local galaxies are moving toward it, it doesn't explain the full motion of local galaxies. The mass of the Great Attractor isn't large enough to account for the pull. When we look at an even larger region of galaxies, we find that the local galaxies and the Great Attractor are moving toward something even larger. It’s known as the Shapley Supercluster. It contains more than 8000 galaxies and has a mass of more than ten million billion Suns.

 

Norma Cluster = Great Attractor

Hi L.A.

As for the second part of your post scientists have known about what they call dark flow for at least 30 years. Not only the Milky Way, the local group, and Andromeda but also all the Superclusters within 2.5 billion light years are heading in the same direction.

At first the cosmologists thought it was a large collection of galaxys known as the Great Attractor in fact that's why it was named that. But I think the WMAP survey changed everything and the Shapley Supercluster is now seen as the biggest attractor.

https://www.nasa.gov/centers/goddard/news/releases/2010/10-023.html

 

As for the first part of your post I think that expansion only works in the voids between the superclusters so gravity certainly can cancel it out. I just didn't know expanding space could push. Kind of trashes my understanding of expansion. But then that's the fun part.

 

Oh and take everything I say with a very large grain of salt. I am no expert.

Hi Delta.

I agree.

Every time it think it have a decent handle (for a layman) on cosmic expansion I start reading and realize I know nothing.

Yehuda Hoffman at the Hebrew University in Jerusalem claims to have discovered a great void that is actually pushing the Milky Way and others towards the Shapley Supercluster.

Scientists have known for sometime that Shapley is pulling us and everything is in our neighborhood but it's gravity is not enough to explain the high velocity of our galaxy.

The part i don't understand is how it is pushing. The article says because of the dearth of mass in the void expansion is moving at a faster rate. So if guess expansion in that area is moving the surrounding stuff out of the way?

Dipole Repeller

 

Astronomers have finally discovered why the Milky Way is barrelling through space faster than the universes rate of expansion. It is being pushed from behind by an enormous void dubbed the dipole repeller.

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Like everywhere else in the universe, the void is expanding, but without the gravity of any galaxies to keep its expansion in check. This means the expanding void pushes on nearby galaxies (including our own) a bit like bubbles of air expanding inside a rising cake.

I think that potential knowledge is infinite but then that's just my opinion.

There is also the grand tack hypothesis that has Jupiter and Saturn migrating inwards to the area occupied by Mars now and traveling back out to there current orbits causing all sorts of chaos along the way.

https://planetplanet.net/2013/08/02/the-grand-tack/

 

 

 

Whoops I put that Jupiter traveled in to Mercuries orbit when it was supposed to be Mars. It's fixed now.

Hi DrKrettin

Your comments are unfair because they imply that the experiment was easy to do. Per the linked article the hydrogen was subjected to 5 million earth atmospheres and minus 270c temperatures. I think the onus is on you to show us why it was easy and should have been accomplished "ages" ago.

 

OTOH the article also quotes several scientists questioning the validity of the experiment so don't get to excited just yet. As Luis already pointed out i am sure an attempt to replicate is already in the works. If confirmed this will be exciting news indeed.

Oh thanks Phil just what I was looking for. The article mentions that as they refine their techniques they should be able to estimate the mass of the moon. Here's hoping they find a binary earth system.

“This is rather as if you imagine a puddle waking up one morning and thinking, 'This is an interesting world I find myself in — an interesting hole I find myself in — fits me rather neatly, doesn't it? In fact it fits me staggeringly well, must have been made to have me in it!' This is such a powerful idea that as the sun rises in the sky and the air heats up and as, gradually, the puddle gets smaller and smaller, frantically hanging on to the notion that everything's going to be alright, because this world was meant to have him in it, was built to have him in it; so the moment he disappears catches him rather by surprise. I think this may be something we need to be on the watch out for.” Douglas Adam, Salmon of Doubt

And it's still not revelant to what I posted or the link I gave.

I was not implying that life could not originate on a moonless planet but rather the stable seasons we enjoy on earth are condusive to life as we know it and also IMO more important than the tide, much more.

Reason is the natural order of truth; but imagination is the organ of meaning

Yeah as others have said I think they go hand in hand.

All the imagination and creativity in the world ain't worth 2 cents if you can't express it.

What has the scientific method given us? A million and one ways to do just that(express ourselves).

All right my first question and first thread all in one. I'm excited and hope you are too.

After doing a search I see that no exoplanet moons have been confirmed but my question is could the mass of some planets be overestimated because it has one or more large moons.

I assume if our earth is being detected by alien astronomers by the same techniques we use the extra mass of our moon wouldn't really matter all that much. But is it possible for two earth sized bodies to have a stable and close orbit or an earth sized body with several large moons.

Could this account for at least some of the superearths?

And the puddle said, "Isn't it remarkable I should have found a hole that is just the right shape for me?"

Hello Ophiolite I read your comment a couple of times and still can't keen the relevance to my post. I was responding to Strange's reply to this:

It would also be intresting to know the part our Moon plays on the life on Earth.

 

I was not implying that life could not originate on a moonless planet but rather the stable seasons we enjoy on earth are condusive to life as we know it and also IMO more important than the tide, much more.

If on the other hand you were musing about what a mud puddle would think of the moon's importance for it's continued survival I imagine it would say "Moon? We don't need no friken moon.

Tides have an effect on organisms living in tidal regions. That is probably about it.

 

Hi Strange I have always understood that the moon stabilizes the earth and limits the amount of precession or wobble thus giving us more stable seasons and that would be pretty important. But while looking for a link for you I found some counter evidence.

http://www.astrobio.net/news-exclusive/the-odds-for-life-on-a-moonless-earth/

From the article

While Earths moon does provide some stability, the new data reveals that the pull of other planets orbiting the Sun especially Jupiter would keep Earth from swinging too wildly, despite its chaotic evolution.

 

"Because Jupiter is the most massive, it really defines the average plane of the solar system," said Barnes.

 

Without a moon, Barnes and his collaborators have determined that Earths obliquity would only vary ten to twenty degrees over a half a billion years.

 

That doesnt sound like much, but the changes of one to two degrees the planet presently exhibits are thought to be partly responsible for the Ice Ages.

 

According to Barnes, the present shift is "a small effect, but in combination with Earths present climate, it causes big changes."

 

Still, a ten degree change is not a huge problem when it comes to life. "(It) would have effects, but not preclude the development of large scale, intelligent life."

I don't know but 10 degrees sounds pretty big to me.

Hi I'm Jon from Alabama. Long time lurker (4 years+) and although I do have a lot of questions I find that most of them have already been answered or will be if I wait long enough. There are a few things I did want to say. The first is that this forum is extremely well maintained and I want to thank the mods and members who cause that to happen and also Dave who apparently does the dirty work. I frequent several different MB's but this is the only one I visit every day. For those few members who complain about lack of free speech, bias,etc. I am sorry but you are just wrong although the mods do make mistakes at times they are few and far between.

I also want to thank the knowledgeable members who have added to my meager education. You probably do not realize the good that you do. I have no way of knowing how many lurkers I might represent with this post but I think there are many like me that come just to learn.

My main interest is astronomy and cosmology but I am seriously math deficient so y'all help a lot. As I am 50 and still work a lot of hours I am probably not going to learn the math anytime soon. Who knows maybe when I retire.