# How fast is the universe expanding? The mystery endures

Scientists have known for decades that the universe is expanding, but research in the past few years has shaken up calculations on the speed of growth—raising tricky questions about theories of the cosmos.

The rate of expansion—known as the "Hubble constant"—is a central part of the quest to discover the origins of the universe, with astrophysicists believing they are getting closer and closer to the exact speed.

In 1998, two teams of researchers found that the rate of expansion accelerated with distance, and that the universe was filled with mysterious "dark energy" that has caused the acceleration for 14 billion years—earning them a 2011 Nobel prize.

The unit of measurement for the Hubble constant is kilometers per second per megaparsec—which is three million light-years.

According to two different methods, the rate of expansion is either 67.4—or 73.

Now a study, written by researchers at the Max Planck Institute of Astrophysics in Germany and other universities, has described a new method of gauging the universe's accelerating growth.

It puts the rate of expansion at 82.4 kilometers per second per megaparsec, higher than previous calculations—though it does admit to a 10 percent margin of error, meaning it could as low as 74 or as high as 90.

**'Unknown physics'**

Scientists say the differences between various methods are not miscalculations, but could be signs of "tension" in understanding of how the Big Bang Theory explains the cosmos.

"There's unknown physics going on in the early universe that we need to study, if the tension is real," said Inh Jee, a cosmologist at the Max Plank Institute and co-author of the study that was published on Thursday in the US journal *Science*.

"We wanted to have another way to validate whether the difference between measurements are real," she told AFP.

Big Bang Theory proposes that the universe began in a cataclysmic explosion and has been expanding ever since.

The various measurement methods mean that galaxies three million light-years away (one megaparsec) would recede by either 67, 73... or perhaps 82 kilometers per second.

The new calculation is based on how light bends around large galaxies.

Jee said the study's large margin of error cannot help fine-tune the Hubble constant, but that its method adds to the debate over whether there are fundamental problems in cosmological theory.

Adam Riess, one of the 2011 Nobel Prize winners, told AFP by email that Thursday's study did not have precise enough results to help solve the continuing controversy.

"I don't think this adds much to the present state of affairs. Still it's nice to see people look for alternative methods, so props (respect) for that," he said.

Explore further

**More information:**I. Jee el al., "A measurement of the Hubble constant from angular diameter distances to two gravitational lenses,"

*Science*(2019). science.sciencemag.org/cgi/doi … 1126/science.aat7371

"An expanding controversy," *Science* (2019). science.sciencemag.org/cgi/doi … 1126/science.aay1331

© 2019 AFP

**Citation**: How fast is the universe expanding? The mystery endures (2019, September 13) retrieved 20 October 2019 from https://phys.org/news/2019-09-fast-universe-mystery.html

## User comments

idjyitBenni.........14 billion years worth of "acceleration"?

OK, what was the speed when all this "acceleration" started"?

And why is it so peculiar that the "acceleration" gradually picks up it's pace in accordance with it's distance from planet Earth, almost as if there is an Inverse Square Law dictating the expansion rate based on distance from the our solar system? It's as if we're the center of the Universe which we know cannot not be the case for barycenter of orbital motion.

The Hubble Constant is measuring the rate of a BARYCENTER of motion, not a rate of EXPANSION, just as is observed in star clusters where there is no single body center of mass.

Anonym324154Da SchneibjimmybobberYou don't understand what an inverse square law is.

Google:

"a law stating that the intensity of an effect such as illumination or gravitational force changes in inverse proportion to the square of the distance from the source."

Recessional velocity would decrease if it followed an inverse square law.

Hubble's Law:

v = Hd

Notice how as d (distance) increases v (velocity) increases! H is Hubble's constant.

If recessional velocity followed an inverse square law it would look something like

v=H/d^2

In that case when d increases v clearly decreases.

You've just proved again that you don't even understand simple mathematical concepts.

MrBojanglesetherairEarth is not the center of the universe, all locations have the same view, the universe recedes everywhere due to expansion happening everywhere. Raisins in baked bread do not expand but they do recede from each other as the bread rises. Similarly, galaxies do not expand but the distance between them grows as the universe expands.

The start point rate of expansion was greater than now, the universe slowed the first five billions years, still expanding but like a rock thrown up the acceleration slowed, stopped, and now is speeding up again.

All this research is just to find the exact numbers of the change. It does not affect life as we know it.

The pattern of rain on a pond is easy to see, but the math to figure where the drops hit is beyond our capability.

hat1208No, no one can, sorry @MrBojangles.

valeriy_polulyakhDa SchneibHyperfuzzytorbjorn_b_g_larssonWell, yes, if you mean the middle: ~ 70. We have been over this before here, and that is where it conservatively stands for now.

Having more methods is nice.

But why would we want to pick this still statistically weak (two lenses) method as a particular arbiter of Hubble rates? We could equally well pick the completely independent, still statistically weak (one event) method of using binary neutron star mergers, which comfortably land us at 69 km/s/Mpc at about half the uncertainty range [ https://arxiv.org...0596.pdf ].

[tbctd]

torbjorn_b_g_larssonThese middle range values do not augur new physics, which the Planck team has looked at the difficulties with in the 2018 data release. The observation of a flat space seems safe, else there is no simple change in physics that predicts a much differing Hubble rate.

But we have to wait and see what will happen.

torbjorn_b_g_larssonThe Hubble rate expansion is analogous to a classical dynamic of a thrown ball, while the expansion rate is decided by the inner state of the system in general relativity/thermodynamics. See e.g. Susskind's cosmology lectures from Stanford University, free on the web.

However, I know understand, I think, that expansion under inflation was pushed by the potential energy of the slow rolling inflation field so as astrophysicists likes to say, 'has put the bang in the big bang'.

[tbctd]

torbjorn_b_g_larssonI fell backwards when I stumbled on Matt O'Dowd's version of the PBS astrophysics series (also free on the web). The previous host was not bad, but personally I did not like his style nor did the series teach me anything new. But O'Dowd is a new generation and he had put up inflation front and center in two recent episodes, which is why I finally grokked the above. (One can still argue about a presumed initial state, but meanwhile eternal inflation makes it superfluous.) Recommended viewing!

He claims astrophysicists now generally define big bang as the Hubble rate period after inflation. (Maybe we should call the previous rate "inflation rate period".) This is more definite stated than particle physicist Matt Strassler's description of people's use of definitions [ https://profmatts...eliable/ ]. I will adopt this "Hubble rate period" instead of my (and Strassler's use of) Hot Big Bang event definition.

copernicusonMimath224Surveillance_Egg_UnitThe Golden Ratio is equal to Fibonacci numbers.

"...different expansion rates are due to gravitational pull of other universes". Where and when have "other universes" ever been seen/detected? Math predictions as proofs don't count.

What is this Sphere Theory? Please explain.

jimmybobber"The Golden Ratio is equal to Fibonacci numbers."

The golden ratio does not equal Fibonacci numbers. That statement is nonsense.

The ratios of successive pairs of Fibonacci numbers converge to the golden ratio.

1/1, 2/1, 3/2, 5/3, 8/5, 13/8....

jimmybobberI believe Copernicuson was referring to the use of a Fibonacci lattice to evenly distribute n points on the surface of a sphere.

Here is a link I found describing it.

http://extremelea...-sphere/

jimmybobber"Math predictions as proofs don't count"

Quote of the day.

Neptune, return of Haley's comet, Higg's Boson, ...

All predicted by math. To name a few.

You should write a book. "Physics with no Math"

That would be a humorous read.

BenniSez jimbo:

No, they were not predicted by math, they were predicted by the observed pertubations of other bodies in the solar system. Based on these OBSERVED PERTURBATIONS calculations were made based on Newtonian Gravity calculations as to where the gravitational sources could be found.

jimmybobberBy using math.

How do you think the calculations were accomplished?

BenniThey were predicted by the observed pertubations of other bodies in the solar system. Based on these OBSERVED PERTURBATIONS calculations were made based on Newtonian Gravity calculations as to where the gravitational sources could be found.

jimmybobberUsing mathematical equations and math.

The math equations, derived by humans, made predictions that were tested and proven to be true.

copernicusonThe Golden Ratio is equal to Fibonacci numbers.

"...different expansion rates are due to gravitational pull of other universes". Where and when have "other universes" ever been seen/detected? Math predictions as proofs don't count.

What is this Sphere Theory? Please explain. If one takes the gravity from an adjacent universe or an adjacent particle the gravity decreases by the square of the distance. If one looks at a uniform solid sphere, the gravity increases in a straight line to maximum at the edge. The equal point between two spheres, mathematically is the inverse golden ratio. Works for charge as well

copernicusonBenniI see you don't like the sequence, make at least half an effort to see which came first:

1. Observed perturbations

2. Calculations made based on #1

Da Schneib3. Make predictions about other things from those calculations and see if they turn out to be correct.

RealityCheckAnd you left out:

4. Confirm or falsify those further predictions via further observations.

5. Proceed through all of the above in recursive manner for as long as deemed necessary for desirable objective scientific/logical modelling/understanding of the original/further objects/situations/processes etc under study.

Sorry, couldn't resist, DS. Just following your lead there, mate. Cheers. :)

Surveillance_Egg_UnitYou put a lot of stock in "predictions" made by math formulae without understanding that predictions could NEVER be predicted and forthcoming UNTIL AND AFTER an optical (preferred) observation or three PRIOR to ANY possibility of a prediction being made and being correct.

Why would any scientist worth his salt decide to make a prediction based on a math formula if the actual event hadn't occurred as yet? IF the prediction was based on other events happening, the prediction can only be in reference to THAT occurrence, nothing else.

Even Albert Einstein was cautious as to his math predictions of future possible events.

Predictions based on math without prior knowledge of the fact itself is no better than the utterances of a clairvoyant or Tarot card foretelling/reading.

Da SchneibIt comes out true every time, too.

Surveillance_Egg_UnitYou're predicting that there will be found adjacent universes? Doubt it. Has it been observed?

Surveillance_Egg_UnitOnly because you had prior experience with it, but it could turn out to be different if your car breaks down; you are stopped by a bobbie for going 50 in a 25 mph zone; or another car hits you; or you have run out of petrol; or...or....

There goes your prediction.

John_C_yPiNot really your car will actually travel 7,200.226194671 seconds to go 200 miles and depending on which direction you are moving in or from a time zone, you simple have no need or way to correct a margin of error any greater than that.

jimmybobberQuote me where I said observations are not needed to derive equations that yield predictions. I never said anything of the sort. Benni twisted what I said into what you are currently spewing.

Da SchneibCranks can't count.

jimmybobberNewton invented calculus in the 1670s to calculate instantaneous velocity. Here we are in 2019 and you and benni can't grasp simple addition and operator precedence.

antigoracleBrays Da Schitebo.

Now predict how much CO2 you are spewing out of your blowhole, jackass.

jimmybobber(50 miles/hour)(2 hours) = 100 miles.

Da Schneib tricked you knowing you can't do math.

And it illustrates how important math and calculations are to make accurate predictions.

You are embarassing.

granville583762It has been known for decades that the universe is expanding

Research in the past few years

Has shaken up calculations

On the speed of that growth

In 1998

It was found that the rate of expansion accelerated with distance

That the universe was filled

With dark energy

That has caused the acceleration for 14 billion years

The unit of measurement

For the Hubble constant

Are kilometres per second per megaparsec

According to two different methods, the rate of expansion is either 67.4 or 73.

Fore in these recent past days

In fact

So recent

You can count the days

On these fingers of our hands

The figure of 40km.s-1 megaparsec was this latest figure

Except for this mystery

As stellar nurseries form and collapse

As galaxies collapses in galactic union

As neutron stars collapse

Into blackholes

As blackholes become supermassive

For how can a 15Billion Ly of Conglomerating Collection of Galaxies be Expanding?

BenniProtoplasmixBenniCirclesBeginningBenniBenniCastrogiovanniEver since you realised that you don't have a clue about either science or mathematics.

jimmybobberYou use the "psycho-babble" phrase whenever you don't understand something or lose an argument. Then after that you poke fun of people adding nothing of value to the conversation.

jimmybobberI serious think you can't even tell us what 1/1 =

I'm actually surprised you can use any language to communicate with us.

Surveillance_Egg_UnitThere you go with your ad hominem, proving that you're just a crank. When did Benni say anything about sciencing without math? And I didn't say it either. You are just making shite up just like Schneib does.

If you read my comments on the topic more carefully, you MIGHT notice that I was referring to how the OPTICAL OBSERVATION of an EVENT SHOULD OCCUR FIRST BEFORE describing the event in mathematical terms. ONCE that EVENT has occurred more than once, afterwards it may be predicted to happen again and again. Otherwise, you're just spitting in the wind.

Learn something about "cause and effect". Yes?

granville583762A foray into this conglomerating expansion

This human emotion

Of this perception

Of expansion

While conglomeration is taking place simultaneously

Tis a quandary

Worthy of investigation

For this worthy investigator

Who steps up to this plate

This quandaries plate of simultaneity

Of expansion in conglomeration

A challenge to test this metal of the most ardent investigator

granville583762Is a super massive blackhole putting on weight

Surveillance_Egg_UnitAs a rule, I don't pay much attention to what Schneib says, as most of the time he spews nothing but what his lord and master, Satan, wants him to say. Isn't that right, CaptStrumpy? LOL

Even so, the possible scenarios that I had described are all good possibilities that Schneib's car could suffer no matter what distance he has to travel and at whatever velocity.

Surveillance_Egg_UnitHave you figured out yet exactly WHERE the Universe is expanding TO? Is it expanding in a straight line somehow, where ALL galaxies are caught up in the STREAM or river that is meandering towards a certain destination? What would happen to all Matter/energies once they arrive at that destination?

There are things that will never be known in anyone's lifetime. The human race will have succumbed to whatever is coming long before this corner of the Universe ever gets near enough to that destination. There are certain truths/secrets, that are to be kept hidden from enquiring minds, and it is nobody's business what they are.

Surveillance_Egg_UnitThe cells of a living organism can often become stressed by disease or old age. When a cell is about to die of old age or a disease, it literally ceases its mechanical functions and practically implodes. Black Holes are like that, except that a BH is more like a cancer where it has 'transmuted' from a Star into a ravenous monster, consuming everything in its path. Cancerous cells are similar because they are invasive and use up all the resources that should go to feed healthy cells. These are similarities that perhaps no scientist has ever considered, or will ever want to consider.

CirclesBeginningThe way I've always thought about it is based on a thought experiment we did in school. If we take a black balloon and draw white dots on it perfectly separated by 1 square inch each, we have a representation of galaxies in the early universe. If we then begin to blow the balloon up, the dots spread out from each other representing the later universe. The dots didn't really expand into anything, the space in-between them just got larger.

The universe does not appear to have direction, that is one of the oldest questions humans had about the universe. As far as we can tell, the universe has no curve and is flat.

Benni....if the Universe is not spherical then ENTROPY does not exist. The normal SHAPE of anything within a random system of distribution is SPHERICAL.

It is Dark Energy Enthusiasts who insist the Universe is flat, this way they avoid the constraints the 2nd Law of Thermodynamics imposes upon their theories of an infinitely expanding Universe without a boundary.

CirclesBeginningYou are correct in that entropy does not really exist, at least in the classical sense. It seems to exist on the quantum scale because of superpositioning but in our macro-scale view of reality entropy is merely an excuse for our limitations when describing a system and it's components.

While the universe appears flat it may be openly curved or posses some exotic geometry however it certainly isn't spherical. I am curious as to what you think these boundaries would be though.

granville583762But then, it can never be flat...

Fore, our proton and scrumptious

Are three dimensional

All be it, in their femto-worl

BenniI have no idea what the composition of the boundary is, but if it's not impermeable the Universe would have ceased existing within femto-seconds of the bigo-bango.

Da SchneibSurveillance_Egg_UnitThe balloon analogy is a poor example since it is inflated, causing the dots to separate. Children are open to it.

Surveillance_Egg_Unit@Circles

If the Universe was actually flat without any curvature and direction, there would be no movement, or very little, of galaxies, as well as no winds. It would be much more similar to a quiet pond with some dead fish in it due to the water having become noxious.

But the Universe isn't flat, which is why galaxies are able to move and gather into clusters as they all move along following the galaxies that are further out. This 'follow-the-leader' method occurs within each galaxy where Stars orbit the galaxy centres like the horses in a carousel.

And in the same way, galaxies orbit the centre of the Universe as I have described in other phorums. Eventually, the galaxies that we are familiar with will follow around, and after billions of years will return to the same region where they started from. The Universe may not be completely spherical like a balloon, but it could be quite like a chubby round bagel.

:)

granville583762For this changing world of physics

Never stands still

In theory and mathematical symbolism

Fore, Protoplasmix

So as to never stagnate

Into this flat featureless world

Fore, if our collection of galaxies is flat

Our proton and scrumptious are three dimensional in their femto-world

In their femto-world, fore to the human eye, a femto-metre, is flat as a pancake

Thanks Protoplasmix, for pointing out this mathematical discrepancy

As to this cosmic acceleration

An earlier phys.org article, on this very same expansionist subject, Protoplasmix

granville583762Digging in these past Hubble recession articles

You are probably asking where this

40km.s-1 megaparsec this latest figure came from

It came

Protoplasmix

From my terrible memory

What was being sought was

On July 16, 2019

New Hubble constant measurement adds to mystery of universe's expansion rate

https://phys.org/...ion.html

Sorry for the mistake Protoplasmix

Red giants at 69.8 are closest to the average of 70.4

granville583762According to two different methods, the rate of expansion is either 67.4—or 73

Now a study

Written by researchers

At the Max Planck Institute

Of Astrophysics

In Germany

And other universities

Has described a new method

Of gauging the universe's accelerating growth.

It puts the rate of expansion

At 82.4 kilometres per second per megaparsec

Higher than previous calculations

Though it does admit

To a 10 percent margin of error

Meaning

It could be

As low as 74

Or as high as 90

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