Tag: Universe

Early Opaque Universe Linked To Galaxy Scarcity

It has long been known that the universe is filled with a web-like network of dark matter and gas.

This “cosmic web” accounts for most of the matter in the universe, whereas galaxies like our own Milky Way make up only a small fraction.

Today, the gas between galaxies is almost totally transparent because it is kept ionized — electrons detached from their atoms — by an energetic bath of ultraviolet radiation.

Over a decade ago, astronomers noticed that in the very distant past — roughly 12.5 billion years ago, or about 1 billion years after the Big Bang — the gas in deep space was not only highly opaque to ultraviolet light, but its transparency varied widely from place to place, obscuring much of the light emitted by distant galaxies.

Then a few years ago, a team led by Becker, then at the University of Cambridge, found that these differences in opacity were so large that either the amount of gas itself, or more likely the radiation in which it is immersed, must vary substantially from place to place.




To find out what created these differences, the team of University of California astronomers from the Riverside, Santa Barbara, and Los Angeles campuses turned to one of the largest telescopes in the world: the Subaru telescope on the summit of Mauna Kea in Hawaii.

Using its powerful camera, the team looked for galaxies in a vast region, roughly 300 million light years in size, where they knew the intergalactic gas was extremely opaque.

For the cosmic web more opacity normally means more gas, and hence more galaxies. But the team found the opposite: this region contained far fewer galaxies than average.

Because the gas in deep space is kept transparent by the ultraviolet light from galaxies, fewer galaxies nearby might make it murkier.

This discovery, reported in the August 2018 issue of the Astrophysical Journal, may eventually shed light on another phase in cosmic history.

In the first billion years after the Big Bang, ultraviolet light from the first galaxies filled the universe and permanently transformed the gas in deep space.

Astronomers believe that this occurred earlier in regions with more galaxies, meaning the large fluctuations in intergalactic radiation inferred by Becker and his team may be a relic of this patchy process, and could offer clues to how and when it occurred.

By studying both galaxies and the gas in deep space, astronomers hope to get closer to understanding how this intergalactic ecosystem took shape in the early universe.

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Pass it on: Popular Science

A Brief History Of The Future

The history of the universe is mind-blowing. But the future of the universe – and how it ends – is even more so.

From the end of the human race to the fate of planet Earth, the solar system, the Milky Way, and beyond, in today’s video, we talk about the far, far future and what it holds for everything.

Puzzling Cosmic Glow Is Caused by Diamond Dust Glamming Up Stars

Diamond dust is responsible for a mysterious glow emanating from certain regions of the Milky Way galaxy, a new study reports.

Astronomers have long known that some type of very small, rapidly spinning particle is throwing off this faint light, which is known as anomalous microwave emission (AME). But they couldn’t identify the exact culprit — until now.

In the new study, researchers used the Green Bank Telescope in West Virginia and the Australia Telescope Compact Array to search for AME light in 14 newborn star systems across the Milky Way.

They spotted the emissions in three of these systems, coming from the planet-forming disks of dust and gas swirling around the stars.

This is the first clear detection of anomalous microwave emission coming from protoplanetary disks,” study co-author David Frayer, an astronomer with the Green Bank Observatory, said in a statement.




The study team also detected the unique infrared-light signatures of nanodiamonds — carbon crystals far smaller than a grain of sand — in these same three systems, and nowhere else.

In fact, these [signatures] are so rare, no other young stars have the confirmed infrared imprint,” study lead author Jane Greaves, an astronomer at Cardiff University in Wales, said in the same statement.

The researchers don’t think this is a coincidence.

One to 2 percent of the total carbon in these protoplanetary disks has been incorporated into nanodiamonds, according to the team’s estimates.

Another leading AME-source candidate, a family of organic molecules known as polycyclic aromatic hydrocarbons (PAHs), doesn’t hold up under scrutiny, the researchers said.

The infrared signature of PAHs has been identified in multiple young star systems that lack an AME glow, they noted.

The new results could help astronomers better understand the universe’s early days, study team members said.

Scientists think the universe expanded far faster than the speed of light shortly after the Big Bang, in a brief period of “cosmic inflation.

If this did indeed happen, it should have left a potentially detectable imprint — an odd polarization of the cosmic microwave background, the ancient light left over from the Big Bang.

The new study provides “good news for those who study polarization of the cosmic microwave background, since the signal from spinning nanodiamonds would be weakly polarized at best,” said co-author Brian Mason, an astronomer at the National Radio Astronomy Observatory in Charlottesville, Virgina.

This means that astronomers can now make better models of the foreground microwave light from our galaxy, which must be removed to study the distant afterglow of the Big Bang,” Mason added.

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Elon Musk Says We’re Probably Characters In Some Advanced Civilization’s Video Game

I don’t want to freak you out here, but there’s a chance you’re not the only ‘you’ in existence.

I’m not talking about the possibility that you might actually have two different brains, which means it’s virtually impossible to tell which one is ‘you’.

I’m talking about the fact that there could well be countless parallel universes, and each one contains a slightly different version of you.

Within that parallel universe construct, our own reality might not be as ‘real’ as you think. Are some of the most massive objects in our Universe nothing but holograms?

Is our Universe itself a hologram? Is this whole thing one giant simulation and we’re just characters in the most advanced video game ever? I swear I’m not high.




Everything I just mentioned is part of actual thought experiments that have been devised and debated over by the world’s best thinkers for years now, because one way or another, we have to make sense of this very strange and incredibly unlikely reality we’ve found ourselves in.

At Recode’s annual Code Conference this week in California, billionaire tech genius Elon Musk was asked about the possibility of us humans being unwitting participants in a giant simulation built by some alien civilization that’s far more advanced than our own.

His argument is pretty simple, if we look at our own history of video games. Forty years ago, video games meant stuff like Pong and Space Invaders.

Now we have photorealistic, three-dimensional stuff that looks like this, and we could have millions, potentially even billions, of people all playing the same game online at the same time.

Sure, there’s a certain ‘uncanny valley‘ quality to our video game counterparts right now, but think of what things are going to look like in another 40, or even 20 years’ time, with virtual and augmented reality already trying to inch its way into our living rooms.

Musk explains:

“If you assume any rate of improvement at all, then the games will become indistinguishable from reality, even if that rate of advancement drops by a thousand from what it is now. Then you just say, okay, let’s imagine it’s 10,000 years in the future, which is nothing on the evolutionary scale.

So given that we’re clearly on a trajectory to have games that are indistinguishable from reality, and those games could be played on any set-top box or on a PC or whatever, and there would probably be billions of such computers or set-top boxes, it would seem to follow that the odds that we’re in base reality is one in billions.”

It might not be the most comforting thing in the world to think about – our reality isn’t at all what we think it is – but Musk says all of this being one big video game is about the best option we could hope for, given the alternatives.

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What Came Before The Big Bang?

It is difficult enough to imagine a time, roughly 13.7 billion years ago, when the entire universe existed as a singularity.

According to the big bang theory, one of the main contenders vying to explain how the universe came to be, all the matter in the cosmos – all of space itself – existed in a form smaller than a subatomic particle.

Once you think about that, an even more difficult question arises: What existed just before the big bang occurred?

The question itself predates modern cosmology by at least 1,600 years. Fourth-century theologian St. Augustine wrestled with the nature of God before the creation of the universe.




His answer? Time was part of God’s creation, and there simply was no “before” that a deity could call home.

Armed with the best physics of the 20th century, Albert Einstein came to very similar conclusions with his theory of relativity.

Just consider the effect of mass on time. A planet’s hefty mass warps time — making time run a tiny bit slower for a human on Earth’s surface than a satellite in orbit.

The difference is too small to notice, but time even runs more slowly for someone standing next to a large boulder than it does for a person standing alone in a field.

The pre-big bang singularity possessed all the mass in the universe, effectively bringing time to a standstill.

Following this line of logic, the title of this article is fundamentally flawed.

According to Einstein’s theory of relativity, time only came into being as that primordial singularity expanded toward its current size and shape.

Case closed? Far from it. This is one cosmological quandary that won’t stay dead.

In the decades following Einstein’s death, the advent of quantum physics and a host of new theories resurrected questions about the pre-big bang universe. Keep reading to learn about some of them.

Here’s a thought: What if our universe is but the offspring of another, older universe? Some astrophysicists speculate that this story is written in the relic radiation left over from the big bang: the cosmic microwave background (CMB).

Astronomers first observed the CMB in 1965, and it quickly created problems for the big bang theory — problems that were subsequently addressed (for a while) in 1981 with the inflation theory.

This theory entails an extremely rapid expansion of the universe in the first few moments of its existence.

It also accounts for temperature and density fluctuations in the CMB, but dictates that those fluctuations should be uniform.

In chaotic inflation theory, this concept goes even deeper: an endless progression of inflationary bubbles, each becoming a universe, and each of these birthing even more inflationary bubbles in an immeasurable multiverse.

Other scientists place the formation of the singularity inside a cycle called the big bounce in which our expanding universe will eventually collapse back in on itself in an event called the big crunch.

A singularity once more, the universe will then expand in another big bang.

This process would be eternal and, as such, every big bang and big crunch the universe ever experiences would be nothing but a rebirth into another phase of existence.

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Astrophysicists Spotted A ‘Galaxy Without Dark Matter’

An unusual galaxy far, far away is stumping astronomers not because of what’s there, but because of what’s missing.

About 65 million light-years away, the galaxy called NGC1052-DF2 is dim and diffuse, coming in at about one two-hundredths the mass of our Milky Way.

Normally, not all of a galaxy’s mass is visible. In addition to a mix of ordinary matter—like stars and planets and manatees—galaxies are expected to contain dark matter, an invisible substance that makes up most of the mass in the universe.

Although we can’t directly observe it, we know dark matter is there because we can see how its gravity affects ordinary matter.

Based on the ratio in other galaxies, an isolated galaxy like NGC1052-DF2 should have about a hundred times more dark matter than ordinary matter. But this one appears to have … almost none, scientists report today in Nature.




How did scientists figure that out?

Using a cluster of lenses called the Dragonfly Telephoto Array, a team led by Yale University’s Pieter van Dokkum took a really close look at NGC1052-DF2.

By tracking the motion of 10 embedded star clusters, the team could determine how much mass is tucked into the galaxy. And surprisingly, it’s about the same amount of mass they’d expect to see from the galaxy’s stars alone.

We really thought dark matter was not just an optional component of galaxies,” van Dokkum says, noting that the team has found several other similarly perplexing galaxies to scrutinize.

Why is this observation important?

One strange observation doesn’t necessarily break a theory. But finding a galaxy that’s more or less devoid of dark matter certainly suggests a few tantalizing things. First, it really challenges ideas about how galaxies form.

In modern galaxy formation theory, our understanding is that galaxies form in a dark matter halo,” says Stanford University’s Risa Wechsler.

There’s a pretty tight relationship between the amount of stars that formed and the dark matter there, at least when the galaxy formed.

In other words, no dark matter, no galaxy.

In theories proposing alternatives to dark matter, such as modifications to our understanding of gravity, whatever is mimicking the dark matter signature is not something that can be turned on or off—it should always be there.

So, van Dokkum says, “by not detecting the dark matter, we actually prove it’s real.”

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NASA Scientists Believe We Will Find Alien Life Within The Next 20 Years

It’s not exactly the Hollywood fantasy of flying saucers beaming down big-headed, wide-eyed aliens to Earth, but top NASA scientists have announced that they think we are tantalizingly close to discovering some form of extraterrestrial life.

In fact, our search tools have become so sophisticated that space researchers believe we will have gathered convincing data for the presence of alien life, most likely microbial, by 2025.

I think we’re going to have strong indications of life beyond Earth within a decade, and I think we’re going to have definitive evidence within 20 to 30 years,” NASA chief scientist Ellen Stofan said this week at a public panel discussion in Washington.

We know where to look. We know how to look. In most cases, we have the technology, and we’re on a path to implementing it.”

This optimism was promoted by recent discoveries that suggest that potentially habitable worlds are much more common than once believed.




Almost every star is now thought to host planets, and one study even suggested that those within our galaxy possess an average of two planets within the habitable range, or “Goldilocks zone,” which is the area where liquid water can exist.

But it’s not just stars that can host these regions; discoveries much closer to home suggest that even giant planets could have habitable zones, which could greatly expand scientists’ search for life.

Jupiter’s icy moon Europa, for example, has a vast and deep subsurface ocean despite residing some 400 million miles away from the sun.

The water within this ocean resists completely freezing over due to strong tidal forces resulting from Jupiter’s gravitational pull.

Jupiter is also home to another interesting satellite, Ganymede, which is also thought to possess a subsurface saltwater ocean.

Although Europa has received the most attention, Saturn’s moon Enceladus also recently became a top candidate for extraterrestrial life following the discovery of a liquid water ocean below its icy surface.

Furthermore, this satellite was also found to possess geysers that spurt out sandy plumes of water and ice, suggesting the presence of hydrothermal activity within the subsurface ocean.

And let’s not forget about Mars; this now parched and barren planet was once a watery world complete with enduring lakes, oceans and flowing rivers, some of which could have lingered long enough for life to have had a chance to evolve.

Not only that, but scientists also recently found evidence of useful nitrogen compounds, which are a crucial source of this element for life on Earth.

While our present set of powerful observatories are obviously capable of churning out exciting data on the subject, things are only set to get more exciting as technology develops.

A mission to Europa is already on the cards, for example, which NASA hopes to launch by 2022.

And before that, the agency hopes to send up their James Webb Space Telescope, which will probe the atmospheres of nearby “super-Earths,” or exoplanets with masses higher than our own planet, with the hope of identifying gases that could have been created by life forms.

Certainly, we have got a lot to look forward to in the coming years.

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Astronomers Found Evidence For A ‘Dark’ Gravitational Force That Might Fix Einstein’s Most Famous Theory

Albert Einstein’s general theory of relativity predicts so much about the universe at large, including the existence of gravitational lenses or “Einstein rings.”

And yet his famous equations struggle to fully explain such objects.

While general relativity says a strong source of gravity — like the sun— will warp the fabric of space, bend light from a distant object, and magnify it to an observer, very big objects like galaxies and galaxy clusters make gravitational lenses that are theoretically too strong.




General relativity also can’t fully explain the spinning motions of galaxies and their stars.

That’s why most physicists think as much as 80% of the mass in the universe is dark matter: invisible mass that hangs out at the edges of galaxies.

Dark matter might be made of hard-to-detect particles, or perhaps an unfathomable number of tiny black holes. But we have yet to find smoking-gun evidence of either.

However, a contentious theory by Erik Verlinde at the University of Amsterdam suggests dark matter may not be matter at all.

What’s more, astronomers say his idea “is remarkable” in its ability to explain the behavior of more than 33,000 galaxies that they studied.

This does not mean we can completely exclude dark matter, because there are still many observations that Verlinde’s theory cannot yet explain,” study leader and physicist Margot Brouwer said in a YouTube video about the research.

However it is a very exciting and promising first step.”

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According To Some Research, Earth’s Nearest Dwarf Planet Ceres Is Still Evolving And May Have Its Own Water Cycle

It may be the largest object in the asteroid belt that sits beyond Mars, but the dwarf planet Ceres has been surprising scientists ever since it was discovered.

The latest findings suggests that water – one of the key ingredients for life – is present across the entire surface of the rocky planetoid.

What’s more, the distribution of these icy patches suggests the dwarf is still evolving suggesting it may have its own water cycle beneath the surface.

Ceres is of particular interest to scientists because it is the closest dwarf planet to Earth and may play host to the building blocks needed for alien life.

NASA’s Dawn probe has been mapping the object since 2015 and, in a new study, experts used images captured by the craft to study chemicals on Ceres’ surface.




Specifically it looked at carbonates, compounds that have previously been detected by Dawn, which are thought to be strong indicators of liquid water.

Researchers at Italy’s Institute of Astrophysics and Space Planetology in Rome used the probe’s visible-infrared mapping spectrometer to anaylse the planet.

They found that sodium carbonates, salts of carbonic acid, can be found across the entire observed surface of Ceres. The camera reads the chemical spectrum of compounds found far below the planet’s exterior to identify them.

Some carbonate patches, which are as long as a kilometre-wide (0.6 miles), featured sodium carbonate in its hydrated form.

This could only occur around liquid water, suggesting the dwarf planet has a subsurface ocean.

The distribution of these icy patches across Ceres suggests the dwarf planet is still evolving and may have its own subsurface water cycle, researchers found. To measure these icy patches, scientists looked at how carbonates (green and purple) were distributed across Ceres.

The Italian team, led by Dr Filippo Carrozzo, wrote in their paper: “Hydrated sodium carbonates could form early in a global ocean in equilibrium with the altered rocky phase and be incorporated in Ceres’ crust upon freezing of that ocean.

The chemicals could have formed as recently as a few million years ago, the researchers said.

Because they haven’t yet dehydrated, scientists suggest the planet must still be spewing water from its surface and hence is still evolving.

Patches of hydrated sodium carbonate were found by the team around craters with domes or mounds.

Some craters showed unique characteristics, such as floor fractures, that the authors say indicate areas where water had been ejected.

Patches of hydrated sodium carbonate (green and red) were found around craters with domes or mounds by the team. Some craters showed unique characteristics, such as floor fractures, that the authors say indicate areas where water had been ejected.

The researchers also focused on patches of ice covering the walls of Ceres’s Jugling impact crater.

The crater, found on Ceres’s southern hemisphere, is shadowy, dark and unlike other northern hemisphere craters where water ice has previously been found.

To better understand Juling’s water ice features, the Italian team analysed light spectrum data previously obtained by the Dawn mission.

Specifically, they compared how the amount of ice on the crater’s walls has changed over time as the sun shone on different regions.

Their results showed a clear increase of the area covered by the crater’s ice-rich wall as time progressed.

According to the authors, the trend between ice abundance and solar flux suggests that seasonal cycles of water are responsible for the observed increase.

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Titan Could Have “Crystals” On Its Surface That Can Support Alien Life

Scientists say there may be crystals on Titan that could provide food for some forms of alien life, according to a study published in the journal ACS Earth and Space Chemistry.

Known as “co-crystals”, they are thought to be the result of ammonia and acetylene creating a salt-like compound, caused by Titan’s methane rain and ethane flooding.

Co-crystals are basically salts that are made of two or more molecular compounds. This allows for some unique properties, such as a different melting point to the original compounds.

However, there is some disagreement over what exactly one is.




The importance of these co-crystals is that they could provide food on Titan’s surface for microbial life.

Some composed of benzene and ethane have been proposed before, but this new type of co-crystal forms more quickly and should be able to survive Titan’s weather.

These co-crystals, or ‘organic minerals’, are an exciting new class of compounds for Titan’s surface,” Morgan Cable from NASA’s Jet Propulsion Laboratory (JPL), the study’s lead author said.

The crystals would be extremely small, just a few microns in size – which is smaller than the width of human hair.

They may grow larger under the right conditions, with Cable noting they could look like fresh snow. What’s more, they could be food for certain types of microbes.

Titan has been a bit of a hot topic lately, with NASA currently considering sending a quadcopter to the surface, flying over the ground to study dozens of sites – including the moon’s lakes and seas of liquid hydrocarbons.

It would launch in 2025 and arrive in 2034.

A recent study also found that Titan’s oceans may be suitable for a submarine at some point in future.

Replicating the temperature and pressure of Titan in the lab, they found that despite the tough conditions, we could feasibly explore these regions.

Titan is the only place other than Earth with known bodies of liquid on its surface. Coupled with its thick atmosphere, it looks like quite an enticing environment for life in one form or another.

Whether it’s truly habitable we might not know for a while, but perhaps these crystals on the surface could help play a part.

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