Taking the temperature of our cosmos, less than a billion years after the Big Bang

the latest tech news, global tech news daily, tech news today, startups, usa tech, asia tech, china tech, eu tech, global tech, in-depth electronics reviews, 24h tech news, 24h tech news, top mobile apps, tech news daily, gaming hardware, big tech news, useful technology tips, expert interviews, reporting on the business of technology, venture capital funding, programing language

Taking the temperature of our cosmos, less than a billion years after the Big Bang

With the IRAM NOEMA telescope array in the French Alps, astronomers have for the first time observed a distant object casting a shadow on the early, hot Big Bang phase of our universe, blocking out some of the light of the so-called cosmic background radiation. The object is a water cloud so distant that we see it as it was a mere 880 million years after the Big Bang. The shadow appears because the colder water absorbs the warmer microwave radiation on its path towards Earth. The degree of darkening reveals the temperature of the cosmic background radiation at that early time: a key data point in our knowledge about our expanding universe. The results have been published in the journal Nature.

the latest tech news, global tech news daily, tech news today, startups, usa tech, asia tech, china tech, eu tech, global tech, in-depth electronics reviews, 24h tech news, 24h tech news, top mobile apps, tech news daily, gaming hardware, big tech news, useful technology tips, expert interviews, reporting on the business of technology, venture capital funding, programing language

Astronomers have made a novel kind of measurements that allows them to measure the temperature of the “cosmic background radiation” filling our cosmos, for early cosmic times. That radiation, a remnant of the hot Big Bang phase of our cosmos, has been cooling down continually. Determining its temperature at an early time, in this case 880 million years after the Big Bang, provides an important consistency check for our cosmological models.

A cooling universe
Around 13.8 billion years ago, in what cosmologists call the Big Bang phase, the universe was in an extremely hot and extremely dense state, filled with a plasma of radiation and elementary particles. But even at that time, the universe was expanding, with its density decreasing quickly over time. By the laws governing thermodynamics, such a decrease in density corresponds to a decrease in temperature: the plasma expands, becomes less dense, and cools down. In line with the plasma, the thermal radiation cools down as well – the light particles (photons) flitting through the plasma, interacting with the electrically charged particles, become ever less energetic.

Global Tech News Daily

After a few hundreds of thousands of years, the plasma had cooled down sufficiently for atoms to form. Before that time, the temperature was so high that if, say, a proton and electron would come together to form a hydrogen atom, that atom would almost instantly have been split apart (ionized), the electron driven away, by a highly-energetic photon, leaving no atom behind.

Viewing the (hot and dense) past
But as the plasma and the thermal radiation cooled down, there were fewer and fewer high-energy photons around. More and more atoms were able to form without having their electrons kicked away by high-energy photons. By the 380,000-year mark, almost all of the atomic nuclei (mostly hydrogen, with some helium-4 thrown in) had combined with electrons to form electrically neutral atoms. From that time onwards, there was very little interaction between those atoms and the remaining thermal radiation. That radiation, which astronomers call the cosmic background radiation, continued to propagate through space virtually unchanged.

Global Tech News Daily

This is where a basic truth of astronomy becomes important. Light from astronomical objects always takes a certain time to reach us. In consequence, we never see, say, the Sun as it is now. Our observations always show the Sun as it was 8 minutes ago, when the light reaching our telescopes now left the surface of the Sun. Similarly, we always see the Andromeda galaxy as it was about 2.5 million years ago, as it takes light 2.5 million years to travel from that galaxy to our telescopes here on Earth.

Our window onto the hot Big Bang phase
But this means we can still observe that primordial cosmic background radiation today! Space, after all, is comparatively empty. If we avoid looking into our own Milky Way galaxy’s dust clouds, and into the stars of distant galaxies, then we can look farther and farther into space – that is, until we are looking at regions that are so far away that their light takes 13.8 billion years to reach us. Those regions, we see as they were 13.8 billion years ago – and remember: at that time the universe was in a hot, dense plasma state.

More specifically, we cannot see into that plasma, as plasma of that kind is opaque. But we can see as far as the time when the cosmic background radiation was released. Put differently: There are regions in the universe that are just the right distance from us so that their cosmic background radiation reaches us at the present time. We can, today, see and measure the light from the end of the hot Big Bang phase, and measurements of that kind have yielded valuable information about the early, hot universe.

There is one important additional effect: We are not just seeing this radiation from very distant regions in an otherwise unchanging universe. Instead, from that early time to the present, the universe has been expanding, and cosmic expansion has the effect of cooling down the early thermal radiation ever further. Thermal radiation of that kind is fully described by a single parameter, its temperature, and in our cosmological models, the effect of cosmic expansion on that temperature is straightforward: In the time that distances between distant galaxies have increased by a factor 2, cosmic background radiation temperature will have fallen by one half.

Expanding universe, cooling radiation
From the time the cosmic background radiation was released to the present, the universe has expanded by a factor of about 1100. The cosmic background radiation, which originally was at a temperature of around 3000 Kelvin and resembled light from some of the kinds of floodlight used to light athletic fields (metal-halide lights), cooled down by that same factor. These days, it reaches Earth mostly in the form of low-energy microwave radiation, which is why another name for it is the “cosmic microwave background”, abbreviated CMB.

The direct link between the expansion of our universe and the CMB temperature means that, over time, the cosmic background radiation carries very valuable information indeed. If we could measure the CMB temperature at different times in cosmic history, we could reconstruct how, in detail, our cosmos has been expanding. This “expansion chronology” is one of the most basic data sets we can obtain about the history of our universe. It is directly linked to one of the great unknowns of modern cosmology: so-called dark energy, an ingredient filling our universe that is responsible for the fact that, at present, the expansion rate of our cosmos is increasing – cosmic expansion is accelerating.

Tracking cosmic expansion, one temperature at a time
What a direct measurement could show is whether this direct link between the expansion of our universe and the cooling of the CMB does indeed hold. A comparison with an alternative measure of cosmic expansion, the so-called cosmological redshift, could rule out some more exotic proposals for the nature of dark energy. Dominik Riechers, the lead author of the University of Cologne, says: “If there were to be any deviations from the expected trends, this could have direct implications for the nature of the elusive dark energy.”

Notably, a deviation from the direct link would be expected in models in which dark energy “decays”, transferring some of its energy to the regular matter and radiation in the universe, which would slow the cooling of the CMB. Some models for the other big unknown in cosmology, Dark Matter, would include similar effects: Certain exotic (and as yet undetected) elementary particles proposed as the constituents of Dark Matter, so-called light axions, could interact with the cosmic background radiation, influencing the way it cools down over time.

However, measuring the CMB temperature at different times in cosmic history is rather difficult. There are some data points: For the cosmic history over the past 6 billion years (redshifts z between 0 and 1), the so-called Sunyaev-Zel’dovich effect provides a way for such measurements. A bit farther out, between 10 and 11.7 billion years before the present (z between 1.8 and 3.3) there are data points indicating that the CMB temperature has just the right value to excite specific energy levels in certain species of atoms or molecules.

Taking the temperature of the cosmos, 880 million years after the Big Bang
The present results go considerably beyond this, contributing a CMB temperature data point from a time nearly 13 billion years before the present – a mere billion years after the Big Bang phase. The protagonist is a cloud of cold water in a starburst galaxy with the catalogue number HFLS3, which we see as it was about 880 million years after the Big Bang. Just as the CMB itself, light from that galaxy is heavily redshifted. All observations for this work were made with the IRAM NOEMA telescope array in the French Alps, a radio observatory that observes at millimeter wavelengths.

A starburst galaxy gets its name from the fact that it has recently produced an unusually high number of new stars in a short period of time. This particular starburst galaxy contains a sizeable cloud of water vapour, H2O, and the CMB acts like a light source that, from the point of view of observers, is behind the cloud. Astronomer know similar situations as they observe stars. In a star, the lower, hotter layers of the so-called photosphere produce almost all of the star’s light. But directly above are somewhat cooler layers of gas. The result are so-called absorption lines: specific wavelengths where the starlight is absorbed by the cooler layers. When astronomers look at the rainbow-like spectrum of a star, those absorption lines indeed appear like darker, line-shaped shadows on the rainbow.

A tell-tale shadow on the cosmic background radiation
The simple version of the new result is very much like that: The water vapour cloud is cooler than the cosmic background radiation. For that reason, it casts a shadow on the cosmic microwave background, something that astronomers had never seen before in the early universe: an absorption line in the rainbow-like decomposition of the CMB, with the strength of the absorption indicating the temperature difference to the cloud – and, by implication, the temperature of the CMB as it passed through the cloud 880 million years after the Big Bang.

Full disclosure: The nitty-gritty details of the situation are somewhat more complicated. The cloud temperature in question is not the temperature of the cloud as a whole, but the temperature corresponding to how many of the water molecules are in a slightly excited (rotation) state relative to the lowest-energy ground state. There is a basic formula linking the fraction of water molecules in the excited state with a temperature; conversely, by measuring how many excited water molecules there are, one can determine that specific temperature.

The fact that this pair-of-states-temperature is lower than that of the CMB comes about only thanks to the infrared light emitted by the galaxy’s many newborn stars – that, after all, is what a starburst galaxy is: a galaxy that is undergoing a short phase of forming many more young stars than usual – and tempered by the galaxy’s clouds of dust. That infrared light effectively shifts the balance of how many molecules are in what particular state – and for the pair of states examined by the astronomers for this study, this is equivalent to a lower temperature, resulting in the creation of a CMB absorption line.

Constraining cosmic evolution
Whether in the simpler or in the more complicated version: The end result depends on the CMB temperature. From their observations, the astronomers deduce that the CMB at that time must have had a temperature between 16.4 and 30.2 Kelvin. This is consistent with the temperature of 20 Kelvin predicted for that time, 880 million years after the Big Bang, by the current cosmological models – given the direct connection between CMB cooling and the cosmic expansion history, an important consistency check.

With this result, the exotic models that predict a disconnect between the temperature and the expansion rate can be excluded. More generally, we now have a data point about cosmic expansion from a period in cosmic history from which there are very few data points to begin with. Fabian Walter, MPIA astronomer involved in this research says: “This new technique provides important new insights into the evolution of the universe, and shows us that the universe in its infancy had some unusual properties quite unlike today.” This is because this particular kind of effect can only occur in the very early universe, before the CMB had cooled down further.

HFLS3 as the prototype for an early temperature survey Now that their early-universe data point is fully analyzed, the researchers are planning for the future. Other starburst galaxies like HFLS3 are known in the early universe, and several of them are known to contain clouds of water vapour. The researchers are now searching in a systematic way for additional examples for the shadow effect using NOEMA, which might allow them to map the cooling of the cosmic background radiation, the echo of the Big Bang, more closely over the first 1.5 billion years of cosmic history.

The research described here has been published as D. Riechers et al., “Microwave Background Temperature at Redshift 6.34 from H2O Absorption” in the journal Nature.

The MPIA scientist involved is Fabian Walter, in collaboration with Dominik Riechers (Cologne University), Axel Weiss (Max Planck Institute for Radio Astronomy), Christopher L. Carilli (NRAO), Pierre Cox (Sorbonne Universite’ and CNRS), Roberto Decarli (INAF Bologna) and Roberto Neri (IRAM).

NOEMA is the most powerful millimeter telescope in the Northern Hemisphere. The observatory operates at over 2500 meters above sea level on one of the most extended European high-altitude sites, the Plateau de Bure in the French Alps. The telescope is operated by the Institut de Radioastronomie Millimetrique (IRAM) and is financed by the Max-Planck Society (Germany), the Centre National de Recherche Scientifique (France) and the Instituto Geografico Nacional (Spain).

Research Report: “Microwave background temperature at a redshift of 6.34 from H2O absorption”

News Related


Space Foundation Launches Space Commerce Institute

Space Foundation, a nonprofit advocate organization founded in 1983 for the global space ecosystem, has launched Space Commerce Institute, a program offered by Center for Innovation and Education to facilitate ... Read more »

Boost for space clusters across the UK

These regional hubs, known as space clusters, will support new and growing companies, building on local expertise and catalysing investment into the space sector. Over 600,000 pounds will go towards ... Read more »

Turion Space and NanoAvionics to build a satellite for orbital reconnaissance mission

US company Turion Space, aiming to build spacecraft to remove orbital-debris, satellite servicing, and domain awareness, has selected NanoAvionics small satellite bus, the MP42, as the basis for its ‘Droid-1’ ... Read more »

Incoming! Debris enroute to the Moon

The Moon is set to gain one more crater. A leftover SpaceX Falcon 9 upper stage will impact the lunar surface in early March, marking the first time that a ... Read more »

Rocket Lab to expand Colorado dootprint with new Space Systems Complex

Rocket Lab USA will open a new space systems complex in Littleton, Colorado to support growing customer demand for flight software, mission simulation, and Guidance, Navigation and Control (GNC) services. ... Read more »

Punxsutawney Phil predicts six more weeks of winter in US

Don’t put away those coats and mittens just yet, America. Punxsutawney Phil, the world’s furriest weather forecaster, is predicting six more weeks of winter. In an annual February 2 tradition, ... Read more »

Animal genomes: Chromosomes almost unchanged for over 600 million years

Animal diversity is fascinating, but how is this reflected in their genetic material, the genome? Is it possible to definitely distinguish animals from one another based on genetic information, and ... Read more »

Newly discovered asteroid just second of its kind

You may have heard of the Trojans, two vast swarms of asteroids that lead and trail Jupiter on its orbit around the Sun. But the king of the planets doesn’t ... Read more »

Did comet's fiery destruction lead to downfall of ancient Hopewell?

The rapid decline of the Hopewell culture about 1,500 years ago might be explained by falling debris from a near-Earth comet that created a devastating explosion over North America, laying ... Read more »

Even dying stars can still give birth to planets

Planets are usually not much older than the stars around which they revolve. Take the Sun: it was born 4.6 billion years ago, and not long after that, Earth came ... Read more »

Study shows 'shocking' way Earth's magnetic field produces plasma jets

Even though Earth’s magnetic field shields us from solar wind and space weather-it doesn’t always offer complete protection. Researchers have discovered a new mechanism in Earth’s space environment that can ... Read more »

China's solar research to get boost from satellite

China’s solar observation satellite has achieved some scientific and technological feats during its ongoing in-orbit trial operation, according to a space official. Zhao Jian, head of the China National Space ... Read more »

SpaceX scrubs launch of Italian satellite from Florida, will try again Friday

SpaceX on Thursday scrubbed its planned launch of an Italian Earth-observation satellite, the COSMO-SkyMed Second Generation 2 and said it plans to try again Friday. “Due to unfavorable weather, now ... Read more »

Lowell helps confirm second Earth Trojan

Supported by observations made with the 4.3-meter Lowell Discovery Telescope (LDT) in northern Arizona, an international team of scientists confirmed the existence of the second-known Earth Trojan Asteroid (ETA), 2020 ... Read more »

NASA details plan to deorbit International Space Station in 2031

NASA has released details of the International Space Station’s transition plan, including destruction of the structure in 2031, and research goals for the interim and the future. The ISS will ... Read more »

The universe much sharper in the picture with new algorithms and supercomputers

With new algorithms and supercomputers, an incredibly detailed radio map of the universe was created. Now astronomers can look at radio data of galaxies with much more precision. This was ... Read more »

Satellogic Announces Strategic Partnership With Palantir Technologies

Satellogic Inc., a leader in sub-meter resolution satellite imagery collection, has announced a new partnership with Palantir Technologies Inc. (NYSE:PLTR), a leading builder of operating systems for the modern enterprise. ... Read more »

Space Sustainability - It's Time for Action

His Royal Highness the Prince of Wales visited Astroscale’s ELSA-d Mission Control Centre this afternoon, to learn more from the first private company to demonstrate a vision for the safe ... Read more »

Scientists identify geological 'Goldilocks zone' for the formation of metal ore deposits

Scientists have identified a mechanism through which important metals, crucial to the manufacturing of renewable energy technologies, are passed from the Earth’s mantle to the crust. The team, including researchers ... Read more »

D-Orbit merges with Breeze Holdings Acquisition Corp. to become Publicly Company

D-Orbit S.p.A., an Italy-based and market leading space logistics and transportation company, has announced that it will become publicly listed through a business combination with Breeze Holdings Acquisition Corp. (NASDAQ: ... Read more »

SpaceX sucessfully launches Italian Earth-observation satellite

SpaceX successfully launched an Italian Earth-observation satellite, the COSMO-SkyMed Second Generation 2, from Florida after several days of setbacks. A Falcon 9 rocket mounted with the spacecraft lifted off at ... Read more »

NASA asteroid tracking system now capable of full sky search

The NASA-funded Asteroid Terrestrial-impact Last Alert System (ATLAS)-a state-of-the-art asteroid detection system operated by the University of Hawaii (UH) Institute for Astronomy (IfA) for the agency’s Planetary Defense Coordination Office ... Read more »

2D material in three dimensions

The carbon material graphene has no well-defined thickness, it merely consists of one single layer of atoms. It is therefore often referred to as a “two-dimensional material”. Trying to make ... Read more »

New funding to support sustainable future of space

The UK Space Agency is providing 1.7 million pounds for new projects to support sustainable space operations, Science Minister George Freeman announced Monday. The 13 new projects will help track ... Read more »

What the rise of oxygen on early Earth tells us about life on other planets

When did the Earth reach oxygen levels sufficient to support animal life? Researchers from McGill University have discovered that a rise in oxygen levels occurred in step with the evolution ... Read more »

Rocket Lab to provide Venture Class Launch Services for NASA

Rocket Lab has been selected by NASA as one of twelve companies to provide launch services for the agency’s Venture-Class Acquisition of Dedicated and Rideshare (VADR) missions, providing new opportunities ... Read more »

How NASA in Silicon Valley will use Webb Telescope to study distant worlds

NASA’s James Webb Space Telescope is getting ready to give us the best view yet of worlds beyond our own solar system, commonly known as exoplanets. Scientists at NASA’s Ames ... Read more »

ESA determines new 'space time'

Since November 2021, ESA’s satellites and ground stations have been running on a newly defined, incredibly precise “ESOC time”. Measured by two atomic clocks in the basement of the ESOC ... Read more »

Exoplanet has Earth-like layered atmosphere made of titanium gas

Scientists have discovered that a planet outside of the solar system may have a complex atmosphere made of metal gases that operate like Earth’s atmosphere. The research, published in the ... Read more »

In space race, Europe faces choice: passenger or pilot

As the race to send people to the Moon and beyond heats up, Europe faces calls to make a choice: Keep paying for seats on spacecraft or finally fly its ... Read more »

Astra Awarded VADR Contract by NASA

Astra Space, Inc. has been awarded of the Venture-Class Acquisition of Dedicated and Rideshare (VADR) Launch Services Indefinite Delivery/Indefinite Quantity (IDIQ) contract from the National Aeronautics and Space Administration (NASA) ... Read more »

New ISS National Laboratory tool expands visibility of ISS-related educational resources

The Center for the Advancement of Science in Space, Inc. (CASIS), manager of the International Space Station (ISS) National Laboratory, has announced the release of a new online tool for ... Read more »

NASA provides updated International Space Station Transition Plan

The International Space Station is a unique laboratory that is returning enormous scientific, educational, and technological developments to benefit people on Earth and is enabling our ability to travel into ... Read more »

When light loses symmetry, it can hold particles

Optical tweezers use light to immobilize microscopic particles as small as a single atom in 3D space. The basic principle behind optical tweezers is the momentum transfer between light and ... Read more »

Chinese satellite reportedly grappled, moved another spacecraft away from orbit

The event was discussed as part of a webinar on managing the risks of satellite close approaches in geostationary orbit, hosted by the Center for Strategic and International Studies and ... Read more »

China's cooperation with int'l space community fruitful

China has been engaged with the international space community over the past five years, yielding fruitful results in space science, technology and application, a Chinese official said Friday. China launched ... Read more »

Extreme exoplanet has a complex and exotic atmosphere

An international team including researchers from the University of Bern and the University of Geneva as well as the National Centre of Competence in Research (NCCR) PlanetS analyzed the atmosphere ... Read more »

China to improve space infrastructure with new satellites, technologies: white paper

China will continue to improve its space infrastructure, and integrate remote-sensing, communications, navigation, and positioning satellite technologies in the next five years, according to a white paper released on Friday. ... Read more »

China to boost satellite services, space technology application: white paper

China will continue to boost public services with satellites and promote the application and transfer of space technology in the next five years, according to a white paper on the ... Read more »

Shining a light on synthetic dimensions

Humans experience the world in three dimensions, but a collaboration in Japan has developed a way to create synthetic dimensions to better understand the fundamental laws of the Universe and ... Read more »