Are aliens altering a star’s light spectrum so the universe can see them?

Wednesday, 19 April, 2017

Broadcast signals, radio and television for instance, might be one way an extraterrestrial intelligence could go about advertising its presence. For all the perils of doing so, of course.

The thing with regular broadcast signals though, is they degrade the further they move from their source. Ideas that any inhabitants of any planets orbiting Regulus – a star eighty light years distant – may be able to tune into TV shows first broadcast on Earth eighty years ago are fanciful, to put it mildly.

How then to tell the rest of the universe you’re there, if signal degradation is a concern? Altering the light spectrum of your host star may be a possibility.

Przybylski’s Star is about three hundred and seventy light years from the Sun, but its optical spectrum is baffling astronomers, on account of the presence of certain heavy elements that should not be there.

The star is laced with oddball elements like europium, gadolinium, terbium and holmium. Moreover, while iron and nickel appear in unusually low abundances, we get short-lived ultra-heavy elements, actinides like actinium, plutonium, americium and einsteinium. Hence the mystery: How can such short-lived elements persist in the atmosphere of a star?

How indeed? Some people have speculated that an alien intelligence is somehow adding in these unusual elements, as a way of drawing attention to themselves. It all sounds a bit complicated though. Why don’t they make a few TV shows, and broadcast them on a strong signal, instead?

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Tea and coffee, and why their brewing methods vary and differ

Monday, 20 March, 2017

Why are there so many ways to brew coffee, yet hardly any for tea? It’s not something I’d really thought about, especially when it comes to coffee. A different beverage, such as cappuccino, requires its own method, right?

Jesse Raub, writing for Serious Eats, decided to investigate. It gets a little scientific, but what he found makes for engrossing reading.

Coffee ground particles are porous; their structure looks a bit like that of a sponge, with little tunnels running through it. The soluble material that’s extracted is embedded throughout the walls of those little tunnels. In some ways, the extraction process sort of looks like the mine cart scene in Indiana Jones and the Temple of Doom when the water starts chasing them through the tunnels. The bigger the coffee particle, the longer the mine cart tunnel system inside that coffee particle, and the more time it will take the water to travel through it, extracting solubles as it goes. If it helps to imagine tiny versions of Indy, Willie, and Short Round being chased by the brewing water inside the coffee particle, feel free.

Fascinating, or what. But here’s what often happens when you make a cup of tea:

Polyphenols comprise a grouping of different plant compounds, like flavanols (and specifically catechins), that contribute body and structure as well as the general blueprint for a tea’s flavor profile. They’re also responsible for a tea’s bitterness. Amino acids, the building blocks of proteins, contribute texture and savory qualities, and essential oils produce aromas and more delicate, complex flavors. Polyphenols dissolve and are extracted fairly quickly, while amino acids take more time, but essential oils are the ringer here: They don’t actually dissolve into a tea, because oils aren’t soluble in liquid. We need enough time during the steeping process for the water to break down the cellular structure of the leaf. This is what allows the essential oils to be released into the brewed tea, where they’ll exist as an integral part of the tasting experience – even though they’re mostly just floating on the surface.

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A map of physics, an introduction to the sprawling science of physics

Tuesday, 7 March, 2017

Physics surrounds us, and penetrates us. It binds the galaxy together. And every other galaxy, and sub atomic particle within the cosmos. Or everything we can see, for that matter. Otherwise, physics is a complete mystery to many of us.

Especially me, given mathematics and physics are inseparable, and maths was something I could never comprehend, at anything more than a basic level, anyway.

Enter then The Map of Physics, by physicist, and science writer, Dominic Walliman, and an explanation of the science, together with its three main constituents: classical physics, relativity, and quantum physics.

Even then, it’s not so straightforward. There are many sub-branches, and many more unknowns.

For instance, physics only describes about five percent of what we know about. Put that down to dark matter, and dark energy, which makes up ninety-five percent of the universe.

In other words, there’s a long way to go before our understanding of the universe will be anywhere near complete. The Map of Physics makes a good starting point though.

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NASA finds seven earth size planets, but are they anything like Earth?

Friday, 24 February, 2017

After days of keeping us in suspense about a new discovery, NASA let the cat out of the bag, in the early hours of yesterday morning. The TRAPPIST optic robotic telescope, located in Chile, recently identified a dwarf star, about forty light years distant from Earth, that is host to seven planets around about the same size as Earth.

Come on now, you didn’t think they were going to announce that an alien civilisation had been found, did you?

This is still a significant discovery though. Particularly as three of the seven bodies orbiting TRAPPIST-1 – the star also takes its name from the Belgian operated telescope – are within its solar system’s so-called Goldilocks, or habitable zone, an area capable of supporting life, that is neither too hot, nor too cold.

It is this bit that is especially of interest, as it means these planets may habour water in liquid form, and, as a result, potentially life of some sort. And that is obviously an exciting prospect. But talk we may one day be able to emigrate there is well wide the mark, to say the least.

There is, you see, a big difference between a planet that is “earth-like”, and one exactly like Earth. Or a planet that could be called an Earth twin, or Earth analog. For example, Proxima b, an exoplanet within the habitable zone around Proxima Centauri, the nearest star to the Sun, is considered to be earth-like, as it is a rocky, or terrestrial planet.

It might have some sort of atmosphere, and possibly there could be liquid water on its surface. But Proxima b may be far from habitable, at least as far as humans are concerned. As Proxima Centauri is a red dwarf star, which are relatively cool, Proxima b would need to be quite close, to be within the habitable zone.

This sort of proximity however could mean Proxima b is tidally locked, meaning the planet’s rotational period matches the time it takes to orbit the star. This result here is only one side of the planet would ever face the star.

Therefore, the sunny side of Proxima b would be quite warm, whereas the night side would be extremely cold. The only spots that might be conducive to life, would be near the day-night terminator. In addition, the planet is also exposed to stellar wind pressures far greater than those that Earth experiences.

Not all that earth-like, after all. So while some form of life may manage to eke out an existence there, it would hardly be suitable for human occupation. The same conditions could well apply to the planets within the Goldilocks zone of TRAPPIST-1, given it to is a relatively cool dwarf star.

At the very least, they’re quite possibly tidally locked. If we’re looking for a new planet to settle on then, it needs to be an Earth twin. This is a planet, as the name suggests, that is identical in almost every way to ours. And if there are at least one hundred billion planets in our galaxy, the Milky Way, then it stands to reason some proportion must be virtually identical to Earth.

But an Earth twin candidate needs to be more than a terrestrial planet, orbiting within the habitable zone of its solar system though. In their book, Rare Earth, published in 2000, US paleontologist Peter D. Ward, and Donald Brownlee, a professor of astronomy, outlined the criteria necessary for a planet to be classified as an Earth twin:

The right distance from a star; habitat for complex life; liquid water near surface; far enough to avoid tidal lock; right mass of star with long enough lifetime and not too much ultraviolet; stable planetary orbits; right planet mass to maintain atmosphere and ocean with a solid molten core and enough heat for plate tectonics; a Jupiter-like neighbor to clear out comets and asteroids; plate tectonics to build up land mass, enhance bio-diversity, and enable a magnetic field; not too much, nor too little ocean; a large moon at the right distance to stabilize tilt; a small Mars-like neighbor as possible source to seed Earth-like planet; maintenance of adequate temperature, composition and pressure for plants and animals; a galaxy with enough heavy elements, not too small, elliptical or irregular; right position the galaxy; few giant impacts like 65 million years ago; enough carbon for life, but not enough for runaway greenhouse effect; evolution of oxygen and photosythesis; and, of course, biological evolution.

That’s an extensive list. Some astronomers think two percent of the Milky Way’s planets may be Earth twins, meaning there could be two billion such bodies. Given the exacting conditions required for their existence though, I think the actual number may be far smaller.

It could a very long time, therefore, before any announcement is made regarding the discovery of a truly earth-like planet, that is, an Earth analog. It also means we have to take greater care of our own Earth. Clearly we’re not going to be emigrating anywhere else in any hurry.

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The Doomsday Clock now sits at two and half minutes to midnight

Friday, 3 February, 2017

The Doomsday Clock, originally developed by the Bulletin of Atomic Scientists in 1947, as a gauge of international events that are dangerous to the world, including a nuclear war, now sits at two and a half minutes to midnight.

This is the nearest that the clock has been to midnight in that last fifty years. It would seem various efforts to make the world a safer place are missing the mark.

Even if nuclear weapons did not exist, climate change and the accelerating loss of biodiversity are serious threats. Damage to ecosystems is already taking place; climate change is causing loss of life and property, as well as affecting natural systems. At the same time, the nations with nuclear weapons are still testing new devices and more sophisticated delivery systems.

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White silver and black lead, that’s the beauty of Science

Thursday, 22 December, 2016

Yes, there is beauty in science, as this footage of white silver and black lead, filmed through a microscope, during metal displacement reactions, demonstrates. This clip is from Beauty of Science, a China based educational project, that aims to raise awareness of the beauty present in science. A great idea.

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Redheads, an endangered species thanks to climate change?

Tuesday, 13 December, 2016

Climate change and redheads may not go together well. Scientists seem to be divided as to whether this might bring about a reduction in our numbers, or our eventual extinction. That’s a cheery thought. And that’s not even the half of it, if this list is anything to go by.

Sun cream is your oxygen. Some reported getting sunburnt when the moon is out. Another claimed to drink sunscreen for internal coverage. Factor 50 in winter is not uncommon.

On the flip side, redheads tend to age better than those with other hair colours. So, swings and roundabouts?

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The universe will end in a vacuum, a false vacuum

Tuesday, 25 October, 2016

Well, this is cheery. A false vacuum may bring about the destruction of the universe. And there’d be no warning that the end was nigh. The only upside is that the process can’t move any faster than the speed of light. So it may be billions of years, if ever, before the entire cosmos succumbs to a false vacuum.

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There’s a mere two trillion galaxies in the night sky. Possibly

Wednesday, 19 October, 2016

A paper recently published in the Astrophysical Journal suggests there may be ten times more galaxies in the universe than was thought. That would make for two trillion of them, including our family of stars, the Milky Way. Incredible.

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Is there life on Proxima b? Is there extraterrestrial life anywhere?

Friday, 26 August, 2016

It’s official. Apparently. It wasn’t on Tuesday, though. The existence of an exoplanet, known as Proxima b, that is located within the habitable zone of the Proxima Centauri solar system, that is situated about four light years from Earth.

So, might there be life of some sort there? For that matter, might there be life anywhere, beyond our solar system? Seth Shostak, Senior Astronomer at SETI Research, discusses the possibility.

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