Categories: "Science"

What was that bright star next to the Moon?

Last night some of you may have seen a bright star close to the Moon, well it wasn't a star it was the planet Jupiter. It's been hanging out towards the south in the evenings for the summer if you hadn't already spotted it.

Close encounter between the Moon and Jupiter

The star to the lower-left of Jupiter is Iota Capricorni. But if you look closely you can see two other "stars" either side of Jupiter. They're not actually stars but two of Jupiter's moons. To the left is Ganymede and to the right is Callisto. The above image has over-exposed the Moon to show the tree around it. The somewhat green flare opposite the Moon in the image is the reflection of the Moon caused by the camera's optics.

Below is a close up of Jupiter.

In this image we can see a third Moon, just poking out around the left limb of Jupiter, this is Io. There's another large Moon that is normally visible and that's Europa, but yesterday evening when these images were taken it was on the far side of Jupiter.

Questions for "evolutionists" - explaining the Cambrian explosion

Continuing in the questions for "evolutionists" series, Mike asks:

How do Darwinists? explain the cambrian explosion? i know there isnt a logical explaination but it kinda points toward creation doesnt it?

First of all, using the term Darwinist, like evolutionist is a tactical ploy on behalf of the creationists. They intend to imply that acceptance of the evidence is equivalent to an ideology, like their own creationism. It's not, it's a science. However it does have its benefits, you know when you're talking to some kind of creationist or evolution denier because they almost exclusively use this sort of language.

Anyway to get to Mike's point or more accurately the point he's repeating from some creationist website, which falsely implies the Cambrian explosion is a problem for biologists.

The Cambrian explosion, unlike its name suggests wasn't an explosion and it certainly wasn't a fast explosion. It refers to a period of about 50 million years over which we see an increasing number of species in the fossil record.

There can be several reasons for this.

Such as increasing oxygen in the Earth's atmosphere, the Earth's early atmosphere contained no free oxygen, all the oxygen in the atmosphere is produced by photosynthesis and this has been steadily increasing over billions of years.

Or an earlier extinction event such as the Ediacaran mass extinction. Life often rebounds with relatively rapid diversification after an extinction event to fill all the available niches. Just look out how mammals have diversified after the extinction of the dinosaurs.

The evolution of skeletons, many species in the pre-Cambrian were soft bodied creatures, in the Cambrian we start to see increasing numbers of creatures with exoskeletons like trilobites (pictured below), this could be due to increasing numbers of animals with hard parts, but it can also simply be an artefact of fossilisation - animals like trilobites fossilise much easier than animals like jellyfish, simply because of their skeletons.

Trilobite

Or something simple like increasing size of planktonic animals, which being larger would have fallen faster to the sea floor when they died could have opened up all new niches deeper in the oceans, which life diversified to fill.

And so on. In science very rarely is one thing the answer, its often a combination of multiple things working together.

The Cambrian explosion certainly isn't evidence for a biblical 6 day creation like you imply.

i mean there were single celled organisms them boom? fossils of almost every species created or known to man? amazing

Sorry Mike, you're wrong. Dead wrong.

There was multi-cellular life before the Cambrian, most if not all of it was soft-bodied, like jellyfish and worms.

Lastly, fossils of *almost* every species known to man? Do you even know what life was alive in the Cambrian? Obviously not as you're trying to imply that all animals and plants suddenly appeared in the Cambrian, they didn't. No animal or plant you'd recognise today was alive in the Cambrian, there were no land animals, no land plants, all life was in the oceans. What we do find are animals like trilobites and opabinia as shown below.

Opabinia

Saturn like you've never seen it before

Who turned out the lights on Saturn's rings?

Saturn

Well nobody, recently Saturn entered its equinox, meaning the Sun is directly above the equator. As the rings are in the same plane as the equator, they receieve much less light showing only an edge on profile towards the Sun.

This happens every 14.8 years as it travels around the Sun but this is the first time we've had a spacecraft in orbit to capture it. The above image is composed of 75 different exposures, and has had the rings brightened to make them more visible.

For the full size, ideal for wallpapers hit the Cassini imaging website.

Questions for "Evolutionists" part 6

I think it's time I return to blogging after taking my somewhat late summer break, what better way to kick it off again than by answering some questions I've received over the last few weeks from some creationists.

Proofneededdesperately posting from South Africa asks:

1. How do we distinguish between right and wrong, according to evolution? Who decided murder/adultery/theft is wrong? Don't animals do it?

2. What is morality and why do we have it if the animals don't?

Actually animals don't go around murdering, committing adultery or stealing.

Firstly, theft requires private property. Private property is a fairly recent human invention. So the concept of theft doesn't really exist in the animal kingdom, simply because private property doesn't exist.

Adultery, again really a human concept, depends on how the species conducts their sexual behaviour. Some species of animals take a mate for life, in other species females may take many mates over the course of their lives, and vice versa. Typically an individual in a species will follow the norm of the species. If you're a bonobo you're at it pretty much all the time with anyone, same sex or not. That's simply the norm, just like it probably was for humans before women could become a man's private property, around the time of the first civilisations.

Animals also don't go around murdering other animals for no reason. Animals kill other animals, for food and in some species to expand or defend their territory; they may fight with members of their own species over resources, but rarely does this result in fatalities. But they don't just randomly murder each other, like us, randomly murdering people is the exception, not the rule.

Mammals certainly possess a level of right and wrong, or morality, whatever you want to call it. Just look at our two closest relatives alive today, chimpanzees and bonobos. They show extremely human traits in their social behaviour. Evolution obviously favours such altruistic and co-operative behaviour, at least in mammals. It makes sense as mammals take a long time to reach sexual maturity, mammal species that went around killing each other randomly would go extinct pretty quickly.

3. Where do emotions and feelings come from? Bacteria don't have them?!?!? (If they do, then we murder them everyday...lol)

Emotions and feelings come from the brain, bacteria do not have brains, nor nervous systems. Even reptiles probably have feelings such as rage and fear. Mammals which possess larger brains, have more emotions.

4. Where are the transitional fossils?

Where aren't the transitional fossils?

Nautiloidea, Bactritida, Ammonoidea, Pikaia, Conodont, Haikouichthys, Arandaspis, Birkenia, Osteolepis, Eusthenopteron, Panderichthys, Tiktaalik, Elginerpeton, Obruchevichthys, Acanthostega, Ichthyostega, Hynerpeton, Tulerpeton, Pederpes, Eryops, Proterogyrinus, Limnoscelis, Tseajaia, Solenodonsaurus, Hylonomus, Paleothyris, Protoclepsydrops, Clepsydrops, Dimetrodon, Procynosuchus, Thrinaxodon, Morganucodon, Yanoconodon, Yixianosaurus, Pedopenna, Archaeopteryx, Confuciusornis, Ichthyornis, Pakicetus, Ambulocetus, Kutchicetus, Artiocetus, Dorudon, Aetiocetus, Basilosaurus, Eurhinodelphis, Mammalodon, Hyracotherium, Mesohippus, Parahippus, Merychippus, Pliohippus, Equus, Darwinius masillae, Pierolapithecus catalaunicus, Ardipithecus, Australopithecus, Homo rudolfensis, Homo habilis, Homo erectus.

And that's just for breakfast.

5. Why would anything want to reproduce, if it would lower it's chances of survival because of competition for resources?

Species that didn't reproduce would go extinct, leaving only species that did.

6.Who evolved sexual reproduction and with who did he/she/it do it?

As there is very little direct evidence of micro-organisms from that long ago, there are several hypotheses which explore this area.

See Wikipedia for an overview, for more details check Barton and Charlesworth 1998, Davies et al. 1999, Paland and Lynch 2006 and Sá Martins 2000.

7. Why are there still single-celled organisms? Didn't they want to evolve too??

Firstly single-celled organisms do not want anything, they are not conscious, nor do they think. Secondly single-celled organisms alive today are just as evolved as we are. We've both been evolving for four billion years. We may be more complex, but not more evolved. This is the standard ladder fallacy, which pretty much all creationists make. Evolution is not a ladder progressing towards some end goal, it's a branching tree. Humans and all other life alive today is at the end of a branch.

New build of WorldWide Telescope

A new build of WorldWide Telescope has gone up, for both Windows and Silverlight platforms.

Grab it from here.

Cosmos view has been re-worked and looks a lot better, the Solar System view has had a view changes, eclipes now work on other planets, the Sun looks a bit better from a distance, although the planets all seem to still be spheres /facepalm I was really hoping that would get sorted in this release. There's also a bunch of new resources for tour creators (woo I had to source my own background music in the past).

Questions for "Evolutionists" part 5

Another question from those crazy creationists.

Evolutionist: What colour was the skin of the first human?

Black.

Black? really!

Yes.

So why are some races made different varieties of colours? Is there a reason for this?

Yes, we call it evolution.

Homo sapiens originated in east Africa around 200,000 years ago. By about 70,000 years ago the human population is estimated to be around 2000 to 5000 individuals. From those about 150 people crossed the Red Sea and went on to inhabit the rest of the world, Asians branched first, settling in southern Asia by about 60,000 years ago, later reaching east Asia by about 30,000 years ago, Europeans branched off the older Asian populations settling in Europe around 50,000 years ago, with members from northern and eastern Asia settling in the Americas between 30,000 and 10,000 years ago.

Because the populations were isolated, any new genetic information couldn't be exchanged between them, resulting in the variation we see today. If we were isolated for a couple of million years longer the changes would have gradually built up until we were all different species.

1 3 5 ...6 ...7 8 9 10 11 12 ... 36