Posts Tagged With: physics

A map which tells the age, origins, and ingredients of our universe – from The Planck Mission

Isn’t that one interesting map – never seen anything like that before – and those dots of blues and yellows reveal so much!
Basically, the mottling in the map represents small changes in the CMB background, which permeates the universe. The cool part is, these deviations are essentially the “seeds” of the stars, galaxies, and clusters we see today – the “seeds” of matter.
I guess the density differences amplified with time – but that’s just me making sense of it…
And the pattern: the age, shape and contents of the universe.
But if you still can’t decipher the map (like myself), check out the picture below. Took this snapshot from the newspaper I was just reading – and I think it’s a wonderful summary of the breakthroughs of the Planck Mission, and also of the timeline of our expanding universe.

Source: The STAR, TUESDAY 26 MARCH 2013, Malaysia

Source: The STAR, TUESDAY 26 MARCH 2013, Malaysia

Though I must add, the Planck Mission (by NASA/ESA) has also proved that temperature differences in the opposite hemispheres of the sky (it’s the first I’m hearing the universe has hemispheres – must read up a bit about this!) are not anomalies of measurement (as they were once thought of), but the real deal…and there’s something about a “cold spot” as well: it’s now proven to be bigger than predicted.
Cool stuff right.

Here’s some links if you’ll like to find out a bit more:

Planck Mission Brings Universe Into Sharp Focus

New View of Primordial Universe Confirms Sudden “Inflation” after Big Bang

The first link is NASA’s article, and has much more detail. The second is by Scientific American, easier to digest 😉

ps. The CMB (cosmic microwave background) is essentially light, the earliest light in our universe, produced when the first elements, Hydrogen and Helium were formed. This was 380 000 years after the formation of our universe. But as the universe expanded, the wavelength of these light waves lengthened, and now it is of the microwave radiation wavelength – wonder if it will ever become radio waves!

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Categories: Misc, Physics, The Universe | Tags: , , , , , , , , , , | 4 Comments

21/12/12 – an interesting sighting

So, Doomsday, couldn’t miss out on that, could I?
Yeah, i know it’s a bit out of date – but anyway…I’ve got an interesting sighting (for myself at least).

Always, Jupiter’s orange bands lie almost horizontal when seen through my scope. Sometimes, they’re in line (on the same plane) with Jupiter’s moons.

But around 11pm, on the 21st December 2012…(ta da da)

The bands were almost vertical.
But Jupiter’s 4 biggest moons, were scattered about the usual horizontal plane.

I had to make a sketch of it. And as soon as I get it scanned, I’d post it.

So, take a look at the sketch and let me know what you think.
Perhaps it’s got something to do with Jupiter’s speedy rotation (one rotation takes 9.9 hours) or tilt-too-much of its axis (if that ever happens).

So intriguing.

Do enlighten me, if you can.

Categories: Amateur Astronomy, Misc, Physics, Planets, Solar System | Tags: , , , , , , , , | Leave a comment

Tides – the origins

It started off with mum and I watching the floods brought by Sandy on CNN and mum asked what’s the cause for waves. Well wind caused Sandy’s waves. But, Daily tides, high and low, are caused by the moon.

The accepted theory is the moon exerts a force of gravity on earth as the moon rotates earth (both the moon and earth rotate counter clockwise, but earth’s rotation is much faster). The parts of earth passed by the moon are pulled towards the moon, and when water is pulled, tides are formed! Yayy! Sounds easy right.

But, there comes this picture

– with the theory that the moon pulls the side closest to it the most, pulls the middle of the Earth with a medium force and the side furthest away with the least force. So the bulge of water on the left of the pic is pulled the least, appearing as a bulge as Earth is moved towards the right.

The sun comes into the picture as well, also exerting a pull on water. But, the moon’s pull beats the sun. Though the suns is massive, it’s too far away (F=GMm/r2, Newton’s Law of Gravitation) And if the moon and sun are on opposite directions to Earth, high tides become lower.

But then again, if the moon pulls pulls parts of Earth with different distances from it with different forces, each part would have a different acceleration. F=ma. The parts closest to the moon would accelerate the most (in the pic above, it would be the right end of Earth) and the opposite end (the left), the least. And so, with one end gaining acceleration compared to the other, Earth would be stretched and eventually pulled apart.

So, there has to be a restraining force. Earth’s gravity and its tension? Or a centrifugal force? Now what about a centripetal force?

If you want to end up confused (like myself), I suggest you read:
1. Tides and Centrifugal Forces by Paolo Sirtoli. Lots of physics explained here – with equations.
2. Tidal Forces and the Effects on the Solar System by Richard McDonald. Simpler physics and much easier to understand.
3. Tidal misconceptions by Donald. E Simanek. This is the most comprehensive to me, though let me warn you its quite long.

And then there’s the belief that tides don’t form on the equator. But I’ve seen it for myself, they do form! In fact, they’re semidiurnal tides (two equal high tides and low tides in a day). One high tide on each of the pair of “bulges” created. Check out ocean motion. to find out about types of tides at different latitudes on Earth.

I’ll keep you updated on tides once I piece everything together (and find some missing links, like I’m sure the moon’s orbit around Earth at at about a 5 degree angle to Earth’s ecliptic would have an effect as well). Let me know if you’ve got any ideas of your own!

And mum has two questions of her own:
1. Why isn’t paper pulled towards the moon when its so light.
To me, it is, but the effect is so small that you’ll never realize it.
2. Why do you get the highest tides on the full moon. This, I don’t know. So let me know if you do pleaseee.

ps. Here’s some videos on movements of the moon and of Earth.

Some cool stuff here!

Categories: Misc, Physics, Solar System, Uncategorized | Tags: , , , , , , , , | 1 Comment

What Really is this Higgs Boson

It’s all over the news  – Scientist at CERN are 99.9% certain that this elusive God Particle truly exist. But, I’m still trying to make some sense of what it really is. Is it a particle? Is it a field? Does it have mass? Does it occupy space? How is it related to the Big Bang?

I’ve been surfing the net trying to find some answers and here’s a list of my favourite picks:

From National Geographic:
The long-sought particle may complete the standard model of physics by explaining why objects in our universe have mass—and in so doing, why galaxies, planets, and even humans have any right to exist.

From BBC:
The Higgs boson, proposed by Peter Higgs in 1964, is if it exists what gives matter mass. It has also been named the name God particle by American physicist Leon Lederman. “He wanted to refer to it as that ‘goddamn particle’ and his editor wouldn’t let him,” Higgs told the Guardian. So “God particle” it was.

From the (once boy genius) physicist’s, Stephen Wolfram’s blog:
At some level I’m actually a little disappointed. I’ve made no secret—even to Peter Higgs—that I’ve never especially liked the Higgs mechanism. It’s always seemed like a hack. And I’ve always hoped that in the end there’d be something more elegant and deep responsible for something as fundamental as the masses of particles. But it appears that nature is just picking what seems like a pedestrian solution to the problem: the Higgs mechanism in the Standard Model.

From the Wall Street Journal:
The press has dubbed the Higgs boson the “God particle,” a nickname that makes many physicists cringe. But there is some logic to it. According to the Bible, God set the universe into motion as he proclaimed “Let there be light!” In physics, the universe started off with a cosmic explosion, the Big Bang, 13.7 billion years ago, which sent the stars and galaxies hurtling in all directions. But the key question is left unanswered: Why did it bang? The big-bang theory says nothing about how and why it banged in the first place.

To put it another way, what was the match that set off the initial cosmic explosion? What put the “bang” in the Big Bang? In quantum physics, it was a Higgs-like particle that sparked the cosmic explosion. In other words, everything we see around us, including galaxies, stars, planets and us, owes its existence to the Higgs boson.

The Higgs boson also answers another profound physical question. Why is the universe so unsymmetrical and broken? When you calculate the masses of the subatomic particles like the electron, proton, neutrino or neutron, at first they seem almost random, displaying no rhyme or reason at all.

The latest thinking is that, just before the Big Bang, the universe was very tiny but also perfectly symmetrical. All the masses of the particles were the same, i.e. zero. But the presence of Higgs-like particles shattered this perfect symmetry. Once the symmetry was broken, the particles were free to assume the various masses we see today.

Despite having read these articles, whatever I’ve gathered thus far still looks like bits of a puzzle to me…and I’ve got a long way to go to piece them all together, to finally uncover what the Higgs Boson really is. So let me know if you have any other ideas of your own!

Categories: Physics | Tags: , , , , , , , , , , | 1 Comment

Why Stars Move

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If you observe the skies at night long enough, you’ll realise that the stars move. You’ll see some constellations disappearing below the horizon and new ones appearing on the other side all in one night. Just like the way the sun and moon rises and sets. Well, It’s not the movement of the stars that causes them to rise and set on the horizon, but rather Earth’s rotation on its axis, around the sun.

Here’s a pic which summarises the rotation of Earth. It spins on its axis which is tilted 23.5 degrees to the perpendicular of its orbit around the sun (the Ecliptic). So, during the course of one Earth rotation (which is one day), it’s Ecliptic appears to shift north and south of the Celestial Equator at a tilt of 23.5 degrees.

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Source: Massey, S. and Quirk, S. 2010. Atlas of the Southern Night Sky Second Edition. Australia: New Holland Publishers

We see stars when Earth faces away from then Sun. Earth is always spinning; Throughout the night, some stars will disappear below the horizon on the West and new ones will appear on the Eastern horizon. And since Earth makes a complete orbital around the sun in a year as it travels on its ecliptic, we journey around the sun seeing all the different constellations in our skies as we, like passengers, are transported by our very own spaceship, Earth.

Categories: Observation Gear, Stars | Tags: , , , , , , , , , , | 1 Comment

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