Cosmological Constants

Guess I am pretty dense. As many books and TV shows as I have read or seen about Einstein, physics, and cosmology, I just understood something for the first time since it was extremely plainly laid out for me. An ever expanding universe requires one or more forces to push matter further apart: cosmological constant. Forces attract or repel. Gravity attracts matter. Yet there is something, still unknown, repelling matter.

Image of God

I picked up Einstein and Religion the other day. Its been a compelling read as I am about 1/3 through in just over 24 hours. Both of these come from pages 74-75.

Maimonides:

Our Knowledge [of God] consist in knowing that we are unable to comprehend Him.

Spinoza:

On your question whether I have a clear idea of God as I have of triangle, I would answer in the affirmative; but on your question whether I have a clear image of God as I have of triangle, I would answer in the negative. For of God no image can be made.

Washington DC

I took a trip with my family to Washington DC last weekend. Below is a sampling of pictures I took. Many more are over at Flickr. Click on any one below to see it larger. Plus the larger view has a link over to Flickr. 😀


The two little girls below are my second cousins.

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Evidence of Dark Matter

NASA – NASA Finds Direct Proof of Dark Matter:

Dark matter and normal matter have been wrenched apart by the tremendous collision of two large clusters of galaxies. The discovery, using NASA’s Chandra X-ray Observatory and other telescopes, gives direct evidence for the existence of dark matter.

These observations provide the strongest evidence yet that most of the matter in the universe is dark. Despite considerable evidence for dark matter, some scientists have proposed alternative theories for gravity where it is stronger on intergalactic scales than predicted by Newton and Einstein, removing the need for dark matter. However, such theories cannot explain the observed effects of this collision.

I find the word “proof” a little strong. Definitely its evidence.

PROJECT: Mess Up My Cube

A number of people have remarked that my cube is too clean. So… Here is a list of things people can get me to help messy up my cube:

Plus there are computer books.

Frying Astronauts One Chromosone At a Time

A few conspiracy theorists who claim we never actually went to the Moon mention the inability of the space suits and craft of the time to hold out the cosmic radiation. Do they have enough time to gauge whether a human could survive a trip to Mars and back? Considering Mars no longer has a magnetic field (why it lost its atmosphere – I watch too much NOVA), getting to Mars will not provide a safe haven.

Maybe I am glad I didn’t become an astronaut?

Was Einstein Wrong about Space Travel? | Science Blog

While the astronaut twin is hurtling through space, Cucinotta explains, his chromosomes are exposed to penetrating cosmic rays. This can damage his telomeres—little molecular “caps” on the ends of his DNA. Here on Earth, the loss of telomeres has been linked to aging.

So far, the risk hasn’t been a major concern: The effect on shuttle and space station astronauts, if any, would be very small. These astronauts orbit inside of Earth’s protective magnetic field, which deflects most cosmic rays.

But by 2018, NASA plans to send humans outside of that protective bubble to return to the moon and eventually travel to Mars. Astronauts on those missions could be exposed to cosmic rays for weeks or months at a time. Naturally, NASA is keen to find out whether or not the danger of “radiation aging” really exists, and if so, how to handle it.