Lisa Randall


American Theoretical Physicist, Expert on Particle Physics and Cosmology,Frank B. Baird, Jr. Professor of Science on the Physics Faculty of Harvard University

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Although there are many possibilities, the branes that will be most interesting to us later on will be the three-dimensional ones. We don?t know why three dimensions should appear to be so special. But branes with three spatial dimensions could be relevant to our world because they could extend along the three spatial dimensions we know. Such branes could appear in a bulk space with any number of dimensions that is more than three?four, five, or more dimensions. Even if the universe does have many dimensions, if the particles and forces with which we are familiar are trapped on a brane that extends in three dimensions, they would still behave as if they lived in only three.

Harvard freshmen are smart, interested, and excited, and it's fun hearing their different perspectives and stuff that they will share.

I think it's a problem that people are considered immoral if they're not religious. That's just not true.... If you do something for a religious reason, you do it because you'll be rewarded in an afterlife or in this world. That's not quite as good as something you do for purely generous reasons.

It was not scientists, but a reporter?Carlos Byars of the Houston Chronicle?who first made the connection. After listening to Hildebrand present the Arizona group?s research at a scientific meeting, Byars told him about Penfield?s earlier discovery of a potential impact crater?helping the scientists bring the mystery of the missing crater to its remarkably satisfying conclusion.

Perhaps a quarter of meteoroid impacts have led to potentially profitable deposits?at least half of which have already been exploited.

Some branes are slices inside the space, but others are slices that bound space, like slices of bread in a sandwich. Either way, a brane is a domain that has fewer dimensions than the full higher-dimensional space that surrounds or borders it.

The process of science is difficult and challenging. It involves always being aware that your ideas might be right or they might be wrong. I think it's that kind of balance that makes science so interesting.

Trillions of solar neutrinos pass through you each second, but interact so weakly that you never notice.

With general relativity, we know that before gravity can act, spacetime has to deform. This process does not happen instantaneously. It takes time. Gravity waves travel at the speed of light. Gravitational effects can kick in at a given position only after the time it takes for a signal to travel there and distort spacetime.

Although we might experience the illusion of a self-contained environment, every day at sunrise and every night when the Moon and the far more distant stars come into view, we are reminded that our planet is not alone. Stars and nebulae are further evidence that we exist in a galaxy that resides within a far larger Universe. We orbit within a Solar System where the seasons remind us further of our orientation and placement within it. Our very measurement of time in terms of days and years signifies the relevance of our surroundings.

How can a four-dimensional and a five-(or ten-) dimensional theory have the same physical implications? What is the analog of an object traveling through the fifth dimension, for example? The answer is that an object moving through the fifth dimension would appear in the dual four-dimensional theory as an object that grows or shrinks.

I think simplicity is a good guide: The more economical a theory, the better. Lisa Randall Good, Simplicity, Guide You can be only a modest distance away from the gravity brane, and gravity will be incredibly weak.

It's hubris to think that the way we see things is everything there is.

Physicists are interested in measuring neutrino properties because they tell us about the structure of the Standard Model, the well-tested theory that describes matter's most basic elements and interactions.

Sometimes I have a sense of what I'm seeing being a small fraction of what's there. Not always there, but probably more often than I realize. Something will come up, and I'll realize I'm thinking about the world a little differently than my friends.

The thing I will say is that probably culturally, women are treated differently, which means, I think, you're criticized more, you have to listen a little bit more, you have to justify yourself.

We certainly don't yet know all the answers. But the universe is about to be pried open.

You can be only a modest distance away from the gravity brane, and gravity will be incredibly weak.

An almost indispensable skill for any creative person is the ability to pose the right questions. Creative people identify promising, exciting, and, most important, accessible routes to progress - and eventually formulate the questions correctly.

However, you will need to know about flavors and generations because of the strong constraints on the particles? properties, which give us vital clues and constraints on the physics that lies beyond the Standard Model. Chief among these constraints is that different flavors of quarks and leptons with the same charges rarely, if ever, turn into one another.

I was always good at math, but I was good at everything. It sounds obnoxious, but I was just smart. In school, it's kind of obvious when you're learning things faster than other kids.

It's not completely obvious what gravity is, fundamentally, or what dimensions are, fundamentally. One of these days we'll understand better what we mean, what is the fundamental thing that's given us space in the first place and dimensions of space in particular.

Physicists have yet to understand why the Higgs boson's mass is what it is,

Sometimes models are surprisingly smart.

The uncertainty principle of quantum mechanics, coupled with the relations of special relativity, tell us that, using physical constants, we can relate a particle?s mass, energy, and momentum to the minimum size of the region in which a particle of that energy can experience forces or interactions.

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American Theoretical Physicist, Expert on Particle Physics and Cosmology,Frank B. Baird, Jr. Professor of Science on the Physics Faculty of Harvard University