Search for Gravitational Strength Forces Below 1 cm

将进行实验以检验牛顿万有引力定律在小于一厘米的质量间距。 对于1厘米到十分之一毫米之间的分离，实验将足够灵敏，以检测重力和牛顿平方反比定律的偏差。 对于更小的分离，实验可以检测到新的短程力，比引力更强，但仍然比其他已知的力弱许多数量级.研究人员将首先用现有的室温设备完成正在进行的实验，然后建造一个新的具有更高灵敏度的低温仪器。 采用平面钨扭振子作为灵敏力检测器。 目前理论物理学家对一厘米以下长度尺度上可能存在新的微弱力的可能性有着浓厚的兴趣。 弦理论试图涵盖所有已知的物理学，包括引力，通常预测光场标度模。 当这些粒子通过某种机制获得质量时，它们可能会传递一毫米范围内的力。探测到这样的力将为弦论提供戏剧性的证据。理论家们还提出，在通常的三个维度之外，可能存在几个新的紧凑空间维度，引力之所以弱，是因为它能够在额外的维度中扩散。 当额外维度的数量为2时，这种观点导致牛顿万有引力定律在大约1毫米处的大偏差。 预测偏差的实验证据将是我们理解基础物理学的一个戏剧性的进步。

Experiments will be conducted to test Newtons law of gravitation atinter-mass separations of less than one centimeter. For separationsbetween one centimeter and one tenth of a millimeter, the experimentswill be sensitive enough to detect gravity and to test for deviationsfrom Newtons inverse-square law. For smaller separations theexperiments could detect proposed new short-range forces stronger thangravity but still many orders of magnitude weaker than other knownforces. The investigators will first complete on-going experiments withan existing room temperature apparatus, and then construct a newcryogenic instrument with greater sensitivity. A planar tungstentorsional oscillator is used as the sensitive force detector. There iscurrently intense interest among theoretical physicists in thepossibility that there may exist new feeble forces at length scalesbelow one centimeter. String theory, which seeks to encompass allknown physics including gravitation, generally predicts light fieldscalled moduli. When these acquire mass through certain mechanisms,they may mediate forces with a range of about one millimeter.Detecting such forces would provide dramatic evidence for stringtheory.Theorists have also proposed that there may exist several new compactspatial dimensions beyond the usual three, and that gravity is weakbecause it is able to spread out in the extra dimensions. When thenumber of extra dimensions is two, this view leads to large deviationsfrom Newtons law of gravitation at about one millimeter. Experimentalevidence of the predicted deviations would be a dramatic step forwardfor our understanding of fundamental physics.